fastjsont转java对象 fastjson转换

首先在使用FastJson时,先去导入jar包,这个jar是阿里巴巴开源的,我们可以到maven仓库中下载.

这是我的测试类:

　　

import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.dao.Customer;
import com.dao.Person;
import com.dao.Role;public class TestFastJson {
	/*
	 * 对象转换成json字符串
	 */
	@Test
	public void run1() {		Customer customer = new Customer();
		customer.setId(100);
		customer.setName("Agust");
		String jsonString = JSON.toJSONString(customer);
		System.out.println(jsonString);
	}
	/*
	 * json字符串转换成对象
	 */
	@Test
	public void run2() {
		String jsonString = "{\"id\":100,\"name\":\"Agust\"}";		Customer object = JSON.parseObject(jsonString, Customer.class);
		System.out.println(object);
	}	/*
	 * 添加同一个对象时 禁止使用引用地址$ref:[{"id":100,"name":"Agust"},{"$ref":"$[0]"}]
	 * 
	 */
	@Test
	public void run3() {		List<Customer> list = new ArrayList<>();
		Customer customer = new Customer();
		customer.setId(100);
		customer.setName("Agust");
		list.add(customer);
		list.add(customer);
		String jsonString = JSON.toJSONString(list, SerializerFeature.DisableCircularReferenceDetect);
		System.out.println(jsonString);
	}
	/*
	 * json数组转换成实体集合
	 * 
	 */
	@Test
	public void run4() {		String jsonString = "[{\"id\":100,\"name\":\"Agust\"},{\"id\":100,\"name\":\"Agust1\"}]";
		List<Customer> parseArray = JSON.parseArray(jsonString, Customer.class);
		for (Customer customer : parseArray) {
			System.out.println(customer);
		}	}
	/*
	 * 
	 * Person中引用Role,在Role中引用了Person
	 * 
	 * 防止循环引用造成栈内存溢出,在实体中加入注解
	 * 
	 * @JSONField(serialize = false) 禁止循环引用
	 * 
	 */	@Test
	public void run5() {		Person person = new Person();
		person.setName("小子");
		Role role = new Role();
		role.setName("姑娘");
		person.setrName(role);
		role.setpName(person);
		String jsonString = JSON.toJSONString(role, SerializerFeature.DisableCircularReferenceDetect);
		System.out.println(jsonString);
	}
}
下面是我测试需要的三个实体类
public class Customer {
	private int id;

	public int getId() {
		return id;
	}	public void setId(int id) {
		this.id = id;
	}	private String name;
	public String getName() {
		return name;
	}	public void setName(String name) {
		this.name = name;
	}	@Override
	public String toString() {
		return "Customer [id=" + id + ", name=" + name + "]";
	}
} 
import com.alibaba.fastjson.annotation.JSONField;
public class Person {
	
	private String name;
	//这是为了阻止循环引用
	@JSONField(serialize = false)
	private Role rName;	public String getName() {
		return name;
	}	public void setName(String name) {
		this.name = name;
	}	public Role getrName() {
		return rName;
	}	public void setrName(Role rName) {
		this.rName = rName;
	}

}public class Role {
	private String name;

	private Person pName;	public String getName() {
		return name;
	}	public void setName(String name) {
		this.name = name;
	}	public Person getpName() {
		return pName;
	}	public void setpName(Person pName) {
		this.pName = pName;
	}

}