java - ByteBuffer 似乎超出范围

Question

我正在尝试读取一个短数组，转换其元素并将它们放入字节数组中。我使用 ByteBuffer 并收回此异常:

线程“main”中的异常 java.lang.IndexOutOfBoundsException我尝试将 .allocateDirect 更改为 16，但得到的结果相同。我尝试了 ByteBuffer.allocateDirect(2) 和 ByteBuffer.allocate(2)

public class int2byte {
    short[] it = new short[4];
    byte[] by = new byte[4];
    public static void main(String [] args){
        int2byte Convert=new int2byte();
        Convert.start();
    }
    public void start(){
       it = new short[]{192,168, 1,2};


ByteBuffer bytBuff = ByteBuffer.allocateDirect(2);
       for(int i=0;i<3;i++){

           bytBuff.putShort(it[i]);
           by[i]=bytBuff.get(it[i]);
           System.out.print("I get " + by[i]+ "\n\n");
       }}}

我知道 Short 不适合单个无符号字节，但稍后我会构建一些防御来读取最多 255 个 Short 。

Answer 1

我认为这段代码可以帮助你理解一些事情。

public class Test {
short[] it = new short[4];
byte[] by = new byte[4];

public static void main(String[] args) {
    Test Convert = new Test();
    Convert.start();
}

public void start() {
    it = new short[] { 192, 168, 1, 2 };

    ByteBuffer bytBuff = ByteBuffer.allocateDirect(2000);
    for (int i = 0; i < it.length; i++) {

        bytBuff.putShort(it[i]);
        by[i] = bytBuff.get(i);
        System.out.print("I get byte  " + by[i] + "\n\n");
        System.out.print("I get short  " + it[i] + "\n\n");
        System.out.print("I get buffer " + bytBuff.get(i) + "\n\n");
    }
}
}