Netty 快速入门系列 - Chapter 6 自定义数据协议【第十五讲】自定义方法Serializer

本文链接：https://blog.youkuaiyun.com/netcobol/article/details/79693302

如何自定义方法Serializer完成 String、List、Map等动态数据序列化呢？

Serializer 接口

package com.john.netty.learn.ch08.core;
import org.jboss.netty.buffer.ChannelBuffer;

public interface Serializer {

public void writeToBuffer(ChannelBuffer writeChanneBuffer);
public void readByBuffer(ChannelBuffer channelBuffer) throws InstantiationException, IllegalAccessException;

}

AbstractSerializer

String序列化&反序列化：长度+byte流（注意：这里支持Null 通过-1区分）

public AbstractSerializer writeString(String value) {
if (value == null) {
writeBuffer.writeShort(-1);
return this;
}
byte[] bytes = value.getBytes(CHARSET);
writeBuffer.writeShort(bytes.length);
if (bytes.length > 0) {
writeBuffer.writeBytes(bytes);
}
return this;

}

public String readString() {
short length = this.readBuffer.readShort();
if (length == -1) {
return null;
}
if (length == 0) {
return "";

}

byte[] bytes = new byte[length];
readBuffer.readBytes(bytes);
return new String(bytes);
}

Date序列化&反序列化：（注意：这里支持Null 通过0区分）

public AbstractSerializer writeDate(Date date) {

if (date == null) {

writeBuffer.writeLong(0);
return this;
}

writeBuffer.writeLong(date.getTime());
return this;

}

public Date readDate() {

long l = readBuffer.readLong();

if (l == 0) {

return null;
}

return new Date(l);
}

List序列化&反序列化： Size+Object byte流（注意：这里支持Null 通过-1区分）

public <T> AbstractSerializer writeList(List<T> list) {

if (isEmpty(list)) {

writeBuffer.writeShort(list == null ? -1 : 0);

return this;
}

writeBuffer.writeShort((short) list.size());

for (T item : list) {
writeObject(item);
}

return this;

}

public <T> List<T> readList(Class<T> clz) throws InstantiationException, IllegalAccessException {

short s = readBuffer.readShort();

if (s == -1) {
return null;
}

List<T> list = new ArrayList<>(s);

for (int i = 0; i < s; i++) {
list.add(readObject(clz));
}

return list;

}

Map序列化&反序列化： size + [Key Object & Value Object] （注意：这里支持Null 通过-1区分）

public <K, V> AbstractSerializer writeMap(Map<K, V> map) {

if (isEmpty(map)) {

writeBuffer.writeShort(map == null ? -1 : 0);

return this;
}

writeBuffer.writeShort((short) map.size());

for (Entry<K, V> entry : map.entrySet()) {

this.writeObject(entry.getKey());
this.writeObject(entry.getValue());
}

return this;

}

public <K, V> Map<K, V> readMap(Class<K> keyClz, Class<V> valClz)
throws InstantiationException, IllegalAccessException {

short s = readBuffer.readShort();

if (s == -1) {

return null;
}

Map<K, V> maps = new HashMap<>(s);

for (int i = 0; i < s; i++) {
maps.put(readObject(keyClz), readObject(valClz));
}

return maps;
}

AbstractSerializer 完成代码：

package com.john.netty.learn.ch08.core;

import java.lang.reflect.Array;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.jboss.netty.buffer.ChannelBuffer;

public abstract class AbstractSerializer implements Serializer {

public static final Charset CHARSET = Charset.forName("UTF-8");

protected ChannelBuffer writeBuffer;

protected ChannelBuffer readBuffer;

protected AbstractSerializer() {

}

public void readByBuffer(ChannelBuffer channelBuffer) throws InstantiationException, IllegalAccessException {

this.readBuffer = channelBuffer;
this.read();

}

public byte[] getSerializerBytes() {

byte[] bytes = new byte[writeBuffer.writerIndex()];

writeBuffer.readBytes(bytes);

writeBuffer.clear();

return bytes;
}

public int readIntValue() {

return readBuffer.readInt();
}

public Integer readInt() {

byte b = readBuffer.readByte();

if (b == 0) {

return null;
}

return readBuffer.readInt();
}

public String readString() {

short length = this.readBuffer.readShort();

if (length == -1) {

return null;
}

if (length == 0) {
return "";
}
byte[] bytes = new byte[length];
readBuffer.readBytes(bytes);

return new String(bytes);
}

public long readLongValue() {

return readBuffer.readLong();
}

public Long readLong() {

byte b = readBuffer.readByte();

if (b == 0) {

return null;
}

return readBuffer.readLong();
}

public Date readDate() {

long l = readBuffer.readLong();

if (l == 0) {

return null;
}

return new Date(l);
}

public <T> List<T> readList(Class<T> clz) throws InstantiationException, IllegalAccessException {

short s = readBuffer.readShort();

if (s == -1) {

return null;
}

List<T> list = new ArrayList<>(s);

for (int i = 0; i < s; i++) {

list.add(readObject(clz));

}

return list;
}

public <K, V> Map<K, V> readMap(Class<K> keyClz, Class<V> valClz)
throws InstantiationException, IllegalAccessException {

short s = readBuffer.readShort();

if (s == -1) {

return null;
}

Map<K, V> maps = new HashMap<>(s);

for (int i = 0; i < s; i++) {

maps.put(readObject(keyClz), readObject(valClz));
}

return maps;
}

public <T> T readObject(Class<T> clz) throws InstantiationException, IllegalAccessException {

if (clz == Integer.class) {

return (T) readInt();
}

if (clz == Long.class) {

return (T) readLong();
}

if (clz == String.class) {

return (T) this.readString();
}

if (clz == Date.class) {

return (T) this.readDate();
}

if (List.class.isAssignableFrom(clz)) {

return (T) this.readList(clz);
}

if (Serializer.class.isAssignableFrom(clz)) {

byte b = this.readBuffer.readByte();

if (b == 0) {

return null;
}

Object obj = clz.newInstance();

((Serializer) obj).readByBuffer(readBuffer);

return (T) obj;

}

throw new IllegalArgumentException("不可序列化的类型:" + clz.getName());

}

/**
* 写入目标buff
*
* @param buffer
* @return
*/

public void writeToBuffer(ChannelBuffer writeChanneBuffer) {

this.writeBuffer = writeChanneBuffer;

this.write();

}

public ChannelBuffer writeToLocalBuff() {

writeBuffer = BufferFactory.getBuffer();

writeToBuffer(writeBuffer);

return writeBuffer;
}

public AbstractSerializer writeByte(byte value) {

writeBuffer.writeByte(value);

return this;
}

public AbstractSerializer writeByte(Byte value) {

if (value == null) {

writeBuffer.writeByte(0);
return this;
}

writeBuffer.writeByte(1);
writeBuffer.writeByte(value);

return this;
}

public AbstractSerializer writeShort(short value) {

writeBuffer.writeShort(value);

return this;
}

public AbstractSerializer writeShort(Short value) {

if (value == null) {

writeBuffer.writeByte(0);

return this;
}

writeBuffer.writeByte(1);
writeBuffer.writeShort(value);

return this;
}

public AbstractSerializer writeInt(int value) {

writeBuffer.writeInt(value);

return this;
}

public AbstractSerializer writeInt(Integer value) {

if (value == null) {

writeBuffer.writeByte(0);
return this;
}

writeBuffer.writeByte(1);
writeBuffer.writeInt(value);

return this;
}

public AbstractSerializer writeDouble(Double value) {

if (value == null) {

writeBuffer.writeByte(0);
return this;
}

writeBuffer.writeByte(1);
writeBuffer.writeDouble(value);

return this;
}

public AbstractSerializer writeDouble(double value) {

writeBuffer.writeDouble(value);

return this;
}

public AbstractSerializer writeLong(Long value) {

if (value == null) {

writeBuffer.writeByte(0);
return this;
}

writeBuffer.writeByte(1);
writeBuffer.writeLong(value);

return this;
}

public AbstractSerializer writeLong(long value) {

writeBuffer.writeLong(value);

return this;
}

public AbstractSerializer writeString(String value) {

if (value == null) {

writeBuffer.writeShort(-1);
return this;
}

byte[] bytes = value.getBytes(CHARSET);

writeBuffer.writeShort(bytes.length);

if (bytes.length > 0) {

writeBuffer.writeBytes(bytes);
}

return this;
}

public AbstractSerializer writeDate(Date date) {

if (date == null) {

writeBuffer.writeLong(0);

return this;
}

writeBuffer.writeLong(date.getTime());

return this;

}

public <T> AbstractSerializer writeList(List<T> list) {

if (isEmpty(list)) {

writeBuffer.writeShort(list == null ? -1 : 0);

return this;
}

writeBuffer.writeShort((short) list.size());

for (T item : list) {

writeObject(item);

}

return this;
}

public <K, V> AbstractSerializer writeMap(Map<K, V> map) {

if (isEmpty(map)) {

writeBuffer.writeShort(map == null ? -1 : 0);

return this;
}

writeBuffer.writeShort((short) map.size());

for (Entry<K, V> entry : map.entrySet()) {

this.writeObject(entry.getKey());
this.writeObject(entry.getValue());
}

return this;
}

public AbstractSerializer writeArray(Array array) {

if (isEmpty(array)) {

writeBuffer.writeShort(array == null ? -1 : 0);

return this;
}

int length = Array.getLength(array);

writeBuffer.writeShort(length);

for (int i = 0; i < length; i++) {

this.writeObject(Array.get(array, i));

}

return this;

}

private boolean isEmpty(Array array) {

return array == null || Array.getLength(array) == 0;
}

public AbstractSerializer writeObject(Object object) {

if (object instanceof Array) {

writeArray((Array) object);

return this;
}

if (object instanceof Byte) {

this.writeByte((Byte) object);

return this;
}

if (object instanceof Short) {

this.writeShort((Short) object);

return this;
}

if (object instanceof Integer) {

this.writeInt((Integer) object);

return this;
}

if (object instanceof Date) {

this.writeDate((Date) object);

return this;
}

if (object instanceof String) {

this.writeString((String) object);

return this;
}

if (object instanceof List) {

this.writeList((List) object);

return this;
}

if (object instanceof Map) {

this.writeMap((Map) object);

return this;
}

if (object instanceof Serializer) {

if (object == null) {

writeByte((byte) 0);

return this;
}

writeByte((byte) 1);

((Serializer) object).writeToBuffer(writeBuffer);

return this;

}

throw new IllegalArgumentException("不可序列化的类型:" + object.getClass());

}

/**
* 反序列化具体实现
*/
protected abstract void read() throws InstantiationException, IllegalAccessException;

/**
* 序列化具体实现
*/
protected abstract void write();

private boolean isEmpty(Map map) {

return map == null || map.isEmpty();
}

private boolean isEmpty(List<?> list) {

return list == null || list.isEmpty();
}

}

测试：

MainSerializer

package com.john.netty.learn.ch08;

import java.util.Arrays;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;

public class MainSerializer {

public static void main(String[] args) throws InstantiationException, IllegalAccessException {

Player player = new Player();

player.setId(null);
player.setAge(10);
player.setName("John hao");

Skill skill = new Skill();
skill.setType(1);
skill.setDesc("Fly");

player.addSkill(skill);

skill = new Skill();
skill.setType(2);
skill.setDesc("Run");

player.addSkill(skill);

player.addScope("Fly", 1);
player.addScope("Run", 2);
player.addScope("Unkown", 3);

player.writeToLocalBuff();

byte[] bytes = player.getSerializerBytes();

System.out.println(Arrays.toString(bytes));

ChannelBuffer channelBuffer = ChannelBuffers.wrappedBuffer(bytes);

Player player2 = new Player();
player2.readByBuffer(channelBuffer);

System.out.println(player2 + " scopes:" + player2.getScopes());

}

}

Player

package com.john.netty.learn.ch08;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.john.netty.learn.ch08.core.AbstractSerializer;

public class Player extends AbstractSerializer {

private Long id;

private String name;

private int age;

private List<Skill> skills = new ArrayList<>();

private Map<String, Integer> scopes = new HashMap<>();

public Player() {

}

public Map<String, Integer> getScopes() {
return scopes;
}

public void setScopes(Map<String, Integer> scopes) {
this.scopes = scopes;
}

public void addScope(String key, Integer value) {

scopes.put(key, value);
}

public Long getId() {
return id;
}

public void setId(Long id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public void addSkill(Skill skill) {
skills.add(skill);
}

public List<Skill> getSkills() {
return skills;
}

public void setSkills(List<Skill> skills) {
this.skills = skills;
}

@Override
protected void read() throws InstantiationException, IllegalAccessException {

this.id = this.readLong();
this.name = this.readString();
this.age = this.readIntValue();

this.skills = this.readList(Skill.class);

this.scopes = this.readMap(String.class, Integer.class);

}

@Override
protected void write() {

this.writeLong(this.id);
this.writeString(this.name);
this.writeInt(this.age);

this.writeList(skills);

this.writeMap(this.scopes);
}

@Override
public String toString() {

return "Id:" + this.id + " name:" + this.name + " age:" + this.age + " skills:" + this.skills;
}

}

package com.john.netty.learn.ch08;

import org.jboss.netty.buffer.ChannelBuffer;
import com.john.netty.learn.ch08.core.AbstractSerializer;
import com.john.netty.learn.ch08.core.Serializer;

public class Skill extends AbstractSerializer implements Serializer {

private int type;

private String desc;

public Skill() {

}

public int getType() {
return type;
}

public void setType(int type) {
this.type = type;
}

public String getDesc() {
return desc;
}

public void setDesc(String desc) {
this.desc = desc;
}

@Override
protected void read() {

this.type = this.readIntValue();
this.desc = this.readString();
}

@Override
protected void write() {

this.writeInt(this.type);
this.writeString(this.desc);
}

@Override
public String toString() {

return "Type:" + this.type +" Desc:" + this.desc;
}
}