Class Structure
- java.lang.Object
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- com.sun.jna.Structure
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- Direct Known Subclasses:
CallbackReference.AttachOptions,Carbon.EventHotKeyID,Carbon.EventTypeSpec,DBT.DEV_BROADCAST_DEVICEINTERFACE,DBT.DEV_BROADCAST_DEVNODE,DBT.DEV_BROADCAST_HANDLE,DBT.DEV_BROADCAST_HDR,DBT.DEV_BROADCAST_NET,DBT.DEV_BROADCAST_OEM,DBT.DEV_BROADCAST_PORT,DBT.DEV_BROADCAST_VOLUME,Ddeml.CONVCONTEXT,Ddeml.CONVINFO,Ddeml.DDEML_MSG_HOOK_DATA,Ddeml.HSZPAIR,Ddeml.MONCBSTRUCT,Ddeml.MONCONVSTRUCT,Ddeml.MONERRSTRUCT,Ddeml.MONHSZSTRUCT,Ddeml.MONLINKSTRUCT,Ddeml.MONMSGSTRUCT,DispatchListener,DispatchVTable,DsGetDC.DOMAIN_CONTROLLER_INFO,DsGetDC.DS_DOMAIN_TRUSTS,DsGetDC.PDOMAIN_CONTROLLER_INFO,Guid.GUID,IPHlpAPI.FIXED_INFO,IPHlpAPI.IP_ADDR_STRING,IPHlpAPI.IP_ADDRESS_STRING,IPHlpAPI.MIB_IF_ROW2,IPHlpAPI.MIB_IFROW,IPHlpAPI.MIB_TCP6ROW_OWNER_PID,IPHlpAPI.MIB_TCP6TABLE_OWNER_PID,IPHlpAPI.MIB_TCPROW_OWNER_PID,IPHlpAPI.MIB_TCPSTATS,IPHlpAPI.MIB_TCPTABLE_OWNER_PID,IPHlpAPI.MIB_UDP6ROW_OWNER_PID,IPHlpAPI.MIB_UDP6TABLE_OWNER_PID,IPHlpAPI.MIB_UDPROW_OWNER_PID,IPHlpAPI.MIB_UDPSTATS,IPHlpAPI.MIB_UDPTABLE_OWNER_PID,Kstat2.Kstat2NV,Kstat2.Kstat2NV.UNION.IntegersArr,Kstat2.Kstat2NV.UNION.StringsArr,LibC.Statvfs,LibC.Sysinfo,LibKstat.Kstat,LibKstat.KstatCtl,LibKstat.KstatIntr,LibKstat.KstatIO,LibKstat.KstatNamed,LibKstat.KstatNamed.UNION.STR,LibKstat.KstatTimer,LMAccess.GROUP_INFO_0,LMAccess.GROUP_INFO_1,LMAccess.GROUP_INFO_2,LMAccess.GROUP_INFO_3,LMAccess.GROUP_USERS_INFO_0,LMAccess.LOCALGROUP_INFO_0,LMAccess.LOCALGROUP_INFO_1,LMAccess.LOCALGROUP_USERS_INFO_0,LMAccess.USER_INFO_0,LMAccess.USER_INFO_1,LMAccess.USER_INFO_23,LMShare.SHARE_INFO_2,LMShare.SHARE_INFO_502,LowLevelMonitorConfigurationAPI.MC_TIMING_REPORT,MacFileUtils.FileManager.FSRef,Netapi32.SESSION_INFO_10,Ntifs.GenericReparseBuffer,Ntifs.MountPointReparseBuffer,Ntifs.REPARSE_DATA_BUFFER,Ntifs.SymbolicLinkReparseBuffer,NTSecApi.LSA_FOREST_TRUST_BINARY_DATA,NTSecApi.LSA_FOREST_TRUST_DOMAIN_INFO,NTSecApi.LSA_FOREST_TRUST_INFORMATION,NTSecApi.LSA_FOREST_TRUST_RECORD,NTSecApi.LSA_UNICODE_STRING,NTSecApi.PLSA_FOREST_TRUST_INFORMATION,NTSecApi.PLSA_FOREST_TRUST_RECORD,OaIdl.ARRAYDESC,OaIdl.CALLCONV,OaIdl.CURRENCY._CURRENCY,OaIdl.DATE,OaIdl.DECIMAL,OaIdl.DECIMAL._DECIMAL1._DECIMAL1_DECIMAL,OaIdl.DECIMAL._DECIMAL2._DECIMAL2_DECIMAL,OaIdl.DESCKIND,OaIdl.ELEMDESC,OaIdl.ElemDescArg,OaIdl.EXCEPINFO,OaIdl.FUNCDESC,OaIdl.FUNCKIND,OaIdl.IDLDESC,OaIdl.INVOKEKIND,OaIdl.LIBFLAGS,OaIdl.PARAMDESC,OaIdl.PARAMDESCEX,OaIdl.SAFEARRAY,OaIdl.SAFEARRAYBOUND,OaIdl.SAFEARRAYByReference,OaIdl.ScodeArg,OaIdl.SYSKIND,OaIdl.TLIBATTR,OaIdl.TYPEATTR,OaIdl.TYPEDESC,OaIdl.TYPEKIND,OaIdl.VARDESC,OaIdl.VARKIND,OleAuto.DISPPARAMS,Pdh.PDH_COUNTER_PATH_ELEMENTS,Pdh.PDH_RAW_COUNTER,Pdh.PDH_TIME_INFO,Perfstat.perfstat_cpu_t,Perfstat.perfstat_cpu_total_t,Perfstat.perfstat_disk_t,Perfstat.perfstat_id_t,Perfstat.perfstat_memory_total_t,Perfstat.perfstat_netinterface_t,Perfstat.perfstat_partition_config_t,Perfstat.perfstat_process_t,Perfstat.perfstat_protocol_t,Perfstat.perfstat_protocol_t.AnonymousStructICMP,Perfstat.perfstat_protocol_t.AnonymousStructICMPv6,Perfstat.perfstat_protocol_t.AnonymousStructIP,Perfstat.perfstat_protocol_t.AnonymousStructIPv6,Perfstat.perfstat_protocol_t.AnonymousStructNFS,Perfstat.perfstat_protocol_t.AnonymousStructNFSclient,Perfstat.perfstat_protocol_t.AnonymousStructNFSserver,Perfstat.perfstat_protocol_t.AnonymousStructNFSv2,Perfstat.perfstat_protocol_t.AnonymousStructNFSv2client,Perfstat.perfstat_protocol_t.AnonymousStructNFSv2server,Perfstat.perfstat_protocol_t.AnonymousStructNFSv3,Perfstat.perfstat_protocol_t.AnonymousStructNFSv3client,Perfstat.perfstat_protocol_t.AnonymousStructNFSv3server,Perfstat.perfstat_protocol_t.AnonymousStructNFSv4,Perfstat.perfstat_protocol_t.AnonymousStructNFSv4client,Perfstat.perfstat_protocol_t.AnonymousStructNFSv4server,Perfstat.perfstat_protocol_t.AnonymousStructRPC,Perfstat.perfstat_protocol_t.AnonymousStructRPCclient,Perfstat.perfstat_protocol_t.AnonymousStructRPCclientdgram,Perfstat.perfstat_protocol_t.AnonymousStructRPCclientstream,Perfstat.perfstat_protocol_t.AnonymousStructRPCserver,Perfstat.perfstat_protocol_t.AnonymousStructRPCserverdgram,Perfstat.perfstat_protocol_t.AnonymousStructRPCserverstream,Perfstat.perfstat_protocol_t.AnonymousStructTCP,Perfstat.perfstat_protocol_t.AnonymousStructUDP,Perfstat.perfstat_value_t,PhysicalMonitorEnumerationAPI.PHYSICAL_MONITOR,Psapi.MODULEINFO,Psapi.PERFORMANCE_INFORMATION,Resource.Rlimit,SetupApi.SP_DEVICE_INTERFACE_DATA,SetupApi.SP_DEVINFO_DATA,ShellAPI.APPBARDATA,ShellAPI.SHELLEXECUTEINFO,ShellAPI.SHFILEOPSTRUCT,ShTypes.STRRET,Sspi.PSecHandle,Sspi.PSecPkgInfo,Sspi.SEC_WINNT_AUTH_IDENTITY,Sspi.SecBuffer,Sspi.SecBufferDesc,Sspi.SecHandle,Sspi.SecPkgContext_Flags,Sspi.SecPkgContext_KeyInfo,Sspi.SecPkgContext_Lifespan,Sspi.SecPkgContext_NegotiationInfo,Sspi.SecPkgContext_PackageInfo,Sspi.SecPkgContext_SessionKey,Sspi.SecPkgContext_Sizes,Sspi.SecPkgCredentials_Names,Sspi.SecPkgInfo,Sspi.SECURITY_INTEGER,Structure.FFIType,SystemB.Group,SystemB.HostCpuLoadInfo,SystemB.HostLoadInfo,SystemB.IFdata,SystemB.IFdata64,SystemB.IFmsgHdr,SystemB.IFmsgHdr2,SystemB.Passwd,SystemB.ProcBsdInfo,SystemB.ProcTaskAllInfo,SystemB.ProcTaskInfo,SystemB.RUsageInfoV2,SystemB.Statfs,SystemB.Timeval,SystemB.Timezone,SystemB.VMMeter,SystemB.VMStatistics,SystemB.VMStatistics64,SystemB.VnodeInfoPath,SystemB.VnodePathInfo,SystemB.XswUsage,Tlhelp32.MODULEENTRY32W,Tlhelp32.PROCESSENTRY32,Tlhelp32.THREADENTRY32,Union,UnknownListener,UnknownVTable,Variant.VARIANT._VARIANT,Variant.VARIANT._VARIANT.__VARIANT.BRECORD,Variant.VariantArg,VerRsrc.VS_FIXEDFILEINFO,Wdm.KEY_BASIC_INFORMATION,WinBase.COMMTIMEOUTS,WinBase.DCB,WinBase.FILE_ATTRIBUTE_TAG_INFO,WinBase.FILE_BASIC_INFO,WinBase.FILE_COMPRESSION_INFO,WinBase.FILE_DISPOSITION_INFO,WinBase.FILE_ID_INFO,WinBase.FILE_ID_INFO.FILE_ID_128,WinBase.FILE_STANDARD_INFO,WinBase.FILETIME,WinBase.FOREIGN_THREAD_START_ROUTINE,WinBase.MEMORYSTATUSEX,WinBase.OVERLAPPED,WinBase.PROCESS_INFORMATION,WinBase.SECURITY_ATTRIBUTES,WinBase.STARTUPINFO,WinBase.SYSTEM_INFO,WinBase.SYSTEM_INFO.PI,WinBase.SYSTEMTIME,WinBase.TIME_ZONE_INFORMATION,WinBase.WIN32_FIND_DATA,Wincon.CONSOLE_SCREEN_BUFFER_INFO,Wincon.COORD,Wincon.INPUT_RECORD,Wincon.KEY_EVENT_RECORD,Wincon.MOUSE_EVENT_RECORD,Wincon.SMALL_RECT,Wincon.WINDOW_BUFFER_SIZE_RECORD,WinCrypt.CERT_CHAIN_CONTEXT,WinCrypt.CERT_CHAIN_ELEMENT,WinCrypt.CERT_CHAIN_PARA,WinCrypt.CERT_CHAIN_POLICY_PARA,WinCrypt.CERT_CHAIN_POLICY_STATUS,WinCrypt.CERT_CONTEXT,WinCrypt.CERT_EXTENSION,WinCrypt.CERT_EXTENSIONS,WinCrypt.CERT_INFO,WinCrypt.CERT_PUBLIC_KEY_INFO,WinCrypt.CERT_REVOCATION_CRL_INFO,WinCrypt.CERT_REVOCATION_INFO,WinCrypt.CERT_SIMPLE_CHAIN,WinCrypt.CERT_STRONG_SIGN_PARA,WinCrypt.CERT_STRONG_SIGN_SERIALIZED_INFO,WinCrypt.CERT_TRUST_LIST_INFO,WinCrypt.CERT_TRUST_STATUS,WinCrypt.CERT_USAGE_MATCH,WinCrypt.CRL_CONTEXT,WinCrypt.CRL_ENTRY,WinCrypt.CRL_INFO,WinCrypt.CRYPT_ALGORITHM_IDENTIFIER,WinCrypt.CRYPT_ATTRIBUTE,WinCrypt.CRYPT_BIT_BLOB,WinCrypt.CRYPT_KEY_PROV_INFO,WinCrypt.CRYPT_KEY_PROV_PARAM,WinCrypt.CRYPT_SIGN_MESSAGE_PARA,WinCrypt.CRYPT_VERIFY_MESSAGE_PARA,WinCrypt.CRYPTPROTECT_PROMPTSTRUCT,WinCrypt.CTL_CONTEXT,WinCrypt.CTL_ENTRY,WinCrypt.CTL_INFO,WinCrypt.CTL_USAGE,WinCrypt.DATA_BLOB,WinDef.POINT,WinDef.RECT,Winevt.EVT_RPC_LOGIN,Winevt.EVT_VARIANT,WinGDI.BITMAP,WinGDI.BITMAPINFO,WinGDI.BITMAPINFOHEADER,WinGDI.DIBSECTION,WinGDI.ICONINFO,WinGDI.PIXELFORMATDESCRIPTOR,WinGDI.RGBQUAD,WinGDI.RGNDATA,WinGDI.RGNDATAHEADER,Wininet.INTERNET_CACHE_ENTRY_INFO,Winioctl.STORAGE_DEVICE_NUMBER,Winnetwk.NETRESOURCE,Winnetwk.REMOTE_NAME_INFO,Winnetwk.UNIVERSAL_NAME_INFO,WinNT.ACE_HEADER,WinNT.ACL,WinNT.BATTERY_REPORTING_SCALE,WinNT.CACHE_DESCRIPTOR,WinNT.EVENTLOGRECORD,WinNT.FILE_NOTIFY_INFORMATION,WinNT.GENERIC_MAPPING,WinNT.GROUP_AFFINITY,WinNT.IO_COUNTERS,WinNT.LARGE_INTEGER,WinNT.LARGE_INTEGER.LowHigh,WinNT.LUID,WinNT.LUID_AND_ATTRIBUTES,WinNT.MEMORY_BASIC_INFORMATION,WinNT.OSVERSIONINFO,WinNT.OSVERSIONINFOEX,WinNT.POWER_ACTION_POLICY,WinNT.PRIVILEGE_SET,WinNT.PROCESSOR_GROUP_INFO,WinNT.PROCESSOR_POWER_INFORMATION,WinNT.PSID,WinNT.SECURITY_DESCRIPTOR,WinNT.SECURITY_DESCRIPTOR_RELATIVE,WinNT.SECURITY_QUALITY_OF_SERVICE,WinNT.SID_AND_ATTRIBUTES,WinNT.SYSTEM_BATTERY_STATE,WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION,WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX,WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION.AnonymousStructNumaNode,WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION.AnonymousStructProcessorCore,WinNT.SYSTEM_POWER_CAPABILITIES,WinNT.SYSTEM_POWER_INFORMATION,WinNT.SYSTEM_POWER_LEVEL,WinNT.SYSTEM_POWER_POLICY,WinNT.TOKEN_GROUPS,WinNT.TOKEN_OWNER,WinNT.TOKEN_PRIMARY_GROUP,WinNT.TOKEN_PRIVILEGES,WinNT.TOKEN_USER,WinPerf.PERF_COUNTER_BLOCK,WinPerf.PERF_COUNTER_DEFINITION,WinPerf.PERF_DATA_BLOCK,WinPerf.PERF_INSTANCE_DEFINITION,WinPerf.PERF_OBJECT_TYPE,WinRas.RAS_STATS,WinRas.RASCONN,WinRas.RASCONNSTATUS,WinRas.RASCREDENTIALS,WinRas.RASDEVSPECIFICINFO,WinRas.RASDIALEXTENSIONS,WinRas.RASDIALPARAMS,WinRas.RASEAPINFO,WinRas.RASENTRY,WinRas.RASIPADDR,WinRas.RASIPV4ADDR,WinRas.RASIPV6ADDR,WinRas.RASPPPIP,WinRas.RASTUNNELENDPOINT,Winspool.JOB_INFO_1,Winspool.LPPRINTER_DEFAULTS,Winspool.NOTIFY_DATA_DATA,Winspool.PRINTER_INFO_1,Winspool.PRINTER_INFO_2,Winspool.PRINTER_INFO_4,Winspool.PRINTER_NOTIFY_INFO,Winspool.PRINTER_NOTIFY_INFO_DATA,Winspool.PRINTER_NOTIFY_OPTIONS,Winspool.PRINTER_NOTIFY_OPTIONS_TYPE,Winsvc.ChangeServiceConfig2Info,Winsvc.ENUM_SERVICE_STATUS,Winsvc.ENUM_SERVICE_STATUS_PROCESS,Winsvc.SC_ACTION,Winsvc.SERVICE_STATUS,Winsvc.SERVICE_STATUS_PROCESS,Winsvc.SERVICE_TABLE_ENTRY,WinUser.BLENDFUNCTION,WinUser.COPYDATASTRUCT,WinUser.CWPSTRUCT,WinUser.FLASHWINFO,WinUser.GUITHREADINFO,WinUser.HARDWAREINPUT,WinUser.INPUT,WinUser.KBDLLHOOKSTRUCT,WinUser.KEYBDINPUT,WinUser.LASTINPUTINFO,WinUser.MONITORINFO,WinUser.MONITORINFOEX,WinUser.MOUSEINPUT,WinUser.MSG,WinUser.MSLLHOOKSTRUCT,WinUser.RAWINPUTDEVICELIST,WinUser.SIZE,WinUser.WINDOWINFO,WinUser.WINDOWPLACEMENT,WinUser.WNDCLASSEX,Wtsapi32.WTS_CLIENT_ADDRESS,Wtsapi32.WTS_PROCESS_INFO_EX,Wtsapi32.WTS_SESSION_INFO,Wtsapi32.WTSINFO,X11.XAnyEvent,X11.XButtonEvent,X11.XCirculateEvent,X11.XCirculateRequestEvent,X11.XClientMessageEvent,X11.XColormapEvent,X11.XConfigureEvent,X11.XConfigureRequestEvent,X11.XCreateWindowEvent,X11.XCrossingEvent,X11.XDestroyWindowEvent,X11.XDeviceByReference,X11.XErrorEvent,X11.XExposeEvent,X11.XFocusChangeEvent,X11.XGCValues,X11.XGenericEvent,X11.XGenericEventCookie,X11.XGraphicsExposeEvent,X11.XGravityEvent,X11.XInputClassInfoByReference,X11.XKeyboardControlRef,X11.XKeyboardStateRef,X11.XKeyEvent,X11.XKeymapEvent,X11.XMapEvent,X11.XMappingEvent,X11.XMapRequestEvent,X11.XModifierKeymapRef,X11.XMotionEvent,X11.XNoExposeEvent,X11.XPoint,X11.XPropertyEvent,X11.XRectangle,X11.Xrender.XRenderDirectFormat,X11.Xrender.XRenderPictFormat,X11.XReparentEvent,X11.XResizeRequestEvent,X11.XSelectionClearEvent,X11.XSelectionEvent,X11.XSelectionRequestEvent,X11.XSetWindowAttributes,X11.XSizeHints,X11.XSizeHints.Aspect,X11.XTextProperty,X11.XUnmapEvent,X11.XVisibilityEvent,X11.XVisualInfo,X11.XWindowAttributes,X11.XWMHints
public abstract class Structure extends java.lang.ObjectRepresents a native structure with a Java peer class. When used as a function parameter or return value, this class corresponds tostruct*. When used as a field within anotherStructure, it corresponds tostruct. The tagging interfacesStructure.ByReferenceandStructure.ByValuemay be used to alter the default behavior. Structures may have variable size, but only by providing an array field (e.g. byte[]).See the overview for supported type mappings for struct fields.
Structure alignment and type mappings are derived by default from the enclosing interface definition (if any) by using
Native.getStructureAlignment(java.lang.Class<?>)andNative.getTypeMapper(java.lang.Class<?>). Alternatively you can explicitly provide alignment, field order, or type mapping by calling the respective Structure functions in your subclass's constructor.Structure fields corresponding to native struct fields must be public. If your structure is to have no fields of its own, it must be declared abstract.
You must annotate the class with
Structure.FieldOrderor implementgetFieldOrder(), whichever you choose it must contain the field names (Strings) indicating the proper order of the fields. If you chose to implementgetFieldOrder()notice that when dealing with multiple levels of subclasses of Structure, you must add to the list provided by the superclassgetFieldOrder()the fields defined in the current class.In the past, most VMs would return them in a predictable order, but the JVM spec does not require it, so
getFieldOrder()is now required to ensure JNA knows the proper order).Structure fields may additionally have the following modifiers:
volatileJNA will not write the field unless specifically instructed to do so viawriteField(String). This allows you to prevent inadvertently overwriting memory that may be updated in real time on another (possibly native) thread.finalJNA will overwrite the field viaread(), but otherwise the field is not modifiable from Java. Take care when using this option, since the compiler will usually assume all accesses to the field (for a given Structure instance) have the same value. This modifier is invalid to use on J2ME.
NOTE: Strings are used to represent native C strings because usage of
char *is generally more common thanwchar_t *. You may provide a type mapper (example here)if you prefer to use String in place ofWStringif your native code predominantly useswchar_t *.NOTE: In general, instances of this class are not synchronized.
- Author:
- Todd Fast, todd.fast@sun.com, twall@users.sf.net
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Nested Class Summary
Nested Classes Modifier and Type Class Description static interfaceStructure.ByReferenceTagging interface to indicate the address of an instance of the Structure type is to be used within aStructuredefinition rather than nesting the full Structure contents.static interfaceStructure.ByValueTagging interface to indicate the value of an instance of theStructuretype is to be used in function invocations rather than its address.(package private) static classStructure.FFITypeThis class auto-generates an ffi_type structure appropriate for a given structure for use by libffi.static interfaceStructure.FieldOrderUsed to declare fields order as metadata instead of method.protected static classStructure.StructField(package private) static classStructure.StructureSetAvoid using a hash-based implementation since the hash code for a Structure is not immutable.
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Field Summary
Fields Modifier and Type Field Description static intALIGN_DEFAULTUse the platform default alignment.static intALIGN_GNUCvalidated for 32-bit x86 linux/gcc; align field size, max 4 bytesstatic intALIGN_MSVCvalidated for w32/msvc; align on field sizestatic intALIGN_NONENo alignment, place all fields on nearest 1-byte boundaryprotected static intCALCULATE_SIZEAlign to an 8-byte boundary.(package private) static java.util.Map<java.lang.Class<?>,java.util.List<java.lang.String>>fieldOrder(package private) static java.util.Map<java.lang.Class<?>,com.sun.jna.Structure.LayoutInfo>layoutInfo
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Constructor Summary
Constructors Modifier Constructor Description protectedStructure()protectedStructure(int alignType)protectedStructure(int alignType, TypeMapper mapper)protectedStructure(Pointer p)Create a structure cast onto pre-allocated memory.protectedStructure(Pointer p, int alignType)protectedStructure(Pointer p, int alignType, TypeMapper mapper)protectedStructure(TypeMapper mapper)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description protected voidallocateMemory()Attempt to allocate memory if sufficient information is available.protected voidallocateMemory(int size)Provided for derived classes to indicate a different size than the default.protected MemoryautoAllocate(int size)Obtain auto-allocated memory for use with struct represenations.voidautoRead()static voidautoRead(Structure[] ss)voidautoWrite()static voidautoWrite(Structure[] ss)(package private) static java.util.Set<Structure>busy()protected voidcacheTypeInfo(Pointer p)Cache native type information for use in native code.protected intcalculateSize(boolean force)Calculate the amount of native memory required for this structure.(package private) intcalculateSize(boolean force, boolean avoidFFIType)voidclear()Clears the native memory associated with this Structure.(package private) voidconditionalAutoRead()Performs auto-read only if uninitialized.static java.util.List<java.lang.String>createFieldsOrder(java.lang.String field)static java.util.List<java.lang.String>createFieldsOrder(java.lang.String... fields)static java.util.List<java.lang.String>createFieldsOrder(java.util.List<java.lang.String> baseFields, java.lang.String... extraFields)static java.util.List<java.lang.String>createFieldsOrder(java.util.List<java.lang.String> baseFields, java.util.List<java.lang.String> extraFields)booleandataEquals(Structure s)Return whether the given Structure's native backing data is identical to this one.booleandataEquals(Structure s, boolean clear)Return whether the given Structure's backing data is identical to this one, optionally clearing and re-writing native memory before checking.protected voidensureAllocated()Ensure this memory has its size and layout calculated and its memory allocated.booleanequals(java.lang.Object o)protected intfieldOffset(java.lang.String name)Returns the calculated offset of the given field.(package private) java.util.Map<java.lang.String,Structure.StructField>fields()Return all fields in this structure (ordered).booleangetAutoRead()Returns whether the structure is read from native memory after a native function call.booleangetAutoWrite()Returns whether the structure is written to native memory prior to a native function call.protected java.util.List<java.lang.reflect.Field>getFieldList()Look up all fields in this class and superclasses.protected java.util.List<java.lang.String>getFieldOrder()Returns this Structure's field names in their proper order.
When defining a newStructureyou shouldn't override this method, but useStructure.FieldOrderannotation to define your field order(this also works with inheritance)
If you want to do something non-standard you can override the method and define it as followedprotected java.util.List<java.lang.reflect.Field>getFields(boolean force)Returns all field names (sorted) provided so far bygetFieldOrder()(package private) Structure.FFITypegetFieldTypeInfo(Structure.StructField f)Override to supply native type information for the given field.(package private) java.lang.ObjectgetFieldValue(java.lang.reflect.Field field)Obtain the value currently in the Java field.protected intgetNativeAlignment(java.lang.Class<?> type, java.lang.Object value, boolean isFirstElement)Overridable in subclasses.protected intgetNativeSize(java.lang.Class<?> nativeType)Return the native size of the given Java type, from the perspective of this Structure.protected intgetNativeSize(java.lang.Class<?> nativeType, java.lang.Object value)Return the native size of the given Java type, from the perspective of this Structure.PointergetPointer()Return aPointerobject to this structure.protected java.lang.StringgetStringEncoding()Encoding to use to convertStringto nativeconst char*.protected intgetStructAlignment()(package private) PointergetTypeInfo()(package private) static Structure.FFITypegetTypeInfo(java.lang.Object obj)Exposed for testing purposes only.(package private) TypeMappergetTypeMapper()inthashCode()static <T extends Structure>
TnewInstance(java.lang.Class<T> type)Create a new Structure instance of the given typestatic <T extends Structure>
TnewInstance(java.lang.Class<T> type, Pointer init)Create a new Structure instance of the given type, initialized with the given memory.voidread()Reads the fields of the struct from native memoryprotected java.lang.ObjectreadField(Structure.StructField structField)Read the given field and return its value.java.lang.ObjectreadField(java.lang.String name)Force a read of the given field from native memory.(package private) static java.util.Map<Pointer,Structure>reading()protected voidsetAlignType(int alignType)Change the alignment of this structure.voidsetAutoRead(boolean auto)Set whether the structure is read from native memory after a native function call.voidsetAutoSynch(boolean auto)Set whether the structure is automatically synchronized to native memory before and after a native function call.voidsetAutoWrite(boolean auto)Set whether the structure is written to native memory prior to a native function call.(package private) voidsetFieldValue(java.lang.reflect.Field field, java.lang.Object value)protected voidsetStringEncoding(java.lang.String encoding)Set the desired encoding to use when writing String fields to native memory.intsize()Returns the size in memory occupied by this Structure.(package private) static intsize(java.lang.Class<? extends Structure> type)Efficiently calculate the size of the given Structure subclass.(package private) static <T extends Structure>
intsize(java.lang.Class<T> type, T value)Efficiently calculate the size of the given Structure subclass.protected voidsortFields(java.util.List<java.lang.reflect.Field> fields, java.util.List<java.lang.String> names)Sort the structure fields according to the given array of names.Structure[]toArray(int size)Returns a view of this structure's memory as an array of structures.Structure[]toArray(Structure[] array)Returns a view of this structure's memory as an array of structures.java.lang.StringtoString()Ifjna.dump_memoryis true, will include a native memory dump of the Structure's backing memory.java.lang.StringtoString(boolean debug)(package private) static <T extends Structure>
TupdateStructureByReference(java.lang.Class<T> type, T s, Pointer address)Only keep the original structure if its native address is unchanged.protected voiduseMemory(Pointer m)Set the memory used by this structure.protected voiduseMemory(Pointer m, int offset)Set the memory used by this structure.(package private) voiduseMemory(Pointer m, int offset, boolean force)Set the memory used by this structure.(package private) static voidvalidate(java.lang.Class<? extends Structure> cls)Indicate whether the given Structure class can be created by JNA.voidwrite()Writes the fields of the struct to native memoryprotected voidwriteField(Structure.StructField structField)voidwriteField(java.lang.String name)Write the given field to native memory.voidwriteField(java.lang.String name, java.lang.Object value)Write the given field value to the field and native memory.
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Field Detail
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ALIGN_DEFAULT
public static final int ALIGN_DEFAULT
Use the platform default alignment.- See Also:
- Constant Field Values
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ALIGN_NONE
public static final int ALIGN_NONE
No alignment, place all fields on nearest 1-byte boundary- See Also:
- Constant Field Values
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ALIGN_GNUC
public static final int ALIGN_GNUC
validated for 32-bit x86 linux/gcc; align field size, max 4 bytes- See Also:
- Constant Field Values
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ALIGN_MSVC
public static final int ALIGN_MSVC
validated for w32/msvc; align on field size- See Also:
- Constant Field Values
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CALCULATE_SIZE
protected static final int CALCULATE_SIZE
Align to an 8-byte boundary.- See Also:
- Constant Field Values
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layoutInfo
static final java.util.Map<java.lang.Class<?>,com.sun.jna.Structure.LayoutInfo> layoutInfo
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fieldOrder
static final java.util.Map<java.lang.Class<?>,java.util.List<java.lang.String>> fieldOrder
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Constructor Detail
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Structure
protected Structure()
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Structure
protected Structure(TypeMapper mapper)
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Structure
protected Structure(int alignType)
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Structure
protected Structure(int alignType, TypeMapper mapper)
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Structure
protected Structure(Pointer p)
Create a structure cast onto pre-allocated memory.
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Structure
protected Structure(Pointer p, int alignType)
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Structure
protected Structure(Pointer p, int alignType, TypeMapper mapper)
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Method Detail
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fields
java.util.Map<java.lang.String,Structure.StructField> fields()
Return all fields in this structure (ordered). This represents the layout of the structure, and will be shared among Structures of the same class except when the Structure can have a variable size. NOTE:ensureAllocated()must be called prior to calling this method.- Returns:
Mapof field names to field representations.
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getTypeMapper
TypeMapper getTypeMapper()
- Returns:
- the type mapper in effect for this Structure.
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setStringEncoding
protected void setStringEncoding(java.lang.String encoding)
Set the desired encoding to use when writing String fields to native memory.- Parameters:
encoding- desired encoding
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getStringEncoding
protected java.lang.String getStringEncoding()
Encoding to use to convertStringto nativeconst char*. Defaults toNative.getDefaultStringEncoding().- Returns:
- Current encoding
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setAlignType
protected void setAlignType(int alignType)
Change the alignment of this structure. Re-allocates memory if necessary. If alignment isALIGN_DEFAULT, the default alignment for the defining class will be used.- Parameters:
alignType- desired alignment type
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autoAllocate
protected Memory autoAllocate(int size)
Obtain auto-allocated memory for use with struct represenations.- Parameters:
size- desired size- Returns:
- newly-allocated memory
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useMemory
protected void useMemory(Pointer m)
Set the memory used by this structure. This method is used to indicate the given structure is nested within another or otherwise overlaid on some other memory block and thus does not own its own memory.- Parameters:
m- Memory to with which to back thisStructure.
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useMemory
protected void useMemory(Pointer m, int offset)
Set the memory used by this structure. This method is used to indicate the given structure is based on natively-allocated data, nested within another, or otherwise overlaid on existing memory and thus does not own its own memory allocation.- Parameters:
m- Base memory to use to back this structure.offset- offset into provided memory where structure mapping should start.
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useMemory
void useMemory(Pointer m, int offset, boolean force)
Set the memory used by this structure. This method is used to indicate the given structure is based on natively-allocated data, nested within another, or otherwise overlaid on existing memory and thus does not own its own memory allocation.- Parameters:
m- Native pointeroffset- offset from pointer to useforce- ByValue structures normally ignore requests to use a different memory offset; this input is settruewhen setting a ByValue struct that is nested within another struct.
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ensureAllocated
protected void ensureAllocated()
Ensure this memory has its size and layout calculated and its memory allocated.
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allocateMemory
protected void allocateMemory()
Attempt to allocate memory if sufficient information is available. Returns whether the operation was successful.
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allocateMemory
protected void allocateMemory(int size)
Provided for derived classes to indicate a different size than the default. Returns whether the operation was successful. Will leave memory untouched if it is non-null and not allocated by this class.- Parameters:
size- how much memory to allocate
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size
public int size()
Returns the size in memory occupied by this Structure.- Returns:
- Native size of this structure, in bytes.
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clear
public void clear()
Clears the native memory associated with this Structure.
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getPointer
public Pointer getPointer()
Return aPointerobject to this structure. Note that if you use the structure's pointer as a function argument, you are responsible for callingwrite()prior to the call andread()after the call. These calls are normally handled automatically by theFunctionobject when it encounters aStructureargument or return value. The returned pointer may not have meaning forStructure.ByValuestructure representations.- Returns:
- Native pointer representation of this structure.
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busy
static java.util.Set<Structure> busy()
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conditionalAutoRead
void conditionalAutoRead()
Performs auto-read only if uninitialized.
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read
public void read()
Reads the fields of the struct from native memory
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fieldOffset
protected int fieldOffset(java.lang.String name)
Returns the calculated offset of the given field.- Parameters:
name- field to examine- Returns:
- return offset of the given field
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readField
public java.lang.Object readField(java.lang.String name)
Force a read of the given field from native memory. The Java field will be updated from the current contents of native memory.- Parameters:
name- field to be read- Returns:
- the new field value, after updating
- Throws:
java.lang.IllegalArgumentException- if no field exists with the given name
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getFieldValue
java.lang.Object getFieldValue(java.lang.reflect.Field field)
Obtain the value currently in the Java field. Does not read from native memory.- Parameters:
field- field to look up- Returns:
- current field value (Java-side only)
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setFieldValue
void setFieldValue(java.lang.reflect.Field field, java.lang.Object value)- Parameters:
field- field to setvalue- value to set
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updateStructureByReference
static <T extends Structure> T updateStructureByReference(java.lang.Class<T> type, T s, Pointer address)
Only keep the original structure if its native address is unchanged. Otherwise replace it with a new object.- Parameters:
type- Structure subclasss- Original Structure objectaddress- the nativestruct *- Returns:
- Updated
Structure.ByReferenceobject
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readField
protected java.lang.Object readField(Structure.StructField structField)
Read the given field and return its value. The Java field will be updated from the contents of native memory.- Parameters:
structField- field to be read- Returns:
- value of the requested field
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write
public void write()
Writes the fields of the struct to native memory
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writeField
public void writeField(java.lang.String name)
Write the given field to native memory. The current value in the Java field will be translated into native memory.- Parameters:
name- which field to synch- Throws:
java.lang.IllegalArgumentException- if no field exists with the given name
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writeField
public void writeField(java.lang.String name, java.lang.Object value)Write the given field value to the field and native memory. The given value will be written both to the Java field and the corresponding native memory.- Parameters:
name- field to writevalue- value to write- Throws:
java.lang.IllegalArgumentException- if no field exists with the given name
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writeField
protected void writeField(Structure.StructField structField)
- Parameters:
structField- internal field representation to synch to native memory
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getFieldOrder
protected java.util.List<java.lang.String> getFieldOrder()
Returns this Structure's field names in their proper order.
When defining a newStructureyou shouldn't override this method, but useStructure.FieldOrderannotation to define your field order(this also works with inheritance)
If you want to do something non-standard you can override the method and define it as followed
IMPORTANT When deriving from an existing Structure subclass, ensure that you augment the list provided by the superclass, e.g.protected ListgetFieldOrder() { return Arrays.asList(...); }
Field order must be explicitly indicated, since the field order as returned byprotected ListgetFieldOrder() { List fields = new LinkedList (super.getFieldOrder()); fields.addAll(Arrays.asList(...)); return fields; } Class.getFields()is not guaranteed to be predictable.- Returns:
- ordered list of field names
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sortFields
protected void sortFields(java.util.List<java.lang.reflect.Field> fields, java.util.List<java.lang.String> names)Sort the structure fields according to the given array of names.- Parameters:
fields- list of fields to be sortednames- list of names representing the desired sort order
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getFieldList
protected java.util.List<java.lang.reflect.Field> getFieldList()
Look up all fields in this class and superclasses.- Returns:
- ordered list of public
Fieldavailable on thisStructureclass.
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createFieldsOrder
public static java.util.List<java.lang.String> createFieldsOrder(java.util.List<java.lang.String> baseFields, java.lang.String... extraFields)
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createFieldsOrder
public static java.util.List<java.lang.String> createFieldsOrder(java.util.List<java.lang.String> baseFields, java.util.List<java.lang.String> extraFields)
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createFieldsOrder
public static java.util.List<java.lang.String> createFieldsOrder(java.lang.String field)
- Parameters:
field- The (single) field name- Returns:
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createFieldsOrder
public static java.util.List<java.lang.String> createFieldsOrder(java.lang.String... fields)
- Parameters:
fields- The structure field names in correct order- Returns:
- An un-modifiable list of the fields
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getFields
protected java.util.List<java.lang.reflect.Field> getFields(boolean force)
Returns all field names (sorted) provided so far bygetFieldOrder()- Parameters:
force- set if results are required immediately- Returns:
- null if not yet able to provide fields, and force is false.
- Throws:
java.lang.Error- if force is true and field order data not yet specified and can't be generated automatically.
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calculateSize
protected int calculateSize(boolean force)
Calculate the amount of native memory required for this structure. May returnCALCULATE_SIZEif the size can not yet be determined (usually due to fields in the derived class not yet being initialized). If theforceparameter istruewill throw anIllegalStateExceptionif the size can not be determined.- Parameters:
force- whether to force size calculation- Returns:
- calculated size, or
CALCULATE_SIZEif the size can not yet be determined. - Throws:
java.lang.IllegalStateException- an array field is not initialized or the size can not be determined whileforceistrue.java.lang.IllegalArgumentException- when an unsupported field type is encountered
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size
static int size(java.lang.Class<? extends Structure> type)
Efficiently calculate the size of the given Structure subclass.- Parameters:
type- Structure subclass to check- Returns:
- native size of the given Structure subclass
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size
static <T extends Structure> int size(java.lang.Class<T> type, T value)
Efficiently calculate the size of the given Structure subclass.- Parameters:
type- Structure subclass to checkvalue- optional instance of the given class- Returns:
- native size of the Structure subclass
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calculateSize
int calculateSize(boolean force, boolean avoidFFIType)- Parameters:
force- whether to force size calculation.avoidFFIType- set false in certain situations to avoid recursive type lookup.- Returns:
- calculated size, or
CALCULATE_SIZEif there is not yet enough information to perform the size calculation.
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getStructAlignment
protected int getStructAlignment()
- Returns:
- current alignment setting for this structure
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getNativeAlignment
protected int getNativeAlignment(java.lang.Class<?> type, java.lang.Object value, boolean isFirstElement)Overridable in subclasses. Calculate the appropriate alignment for a field of a given type within this struct.- Parameters:
type- field typevalue- field value, if availableisFirstElement- is this field the first element in the struct?- Returns:
- the native byte alignment
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toString
public java.lang.String toString()
Ifjna.dump_memoryis true, will include a native memory dump of the Structure's backing memory.- Overrides:
toStringin classjava.lang.Object- Returns:
- String representation of this object.
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toString
public java.lang.String toString(boolean debug)
- Parameters:
debug- If true, will include a native memory dump of the Structure's backing memory.- Returns:
- String representation of this object.
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toArray
public Structure[] toArray(Structure[] array)
Returns a view of this structure's memory as an array of structures. Note that thisStructuremust have a public, no-arg constructor. If the structure is currently using auto-allocatedMemorybacking, the memory will be resized to fit the entire array.- Parameters:
array- Structure[] object to populate- Returns:
- array of Structure mapped onto the available memory
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toArray
public Structure[] toArray(int size)
Returns a view of this structure's memory as an array of structures. Note that thisStructuremust have a public, no-arg constructor. If the structure is currently using auto-allocatedMemorybacking, the memory will be resized to fit the entire array.- Parameters:
size- desired number of elements- Returns:
- array of Structure (individual elements will be of the appropriate type, as will the Structure[]).
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dataEquals
public boolean dataEquals(Structure s)
Return whether the given Structure's native backing data is identical to this one.- Parameters:
s- Structure to compare- Returns:
- equality result
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dataEquals
public boolean dataEquals(Structure s, boolean clear)
Return whether the given Structure's backing data is identical to this one, optionally clearing and re-writing native memory before checking.- Parameters:
s- Structure to compareclear- whether to clear native memory- Returns:
- equality result
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equals
public boolean equals(java.lang.Object o)
- Overrides:
equalsin classjava.lang.Object- Returns:
- whether the given structure's type and pointer match.
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hashCode
public int hashCode()
- Overrides:
hashCodein classjava.lang.Object- Returns:
- hash code for this structure's pointer.
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cacheTypeInfo
protected void cacheTypeInfo(Pointer p)
Cache native type information for use in native code.- Parameters:
p- Native pointer to the type information
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getFieldTypeInfo
Structure.FFIType getFieldTypeInfo(Structure.StructField f)
Override to supply native type information for the given field.- Parameters:
f- internal field representation- Returns:
- Native pointer to the corresponding type information
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getTypeInfo
Pointer getTypeInfo()
- Returns:
- native type information for this structure.
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setAutoSynch
public void setAutoSynch(boolean auto)
Set whether the structure is automatically synchronized to native memory before and after a native function call. Convenience method for
For extremely large or complex structures where you only need to access a small number of fields, you may see a significant performance benefit by avoiding automatic structure reads and writes. If auto-read and -write are disabled, it is up to you to ensure that the Java fields of interest are synched before and after native function calls viaboolean auto = ...; setAutoRead(auto); setAutoWrite(auto);readField(String)andwriteField(String,Object). This is typically most effective when a native call populates a large structure and you only need a few fields out of it. After the native call you can callreadField(String)on only the fields of interest.- Parameters:
auto- whether to automatically synch with native memory.
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setAutoRead
public void setAutoRead(boolean auto)
Set whether the structure is read from native memory after a native function call.- Parameters:
auto- whether to automatically synch from native memory.
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getAutoRead
public boolean getAutoRead()
Returns whether the structure is read from native memory after a native function call.- Returns:
- whether automatic synch from native memory is enabled.
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setAutoWrite
public void setAutoWrite(boolean auto)
Set whether the structure is written to native memory prior to a native function call.- Parameters:
auto- whether to automatically synch to native memory.
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getAutoWrite
public boolean getAutoWrite()
Returns whether the structure is written to native memory prior to a native function call.- Returns:
- whether automatic synch to native memory is enabled.
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getTypeInfo
static Structure.FFIType getTypeInfo(java.lang.Object obj)
Exposed for testing purposes only.- Parameters:
obj- object to query- Returns:
- native pointer to type information
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newInstance
public static <T extends Structure> T newInstance(java.lang.Class<T> type, Pointer init) throws java.lang.IllegalArgumentException
Create a new Structure instance of the given type, initialized with the given memory.- Parameters:
type- desired Structure typeinit- initial memory- Returns:
- the new instance
- Throws:
java.lang.IllegalArgumentException- if the instantiation fails
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newInstance
public static <T extends Structure> T newInstance(java.lang.Class<T> type) throws java.lang.IllegalArgumentException
Create a new Structure instance of the given type- Parameters:
type- desired Structure type- Returns:
- the new instance
- Throws:
java.lang.IllegalArgumentException- if the instantiation fails
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autoRead
public static void autoRead(Structure[] ss)
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autoRead
public void autoRead()
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autoWrite
public static void autoWrite(Structure[] ss)
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autoWrite
public void autoWrite()
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getNativeSize
protected int getNativeSize(java.lang.Class<?> nativeType)
Return the native size of the given Java type, from the perspective of this Structure.- Parameters:
nativeType- field type to examine- Returns:
- native size (in bytes) of the requested field type
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getNativeSize
protected int getNativeSize(java.lang.Class<?> nativeType, java.lang.Object value)Return the native size of the given Java type, from the perspective of this Structure.- Parameters:
nativeType- field type to examinevalue- instance of the field type- Returns:
- native size (in bytes) of the requested field type
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validate
static void validate(java.lang.Class<? extends Structure> cls)
Indicate whether the given Structure class can be created by JNA.- Parameters:
cls- Structure subclass to check
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