Java 序列化

Serializable 接口

对象实现了 Serializable 接口，就表示可以被序列化，它只是一个标记接口，也叫空接口，没有任何方法，所以实现了接口也不需要实现方法。

转换成 JSON 数据的对象可通过反序列化再次转化成对象JSON.parseObject(info, User.class)

实例

Apartment

import java.io.Serializable;

public class Apartment extends Building implements Serializable {

  private int totalRooms;
  private String builtupArea;

  public int getTotalRooms() {
    return totalRooms;
  }

  public void setTotalRooms(int totalRooms) {
    this.totalRooms = totalRooms;
  }

  public String getBuiltupArea() {
    return builtupArea;
  }

  public void setBuiltupArea(String builtupArea) {
    this.builtupArea = builtupArea;
  }
}

Building

public class Building {
  private String name;
  private String address;

  public String getName() {
    return name;
  }

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

  public String getAddress() {
    return address;
  }

  public void setAddress(String address) {
    this.address = address;
  }
}

ObjectAssembler

public class ObjectAssembler {
  public static void main(String[] args) {
    Apartment apartment = new Apartment();
    apartment.setName("研究生公寓");
    apartment.setAddress("杭州市江干区学林街628号");
    apartment.setTotalRooms(54);
    apartment.setBuiltupArea("380平米");

    String content = JSON.toJSONString(apartment);
    System.out.println("Apartment 对象=" + content);

    Apartment b2 = JSON.parseObject(content, Apartment.class);
    String name = b2.getName();
    System.out.println("Apartment 对象名称=" + name);

    Map bInfo = JSON.parseObject(content, Map.class);
    String name2 = (String) bInfo.get("name");
    System.out.println("Map.name 值=" + name2);
  }
}

排除序列化

解决当前对象部分属性不想被序列化，下面方法任选其一：

1. 通过在字段上增加一个 @JSONField(serialize=false)注解，这个注解是 fastjson 库提供的。
2. 在声明字段时，增加一个 transient 修饰关键字，这个关键字是 JDK 本身提供的。

Building

import com.alibaba.fastjson.annotation.JSONField;
import java.io.Serializable;

public class Building implements Serializable {
  // 自定义serialVersionUID
  private static final long serialVersionUID = 8735132092273200831L;

  private transient String name;

  @JSONField(serialize=false)
  private String address;

  public String getName() {
    return name;
  }

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

  public String getAddress() {
    return address;
  }

  public void setAddress(String address) {
    this.address = address;
  }
}