Derive from this interface for all native library definitions. Define an instance of your library like this:


MyNativeLibrary INSTANCE = (MyNativeLibrary)
    Native.load("mylib", MyNativeLibrary.class);

By convention, method names are identical to the native names, although you can map java names to different native names by providing a FunctionMapper as a value for key OPTION_FUNCTION_MAPPER in the options map passed to the Native#load(String, Class, Map) call.

Although the names for structures and structure fields may be chosen arbitrarily, they should correspond as closely as possible to the native definitions. The same is true for parameter names.

This interface supports multiple, concurrent invocations of any library methods on the Java side. Check your library documentation for its multi-threading requirements on the native side. If a library is not safe for simultaneous multi-threaded access, consider using Native#synchronizedLibrary to prevent simultaneous multi-threaded access to the native code.

Optional fields
Interface options will be automatically propagated to structures defined within the library provided a call to Native#load(String, Class, Map) is made prior to instantiating any of those structures. One common way of ensuring this is to declare an INSTANCE field in the interface which holds the load result.

OPTIONS (an instance of Map), TYPE_MAPPER (an instance of TypeMapper), STRUCTURE_ALIGNMENT (one of the alignment types defined in Structure), and STRING_ENCODING (a String) may also be defined. If no instance of the interface has been instantiated, these fields will be used to determine customization settings for structures and methods defined within the interface.

Nested and Inner Type Summary

Modifier and Type	Class and Description
public static class	Library.Handler

Field Summary

Modifier and Type	Field and Description
public static final String	OPTION_ALLOW_OBJECTS Option key for a boolean flag to allow any Java class instance as a parameter.
public static final String	OPTION_CALLING_CONVENTION Calling convention for the entire library.
public static final String	OPTION_CLASSLOADER Class loader to use when searching for native libraries on the resource path (classpath).
public static final String	OPTION_FUNCTION_MAPPER Option key for a `FunctionMapper` for the library.
public static final String	OPTION_INVOCATION_MAPPER Option key for an `InvocationMapper` for the library.
public static final String	OPTION_OPEN_FLAGS Flags to use when opening the native library (see `Native#open(String, int)`)
public static final String	OPTION_STRING_ENCODING Option key for per-library String encoding.
public static final String	OPTION_STRUCTURE_ALIGNMENT Option key for structure alignment type (`Integer`), which should be one of the predefined alignment types in `Structure`.
public static final String	OPTION_SYMBOL_PROVIDER Supports a custom symbol provider for the NativeLibrary (see `SymbolProvider`)
public static final String	OPTION_TYPE_MAPPER Option key for a `TypeMapper` for the library.

Field Detail

OPTION_ALLOW_OBJECTS	back to summary
public static final String OPTION_ALLOW_OBJECTS Option key for a boolean flag to allow any Java class instance as a parameter. If no type mapper is found, the object is passed as a pointer Note This is for use with raw JNI interactions via the JNIEnv data structure.

OPTION_CALLING_CONVENTION	back to summary
public static final String OPTION_CALLING_CONVENTION Calling convention for the entire library.

OPTION_CLASSLOADER	back to summary
public static final String OPTION_CLASSLOADER Class loader to use when searching for native libraries on the resource path (classpath). If not provided the current thread's context class loader is used. If extracted from the resource path (i.e. bundled in a jar file), the loaded library's lifespan will mirror that of the class loader, which means you can use the same library in isolated contexts without conflict.

OPTION_CLASSLOADER

back to summary

public static final String OPTION_CLASSLOADER

Class loader to use when searching for native libraries on the resource path (classpath). If not provided the current thread's context class loader is used.

If extracted from the resource path (i.e. bundled in a jar file), the loaded library's lifespan will mirror that of the class loader, which means you can use the same library in isolated contexts without conflict.

OPTION_FUNCTION_MAPPER	back to summary
public static final String OPTION_FUNCTION_MAPPER Option key for a `FunctionMapper` for the library.

OPTION_INVOCATION_MAPPER	back to summary
public static final String OPTION_INVOCATION_MAPPER Option key for an `InvocationMapper` for the library.

OPTION_OPEN_FLAGS	back to summary
public static final String OPTION_OPEN_FLAGS Flags to use when opening the native library (see `Native#open(String, int)`)

OPTION_STRING_ENCODING	back to summary
public static final String OPTION_STRING_ENCODING Option key for per-library String encoding. This affects conversions between Java unicode and native (`const char*`) strings (as arguments or Structure fields). Defaults to `Native#getDefaultStringEncoding()`.

OPTION_STRUCTURE_ALIGNMENT	back to summary
public static final String OPTION_STRUCTURE_ALIGNMENT Option key for structure alignment type (`Integer`), which should be one of the predefined alignment types in `Structure`.

OPTION_SYMBOL_PROVIDER	back to summary
public static final String OPTION_SYMBOL_PROVIDER Supports a custom symbol provider for the NativeLibrary (see `SymbolProvider`)

OPTION_TYPE_MAPPER	back to summary
public static final String OPTION_TYPE_MAPPER Option key for a `TypeMapper` for the library.

com.sun.jna back to summary

public Class Library.Handler

Class Inheritance

extends Object
implements InvocationHandler

java.lang.Object
com.sun.jna.Library.Handler

All Implemented Interfaces

java.lang.reflect.InvocationHandler

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	Library.Handler.FunctionInfo FunctionInfo has to be immutable to to make the object visible to other threads fully initialized.

Field Summary

Modifier and Type	Field and Description
private final Map<Method, Library.Handler.FunctionInfo>	functions
private final Class<?>	interfaceClass
private final InvocationMapper	invocationMapper
private final NativeLibrary	nativeLibrary
pack-priv static final Method	OBJECT_EQUALS
pack-priv static final Method	OBJECT_HASHCODE
pack-priv static final Method	OBJECT_TOSTRING
private final Map<String, Object>	options

Constructor Summary

Access	Constructor and Description
public	Handler(String libname, Class<?> interfaceClass, Map<String, ?> options)

Method Summary

Modifier and Type	Method and Description
public Class<?>	getInterfaceClass()
public String	getLibraryName()
public NativeLibrary	getNativeLibrary()
public Object	invoke(Object the proxy instance that the method was invoked on proxy, Method the `Method` instance corresponding to the interface method invoked on the proxy instance. The declaring class of the `Method` object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. method, Object[] an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or `null` if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as `java.lang.Integer` or `java.lang.Boolean`. inArgs) Implements java.lang.reflect.InvocationHandler.invoke. Processes a method invocation on a proxy instance and returns the result.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

functions	back to summary
private final Map<Method, Library.Handler.FunctionInfo> functions

interfaceClass	back to summary
private final Class<?> interfaceClass

invocationMapper	back to summary
private final InvocationMapper invocationMapper

nativeLibrary	back to summary
private final NativeLibrary nativeLibrary

OBJECT_EQUALS	back to summary
pack-priv static final Method OBJECT_EQUALS

OBJECT_HASHCODE	back to summary
pack-priv static final Method OBJECT_HASHCODE

OBJECT_TOSTRING	back to summary
pack-priv static final Method OBJECT_TOSTRING

options	back to summary
private final Map<String, Object> options

Constructor Detail

Handler	back to summary
public Handler(String libname, Class<?> interfaceClass, Map<String, ?> options)

Method Detail

getInterfaceClass	back to summary
public Class<?> getInterfaceClass()

getLibraryName	back to summary
public String getLibraryName()

getNativeLibrary	back to summary
public NativeLibrary getNativeLibrary()

invoke back to summary

invoke	back to summary
public Object invoke(Object proxy, Method method, Object[] inArgs) throws Throwable Implements java.lang.reflect.InvocationHandler.invoke. Doc from java.lang.reflect.InvocationHandler.invoke. Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with. Parameters proxy:Object the proxy instance that the method was invoked on method:Method the `Method` instance corresponding to the interface method invoked on the proxy instance. The declaring class of the `Method` object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. inArgs:Object[] an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or `null` if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as `java.lang.Integer` or `java.lang.Boolean`. Returns:Object the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is `null` and the interface method's return type is primitive, then a `NullPointerException` will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a `ClassCastException` will be thrown by the method invocation on the proxy instance. Annotations @Override Exceptions Throwable: the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the `throws` clause of the interface method or to the unchecked exception types `java.lang.RuntimeException` or `java.lang.Error`. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the `throws` clause of the interface method, then an `UndeclaredThrowableException` containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

public Object invoke(Object proxy, Method method, Object[] inArgs) throws Throwable

Implements java.lang.reflect.InvocationHandler.invoke.

Doc from java.lang.reflect.InvocationHandler.invoke.

Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with.

Parameters

proxy:Object: the proxy instance that the method was invoked on
method:Method: the Method instance corresponding to the interface method invoked on the proxy instance. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.
inArgs:Object[]: an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

Returns:Object

the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is null and the interface method's return type is primitive, then a NullPointerException will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a ClassCastException will be thrown by the method invocation on the proxy instance.

Annotations

@Override

Exceptions

Throwable:: the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the throws clause of the interface method or to the unchecked exception types java.lang.RuntimeException or java.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the throws clause of the interface method, then an UndeclaredThrowableException containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

com.sun.jna back to summary

private final Class Library.Handler.FunctionInfo

Class Inheritance

extends Object

java.lang.Object
com.sun.jna.Library.Handler.FunctionInfo

FunctionInfo has to be immutable to to make the object visible to other threads fully initialized. This is a prerequisite for using the class in the double checked locking scenario of Handler#invoke(Object, Method, Object[])

Field Summary

Modifier and Type	Field and Description
pack-priv final Function	function
pack-priv final InvocationHandler	handler
pack-priv final boolean	isVarArgs
pack-priv final Object	methodHandle
pack-priv final Map<String, ?>	options
pack-priv final Class<?>[]	parameterTypes

Constructor Summary

Access	Constructor and Description
pack-priv	FunctionInfo(Object mh)
pack-priv	FunctionInfo(InvocationHandler handler, Function function, Class<?>[] parameterTypes, boolean isVarArgs, Map<String, ?> options)

Method Summary

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

function	back to summary
pack-priv final Function function

handler	back to summary
pack-priv final InvocationHandler handler

isVarArgs	back to summary
pack-priv final boolean isVarArgs

methodHandle	back to summary
pack-priv final Object methodHandle

options	back to summary
pack-priv final Map<String, ?> options

parameterTypes	back to summary
pack-priv final Class<?>[] parameterTypes

Constructor Detail

FunctionInfo	back to summary
pack-priv FunctionInfo(Object mh)

FunctionInfo	back to summary
pack-priv FunctionInfo(InvocationHandler handler, Function function, Class<?>[] parameterTypes, boolean isVarArgs, Map<String, ?> options)

public Interface Library

Nested and Inner Type Summary

Field Summary

Field Detail

public Class Library.Handler

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class Library.Handler.FunctionInfo

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail