ByteBuffer

Question

我正在尝试将 long 转换为 4 字符数组。

最后一个字符似乎没有写入缓冲区。

为什么这不起作用？

//convert long to char array

long longValZ = 219902744986400000L;

ByteBuffer bbX = ByteBuffer.allocate(8);
bbX.putLong(longValZ); 
//longValZ = 219902744986400000

char [] charArr1 = new char[4];
charArr1[0] = bbX.getChar(0);
charArr1[1] = bbX.getChar(1);
charArr1[2] = bbX.getChar(2);
charArr1[3] = bbX.getChar(3);

long longValX = bbX.getLong(0); 
//longValX = 219902744986400000


//convert char array to long

ByteBuffer bbY = ByteBuffer.allocate(8);

bbY.putChar(0,charArr1[0]);
bbY.putChar(1,charArr1[1]);
bbY.putChar(2,charArr1[2]);
bbY.putChar(3,charArr1[3]);

long longValY = bbY.getLong(0); 
//longValY = 219902744985600000 --> why is longValY different than longValZ ?

Answer 1

感谢 Sotirios，这是正确答案：

//convert long to char array

long longValZ = 219902744986400000L;

ByteBuffer bbX = ByteBuffer.allocate(8);
bbX.putLong(longValZ); 

char [] charArr1 = new char[4];
charArr1[0] = bbX.getChar(0);
charArr1[1] = bbX.getChar(2);
charArr1[2] = bbX.getChar(4);
charArr1[3] = bbX.getChar(6);



//convert char array to long

ByteBuffer bbY = ByteBuffer.allocate(8);
bbY.putChar(0,charArr1[0]);
bbY.putChar(2,charArr1[1]);
bbY.putChar(4,charArr1[2]);
bbY.putChar(6,charArr1[3]);

long longValY = bbY.getLong(0);

Answer 2

您无需提供索引

long longValZ = 219902744986400000L;

ByteBuffer bbX = ByteBuffer.allocate(8);
bbX.putLong(longValZ); 

char[] charArr1 = new char[4];
for (int i = 0; i < charArr1.length; i++)
   charArr1[i] = bbX.getChar();



//convert char array to long

ByteBuffer bbY = ByteBuffer.allocate(8);
for (int i = 0; i < charArr1.length; i++)
    bbY.putChar(charArr1[i]);

long longValY = bbY.getLong(0);

ByteBuffer - 将 long 转换为 char 数组，反之亦然

ByteBuffer - convert long to char array and vice versa

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