详解Gson使用(四)Map对象转化

项目地址：

Github：https://github.com/smileysx/GsonTest

Oschina：https://git.oschina.net/ysx_xx/GsonText

 

详解Gson使用(一)简单对象转化

http://blog.youkuaiyun.com/a249900679/article/details/51385913

详解Gson使用(二)带泛型的List转化

http://blog.youkuaiyun.com/a249900679/article/details/51386028

详解Gson使用(三)使用注解

http://blog.youkuaiyun.com/a249900679/article/details/51386509

详解Gson使用(四)Map对象转化
http://blog.youkuaiyun.com/a249900679/article/details/51386660
详解Gson使用(五)实现百度翻译功能

http://blog.youkuaiyun.com/a249900679/article/details/51386727

接下来介绍Map对象与json的相互转换

Map类型的转换就需要用到

 

GsonBuilder().enableComplexMapKeySerialization().create()类生成Gson对象

 

1.      Map<String, String>类型的转换：

这里直接贴关键代码，其他代码可参考前两篇文章，或下载代码。

1. private String seven() {

2. Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();

3. Map<String, String> map = new HashMap<String, String>();

4. map.put("key1", "value1");

5. map.put("key2", "value2");

6. map.put("key3", "value3");

7.  

8. return gson2.toJson(map);

9. }

 

结果为：

把json数据转换为Map<String, String>：

1. private String seven() {

2. Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();

3. Map<String, String> map = new HashMap<String, String>();

4. map.put("key1", "value1");

5. map.put("key2", "value2");

6. map.put("key3", "value3");

7.  

8. String jsonString = gson.toJson(map);

9. Type type = new TypeToken<Map<String, String>>() {}.getType();

10. Map<String, String> map2 = gson2.fromJson(jsonString, type);

11.  

12. String showString = "";

13. for (String keyString : map2.keySet()) {

14. showString += keyString + ":" + map2.get(keyString) + "\n-----\n";

15. }

16.  

17. showString += "----------------------\n";

18. return showString;

19. }

 

结果为：

2.      Map<Object, String>类型的转换：

 

1. private String eight() {

2. Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();

3. Map<ToJsonBeanOne, String> map = new LinkedHashMap<ToJsonBeanOne, String>();

4. map.put(new ToJsonBeanOne(1, "小熊1", 21), "value1");

5. map.put(new ToJsonBeanOne(2, "小熊2", 21), "value2");

6. map.put(new ToJsonBeanOne(3, "小熊3", 21), "value3");

7.  

8. return gson2.toJson(map);

9. }

 

结果为：

把json数据转换为Map<Object, String>：

1. private String eight() {

2. Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();

3. Map<ToJsonBeanOne, String> map = new LinkedHashMap<ToJsonBeanOne, String>();

4. map.put(new ToJsonBeanOne(1, "小熊1", 21), "value1");

5. map.put(new ToJsonBeanOne(2, "小熊2", 21), "value2");

6. map.put(new ToJsonBeanOne(3, "小熊3", 21), "value3");

7.  

8. String jsonString = gson2.toJson(map);

9.  

10. Type type = new TypeToken<Map<ToJsonBeanOne, String>>() {}.getType();

11. Map<ToJsonBeanOne, String> map2 = gson.fromJson(jsonString, type);

12.  

13. String showString = "";

14. for (ToJsonBeanOne beanOne : map2.keySet()) {

15. showString += "key:\n" + beanOne.toString() + "value:" + map2.get(beanOne) + "\n-----\n";

16. }

17.  

18. showString += "----------------------\n";

19. return showString;

20. }

结果为：

 

3. Map<String, Object>类型的转换：

 

1. private String nine() {

2. Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();

3. Map<String, ToJsonBeanOne> map = new LinkedHashMap<String, ToJsonBeanOne>();

4. map.put("key1", new ToJsonBeanOne(1, "小熊1", 21));

5. map.put("key2", new ToJsonBeanOne(2, "小熊2", 21));

6. map.put("key3", new ToJsonBeanOne(3, "小熊3", 21));

7.  

8. return gson2.toJson(map);

9. }

 

 

结果为：

 

把json数据转换为Map<String, Object>：

1. private String nine() {

2. Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();

3. Map<String, ToJsonBeanOne> map = new LinkedHashMap<String, ToJsonBeanOne>();

4. map.put("key1", new ToJsonBeanOne(1, "小熊1", 21));

5. map.put("key2", new ToJsonBeanOne(2, "小熊2", 21));

6. map.put("key3", new ToJsonBeanOne(3, "小熊3", 21));

7. String jsonString = gson2.toJson(map);

8.  

9. Type type = new TypeToken<Map<String, ToJsonBeanOne>>() {}.getType();

10. Map<String, ToJsonBeanOne> map2 = gson.fromJson(jsonString, type);

11.  

12. String showString = "";

13. for (String keyString : map2.keySet()) {

14. showString += "key:\n" + keyString + "\nvalue:\n" + map2.get(keyString).toString() + "-----\n";

15. }

16.  

17. showString += "----------------------\n";

18. return showString;

19. }

 

结果为：