Convert between objects and JSON strings using Google's Gson

Convert between objects and JSON strings using Google's Gson

Need Gson.jar

1.jsonutil.java

Java code

2. Package Com.snail.json;
6. Import Java.lang.reflect.Type;
8. Import Com.google.gson.Gson;
10. /**
12. * Java object and JSON string Mutual conversion tool class
14. * @author Penghuaiyi
16. * @date 2013-08-10
18. */
20. Public Final class Jsonutil {
24. Private Jsonutil () {}
28. /** 
30. * Object converted to JSON string
32. * @param obj
34. * @return
36. */
38. public static String ToJson (Object obj) {
40. Gson Gson = new Gson ();
42. return Gson.tojson (obj);
44. }
48. /** 
50. * JSON strings are converted to objects
52. * @param str
54. * @param type
56. * @return
58. */
60. public static <T> T Fromjson (String str, type type) {
62. Gson Gson = new Gson ();
64. return Gson.fromjson (str, type);
66. }
70. /** 
72. * JSON strings are converted to objects
74. * @param str
76. * @param type
78. * @return
80. */
82. public static <T> T Fromjson (String str, class<t> type) {
84. Gson Gson = new Gson ();
86. return Gson.fromjson (str, type);
88. }
92. }

2. Person.java

Java code

2. Package Com.snail.json;
6. Public class Person {
8. private int id;
10. private String name;
14. public int getId () {
16. return ID;
18. }
20. public void setId (int id) {
22. this.id = ID;
24. }
26. Public String GetName () {
28. return name;
30. }
32. public void SetName (String name) {
34. this.name = name;
36. }
40. }

3. Test.java

Java code

2. Package Com.snail.json;
6. Import java.util.ArrayList;
8. Import Java.util.HashMap;
10. Import java.util.List;
12. Import Java.util.Map;
14. Import Java.util.Map.Entry;
18. Import Com.google.gson.reflect.TypeToken;
22. Public class Test {
26. /** 
28. * Conversion of General objects
30. */
32. public static void Objecttojson () {
34. Person person = new Person ();
36. Person.setid (1);
38. Person.setname ("one");
40. //javabean Convert to JSON string
42. String jsonstr = Jsonutil.tojson (person);
44. System.out.println (JSONSTR);
48. //json string converted to JavaBean
50. Person Newperson = Jsonutil.fromjson (jsonstr, person.   Class);
52. System.out.println (person = = Newperson);
54. System.out.println (Newperson.getid () +"," +newperson.getname ());
56. }
60. /** 
62. * Composite structure Data conversion (List)
64. */
66. public static void Listtojson () {
68. Person Person1 = new Person ();
70. Person1.setid (1);
72. Person1.setname ("one");
76. Person Person2 = new Person ();
78. Person2.setid (2);
80. Person2.setname ("both");
84. list<person> list = new arraylist<person> ();
86. List.add (Person1);
88. List.add (Person2);
92. //javabean Convert to JSON string
94. String jsonstr = Jsonutil.tojson (list);
96. System.out.println (JSONSTR);
102. //json strings into JavaBean objects
104. List<person> RTN = Jsonutil.fromjson (jsonstr, new typetoken<list<person>> () {}.getType ());
106. For (person Person:rtn) {
108. System.out.println (Person.getid () +"," +person.getname ());
110. }
112. }
116. /** 
118. * Composite structure Data conversion (MAP)
120. */
122. public static void Maptojson () {
124. Person Person1 = new Person ();
126. Person1.setid (1);
128. Person1.setname ("one");
130. Person Person2 = new Person ();
132. Person2.setid (2);
134. Person2.setname ("both");
138. map<integer,person> map = new hashmap<integer,person> ();
140. Map.put (Person1.getid (), Person1);
142. Map.put (Person2.getid (), Person2);
146. //javabean Convert to JSON string
148. String jsonstr = Jsonutil.tojson (map);
150. System.out.println (JSONSTR);
154. //json strings into map objects
156. Map<integer,person> RTN = Jsonutil.fromjson (jsonstr, new Typetoken<map<integer,person>> () {}.  GetType ());
158. for (Entry<integer, person> entry:rtn.entrySet ()) {
160. Integer key = Entry.getkey ();
162. Person Newperson = Entry.getvalue ();
164. System.out.println ("key:" +key+"," +newperson.getid () +"," +newperson.getname () ");
166. }
168. }
174. public static void Main (string[] args) {
176. Objecttojson ();
178. System.out.println ("****************************");
180. Listtojson ();
182. System.out.println ("****************************");
184. Maptojson ();
186. }
194. }

Convert between objects and JSON strings using Google's Gson