第八課 protocol buffer實戰

• 1.protocol buff是一種協議，是谷歌推出的一種序列化協議

• 2.Java序列化協議也是一種協議

• 3.兩者的目的是，將對象序列化成字節數組，或者說是二進制數據

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java序列化示例

public class JAVA2Bytes {

    public static void main(String[] args) throws Exception {
        byte[] bytes = toBytes();
        toPlayer(bytes);
    }


    /**
     * 序列化
     * @throws IOException 
     */
    public static byte[] toBytes() throws IOException{
        //新建一個Player類
        Player player = new Player(101, 20, "peter");
        player.getSkills().add(1001);

        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);

        //寫入對象
        objectOutputStream.writeObject(player);

        //獲取 字節數組
        byte[] byteArray = byteArrayOutputStream.toByteArray();
        System.out.println(Arrays.toString(byteArray));
        return byteArray;
    }


    /**
     * 反序列化
     * @param bs
     * @throws Exception 
     */
    public static void toPlayer(byte[] bs) throws Exception{

        ObjectInputStream inputStream = new ObjectInputStream(new ByteArrayInputStream(bs));
        Player player = (Player)inputStream.readObject();

        //打印
         System.out.println("playerId:" + player.getPlayerId());
         System.out.println("age:" + player.getAge());
         System.out.println("name:" + player.getName());
         System.out.println("skills:" + (Arrays.toString(player.getSkills().toArray())));
    }

}

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protocol buffer序列化實例

1 定義要序列化的對象

option java_package = "com.proto";
option java_outer_classname = "PlayerModule";

message PBPlayer{
    required int64 playerId = 1;

    required int32 age = 2;

    required string name = 3;

    repeated int32 skills = 4;
}

message PBResource{
    required int64 gold = 1;

    required int32 energy = 2;
}

2.使用protoc.exe生成PlayerModule類

3.使用protocol進行序列化

public class PB2Bytes {

    public static void main(String[] args) throws Exception {
        byte[] bytes = toBytes();
        toPlayer(bytes);

    }

    /**
     * 序列化
     */
    public static byte[] toBytes(){
        //獲取一個PBPlayer的構造器
        Builder builder = PlayerModule.PBPlayer.newBuilder();
        //設置數據
        builder.setPlayerId(101).setAge(20).setName("jay").addSkills(1001);
        //構造出對象
        PBPlayer player = builder.build();
        //序列化成字節數組
        byte[] byteArray = player.toByteArray();

        System.out.println("系列化後生成的數組:"+Arrays.toString(byteArray));

        return byteArray;
    }

    /**
     * 反序列化
     * @param bs
     * @throws Exception 
     */
    public static void toPlayer(byte[] bs) throws Exception{

         PBPlayer player = PlayerModule.PBPlayer.parseFrom(bs);

         System.out.println("playerId:" + player.getPlayerId());
         System.out.println("age:" + player.getAge());
         System.out.println("name:" + player.getName());
         System.out.println("skills:" + (Arrays.toString(player.getSkillsList().toArray())));
    }
}

根據打印的序列化後的數組可以看出protocol序列化後的數組長度遠遠小於java自帶的序列化方式，因此protocol傳輸的字節就會少減少帶寬消耗。