FastJson基本用法

基本用法：String objJson = JSON.toJSONString(Object object);
例一：解析基本json格式
例二：解析list
例三：解析复杂格式
例四：自定义需要序列化字段
例五：反序列化
例六：反序列化，复杂转换
例七：解析Map
例八：解析List嵌套Map
例九：对日期进行格式化
例十：输出为null的字段（FastJSON不输入为值Null的字段）

public class Fastjson {    public static void main(String[] args) {        //Student类和teacher类放在最后，需要get、set、需要空参构造和有参构造，toString方法。        //例一：解析基本json格式        //创建一个student对象        Student student = new Student(0,18,"sun");        System.out.println(student);        System.out.println(JSON.toJSONString(student));        //true会格式化输出样式        System.out.println(JSON.toJSONString(student,true));        //SerializerFeature属性：PrettyFormat格式化；(效果等同于true)        System.out.println(JSON.toJSONString(student,SerializerFeature.PrettyFormat));        //例二：解析list        //创建一个students集合        List<Student> students = new ArrayList<Student>();        for (int i = 0; i < 3; i++) {            Student st = new Student(i,18+i,"sun"+i);            students.add(st);        }           System.out.println(JSON.toJSONString(students));        //例三：解析复杂格式        //创建一个teacher集合（包含students1集合）        List<Teacher> teachers = new ArrayList<Teacher>();        for (int i = 0; i < 2; i++) {            Teacher teacher = new Teacher(i,"teacher"+i);            List<Student> students1 = new ArrayList<Student>();            for (int j = 0; j < 3; j++) {                Student st = new Student(j,18+j,"sun"+j);                students1.add(st);            }            teacher.setStudnets(students1);            teachers.add(teacher);        }        System.out.println(JSON.toJSONString(teachers));        //序列化就是指 把JavaBean对象转成JSON格式的字符串。        //例四：自定义需要序列化字段        SimplePropertyPreFilter simple = new SimplePropertyPreFilter(Student.class,"id","age");        System.out.println(JSON.toJSONString(students,simple));        //例五：反序列化        //需要对应的class有默认构造方法，不然转换会报错（default constructor not found. class csdn.fastjson.Student）        String string = JSON.toJSONString(student);        System.out.println(JSON.parseObject(string,Student.class));        //例六：反序列化，复杂转换        //fastjson框架的 TypeReference 可将json串转成定义好的泛型对象        String str = JSON.toJSONString(students);        List<Student> stu = JSON.parseObject(str, new TypeReference<List<Student>>(){});        for(int i=0;i<stu.size();i++)           {              System.out.println(stu.get(i));          }         //例七：解析Map        //创建一个map集合        Map<String,Object> map = new HashMap<String,Object>();        map.put("id", 1);        map.put("姓名", "太阳");        map.put("年龄", 18);        System.out.println(JSON.toJSON(map));        //例八：解析List<Map<String,Object>>        //list嵌套map        List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();        for (int i = 0; i < 3; i++) {            Map<String,Object> m = new HashMap<String,Object>();            m.put("id", i);            m.put("姓名", "姓名"+i);            m.put("年龄", 18+i);            list.add(m);        }        System.out.println(JSON.toJSON(list));        //例九：对日期进行格式化        //在没有设置格式的时候，FastJSON会将Date转成long        System.out.println(JSON.toJSONString(new Date()));        //SerializerFeature格式化日期        System.out.println(JSON.toJSONString(new Date(), SerializerFeature.WriteDateUseDateFormat));        //指定输出日期的格式        System.out.println(JSON.toJSONStringWithDateFormat(new Date(), "yyyy-MM-dd HH:mm:ss.SSS"));        //例十：输出为null的字段（FastJSON不输入为值Null的字段）        map.put("学历", null);        map.put("籍贯", null);        students.add(new Student(10,10,null));        System.out.println("例九：输出为null的字段（FastJSON不输入为值Null的字段）");        System.out.println(JSON.toJSONString(map));        System.out.println(JSON.toJSONString(map, SerializerFeature.WriteMapNullValue));        System.out.println(JSON.toJSONString(students));        System.out.println(JSON.toJSONString(students, SerializerFeature.WriteMapNullValue));    }}

运行结果：
student [id=0, age=18, name=sun]
例一：解析基本json格式
{“age”:18,”id”:0,”name”:”sun”}
例一：true会格式化输出样式
{
“age”:18,
“id”:0,
“name”:”sun”
}
例一：SerializerFeature.PrettyFormat
{
“age”:18,
“id”:0,
“name”:”sun”
}
例二：解析list
[{“age”:18,”id”:0,”name”:”sun0”},{“age”:19,”id”:1,”name”:”sun1”},{“age”:20,”id”:2,”name”:”sun2”}]
例三：解析复杂格式
[{“id”:0,”name”:”teacher0”,”studnets”:[{“age”:18,”id”:0,”name”:”sun0”},{“age”:19,”id”:1,”name”:”sun1”},{“age”:20,”id”:2,”name”:”sun2”}]},{“id”:1,”name”:”teacher1”,”studnets”:[{“age”:18,”id”:0,”name”:”sun0”},{“age”:19,”id”:1,”name”:”sun1”},{“age”:20,”id”:2,”name”:”sun2”}]}]
例四：自定义需要解析字段，自定义id,age
[{“age”:18,”id”:0},{“age”:19,”id”:1},{“age”:20,”id”:2}]
例五：反序列化
student [id=0, age=18, name=sun]
例六：反序列化，复杂转换
student [id=0, age=18, name=sun0]
student [id=1, age=19, name=sun1]
student [id=2, age=20, name=sun2]
例七：解析Map
{“id”:1,”年龄”:18,”姓名”:”太阳”}
例八：解析List嵌套Map
[{“id”:0,”年龄”:18,”姓名”:”姓名0”},{“id”:1,”年龄”:19,”姓名”:”姓名1”},{“id”:2,”年龄”:20,”姓名”:”姓名2”}]
例九：对日期进行格式化(无格式)
1508315881771
例九：SerializerFeature格式化日期
“2017-10-18 16:38:01”
例九：指定输出日期的格式
“2017-10-18 16:38:01.812”
例十：输出为null的字段（FastJSON不输入为值Null的字段）
{“id”:1,”姓名”:”太阳”,”年龄”:18}
{“id”:1,”姓名”:”太阳”,”籍贯”:null,”学历”:null,”年龄”:18}
[{“age”:18,”id”:0,”name”:”sun0”},{“age”:19,”id”:1,”name”:”sun1”},{“age”:20,”id”:2,”name”:”sun2”},{“age”:10,”id”:10}]
[{“age”:18,”id”:0,”name”:”sun0”},{“age”:19,”id”:1,”name”:”sun1”},{“age”:20,”id”:2,”name”:”sun2”},{“age”:10,”id”:10,”name”:null}]