1.3.7 判断只读

boolean isReadOnly（）方法的作用：告知此缓冲区是否为只读缓冲区。

示例代码如下：

public class Test6 {

public static void main(String[] args) {
    byte[] byteArray = new byte[] { 1, 2, 3 };
    short[] shortArray = new short[] { 1, 2, 3, 4 };
    int[] intArray = new int[] { 1, 2, 3, 4, 5 };
    long[] longArray = new long[] { 1, 2, 3, 4, 5, 6 };
    float[] floatArray = new float[] { 1, 2, 3, 4, 5, 6, 7 };
    double[] doubleArray = new double[] { 1, 2, 3, 4, 5, 6, 7, 8 };
    char[] charArray = new char[] { 'a', 'b', 'c', 'd' };

    ByteBuffer bytebuffer = ByteBuffer.wrap(byteArray);
    ShortBuffer shortBuffer = ShortBuffer.wrap(shortArray);
    IntBuffer intBuffer = IntBuffer.wrap(intArray);
    LongBuffer longBuffer = LongBuffer.wrap(longArray);
    FloatBuffer floatBuffer = FloatBuffer.wrap(floatArray);
    DoubleBuffer doubleBuffer = DoubleBuffer.wrap(doubleArray);
    CharBuffer charBuffer = CharBuffer.wrap(charArray);

    System.out.println("bytebuffer.isReadOnly=" + bytebuffer.isReadOnly());
    System.out.println("shortBuffer.isReadOnly=" + shortBuffer.isReadOnly());
    System.out.println("intBuffer.isReadOnly=" + intBuffer.isReadOnly());
    System.out.println("longBuffer.isReadOnly=" + longBuffer.isReadOnly());
    System.out.println("floatBuffer.isReadOnly=" + floatBuffer.isReadOnly());
    System.out.println("doubleBuffer.isReadOnly=" + doubleBuffer.isReadOnly());
    System.out.println("charBuffer.isReadOnly=" + charBuffer.isReadOnly());

}
}

程序运行结果如下： MQRQfIr8Ur+RqG5tkZAUUuN2mwkksdtHjtSM+PHxWNb4+eQjHVi5MY7IIRB2NbEE

bytebuffer.isReadOnly=false
shortBuffer.isReadOnly=false
intBuffer.isReadOnly=false
longBuffer.isReadOnly=false
floatBuffer.isReadOnly=false
doubleBuffer.isReadOnly=false
charBuffer.isReadOnly=false