byte 常用 操作
阿新 • • 發佈：2017-05-05
exceptio cat 移動 ror 位置 all const 長度 ear /**
* 低位在前，高位在後
*
* @param data
* @return
*/
private byte[] intToBytes(int value) {
byte[] src = new byte[4];
src[3] = (byte) ((value >> 24) & 0xFF);
src[2] = (byte) ((value >> 16) & 0xFF);
src[1] = (byte) ((value >> 8) & 0xFF);
src[0] = (byte) (value & 0xFF);
return src;
}
public int bytesToInt(byte[] src) {
int value;
value = (int) ((src[0] & 0xFF)
| ((src[1] & 0xFF)<<8)
| ((src[2] & 0xFF)<<16)
| ((src[3] & 0xFF)<<24));
return value;
}
/**
* 對象轉byte
*
* @param obj
* @return
*/
public byte[] objectToByte(Object obj) {
byte[] bytes = null;
ByteArrayOutputStream byteOutput = null;
ObjectOutputStream objOutput = null;
try {
// object to bytearray
byteOutput = new ByteArrayOutputStream();
objOutput = new ObjectOutputStream(byteOutput);
objOutput.writeObject(obj);
bytes = byteOutput.toByteArray();
byteOutput.close();
objOutput.close();
} catch (Exception e) {
logger.error("ObjectToByte異常", e);
} finally {
try {
if (byteOutput != null) {
byteOutput.close();
}
if (objOutput != null) {
objOutput.close();
}
} catch (IOException e) {
logger.error("ObjectToByte異常", e);
}
}
return bytes;
}
/**
* byte 轉對象
*
* @param bytes
* @return
*/
public Object byteToObject(byte[] bytes) throws Exception {
Object obj = null;
ByteArrayInputStream byteInput = null;
ObjectInputStream objectInput = null;
try {
// bytearray to object
if (bytes != null) {
byteInput = new ByteArrayInputStream(bytes);
objectInput = new ObjectInputStream(byteInput);
obj = objectInput.readObject();
byteInput.close();
objectInput.close();
}
} catch (Exception e) {
logger.error("ByteToObject異常", e);
throw e;
} finally {
try {
if (byteInput != null) {
byteInput.close();
}
if (objectInput != null) {
objectInput.close();
}
} catch (IOException e) {
logger.error("byteToObject異常", e);
}
}
return obj;
}
public byte[] streamToBytes(InputStream inputStream, int len) {
/**
* inputStream.read(要復制到得字節數組,起始位置下標,要復制的長度)
* 該方法讀取後input的下標會自動的後移，下次讀取的時候還是從上次讀取後移動到的下標開始讀取 所以每次讀取後就不需要在制定起始的下標了
*/
byte[] bytes = new byte[len];
try {
inputStream.read(bytes, 0, len);
} catch (IOException e) {
logger.error(ConstantUtils.LOG_EXCEPTION, e);
}
return bytes;
}
byte 常用 操作