一、项目结构

一个学生类。当中学生类中能够包括Course类对象

使用Maven管理项目的能够加入fastjson的坐标：

 <dependency>

       <groupId>com.alibaba</groupId>

       <artifactId>fastjson</artifactId>

       <version>1.2.4</version>

 </dependency>

二、数据对象转化为Json字符串

GenerateJson.java代码标识转化为json字符串

（1）将学生对象转化为json，当中学生中包括Course对象

@Test

    public void testSimpleJSON(){

        Student stu = new Student("xuliugen", "nan", "123123", "100");

        Course course = new Course("JAVA", "xiaobin", "100");

        stu.setCourse(course);

        String json = JSON.toJSONString(stu);

        System.out.println(json);

    }

{

    "course":{

        "coursename":"JAVA",

        "coursescore":"100",

        "courseteacher":"xiaobin"

    },

    "password":"123123",

    "score":"100",

    "sex":"nan",

    "username":"xuliugen"

}

（2）将一个单独的实体对象转化为json

@Test

    public void testListJSON(){

        JSONTest jt1 = new JSONTest("xuliugen", "nan");

        JSONTest jt2 = new JSONTest("xieyan", "nv");

        List<JSONTest> li = new ArrayList<JSONTest>();

        li.add(jt1);

        li.add(jt2);

        String jsonstr = JSON.toJSONString(li);

        System.out.println(jsonstr);

    }

[{"name":"xuliugen","sex":"nan"},{"name":"xieyan","sex":"nv"}]

（3）将包括多个相似于（1）中的实体对象转化为json

@Test

    public void testMulJSON(){

        Student stu = new Student("xuliugen", "nan", "123123", "100");

        Course course = new Course("JAVA", "xiaobin", "100");

        stu.setCourse(course);

        Student stu2 = new Student("xieyan", "nan", "123123", "100");

        Course course2 = new Course("music", "qwe", "100");

        stu2.setCourse(course2);

        List<Student> stuList = new ArrayList<Student>();

        stuList.add(stu);

        stuList.add(stu2);

        String json2 = JSON.toJSONString(stuList);

        System.out.println(json2);

    }

[

    {

        "course":{

            "coursename":"JAVA",

            "coursescore":"100",

            "courseteacher":"xiaobin"

        },

        "password":"123123",

        "score":"100",

        "sex":"nan",

        "username":"xuliugen"

    },

    {

        "course":{

            "coursename":"music",

            "coursescore":"100",

            "courseteacher":"qwe"

        },

        "password":"123123",

        "score":"100",

        "sex":"nan",

        "username":"xieyan"

    }

]

三、解析json数据到实体对象

（1）解析上述（1）中学生中包括Course的对象

[{"name":"xuliugen","sex":"nan"},{"name":"xieyan","sex":"nv"}]

    @Test

    public void testParseSimpleJSON(){

        String json = "[{\"name\":\"xuliugen\",\"sex\":\"nan\"},{\"name\":\"xieyan\",\"sex\":\"nv\"}]";

        JSONArray jsonArray = JSON.parseArray(json);

        String str = jsonArray.getString(0);

        JSONTest jsonTest = JSON.parseObject(str,JSONTest.class);

        System.out.println(jsonTest.getSex());

    }

{

    "course":{

        "coursename":"JAVA",

        "coursescore":"100",

        "courseteacher":"xiaobin"

    },

    "password":"123123",

    "score":"100",

    "sex":"nan",

    "username":"xuliugen"

}

（2）因为仅仅有一个对象，解析例如以下：

@Test

    public void testParseStudentIncludeCourseJSON() {

        String json = "{\"course\":{\"coursename\":\"JAVA\",\"coursescore\":\"100\",\"courseteacher\":\"xiaobin\"},\"password\":\"123123\",\"score\":\"100\",\"sex\":\"nan\",\"username\":\"xuliugen\"}";

        Student stu = JSON.parseObject(json,Student.class);

        System.out.println(stu.getPassword());

    }

（3）将上述中的（3）当有多个上述的对象的时候，解析例如以下：

[

    {

    "course":{

        "coursename":"JAVA",

        "coursescore":"100",

        "courseteacher":"xiaobin"

    },

    "password":"123123",

    "score":"100",

    "sex":"nan",

    "username":"xuliugen"

    },

    {

    "course":{

        "coursename":"music",

        "coursescore":"100",

        "courseteacher":"qwe"

    },

    "password":"123123",

    "score":"100",

    "sex":"nan",

    "username":"xieyan"

    }

]

解析例如以下：

@Test

    public void testParseListStudentIncludeCourseJSON() {

        String json = "[{\"course\":{\"coursename\":\"JAVA\",\"coursescore\":\"100\",\"courseteacher\":\"xiaobin\"},\"password\":\"123123\",\"score\":\"100\",\"sex\":\"nan\",\"username\":\"xuliugen123\"},{\"course\":{\"coursename\":\"music\",\"coursescore\":\"100\",\"courseteacher\":\"qwe\"},\"password\":\"123123\",\"score\":\"100\",\"sex\":\"nan\",\"username\":\"xieyan\"}]";

        JSONArray jsonArray = JSON.parseArray(json);

        String str = jsonArray.getString(0);

        Student stu = JSON.parseObject(str, Student.class);

        System.out.println(stu.getUsername());

    }