JSON详细学习之JSONObject in JAVA

 

需要依赖的jar包: commons-lang.jar commons-beanutils.jar commons-collections.jar commons-logging.jar  ezmorph.jar json-lib-2.2.2-jdk15.jar

首先简单地看一下JSONObject,JSONArray对象的创建以及Json字符串的解析：

[java] view plain copy

1. package com.peter.jsonobj.test;  
2.   
3. import java.util.ArrayList;  
4. import java.util.HashMap;  
5.   
6. import net.sf.json.JSONArray;  
7. import net.sf.json.JSONObject;  
8.   
9.   
10. public class Test2 {  
11.         public static void main(String[] args) {  
12.             //JsonObject和JsonArray区别就是JsonObject是对象形式，JsonArray是数组形式  
13.             //创建JsonObject第一种方法  
14.             JSONObject jsonObject = new JSONObject();  
15.             jsonObject.put("UserName", "ZHULI");  
16.             jsonObject.put("age", "30");  
17.             jsonObject.put("workIn", "ALI");  
18.             System.out.println("jsonObject1：" + jsonObject);  
19.               
20.             //创建JsonObject第二种方法  
21.             HashMap<String, String> hashMap = new HashMap<String, String>();  
22.             hashMap.put("UserName", "ZHULI");  
23.             hashMap.put("age", "30");  
24.             hashMap.put("workIn", "ALI");  
25.             System.out.println("jsonObject2：" + JSONObject.fromObject(hashMap));  
26.               
27.             //创建一个JsonArray方法1  
28.             JSONArray jsonArray = new JSONArray();  
29.             jsonArray.add(0, "ZHULI");  
30.             jsonArray.add(1, "30");  
31.             jsonArray.add(2, "ALI");  
32.             System.out.println("jsonArray1：" + jsonArray);  
33.               
34.             //创建JsonArray方法2  
35.             ArrayList<String> arrayList = new ArrayList<String>();  
36.             arrayList.add("ZHULI");  
37.             arrayList.add("30");  
38.             arrayList.add("ALI");  
39.             System.out.println("jsonArray2：" + JSONArray.fromObject(arrayList));  
40.               
41.             //如果JSONArray解析一个HashMap，则会将整个对象的放进一个数组的值中  
42.             System.out.println("jsonArray FROM HASHMAP：" + JSONArray.fromObject(hashMap));  
43.               
44.             //组装一个复杂的JSONArray  
45.             JSONObject jsonObject2 = new JSONObject();  
46.             jsonObject2.put("UserName", "ZHULI");  
47.             jsonObject2.put("age", "30");  
48.             jsonObject2.put("workIn", "ALI");  
49.             jsonObject2.element("Array", arrayList);  
50.             System.out.println("jsonObject2：" + jsonObject2);  
51.               
52.               
53.             //解析JSON字符串：  
54.             String jsonString = "{\"UserName\":\"ZHULI\",\"age\":\"30\",\"workIn\":\"ALI\",\"Array\":[\"ZHULI\",\"30\",\"ALI\"]}";  
55.             //将Json字符串转为java对象  
56.             JSONObject obj = JSONObject.fromObject(jsonString);  
57.             //获取Object中的UserName  
58.             if (obj.has("UserName")) {  
59.                 System.out.println("UserName:" + obj.getString("UserName"));  
60.             }  
61.             //获取ArrayObject  
62.             if (obj.has("Array")) {  
63.                 JSONArray transitListArray = obj.getJSONArray("Array");  
64.                 for (int i = 0; i < transitListArray.size(); i++) {  
65.                     System.out.print("Array:" + transitListArray.getString(i) + " ");  
66.                 }  
67.             }  
68.         }  
69. }  

结果如下：

jsonObject1：{"workIn":"ALI","age":"30","UserName":"ZHULI"}
jsonObject2：{"workIn":"ALI","age":"30","UserName":"ZHULI"}
jsonArray1：["ZHULI","30","ALI"]
jsonArray2：["ZHULI","30","ALI"]
jsonArray FROM HASHMAP：[{"workIn":"ALI","age":"30","UserName":"ZHULI"}]
jsonObject2：{"workIn":"ALI","age":"30","Array":["ZHULI","30","ALI"],"UserName":"ZHULI"}
UserName:ZHULI
Array:ZHULI Array:30 Array:ALI 

由于我们涉及更多的是对象(Bean)与Json字符串之间的转换.这里我创建了我的Model类

[java] view plain copy

1. package com.peter.model;  
2.   
3. import java.io.Serializable;  
4. import java.util.ArrayList;  
5. import java.util.List;  
6.   
7.   
8. public class ClassInfo implements Serializable{  
9.     private String className;  
10.     private int  classNum;  
11.     private Teacher teacher;  
12.     private List<Student> students=new ArrayList<Student>();  
13.     public String getClassName() {  
14.         return className;  
15.     }  
16.     public void setClassName(String className) {  
17.         this.className = className;  
18.     }  
19.       
20.     public Teacher getTeacher() {  
21.         return teacher;  
22.     }  
23.     public void setTeacher(Teacher teacher) {  
24.         this.teacher = teacher;  
25.     }  
26.     public List<Student> getStudents() {  
27.         return students;  
28.     }  
29.     public void setStudents(List<Student> students) {  
30.         this.students = students;  
31.     }  
32.     public int getClassNum() {  
33.         return classNum;  
34.     }  
35.     public void setClassNum(int classNum) {  
36.         this.classNum = classNum;  
37.     }  
38.     @Override  
39.     public String toString() {  
40.         return "ClassInfo [className=" + className + ", classNum=" + classNum  
41.                 + ", teacher=" + teacher + ", students=" + students + "]";  
42.     }  
43.       
44. }  

[java] view plain copy

1. package com.peter.model;  
2. import java.io.Serializable;  
3.   
4. import java.util.Date;  
5.   
6. public class Student implements Serializable{    
7.     private int id;    
8.     private String name;    
9.     private Date birthDay;    
10.     
11.     public int getId() {    
12.         return id;    
13.     }    
14.     
15.     public void setId(int id) {    
16.         this.id = id;    
17.     }    
18.     
19.     public String getName() {    
20.         return name;    
21.     }    
22.     
23.     public void setName(String name) {    
24.         this.name = name;    
25.     }    
26.     
27.     public Date getBirthDay() {    
28.         return birthDay;    
29.     }    
30.     
31.     public void setBirthDay(Date birthDay) {    
32.         this.birthDay = birthDay;    
33.     }    
34.     
35.     @Override    
36.     public String toString() {    
37.         return "Student [birthDay=" + birthDay + ", id=" + id + ", name="    
38.                 + name + "]";    
39.     }    
40.     
41. }    

[java] view plain copy

1. <pre name="code" class="java">package com.peter.model;  
2.   
3. import java.io.Serializable;  
4.   
5. public class Teacher implements Serializable{  
6.         private String name;  
7.         private String jabNum;  
8.         public String getName() {  
9.             return name;  
10.         }  
11.         public void setName(String name) {  
12.             this.name = name;  
13.         }  
14.         public String getJabNum() {  
15.             return jabNum;  
16.         }  
17.         public void setJabNum(String jabNum) {  
18.             this.jabNum = jabNum;  
19.         }  
20.         @Override  
21.         public String toString() {  
22.             return "Teacher [name=" + name + ", jabNum=" + jabNum + "]";  
23.         }  
24.           
25. }  

以上的model基本上能满足所有的Json字符串格式.

[java] view plain copy

1. package com.peter.jsonobj.test;  
2.   
3. import java.text.SimpleDateFormat;  
4. import java.util.ArrayList;  
5. import java.util.Date;  
6. import java.util.List;  
7.   
8. import net.sf.json.JSONArray;  
9. import net.sf.json.JSONObject;  
10. import net.sf.json.JSONSerializer;  
11. import net.sf.json.JsonConfig;  
12. import net.sf.json.processors.JsonValueProcessor;  
13. import net.sf.json.util.CycleDetectionStrategy;  
14.   
15. import com.peter.model.ClassInfo;  
16. import com.peter.model.Student;  
17. import com.peter.model.Teacher;  
18.   
19. public class Test {  
20.     public static void main(String[] args) {  
21.   
22.         Student student1 = new Student();  
23.         student1.setId(1);  
24.         student1.setName("李坤");  
25.         student1.setBirthDay(new Date());  
26.   
27.         // //////////////////////////////////////////////////////////  
28.         System.out.println("----------简单对象之间的转化-------------");  
29.         // 简单的bean转为json  
30.         // 默认日期："birthDay":{"time":1445158142832,"minutes":49,"seconds":2,"hours":16,"month":9,"year":115,"timezoneOffset":-480,"day":0,"date":18}  
31.         JSONObject jso = JSONObject.fromObject(student1);  
32.         String s1 = jso.toString();  
33.         System.out.println("(默认日期)简单Bean转化为Json===" + s1);  
34.   
35.         JSONObject jso1 = JSONObject.fromObject(student1, getConfig());  
36.         s1 = jso1.toString();  
37.         System.out.println("(设置日期)简单Bean转化为Json===" + s1);  
38.   
39.         // // json转为简单Bean  
40.         JSONObject o1 = (JSONObject) JSONSerializer.toJSON(s1);  
41.         Student student = (Student) JSONObject.toBean(o1, Student.class);  
42.         System.out.println("Json转为简单Bean===" + student);  
43.   
44.         Student student2 = new Student();  
45.         student2.setId(2);  
46.         student2.setName("曹贵生");  
47.         student2.setBirthDay(new Date());  
48.   
49.         Student student3 = new Student();  
50.         student3.setId(3);  
51.         student3.setName("柳波");  
52.         student3.setBirthDay(new Date());  
53.   
54.         List<Student> list = new ArrayList<Student>();  
55.         list.add(student1);  
56.         list.add(student2);  
57.         list.add(student3);  
58.   
59.         System.out.println("----------带泛型的List之间的转化-------------");  
60.         JSONArray jary1 = JSONArray.fromObject(list, getConfig());  
61.         // 带泛型的list转化为json  
62.         String s2 = jary1.toString();  
63.         System.out.println("带泛型的list转化为json==" + s2);  
64.         // json转为带泛型的list  
65.         // 数组  
66.         Student[] arrList = (Student[]) JSONArray.toArray(jary1, Student.class);  
67.   
68.         // 集合  
69.         @SuppressWarnings("unchecked")  
70.         List<Student> lists = JSONArray.toList(jary1, Student.class);  
71.         for (Student stu : arrList) {  
72.             System.out.println(stu.getName());  
73.         }  
74.         for (Student stu : lists) {  
75.             System.out.println(stu.getName());  
76.         }  
77.         //  
78.         Teacher t = new Teacher();  
79.         t.setJabNum("t101");  
80.         t.setName("lijun");  
81.         ClassInfo ci = new ClassInfo();  
82.         ci.setClassName("cna");  
83.         ci.setClassNum(101);  
84.         ci.setStudents(list);  
85.         ci.setTeacher(t);  
86.         JSONObject clajso = JSONObject.fromObject(ci, getConfig());  
87.         String c = clajso.toString();  
88.         System.out.println("ci to json  //////////////");  
89.         System.out.println(c);  
90.   
91.         System.out.println("json to ci //////////");  
92.         JSONObject o2 = (JSONObject) JSONSerializer.toJSON(c);  
93.         ClassInfo cijson = (ClassInfo) JSONObject.toBean(o2, ClassInfo.class);  
94.         JSONArray array = o2.getJSONArray("students");  
95.         System.out.println(array.size());  
96.         for (int i = 0; i < array.size(); i++) {  
97.             JSONObject object = (JSONObject) array.get(i);  
98.             Student studentaa = (Student) JSONObject.toBean(object,  
99.                     Student.class);  
100.             cijson.getStudents().add(studentaa);  
101.         }  
102.         System.out.println(cijson);  
103.   
104.     }  
105.   
106.     public static JsonConfig getConfig() {  
107.         // 设置日期格式  
108.         JsonConfig config = new JsonConfig();  
109.         // 防止对象间的循环引用所产生的jsonString  
110.         config.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);  
111.         config.registerJsonValueProcessor(Date.class, new JsonValueProcessor() {  
112.   
113.             public Object processObjectValue(String arg0, Object arg1,  
114.                     JsonConfig arg2) {  
115.                 SimpleDateFormat sdf = new SimpleDateFormat(  
116.                         "yyyy-MM-dd HH:mm:ss.SSS");  
117.                 Date d = (Date) arg1;  
118.                 return sdf.format(d);  
119.             }  
120.   
121.             public Object processArrayValue(Object arg0, JsonConfig arg1) {  
122.                 // TODO Auto-generated method stub  
123.                 return null;  
124.             }  
125.         });  
126.         return config;  
127.     }  
128. }  

结果如下：

----------简单对象之间的转化-------------
(默认日期)简单Bean转化为Json==={"id":1,"name":"李坤","birthDay":{"time":1466596005549,"minutes":46,"seconds":45,"hours":19,"month":5,"year":116,"timezoneOffset":-480,"day":3,"date":22}}
(设置日期)简单Bean转化为Json==={"id":1,"name":"李坤","birthDay":"2016-06-22 19:46:45.549"}
Json转为简单Bean===Student [birthDay=Wed Jun 22 19:46:45 CST 2016, id=1, name=李坤]
----------带泛型的List之间的转化-------------
带泛型的list转化为json==[{"id":1,"name":"李坤","birthDay":"2016-06-22 19:46:45.549"},{"id":2,"name":"曹贵生","birthDay":"2016-06-22 19:46:45.938"},{"id":3,"name":"柳波","birthDay":"2016-06-22 19:46:45.938"}]

李坤
曹贵生
柳波
李坤
曹贵生
柳波
ci to json  //////////////
{"students":[{"id":1,"name":"李坤","birthDay":"2016-06-22 19:46:45.549"},{"id":2,"name":"曹贵生","birthDay":"2016-06-22 19:46:45.938"},{"id":3,"name":"柳波","birthDay":"2016-06-22 19:46:45.938"}],"className":"cna","teacher":{"name":"lijun","jabNum":"t101"},"classNum":101}
json to ci //////////
3

ClassInfo [className=cna, classNum=101, teacher=Teacher [name=lijun, jabNum=t101], students=[net.sf.ezmorph.bean.MorphDynaBean@331ae2ce[
  {id=1, name=李坤, birthDay=2016-06-22 19:46:45.549}
], net.sf.ezmorph.bean.MorphDynaBean@36293b29[
  {id=2, name=曹贵生, birthDay=2016-06-22 19:46:45.938}
], net.sf.ezmorph.bean.MorphDynaBean@4ceb1c86[
  {id=3, name=柳波, birthDay=2016-06-22 19:46:45.938}
], Student [birthDay=Wed Jun 22 19:46:46 CST 2016, id=1, name=李坤], Student [birthDay=Wed Jun 22 19:46:46 CST 2016, id=2, name=曹贵生], Student [birthDay=Wed Jun 22 19:46:46 CST 2016, id=3, name=柳波]]]

以上的例子,相信能够解决我们大部分的问题,在此顺便提供其API,方便大家查看学习

http://json-lib./apidocs/jdk15/index.html