详解Gson使用(四)Map对象转化

墨蓝 2022-05-13 21:09 1824阅读 0赞

项目地址：

Github：[https://github.com/smileysx/GsonTest][https_github.com_smileysx_GsonTest]

Oschina：[https://git.oschina.net/ysx\_xx/GsonText][https_git.oschina.net_ysx_xx_GsonText]

详解Gson使用(一)简单对象转化

[http://blog.csdn.net/a249900679/article/details/51385913][http_blog.csdn.net_a249900679_article_details_51385913]

详解Gson使用(二)带泛型的List转化

[http://blog.csdn.net/a249900679/article/details/51386028][http_blog.csdn.net_a249900679_article_details_51386028]

详解Gson使用(三)使用注解

[http://blog.csdn.net/a249900679/article/details/51386509][http_blog.csdn.net_a249900679_article_details_51386509]

详解Gson使用(四)Map对象转化  
[http://blog.csdn.net/a249900679/article/details/51386660][http_blog.csdn.net_a249900679_article_details_51386660]  
详解Gson使用(五)实现百度翻译功能

[http://blog.csdn.net/a249900679/article/details/51386727][http_blog.csdn.net_a249900679_article_details_51386727]

![70][]

![70 1][]

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。

结果为：

![SouthEast][]

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：

![SouthEast 1][]

2.      Map<Object, String>类型的转换：

结果为：

![SouthEast 2][]

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：

![SouthEast 3][]

3. Map<String, Object>类型的转换：

结果为：

![SouthEast 4][]

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：

![SouthEast 5][]

[https_github.com_smileysx_GsonTest]: https://github.com/smileysx/GsonTest
[https_git.oschina.net_ysx_xx_GsonText]: https://git.oschina.net/ysx_xx/GsonText
[http_blog.csdn.net_a249900679_article_details_51385913]: http://blog.csdn.net/a249900679/article/details/51385913
[http_blog.csdn.net_a249900679_article_details_51386028]: http://blog.csdn.net/a249900679/article/details/51386028
[http_blog.csdn.net_a249900679_article_details_51386509]: http://blog.csdn.net/a249900679/article/details/51386509
[http_blog.csdn.net_a249900679_article_details_51386660]: http://blog.csdn.net/a249900679/article/details/51386660
[http_blog.csdn.net_a249900679_article_details_51386727]: http://blog.csdn.net/a249900679/article/details/51386727
[70]: /images/20220514/12778299f13947ef919bde767e782a89.png
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