Java实体类与byte数组相互转换

1.使用ByteArrayStream 和 ObjectStream

public abstract class ByteConvert {


    public byte[] getByte(){



        try (   ByteArrayOutputStream out =new ByteArrayOutputStream();
                ObjectOutputStream objectOutputStream = new ObjectOutputStream(out)) {

                objectOutputStream.writeObject(this);
                objectOutputStream.flush();
                return out.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }


    public   <T extends ByteUtil> T getObject(byte[] bytes){

        try(
                ByteArrayInputStream byteInputStream = new ByteArrayInputStream(bytes);
                ObjectInputStream b = new ObjectInputStream(byteInputStream)) {

            return (T) b.readObject();



        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return null ;
    }

2.使用proto

public abstract class ByteConvert  {


    public byte[] getByte(){
        return ProtostuffUtils.serialize(this);
    }


    public   <T extends ByteUtil> T getObject(byte[] bytes){
        return (T) ProtostuffUtils.deserialize(bytes,this.getClass());
    }


}

ProtostuffUtils

1. 引入pom

     <!--引入protostuff依赖-->
        <dependency>
            <groupId>io.protostuff</groupId>
            <artifactId>protostuff-core</artifactId>
            <version>1.6.0</version>
        </dependency>

        <dependency>
            <groupId>io.protostuff</groupId>
            <artifactId>protostuff-runtime</artifactId>
            <version>1.6.0</version>
        </dependency>

2.编写工具类

public class ProtostuffUtils {
    /**
     * 避免每次序列化都重新申请Buffer空间
     */
    private static LinkedBuffer buffer = LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE);
    /**
     * 缓存Schema
     */
    private static Map<Class<?>, Schema<?>> schemaCache = new ConcurrentHashMap<>();

    /**
     * 序列化方法，把指定对象序列化成字节数组
     *
     * @param obj
     * @param <T>
     * @return
     */
    @SuppressWarnings("unchecked")
    public static <T> byte[] serialize(T obj) {
        Class<T> clazz = (Class<T>) obj.getClass();
        Schema<T> schema = getSchema(clazz);
        byte[] data;
        try {
            data = ProtostuffIOUtil.toByteArray(obj, schema, buffer);
        } finally {
            buffer.clear();
        }

        return data;
    }

    /**
     * 反序列化方法，将字节数组反序列化成指定Class类型
     *
     * @param data
     * @param clazz
     * @param <T>
     * @return
     */
    public static <T> T deserialize(byte[] data, Class<T> clazz) {
        Schema<T> schema = getSchema(clazz);
        T obj = schema.newMessage();
        ProtostuffIOUtil.mergeFrom(data, obj, schema);
        return obj;
    }

    @SuppressWarnings("unchecked")
    private static <T> Schema<T> getSchema(Class<T> clazz) {
        Schema<T> schema = (Schema<T>) schemaCache.get(clazz);
        if (Objects.isNull(schema)) {
            //这个schema通过RuntimeSchema进行懒创建并缓存
            //所以可以一直调用RuntimeSchema.getSchema(),这个方法是线程安全的
            schema = RuntimeSchema.getSchema(clazz);
            if (Objects.nonNull(schema)) {
                schemaCache.put(clazz, schema);
            }
        }

        return schema;
    }

}