序列化器

枚举实现多种序列化方式选择。

package cn.itcast.protocol;

import com.google.gson.*;

import java.io.*;
import java.lang.reflect.Type;
import java.nio.charset.StandardCharsets;

/**
* 用于扩展序列化、反序列化算法
*/
public interface Serializer {

// 反序列化方法
<T> T deserialize(Class<T> clazz, byte[] bytes);

// 序列化方法
<T> byte[] serialize(T object);

enum Algorithm implements Serializer {

Java {
@Override
public <T> T deserialize(Class<T> clazz, byte[] bytes) {
try {
ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(bytes));
return (T) ois.readObject();
} catch (IOException | ClassNotFoundException e) {
throw new RuntimeException("反序列化失败", e);
}
}

@Override
public <T> byte[] serialize(T object) {
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(object);
return bos.toByteArray();
} catch (IOException e) {
throw new RuntimeException("序列化失败", e);
}
}
},

Json {
@Override
public <T> T deserialize(Class<T> clazz, byte[] bytes) {
Gson gson = new GsonBuilder().registerTypeAdapter(Class.class, new Serializer.ClassCodec()).create();
String json = new String(bytes, StandardCharsets.UTF_8);
return gson.fromJson(json, clazz);
}

@Override
public <T> byte[] serialize(T object) {
Gson gson = new GsonBuilder().registerTypeAdapter(Class.class, new Serializer.ClassCodec()).create();
String json = gson.toJson(object);
return json.getBytes(StandardCharsets.UTF_8);
}
}
}
class ClassCodec implements JsonSerializer<Class<?>>, JsonDeserializer<Class<?>> {

@Override
public Class<?> deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
try {
String str = json.getAsString();
return Class.forName(str);
} catch (ClassNotFoundException e) {
throw new JsonParseException(e);
}
}

@Override // String.class
public JsonElement serialize(Class<?> src, Type typeOfSrc, JsonSerializationContext context) {
// class -> json
return new JsonPrimitive(src.getName());
}
}
}