Fastjson的基本用法

• 一引入依赖

<!-- json解析用 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.76</version>
</dependency>
<!-- 简化代码，方便日志打印 -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.24</version> 
</dependency>

• 二用到的测试实体

@Data
@AllArgsConstructor
public class Student implements Serializable,Cloneable {

    private static final long serialVersionUID = 6447932156561222739L;
    private Integer sNo;
    private String name;
    private Date birthday;
    private Integer classNo;
    private String grade;

    /**
     * 方便对象复制
     * @return
     * @throws CloneNotSupportedException
     */
    @Override
    protected Student clone() throws CloneNotSupportedException {
        return (Student) super.clone();
    }
}

• 三转json（序列化）

1. 实体转json

Student s1 = new Student(1,"张三",new Date(),1001,"一年级");
String s1Json = JSON.toJSONString(s1);
log.info("fastjson将Student转的json为{}",s1Json);

2. Map转json

Student s1 = new Student(1,"张三",new Date(),1001,"一年级");
Student s2 = s1.clone();
s2.setSNo(2);
Student s3 = s1.clone();
s3.setSNo(3);
Student s4 = s1.clone();
s4.setSNo(4);
Map<String,Student> data = new LinkedHashMap();
data.put("s1",s1);
data.put("s2",s2);
data.put("s3",s3);
data.put("s4",s4);

String mapJson = JSON.toJSONString(data);
log.info("fastjson将map转的json为{}",mapJson);

3. List转json

Student s1 = new Student(1,"张三",new Date(),1001,"一年级");
Student s2 = s1.clone();
s2.setSNo(2);
Student s3 = s1.clone();
s3.setSNo(3);
Student s4 = s1.clone();
s4.setSNo(4);

List<Student> studentList = new ArrayList<>(Arrays.asList(s1,s2,s3,s4));
String listJson = JSON.toJSONString(studentList);
log.info("fastjson将List转的json为{}",listJson);

• 四转Java对象（反序列化）

1. json转实体

Student s1 = new Student(1,"张三",new Date(),1001,"一年级");
String s1Json = JSON.toJSONString(s1);
log.info("fastjson将Student转的json为{}",s1Json);


Student json1Student = JSON.parseObject(s1Json,Student.class);
log.info("json转实体Student结果：{}",json1Student);

2. json转Map

Student s1 = new Student(1,"张三",new Date(),1001,"一年级");
Student s2 = s1.clone();
s2.setSNo(2);
Student s3 = s1.clone();
s3.setSNo(3);
Student s4 = s1.clone();
s4.setSNo(4);

Map<String,Student> data = new LinkedHashMap();
data.put("s1",s1);
data.put("s2",s2);
data.put("s3",s3);
data.put("s4",s4);
String mapJson = JSON.toJSONString(data);
log.info("fastjson将map转的json为{}",mapJson);

Map<String,Student> json2map = JSON.parseObject(mapJson,Map.class);
log.info("json转Map结果：{}",json2map);

3. json转List

Student s1 = new Student(1,"张三",new Date(),1001,"一年级");
Student s2 = s1.clone();
s2.setSNo(2);
Student s3 = s1.clone();
s3.setSNo(3);
Student s4 = s1.clone();
s4.setSNo(4);

List<Student> studentList = new ArrayList<>(Arrays.asList(s1,s2,s3,s4));
String listJson = JSON.toJSONString(studentList);
log.info("fastjson将List转的json为{}",listJson);

List<Student> json2List = JSON.parseObject(listJson,new TypeReference<List<Student>>(){});
log.info("json转List结果：{}",json2List);