< excerpt >gson conversion between a Java nested object and a JSON string

JSON (JavaScript Object Notation) is a lightweight data interchange format with good cross-platform features. In recent years, as XML has become a widely used data format in the C/s architecture. For more information on JSON, refer to the following: http://json.org/json-zh.html

Communication between the server and client using the JSON data format often involves conversions between Java objects and JSON strings. In general, we can use some JSON parsing tools, such as: Gson,fastjson, and so on. Of course, we can also manually parse, but it will be more cumbersome.

The following example describes the use of Gson to convert between Java nested objects and JSON strings.

Mainactivity

[Java]View Plaincopy

2. Package com.example.jsonsample;
6. Import java.util.ArrayList;
10. Import android.app.Activity;
12. Import Android.os.Bundle;
14. Import Android.view.Menu;
16. Import Android.widget.TextView;
20. Import com.example.jsonsample.data.Student;
22. Import Com.example.jsonsample.data.Subject;
24. Import Com.google.gson.Gson;
28. Public class Mainactivity extends Activity {
32. private TextView Mtextview;
38. @Override
40. public void OnCreate (Bundle savedinstancestate) {
42. super.oncreate (savedinstancestate);
44. Setcontentview (R.layout.activity_main);
48. Mtextview = (TextView) Findviewbyid (R.id.mytextview);
52. Gson Gson = new Gson ();
54. //Create a Student object
56. Student originstudent = Getstudent ();
60. //Convert student objects to JSON string
62. String reponse = Gson.tojson (originstudent);
66. //Restore the JSON string to a student object
68. Student newstudent = Gson.fromjson (reponse, Student.   Class);
72. Mtextview.settext (reponse);
74. }
78. Public Student getstudent () {
80. Subject sub1 = new Subject ();
82. Sub1.setsubject_name ("language");
84. Sub1.setteacher_name ("Miss Zhang");
88. Subject sub2 = new Subject ();
90. Sub2.setsubject_name ("mathematics");
92. Sub2.setteacher_name ("Miss Huang");
96. Subject sub3 = new Subject ();
98. Sub3.setsubject_name ("English");
100. Sub3.setteacher_name ("Mr. Lin");
104. arraylist<subject> subjects = new arraylist<subject> ();
106. Subjects.add (SUB1);
108. Subjects.add (SUB2);
110. Subjects.add (SUB3);
114. Student Student = new Student ();
116. Student.setname ("Yang Hui");
118. Student.setsubjects (subjects);
122. return student;
124. }
134. @Override
136. Public Boolean oncreateoptionsmenu (Menu menu) {
138. Getmenuinflater (). Inflate (R.menu.activity_main, menu);
140. return true;
142. }
144. }

Student

[Java]View Plaincopy

2. Package com.example.jsonsample.data;
6. Import java.io.Serializable;
8. Import java.util.ArrayList;
10. /**
12. * Student class, including student name and subject list
14. *
16. * @author Yanghui<[email protected]>
18. */
20. Public class Student implements Serializable {
24. /** 
26. * Serializable
28. */
30. private Static final long serialversionuid = -2689979321936117293l;
34. private String name;
38. private arraylist<subject> subjects;
42. /** 
44. *
46. * @return Name Student names
48. */
50. Public String GetName () {
52. return name;
54. }
58. /** 
60. *
62. * @param name Student names
64. */
66. public void SetName (String name) {
68. this.name = name;
70. }
74. /** 
76. *
78. * @return Subjects Subject List
80. */
82. Public arraylist<subject> getsubjects () {
84. return subjects;
86. }
90. /** 
92. *
94. * @param subjects Subject List
96. */
98. public void Setsubjects (arraylist<subject> subjects) {
100. this.subjects = subjects;
102. }
108. }

Subject

[Java]View Plaincopy

2. Package com.example.jsonsample.data;
6. Import java.io.Serializable;
10. /**
12. * Subject class, including subject name and subject teacher name
14. *
16. * @author Yanghui<[email protected]>
18. */
20. Public class Subject implements serializable{
24. /** 
26. * Serialversionuid
28. */
30. private Static final long serialversionuid = -2574980011831897251l;
34. private String Subject_name;
36. private String Teacher_name;
40. /** 
42. *
44. * @return Subject_name Subject Name
46. */
48. Public String Getsubject_name () {
50. return subject_name;
52. }
56. /** 
58. * @param subject_name Subject Name
60. */
62. public void Setsubject_name (String subject_name) {
64. this.subject_name = subject_name;
66. }
70. /** 
72. *
74. * @return Teacher_name subject Teacher's name
76. */
78. Public String Getteacher_name () {
80. return teacher_name;
82. }
86. /** 
88. *
90. * @param teacher_name subject Teacher's name
92. */
94. public void Setteacher_name (String teacher_name) {
96. this.teacher_name = teacher_name;
98. }
100. }

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< excerpt >gson conversion between a Java nested object and a JSON string