public static byte[] int2byte(int res) {byte[] targets = new byte[4];targets[0] = (byte) (res & 0xff);// 最低位 targets[1] = (byte) ((res >> 8) & 0xff);// 次低位 targets[2] = (byte) ((res >> 16) & 0xff);// 次高位 targets[3] = (byte) (res >>> 24);// 最高位,無符號右移。 return targets; } public static int byte2int(byte[] res) { // 一個byte數(shù)據(jù)左移24位變成0x??000000，再右移8位變成0x00??0000 int targets = (res[0] & 0xff) | ((res[1] << 8) & 0xff00) // | 表示安位或 | ((res[2] << 24) >>> 8) | (res[3] << 24); return targets; } 

public static void main(String[] args) {     ByteArrayOutputStream baos = new ByteArrayOutputStream();     DataOutputStream dos = new DataOutputStream(baos);     try {       dos.writeByte(4);       dos.writeByte(1);       dos.writeByte(1);       dos.writeShort(217);      } catch (IOException e) {     e.printStackTrace();   }    byte[] aa = baos.toByteArray();   ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());   DataInputStream dis = new DataInputStream(bais);    try {     System.out.println(dis.readByte());     System.out.println(dis.readByte());     System.out.println(dis.readByte());     System.out.println(dis.readShort());   } catch (IOException e) {     e.printStackTrace();   }   try {     dos.close();     dis.close();   } catch (IOException e) {     e.printStackTrace();   } }