本文共 10906 字，大约阅读时间需要 36 分钟。
使用位移 与大小端存储对象。
import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.util.Arrays;public class Test1 { public static void main(String[] args) throws IOException { int id = 101; int age = 21; ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream(); arrayOutputStream.write(int2bytes(id)); arrayOutputStream.write(int2bytes(age)); byte[] byteArray = arrayOutputStream.toByteArray(); System.out.println(Arrays.toString(byteArray)); //============================================================== ByteArrayInputStream arrayInputStream = new ByteArrayInputStream(byteArray); byte[] idBytes = new byte[4]; arrayInputStream.read(idBytes); System.out.println("id:" + bytes2int(idBytes)); byte[] ageBytes = new byte[4]; arrayInputStream.read(ageBytes); System.out.println("age:" + bytes2int(ageBytes)); } /** * 大端字节序列(先写高位，再写低位) * 百度下 大小端字节序列 * @param i * @return */ public static byte[] int2bytes(int i){ byte[] bytes = new byte[4]; bytes[0] = (byte)(i >> 3*8); bytes[1] = (byte)(i >> 2*8); bytes[2] = (byte)(i >> 1*8); bytes[3] = (byte)(i >> 0*8); return bytes; } /** * 大端 * @param bytes * @return */ public static int bytes2int(byte[] bytes){ return (bytes[0] << 3*8) | (bytes[1] << 2*8) | (bytes[2] << 1*8) | (bytes[3] << 0*8); }} import java.nio.ByteBuffer;import java.util.Arrays;public class Test2 { public static void main(String[] args) { int id = 101; int age = 21; ByteBuffer buffer = ByteBuffer.allocate(8); buffer.putInt(id); buffer.putInt(age); byte[] array = buffer.array(); System.out.println(Arrays.toString(buffer.array())); //==================================================== ByteBuffer buffer2 = ByteBuffer.wrap(array); System.out.println("id:"+buffer2.getInt()); System.out.println("age:"+buffer2.getInt()); }} import java.util.Arrays;import org.jboss.netty.buffer.ChannelBuffer;import org.jboss.netty.buffer.ChannelBuffers;public class Test3 { public static void main(String[] args) { ChannelBuffer buffer = ChannelBuffers.dynamicBuffer(); buffer.writeInt(101); buffer.writeDouble(80.1); byte[] bytes = new byte[buffer.writerIndex()]; buffer.readBytes(bytes); System.out.println(Arrays.toString(bytes)); System.out.println("abc".getBytes()); //================================================ ChannelBuffer wrappedBuffer = ChannelBuffers.wrappedBuffer(bytes); System.out.println(wrappedBuffer.readInt()); System.out.println(wrappedBuffer.readDouble()); }} Serializer
import java.nio.charset.Charset;import java.util.ArrayList;import java.util.Collection;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.Map.Entry;import org.jboss.netty.buffer.ChannelBuffer;/** * 自定义序列化接口 * * */public abstract class Serializer { public static final Charset CHARSET = Charset.forName("UTF-8"); protected ChannelBuffer writeBuffer; protected ChannelBuffer readBuffer; /** * 反序列化具体实现 */ protected abstract void read(); /** * 序列化具体实现 */ protected abstract void write(); /** * 从byte数组获取数据 * @param bytes 读取的数组 */ public Serializer readFromBytes(byte[] bytes) { readBuffer = BufferFactory.getBuffer(bytes); read(); readBuffer.clear(); return this; } /** * 从buff获取数据 * @param readBuffer */ public void readFromBuffer(ChannelBuffer readBuffer) { this.readBuffer = readBuffer; read(); } /** * 写入本地buff * @return */ public ChannelBuffer writeToLocalBuff(){ writeBuffer = BufferFactory.getBuffer(); write(); return writeBuffer; } /** * 写入目标buff * @param buffer * @return */ public ChannelBuffer writeToTargetBuff(ChannelBuffer buffer){ writeBuffer = buffer; write(); return writeBuffer; } /** * 返回buffer数组 * * @return */ public byte[] getBytes() { writeToLocalBuff(); byte[] bytes = null; if (writeBuffer.writerIndex() == 0) { bytes = new byte[0]; } else { bytes = new byte[writeBuffer.writerIndex()]; writeBuffer.readBytes(bytes); } writeBuffer.clear(); return bytes; } public byte readByte() { return readBuffer.readByte(); } public short readShort() { return readBuffer.readShort(); } public int readInt() { return readBuffer.readInt(); } public long readLong() { return readBuffer.readLong(); } public float readFloat() { return readBuffer.readFloat(); } public double readDouble() { return readBuffer.readDouble(); } public String readString() { int size = readBuffer.readShort(); if (size <= 0) { return ""; } byte[] bytes = new byte[size]; readBuffer.readBytes(bytes); return new String(bytes, CHARSET); } public List readList(Class clz) { List list = new ArrayList<>(); int size = readBuffer.readShort(); for (int i = 0; i < size; i++) { list.add(read(clz)); } return list; } public Map readMap(Class keyClz, Class valueClz) { Map map = new HashMap<>(); int size = readBuffer.readShort(); for (int i = 0; i < size; i++) { K key = read(keyClz); V value = read(valueClz); map.put(key, value); } return map; } @SuppressWarnings("unchecked") public I read(Class clz) { Object t = null; if ( clz == int.class || clz == Integer.class) { t = this.readInt(); } else if (clz == byte.class || clz == Byte.class){ t = this.readByte(); } else if (clz == short.class || clz == Short.class){ t = this.readShort(); } else if (clz == long.class || clz == Long.class){ t = this.readLong(); } else if (clz == float.class || clz == Float.class){ t = readFloat(); } else if (clz == double.class || clz == Double.class){ t = readDouble(); } else if (clz == String.class ){ t = readString(); } else if (Serializer.class.isAssignableFrom(clz)){ try { byte hasObject = this.readBuffer.readByte(); if(hasObject == 1){ Serializer temp = (Serializer)clz.newInstance(); temp.readFromBuffer(this.readBuffer); t = temp; }else{ t = null; } } catch (Exception e) { e.printStackTrace(); } } else { throw new RuntimeException(String.format("不支持类型:[%s]", clz)); } return (I) t; } public Serializer writeByte(Byte value) { writeBuffer.writeByte(value); return this; } public Serializer writeShort(Short value) { writeBuffer.writeShort(value); return this; } public Serializer writeInt(Integer value) { writeBuffer.writeInt(value); return this; } public Serializer writeLong(Long value) { writeBuffer.writeLong(value); return this; } public Serializer writeFloat(Float value) { writeBuffer.writeFloat(value); return this; } public Serializer writeDouble(Double value) { writeBuffer.writeDouble(value); return this; } public Serializer writeList(List list) { if (isEmpty(list)) { writeBuffer.writeShort((short) 0); return this; } writeBuffer.writeShort((short) list.size()); for (T item : list) { writeObject(item); } return this; } public Serializer writeMap(Map map) { if (isEmpty(map)) { writeBuffer.writeShort((short) 0); return this; } writeBuffer.writeShort((short) map.size()); for (Entry entry : map.entrySet()) { writeObject(entry.getKey()); writeObject(entry.getValue()); } return this; } public Serializer writeString(String value) { if (value == null || value.isEmpty()) { writeShort((short) 0); return this; } byte data[] = value.getBytes(CHARSET); short len = (short) data.length; writeBuffer.writeShort(len); writeBuffer.writeBytes(data); return this; } public Serializer writeObject(Object object) { if(object == null){ writeByte((byte)0); }else{ if (object instanceof Integer) { writeInt((int) object); return this; } if (object instanceof Long) { writeLong((long) object); return this; } if (object instanceof Short) { writeShort((short) object); return this; } if (object instanceof Byte) { writeByte((byte) object); return this; } if (object instanceof String) { String value = (String) object; writeString(value); return this; } if (object instanceof Serializer) { writeByte((byte)1); Serializer value = (Serializer) object; value.writeToTargetBuff(writeBuffer); return this; } throw new RuntimeException("不可序列化的类型:" + object.getClass()); } return this; } private boolean isEmpty(Collection c) { return c == null || c.size() == 0; } public boolean isEmpty(Map c) { return c == null || c.size() == 0; }} BufferFactory
import java.nio.ByteOrder;import org.jboss.netty.buffer.ChannelBuffer;import org.jboss.netty.buffer.ChannelBuffers;/** * buff工厂 * * */public class BufferFactory { public static ByteOrder BYTE_ORDER = ByteOrder.BIG_ENDIAN; /** * 获取一个buffer * * @return */ public static ChannelBuffer getBuffer() { ChannelBuffer dynamicBuffer = ChannelBuffers.dynamicBuffer(); return dynamicBuffer; } /** * 将数据写入buffer * @param bytes * @return */ public static ChannelBuffer getBuffer(byte[] bytes) { ChannelBuffer copiedBuffer = ChannelBuffers.copiedBuffer(bytes); return copiedBuffer; }} Player
import java.util.ArrayList;import java.util.List;import com.cn.core.Serializer;public class Player extends Serializer{ private long playerId; private int age; private List skills = new ArrayList<>(); private Resource resource = new Resource(); public Resource getResource() { return resource; } public void setResource(Resource resource) { this.resource = resource; } public long getPlayerId() { return playerId; } public void setPlayerId(long playerId) { this.playerId = playerId; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public List getSkills() { return skills; } public void setSkills(List skills) { this.skills = skills; } @Override protected void read() { this.playerId = readLong(); this.age = readInt(); this.skills = readList(Integer.class); this.resource = read(Resource.class); } @Override protected void write() { writeLong(playerId); writeInt(age); writeList(skills); writeObject(resource); }} Resource
import com.cn.core.Serializer;public class Resource extends Serializer { private int gold; public int getGold() { return gold; } public void setGold(int gold) { this.gold = gold; } @Override protected void read() { this.gold = readInt(); } @Override protected void write() { writeInt(gold); }} Test4
import java.util.Arrays;public class Test4 { public static void main(String[] args) { Player player = new Player(); player.setPlayerId(10001); player.setAge(22); player.getSkills().add(101); player.getResource().setGold(99999); byte[] bytes = player.getBytes(); System.out.println(Arrays.toString(bytes)); //============================================== Player player2 = new Player(); player2.readFromBytes(bytes); System.out.println(player2.getPlayerId() + " " + player2.getAge() + " " + Arrays.toString(player2.getSkills().toArray()) + " " + player2.getResource().getGold()); }} 转载地址：http://nclnn.baihongyu.com/