com.sun.jna

## Class Structure

- java.lang.Object
- - com.sun.jna.Structure

- 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, DsGetDC.DOMAIN_CONTROLLER_INFO, DsGetDC.DS_DOMAIN_TRUSTS, DsGetDC.PDOMAIN_CONTROLLER_INFO, Guid.GUID, 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, MacFileUtils.FileManager.FSRef, 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.ELEMDESC, OaIdl.EXCEPINFO, OaIdl.FUNCDESC, OaIdl.FUNCKIND, OaIdl.IDLDESC, OaIdl.INVOKEKIND, OaIdl.PARAMDESC, OaIdl.PARAMDESCEX, OaIdl.SAFEARRAY, OaIdl.SAFEARRAYBOUND, OaIdl.TLIBATTR, OaIdl.TYPEATTR, OaIdl.TYPEDESC, OaIdl.VARDESC, OaIdl.VARKIND, OleAuto.DISPPARAMS, SetupApi.SP_DEVICE_INTERFACE_DATA, SetupApi.SP_DEVINFO_DATA, ShellAPI.APPBARDATA, ShellAPI.SHFILEOPSTRUCT, Sspi.PSecHandle, Sspi.PSecPkgInfo, Sspi.SecBuffer, Sspi.SecBufferDesc, Sspi.SecHandle, Sspi.SecPkgInfo, Sspi.SECURITY_INTEGER, Structure.FFIType, Tlhelp32.PROCESSENTRY32, Union, Variant.VARIANT._VARIANT, Variant.VARIANT._VARIANT.__VARIANT.BRECORD, Variant.VariantArg, VerRsrc.VS_FIXEDFILEINFO, Wdm.KEY_BASIC_INFORMATION, WinBase.FILETIME, WinBase.MEMORYSTATUSEX, WinBase.OVERLAPPED, WinBase.PROCESS_INFORMATION, WinBase.SECURITY_ATTRIBUTES, WinBase.STARTUPINFO, WinBase.SYSTEM_INFO, WinBase.SYSTEM_INFO.PI, WinBase.SYSTEMTIME, WinCrypt.CRYPTPROTECT_PROMPTSTRUCT, WinCrypt.DATA_BLOB, WinDef.POINT, WinDef.RECT, WinGDI.BITMAPINFO, WinGDI.BITMAPINFOHEADER, WinGDI.RGBQUAD, WinGDI.RGNDATA, WinGDI.RGNDATAHEADER, Winioctl.STORAGE_DEVICE_NUMBER, WinNT.ACEStructure, WinNT.ACL, WinNT.CACHE_DESCRIPTOR, WinNT.EVENTLOGRECORD, WinNT.FILE_NOTIFY_INFORMATION, WinNT.LARGE_INTEGER, WinNT.LARGE_INTEGER.LowHigh, WinNT.LUID, WinNT.LUID_AND_ATTRIBUTES, WinNT.OSVERSIONINFO, WinNT.OSVERSIONINFOEX, WinNT.PSID, WinNT.SECURITY_DESCRIPTOR, WinNT.SECURITY_DESCRIPTOR_RELATIVE, WinNT.SID_AND_ATTRIBUTES, WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION, WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION.AnonymousStructNumaNode, WinNT.SYSTEM_LOGICAL_PROCESSOR_INFORMATION.AnonymousStructProcessorCore, WinNT.TOKEN_GROUPS, WinNT.TOKEN_OWNER, WinNT.TOKEN_PRIVILEGES, WinNT.TOKEN_USER, Winspool.PRINTER_INFO_1, Winspool.PRINTER_INFO_4, Winsvc.SERVICE_STATUS, Winsvc.SERVICE_STATUS_PROCESS, WinUser.BLENDFUNCTION, WinUser.FLASHWINFO, WinUser.GUITHREADINFO, WinUser.HARDWAREINPUT, WinUser.INPUT, WinUser.KBDLLHOOKSTRUCT, WinUser.KEYBDINPUT, WinUser.LASTINPUTINFO, WinUser.MOUSEINPUT, WinUser.MSG, WinUser.POINT, WinUser.SIZE, WinUser.WINDOWINFO, WinUser.WNDCLASSEX, 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.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.Object

  Represents a native structure with a Java peer class. When used as a function parameter or return value, this class corresponds to `struct*`. When used as a field within another `Structure`, it corresponds to `struct`. The tagging interfaces `Structure.ByReference` and `Structure.ByValue` may 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)` and `Native.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 define `getFieldOrder()` to return a List of field names (Strings) indicating the proper order of the fields. When dealing with multiple levels of subclasses of Structure, you must add to the list provided by the superclass `getFieldOrder()` 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:
  - `volatile` JNA will not write the field unless specifically instructed to do so via `writeField(String)`. This allows you to prevent inadvertently overwriting memory that may be updated in real time on another (possibly native) thread.
  - `final` JNA will overwrite the field via `read()`, 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 than `wchar_t *`. You may provide a type mapper (`example here)` if you prefer to use String in place of `WString` if your native code predominantly uses `wchar_t *`.

  NOTE: In general, instances of this class are not synchronized.

  Author:
    Todd Fast, todd.fast@sun.com, twall@users.sf.net

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static interface` | `Structure.ByReference` Tagging interface to indicate the address of an instance of the Structure type is to be used within a `Structure` definition rather than nesting the full Structure contents.
    `static interface` | `Structure.ByValue` Tagging interface to indicate the value of an instance of the `Structure` type is to be used in function invocations rather than its address.
    `(package private) static class` | `Structure.FFIType` This class auto-generates an ffi_type structure appropriate for a given structure for use by libffi.
    `protected static class` | `Structure.StructField`

  - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `ALIGN_DEFAULT` Use the platform default alignment.
    `static int` | `ALIGN_GNUC` validated for 32-bit x86 linux/gcc; align field size, max 4 bytes
    `static int` | `ALIGN_MSVC` validated for w32/msvc; align on field size
    `static int` | `ALIGN_NONE` No alignment, place all fields on nearest 1-byte boundary
    `protected static int` | `CALCULATE_SIZE` Align to an 8-byte boundary.
    `(package private) static java.util.Map` | `fieldOrder`
    `(package private) static java.util.Map` | `layoutInfo`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `Structure()`
    `protected` | `Structure(int alignType)`
    `protected` | `Structure(int alignType, TypeMapper mapper)`
    `protected` | `Structure(Pointer p)` Create a structure cast onto pre-allocated memory.
    `protected` | `Structure(Pointer p, int alignType)`
    `protected` | `Structure(Pointer p, int alignType, TypeMapper mapper)`
    `protected` | `Structure(TypeMapper mapper)`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected void` | `allocateMemory()` Attempt to allocate memory if sufficient information is available.
    `protected void` | `allocateMemory(int size)` Provided for derived classes to indicate a different size than the default.
    `protected Memory` | `autoAllocate(int size)`
    `void` | `autoRead()`
    `static void` | `autoRead(Structure[] ss)`
    `void` | `autoWrite()`
    `static void` | `autoWrite(Structure[] ss)`
    `(package private) static java.util.Set` | `busy()`
    `protected void` | `cacheTypeInfo(Pointer p)` Cache native type information for use in native code.
    `(package private) int` | `calculateSize(boolean force, boolean avoidFFIType)`
    `void` | `clear()` Clears the native memory associated with this Structure.
    `(package private) void` | `conditionalAutoRead()` Performs auto-read only if uninitialized.
    `protected void` | `ensureAllocated()` Ensure this memory has its size and layout calculated and its memory allocated.
    `boolean` | `equals(java.lang.Object o)` This structure is equal to another based on the same data type and memory contents.
    `protected int` | `fieldOffset(java.lang.String name)` Returns the calculated offset of the given field.
    `(package private) java.util.Map` | `fields()` Return all fields in this structure (ordered).
    `boolean` | `getAutoRead()` Returns whether the structure is read from native memory prior to a native function call.
    `boolean` | `getAutoWrite()` Returns whether the structure is written to native memory after a native function call.
    `protected java.util.List` | `getFieldList()` Look up all fields in this class and superclasses.
    `protected abstract java.util.List` | `getFieldOrder()` Return this Structure's field names in their proper order.
    `protected java.util.List` | `getFields(boolean force)` Returns all field names (sorted) provided so far by `getFieldOrder()`
    `(package private) Pointer` | `getFieldTypeInfo(Structure.StructField f)` Override to supply native type information for the given field.
    `(package private) java.lang.Object` | `getFieldValue(java.lang.reflect.Field field)` Obtain the value currently in the Java field.
    `protected int` | `getNativeAlignment(java.lang.Class type, java.lang.Object value, boolean isFirstElement)` Overridable in subclasses.
    `protected int` | `getNativeSize(java.lang.Class nativeType)` Return the native size of the given Java type, from the perspective of this Structure.
    `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.
    `Pointer` | `getPointer()` Return a `Pointer` object to this structure.
    `protected java.lang.String` | `getStringEncoding()` Encoding to use to convert `String` to native `const char*`.
    `protected int` | `getStructAlignment()`
    `(package private) Pointer` | `getTypeInfo()` Obtain native type information for this structure.
    `(package private) static Pointer` | `getTypeInfo(java.lang.Object obj)` Exposed for testing purposes only.
    `(package private) TypeMapper` | `getTypeMapper()` Return the type mapper in effect for this Structure.
    `int` | `hashCode()` Since `equals(java.lang.Object)` depends on the contents of memory, use that as the basis for the hash code.
    `static Structure` | `newInstance(java.lang.Class type)` Create a new Structure instance of the given type
    `static Structure` | `newInstance(java.lang.Class type, Pointer init)` Create a new Structure instance of the given type, initialized with the given memory.
    `void` | `read()` Reads the fields of the struct from native memory
    `java.lang.Object` | `readField(java.lang.String name)` Force a read of the given field from native memory.
    `protected java.lang.Object` | `readField(Structure.StructField structField)` Read the given field and return its value.
    `(package private) static java.util.Map` | `reading()`
    `protected void` | `setAlignType(int alignType)` Change the alignment of this structure.
    `void` | `setAutoRead(boolean auto)` Set whether the structure is read from native memory prior to a native function call.
    `void` | `setAutoSynch(boolean auto)` Set whether the structure is automatically synchronized to native memory before and after a native function call.
    `void` | `setAutoWrite(boolean auto)` Set whether the structure is written to native memory after a native function call.
    `protected void` | `setFieldOrder(java.lang.String[] fields)` Deprecated. Use the required method getFieldOrder() instead to indicate the order of fields in this structure.
    `(package private) void` | `setFieldValue(java.lang.reflect.Field field, java.lang.Object value)`
    `protected void` | `setStringEncoding(java.lang.String encoding)` Set the desired encoding to use when writing String fields to native memory.
    `int` | `size()` Returns the size in memory occupied by this Structure.
    `(package private) static int` | `size(java.lang.Class type)` Efficiently calculate the size of the given Structure subclass.
    `(package private) static int` | `size(java.lang.Class type, Structure value)` Efficiently calculate the size of the given Structure subclass.
    `protected void` | `sortFields(java.util.List fields, java.util.List 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.String` | `toString()`
    `java.lang.String` | `toString(boolean debug)`
    `(package private) Structure.StructField` | `typeInfoField()` Keep track of the largest aggregate field of the union to use for FFI type information.
    `(package private) static Structure` | `updateStructureByReference(java.lang.Class type, Structure s, Pointer address)` Only keep the original structure if its native address is unchanged.
    `protected void` | `useMemory(Pointer m)` Set the memory used by this structure.
    `protected void` | `useMemory(Pointer m, int offset)` Set the memory used by this structure.
    `(package private) static void` | `validate(java.lang.Class cls)` Indicate whether the given Structure class can be created by JNA.
    `void` | `write()` Writes the fields of the struct to native memory
    `void` | `writeField(java.lang.String name)` Write the given field to native memory.
    `void` | `writeField(java.lang.String name, java.lang.Object value)` Write the given field value to the field and native memory.
    `protected void` | `writeField(Structure.StructField structField)`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### ALIGN_DEFAULT

          public static final int ALIGN_DEFAULT

      Use the platform default alignment.
      See Also:
        Constant Field Values

    - #### ALIGN_NONE

          public static final int ALIGN_NONE

      No alignment, place all fields on nearest 1-byte boundary
      See Also:
        Constant Field Values

    - #### 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

    - #### ALIGN_MSVC

          public static final int ALIGN_MSVC

      validated for w32/msvc; align on field size
      See Also:
        Constant Field Values

    - #### CALCULATE_SIZE

          protected static final int CALCULATE_SIZE

      Align to an 8-byte boundary.
      See Also:
        Constant Field Values

    - #### layoutInfo

          static final java.util.Map layoutInfo

    - #### fieldOrder

          static final java.util.Map fieldOrder

  - ### Constructor Detail

    - #### Structure

          protected Structure()

    - #### Structure

          protected Structure(TypeMapper mapper)

    - #### Structure

          protected Structure(int alignType)

    - #### Structure

          protected Structure(int alignType,
                   TypeMapper mapper)

    - #### Structure

          protected Structure(Pointer p)

      Create a structure cast onto pre-allocated memory.

    - #### Structure

          protected Structure(Pointer p,
                   int alignType)

    - #### Structure

          protected Structure(Pointer p,
                   int alignType,
                   TypeMapper mapper)

  - ### Method Detail

    - #### fields

          java.util.Map 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.

    - #### getTypeMapper

          TypeMapper getTypeMapper()

      Return the type mapper in effect for this Structure.

    - #### setStringEncoding

          protected void setStringEncoding(java.lang.String encoding)

      Set the desired encoding to use when writing String fields to native memory.

    - #### getStringEncoding

          protected java.lang.String getStringEncoding()

      Encoding to use to convert `String` to native `const char*`. Defaults to `Native.getDefaultStringEncoding()`.

    - #### setAlignType

          protected void setAlignType(int alignType)

      Change the alignment of this structure. Re-allocates memory if necessary. If alignment is `ALIGN_DEFAULT`, the default alignment for the defining class will be used.

    - #### autoAllocate

          protected Memory autoAllocate(int size)

    - #### 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.

    - #### 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.

    - #### ensureAllocated

          protected void ensureAllocated()

      Ensure this memory has its size and layout calculated and its memory allocated.

    - #### allocateMemory

          protected void allocateMemory()

      Attempt to allocate memory if sufficient information is available. Returns whether the operation was successful.

    - #### 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.

    - #### size

          public int size()

      Returns the size in memory occupied by this Structure.

    - #### clear

          public void clear()

      Clears the native memory associated with this Structure.

    - #### getPointer

          public Pointer getPointer()

      Return a `Pointer` object to this structure. Note that if you use the structure's pointer as a function argument, you are responsible for calling `write()` prior to the call and `read()` after the call. These calls are normally handled automatically by the `Function` object when it encounters a `Structure` argument or return value.

    - #### busy

          static java.util.Set busy()

    - #### reading

          static java.util.Map reading()

    - #### conditionalAutoRead

          void conditionalAutoRead()

      Performs auto-read only if uninitialized.

    - #### read

          public void read()

      Reads the fields of the struct from native memory

    - #### fieldOffset

          protected int fieldOffset(java.lang.String name)

      Returns the calculated offset of the given field.

    - #### 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.
      Returns:
        the new field value, after updating
      Throws:
        `java.lang.IllegalArgumentException` - if no field exists with the given name

    - #### getFieldValue

          java.lang.Object getFieldValue(java.lang.reflect.Field field)

      Obtain the value currently in the Java field. Does not read from memory.

    - #### setFieldValue

          void setFieldValue(java.lang.reflect.Field field,
                           java.lang.Object value)

    - #### updateStructureByReference

          static Structure updateStructureByReference(java.lang.Class type,
                                             Structure s,
                                             Pointer address)

      Only keep the original structure if its native address is unchanged. Otherwise replace it with a new object.
      Parameters:
        `type` - Structure subclass
        `s` - Original Structure object
        `address` - the native `struct *`
      Returns:
        Updated `Structure.ByReference` object

    - #### 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.

    - #### write

          public void write()

      Writes the fields of the struct to native memory

    - #### 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.
      Throws:
        `java.lang.IllegalArgumentException` - if no field exists with the given name

    - #### 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.
      Throws:
        `java.lang.IllegalArgumentException` - if no field exists with the given name

    - #### writeField

          protected void writeField(Structure.StructField structField)

    - #### getFieldOrder

          protected abstract java.util.List getFieldOrder()

      Return this Structure's field names in their proper order. For example,

           protected List getFieldOrder() {
               return Arrays.asList(new String[] { ... });
           }

      IMPORTANT When deriving from an existing Structure subclass, ensure that you augment the list provided by the superclass, e.g.

           protected List getFieldOrder() {
               List fields = new ArrayList(super.getFieldOrder());
               fields.addAll(Arrays.asList(new String[] { ... }));
               return fields;
           }

      Field order must be explicitly indicated, since the field order as returned by `Class.getFields()` is not guaranteed to be predictable.

    - #### setFieldOrder

          protected final void setFieldOrder(java.lang.String[] fields)

      Deprecated. Use the required method getFieldOrder() instead to indicate the order of fields in this structure.
      Force a compile-time error on the old method of field definition

    - #### sortFields

          protected void sortFields(java.util.List fields,
                        java.util.List names)

      Sort the structure fields according to the given array of names.

    - #### getFieldList

          protected java.util.List getFieldList()

      Look up all fields in this class and superclasses.

    - #### getFields

          protected java.util.List getFields(boolean force)

      Returns all field names (sorted) provided so far by `getFieldOrder()`
      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.

    - #### size

          static int size(java.lang.Class type)

      Efficiently calculate the size of the given Structure subclass.

    - #### size

          static int size(java.lang.Class type,
                 Structure value)

      Efficiently calculate the size of the given Structure subclass.

    - #### calculateSize

          int calculateSize(boolean force,
                          boolean avoidFFIType)

    - #### getStructAlignment

          protected int getStructAlignment()

    - #### getNativeAlignment

          protected int getNativeAlignment(java.lang.Class type,
                               java.lang.Object value,
                               boolean isFirstElement)

      Overridable in subclasses.

    - #### toString

          public java.lang.String toString()

      Overrides:
        `toString` in class `java.lang.Object`

    - #### toString

          public java.lang.String toString(boolean debug)

    - #### toArray

          public Structure[] toArray(Structure[] array)

      Returns a view of this structure's memory as an array of structures. Note that this `Structure` must have a public, no-arg constructor. If the structure is currently using auto-allocated `Memory` backing, the memory will be resized to fit the entire array.

    - #### toArray

          public Structure[] toArray(int size)

      Returns a view of this structure's memory as an array of structures. Note that this `Structure` must have a public, no-arg constructor. If the structure is currently using auto-allocated `Memory` backing, the memory will be resized to fit the entire array.

    - #### equals

          public boolean equals(java.lang.Object o)

      This structure is equal to another based on the same data type and memory contents.
      Overrides:
        `equals` in class `java.lang.Object`

    - #### hashCode

          public int hashCode()

      Since `equals(java.lang.Object)` depends on the contents of memory, use that as the basis for the hash code.
      Overrides:
        `hashCode` in class `java.lang.Object`

    - #### cacheTypeInfo

          protected void cacheTypeInfo(Pointer p)

      Cache native type information for use in native code.

    - #### getFieldTypeInfo

          Pointer getFieldTypeInfo(Structure.StructField f)

      Override to supply native type information for the given field.

    - #### getTypeInfo

          Pointer getTypeInfo()

      Obtain native type information for this structure.

    - #### 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

                  boolean auto = ...;
                  setAutoRead(auto);
                  setAutoWrite(auto);

      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 via `readField(String)` and `writeField(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 call `readField(String)` on only the fields of interest.

    - #### setAutoRead

          public void setAutoRead(boolean auto)

      Set whether the structure is read from native memory prior to a native function call.

    - #### getAutoRead

          public boolean getAutoRead()

      Returns whether the structure is read from native memory prior to a native function call.

    - #### setAutoWrite

          public void setAutoWrite(boolean auto)

      Set whether the structure is written to native memory after a native function call.

    - #### getAutoWrite

          public boolean getAutoWrite()

      Returns whether the structure is written to native memory after a native function call.

    - #### getTypeInfo

          static Pointer getTypeInfo(java.lang.Object obj)

      Exposed for testing purposes only.

    - #### newInstance

          public static Structure newInstance(java.lang.Class 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 type
        `init` - initial memory
      Returns:
        the new instance
      Throws:
        `java.lang.IllegalArgumentException` - if the instantiation fails

    - #### newInstance

          public static Structure newInstance(java.lang.Class 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

    - #### typeInfoField

          Structure.StructField typeInfoField()

      Keep track of the largest aggregate field of the union to use for FFI type information.

    - #### autoRead

          public static void autoRead(Structure[] ss)

    - #### autoRead

          public void autoRead()

    - #### autoWrite

          public static void autoWrite(Structure[] ss)

    - #### autoWrite

          public void autoWrite()

    - #### getNativeSize

          protected int getNativeSize(java.lang.Class nativeType)

      Return the native size of the given Java type, from the perspective of this Structure.

    - #### 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.

    - #### validate

          static void validate(java.lang.Class cls)

      Indicate whether the given Structure class can be created by JNA.

Copyright © 2007-2013 Timothy Wall. All Rights Reserved.