Simple Meaningful Example

Input Header

struct Pair {
    /// Comment on both first and second int first, second;
};

#define PAIRS_COUNT 10

#define EXPRESSION (1 << 10) | (1 << 5)

enum Values {
First, // first comments
Second, // comments on second
Last // not a real value
};

struct BiggerStruct {
    Values enumValue;
    bool (*hook)(int val);
    long longValue;
    int intArray[sizeof(Pair) * PAIRS_COUNT];
};

// Wonderful comments on Test function
void Test(BiggerStruct& s);

// Be careful with that one : intArray and source are const, dest is not void
CopyBytes(char* dest, const char* source, size_t n, const int* intArray);

Command-line

java -jar jnaerator.jar -library Test Test.h -o . -v -noJar -noComp

(see Command Line Options And Environment Variables for more options)

JNAerator output

File test/TestLibrary.java:

package test;

/// JNA Wrapper for library test

public interface TestLibrary extends com.sun.jna.Library {

    public TestLibrary INSTANCE =(TestLibrary)com.sun.jna.Native.loadLibrary("test", TestLibrary.class);

    /**
     * <i>native declaration : /Users/ochafik/Prog/Java/null:9</i><br>
     * enum values
     */
    public static interface Values {
        /// first comments
        public static final int First = 0;
        /// comments on second
        public static final int Second = 1;
        /// not a real value
        public static final int Last = 2;
    }

    public static final int PAIRS_COUNT = 10;

    public static final int EXPRESSION = (1 << 10) | (1 << 5);

    /// <i>native declaration : /Users/ochafik/Prog/Java/null:1</i>
    public static class Pair extends com.sun.jna.Structure {
        /// Allocate a new Pair struct on the heap
        public Pair() {}
        /// Cast data at given memory location (pointer + offset) as an existing Pair struct
        public Pair(com.sun.jna.Pointer pointer, int offset) {
            super();
            useMemory(pointer, offset);
            read();
        }

        /// Create an instance that shares its memory with another Pair instance
        public Pair(Pair struct) { this(struct.getPointer(), 0);
        }
        public static class ByReference extends Pair implements com.sun.jna.Structure.ByReference {
            /// Allocate a new Pair.ByRef struct on the heap
            public ByReference() {}
            /// Create an instance that shares its memory with another Pair instance
            public ByReference(Pair struct) { super(struct.getPointer(), 0);
            }
        }
        public static class ByValue extends Pair implements com.sun.jna.Structure.ByValue {
            /// Allocate a new Pair.ByVal struct on the heap
            public ByValue() {}
            /// Create an instance that shares its memory with another Pair instance
            public ByValue(Pair struct) { super(struct.getPointer(), 0);
            }
        }
        /// Comment on both first and second
        public int first;
        /// Comment on both first and second
        public int second;
    }

    /// <i>native declaration : /Users/ochafik/Prog/Java/null:15</i>
    public static class BiggerStruct extends com.sun.jna.Structure {
        /// Allocate a new BiggerStruct struct on the heap
        public BiggerStruct() {}
        /// Cast data at given memory location (pointer + offset) as an existing BiggerStruct struct
        public BiggerStruct(com.sun.jna.Pointer pointer, int offset) {
            super();
            useMemory(pointer, offset);
            read();
        }
        /// Create an instance that shares its memory with another BiggerStruct instance
        public BiggerStruct(BiggerStruct struct) { this(struct.getPointer(), 0); }
        public static class ByReference extends BiggerStruct implements com.sun.jna.Structure.ByReference {
            /// Allocate a new BiggerStruct.ByRef struct on the heap
            public ByReference() {}
            /// Create an instance that shares its memory with another BiggerStruct instance
            public ByReference(BiggerStruct struct) { super(struct.getPointer(), 0); }
        }
        public static class ByValue extends BiggerStruct implements com.sun.jna.Structure.ByValue {
            /// Allocate a new BiggerStruct.ByVal struct on the heap
            public ByValue() {}
            /// Create an instance that shares its memory with another BiggerStruct instance
            public ByValue(BiggerStruct struct) { super(struct.getPointer(), 0); }
        }
        /// @see Values
        public int enumValue;
        public hook_callback hook;
        public com.sun.jna.NativeLong longValue;
        public int[] intArray = new int[(new Pair().size() * 10)];
        /// <i>native declaration : /Users/ochafik/Prog/Java/null</i>
        public interface hook_callback extends com.sun.jna.Callback {
            /// Original signature : <code>bool hook_callback(int)</code>
            boolean invoke(int val1);
        }
    }

    /**
     * Wonderful comments on Test function<br>
     * Original signature : <code>void Test(BiggerStruct&)</code><br>
     * <i>native declaration : /Users/ochafik/Prog/Java/null</i>
     */
    void Test(BiggerStruct s1);

    /**
     * Be careful with that one : intArray and source are const, dest is not<br>
     * Original signature : <code>void CopyBytes(char*, const char*, size_t, const int*)</code><br>
     * <i>native declaration : /Users/ochafik/Prog/Java/null</i><br>
     * @deprecated use the safer methods {@link #CopyBytes(java.nio.ByteBuffer, java.lang.String, com.sun.jna.NativeLong, int[])} and {@link #CopyBytes(java.nio.ByteBuffer, java.lang.String, com.sun.jna.NativeLong, java.nio.IntBuffer)} instead
     */
    @Deprecated
    void CopyBytes(com.sun.jna.ptr.ByteByReference dest1, com.sun.jna.ptr.ByteByReference source2, com.sun.jna.NativeLong n3, com.sun.jna.ptr.IntByReference intArray4);

    /**
     * Be careful with that one : intArray and source are const, dest is not<br>
     * Original signature : <code>void CopyBytes(char*, const char*, size_t, const int*)</code><br>
     * <i>native declaration : /Users/ochafik/Prog/Java/null</i
     */
    void CopyBytes(java.nio.ByteBuffer dest1, java.lang.String source2, com.sun.jna.NativeLong n3, int intArray4[]);

    /**
     * Be careful with that one : intArray and source are const, dest is not<br>
     * Original signature : <code>void CopyBytes(char*, const char*, size_t, const int*)</code><br>
     * <i>native declaration : /Users/ochafik/Prog/Java/null</i>
     */
    void CopyBytes(java.nio.ByteBuffer dest1, java.lang.String source2, com.sun.jna.NativeLong n3, java.nio.IntBuffer intArray4);
}

More examples

Please read the page Documentation.

Try it for yourself !

Simply download jna.jar and jnaerator.jar and you'll be generating your JNA interfaces in a minute !

Nothing works as expected ?

Please read JNAerator FAQ and Troubleshooting JNAeration, or post your question to the JNA users mailing list.