申明:沒工做以前都沒聽過JSON,多是本身太菜了。可能在前臺AJAX接觸到JSON,這幾天要求在純java的編程中,返回JSON字符串形式。java
網上有兩種解析JSON對象的jar包:JSON-lib.jar和json.jar,這裏主要介紹JSON-lib.jar。編程
jar包地址以下:json
json-lib-2.4-jdk15.jar所需所有JAR包.rar數組
1、JSON-lib.jar還依賴如下jar包:spa
2、應用code
JSON也是以key-value形式存在的。key是字符串,value能夠是基本類型、JSONArray、JSONObject.對象
JSONArray:[],望文生義也知道,他是數組形式,又可要放多個JSONblog
JSONObject:{}就放一個JSON。字符串
因爲他們的他們能夠嵌套形式就比較多。get
3、輸出JSON實例考慮到對[]、{}進行對比,區別重複的變量,對變量名進行了首字母大寫,顯得不規範了。
import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class JSONTest { public static void main(String[] args) { JSONObject container1 = new JSONObject(); container1.put("ClassName", "高三一班"); System.out.println(container1.toString()); JSONArray className = new JSONArray(); className.add("高三一班"); container1.put("className", className); System.out.println(container1.toString()); JSONObject classInfo = new JSONObject(); classInfo.put("stuCount", 50); classInfo.put("leader", "rah"); container1.put("classInfo", classInfo); System.out.println(container1); JSONObject ClassInfo = new JSONObject(); JSONArray stuCount = new JSONArray(); stuCount.add(50); JSONArray leader = new JSONArray(); leader.add("rah"); ClassInfo.put("stuCount", stuCount); ClassInfo.put("leader", leader); container1.put("ClassInfo", ClassInfo); System.out.println(container1); JSONArray students = new JSONArray(); JSONObject studentOne = new JSONObject(); studentOne.put("name", "張麻子"); studentOne.put("sex", "男"); studentOne.put("age", 12); studentOne.put("hobby", "java develop"); JSONObject studentTwo = new JSONObject(); studentTwo.put("name", "王瘸子"); studentTwo.put("sex", "男"); studentTwo.put("age", 13); studentTwo.put("hobby", "C/C++ develop"); students.add(studentOne); students.add(studentTwo); container1.put("students", students); System.out.println(container1); JSONArray Students = new JSONArray(); JSONObject StudnetOne = new JSONObject(); JSONArray name1 = new JSONArray(); name1.add("張麻子"); JSONArray sex1 = new JSONArray(); sex1.add("男"); JSONArray age1= new JSONArray(); age1.add("12"); JSONArray hobby1 = new JSONArray(); hobby1.add("java develop"); StudnetOne.put("name", name1); StudnetOne.put("sex", sex1); StudnetOne.put("age", age1); StudnetOne.put("hobby", hobby1); JSONObject StudnetTwo = new JSONObject(); JSONArray name2 = new JSONArray(); name2.add("王瘸子"); JSONArray sex2 = new JSONArray(); sex2.add("男"); JSONArray age2= new JSONArray(); age2.add("13"); JSONArray hobby2 = new JSONArray(); hobby2.add("C/C++ develop"); StudnetTwo.put("name", name2); StudnetTwo.put("sex", sex2); StudnetTwo.put("age", age2); StudnetTwo.put("hobby", hobby2); Students.add(StudnetOne); Students.add(StudnetTwo); container1.put("Students", Students); System.out.println(container1); JSONArray teachers = new JSONArray(); teachers.add(0,"王老師"); teachers.add(1,"李老師 "); container1.put("teachers", teachers); System.out.println(container1); JSONArray Teachers = new JSONArray(); JSONObject teacher1 = new JSONObject(); teacher1.put("name", "小梅"); teacher1.put("introduce","他是一個好老師"); JSONObject teacher2 = new JSONObject(); teacher2.put("name", "小李"); teacher2.put("introduce","他是一個合格的老師"); Teachers.add(0,teacher1); Teachers.add(1,teacher2); container1.put("Teachers", Teachers); System.out.println(container1); } }
運行結果:
{"ClassName":"高三一班"}
{"ClassName":"高三一班","className":["高三一班"]}
{"ClassName":"高三一班","className":["高三一班"],"classInfo":{"stuCount":50,"leader":"rah"}}
{"ClassName":"高三一班","className":["高三一班"],"classInfo":{"stuCount":50,"leader":"rah"},"ClassInfo":{"stuCount":[50],"leader":["rah"]}}
{"ClassName":"高三一班","className":["高三一班"],"classInfo":{"stuCount":50,"leader":"rah"},"ClassInfo":{"stuCount":[50],"leader":["rah"]},"students":[{"name":"張麻子","sex":"男","age":12,"hobby":"java develop"},{"name":"王瘸子","sex":"男","age":13,"hobby":"C/C++ develop"}]}
{"ClassName":"高三一班","className":["高三一班"],"classInfo":{"stuCount":50,"leader":"rah"},"ClassInfo":{"stuCount":[50],"leader":["rah"]},"students":[{"name":"張麻子","sex":"男","age":12,"hobby":"java develop"},{"name":"王瘸子","sex":"男","age":13,"hobby":"C/C++ develop"}],"Students":[{"name":["張麻子"],"sex":["男"],"age":["12"],"hobby":["java develop"]},{"name":["王瘸子"],"sex":["男"],"age":["13"],"hobby":["C/C++ develop"]}]}
{"ClassName":"高三一班","className":["高三一班"],"classInfo":{"stuCount":50,"leader":"rah"},"ClassInfo":{"stuCount":[50],"leader":["rah"]},"students":[{"name":"張麻子","sex":"男","age":12,"hobby":"java develop"},{"name":"王瘸子","sex":"男","age":13,"hobby":"C/C++ develop"}],"Students":[{"name":["張麻子"],"sex":["男"],"age":["12"],"hobby":["java develop"]},{"name":["王瘸子"],"sex":["男"],"age":["13"],"hobby":["C/C++ develop"]}],"teachers":["王老師","李老師 "]}
{"ClassName":"高三一班","className":["高三一班"],"classInfo":{"stuCount":50,"leader":"rah"},"ClassInfo":{"stuCount":[50],"leader":["rah"]},"students":[{"name":"張麻子","sex":"男","age":12,"hobby":"java develop"},{"name":"王瘸子","sex":"男","age":13,"hobby":"C/C++ develop"}],"Students":[{"name":["張麻子"],"sex":["男"],"age":["12"],"hobby":["java develop"]},{"name":["王瘸子"],"sex":["男"],"age":["13"],"hobby":["C/C++ develop"]}],"teachers":["王老師","李老師 "],"Teachers":[{"name":"小梅","introduce":"他是一個好老師"},{"name":"小李","introduce":"他是一個合格的老師"}]}
4、遍歷JSON實例
以上面的輸出的JSON字符串進行按順序給它遍歷
String ClassName1 = (String) container1.get("ClassName"); System.out.println("ClassName data is: " + ClassName1); JSONArray className1 = container1.getJSONArray("className"); System.out.println("className data is: " + className1); JSONObject classInfo1 = container1.getJSONObject("classInfo"); System.out.println("classInfo data is: " + classInfo1); JSONObject ClassInfo1 = container1.getJSONObject("ClassInfo"); System.out.println("ClassInfo data is: " + ClassInfo1); JSONArray students1 = container1.getJSONArray("students"); System.out.println("students data is: " + students1); JSONArray Students1 = container1.getJSONArray("Students"); System.out.println("Students data is: " + Students1); JSONArray teachers1 = container1.getJSONArray("teachers"); for(int i=0; i < teachers1.size(); i++){ System.out.println("teahcer " + i + " is: "+ teachers1.get(i)); } JSONArray Teachers1 = container1.getJSONArray("Teachers"); for(int i=0; i < Teachers1.size(); i++){ System.out.println("Teachers " + i + " is: "+ Teachers1.get(i)); }
遍歷結果:
ClassName data is: 高三一班 className data is: ["高三一班"] classInfo data is: {"stuCount":50,"leader":"rah"} ClassInfo data is: {"stuCount":[50],"leader":["rah"]} students data is: [{"name":"張麻子","sex":"男","age":12,"hobby":"java develop"},{"name":"王瘸子","sex":"男","age":13,"hobby":"C/C++ develop"}] Students data is: [{"name":["張麻子"],"sex":["男"],"age":["12"],"hobby":["java develop"]},{"name":["王瘸子"],"sex":["男"],"age":["13"],"hobby":["C/C++ develop"]}] teahcer 0 is: 王老師 teahcer 1 is: 李老師 Teachers 0 is: {"name":"小梅","introduce":"他是一個好老師"} Teachers 1 is: {"name":"小李","introduce":"他是一個合格的老師"}
上面包括了大部份的JSON的嵌套形式,可能有忽略的也能夠參考上面的內容。