详解Gson使用(四)Map对象转化

来源：互联网发布：做奥数题的软件编辑：程序博客网时间：2024/05/29 13:00

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.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

详解Gson使用(三)使用注解

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
详解Gson使用(五)实现百度翻译功能

http://blog.csdn.net/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。

private String seven() {Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();Map<String, String> map = new HashMap<String, String>();map.put("key1", "value1");map.put("key2", "value2");map.put("key3", "value3");return gson2.toJson(map);}

结果为：

把json数据转换为Map<String, String>：

private String seven() {Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();Map<String, String> map = new HashMap<String, String>();map.put("key1", "value1");map.put("key2", "value2");map.put("key3", "value3");String jsonString = gson.toJson(map);Type type = new TypeToken<Map<String, String>>() {}.getType();Map<String, String> map2 = gson2.fromJson(jsonString, type);String showString = "";for (String keyString : map2.keySet()) {showString += keyString + ":" + map2.get(keyString) + "\n-----\n";}showString += "----------------------\n";return showString;}

结果为：

2. Map<Object, String>类型的转换：

private String eight() {Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();Map<ToJsonBeanOne, String> map = new LinkedHashMap<ToJsonBeanOne, String>();map.put(new ToJsonBeanOne(1, "小熊1", 21), "value1");map.put(new ToJsonBeanOne(2, "小熊2", 21), "value2");map.put(new ToJsonBeanOne(3, "小熊3", 21), "value3");return gson2.toJson(map);}

结果为：

把json数据转换为Map<Object, String>：

private String eight() {Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();Map<ToJsonBeanOne, String> map = new LinkedHashMap<ToJsonBeanOne, String>();map.put(new ToJsonBeanOne(1, "小熊1", 21), "value1");map.put(new ToJsonBeanOne(2, "小熊2", 21), "value2");map.put(new ToJsonBeanOne(3, "小熊3", 21), "value3");String jsonString = gson2.toJson(map);Type type = new TypeToken<Map<ToJsonBeanOne, String>>() {}.getType();Map<ToJsonBeanOne, String> map2 = gson.fromJson(jsonString, type);String showString = "";for (ToJsonBeanOne beanOne : map2.keySet()) {showString += "key:\n" + beanOne.toString() + "value:" + map2.get(beanOne) + "\n-----\n";}showString += "----------------------\n";return showString;}

结果为：

3. Map<String, Object>类型的转换：

private String nine() {Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();Map<String, ToJsonBeanOne> map = new LinkedHashMap<String, ToJsonBeanOne>();map.put("key1", new ToJsonBeanOne(1, "小熊1", 21));map.put("key2", new ToJsonBeanOne(2, "小熊2", 21));map.put("key3", new ToJsonBeanOne(3, "小熊3", 21));return gson2.toJson(map);}

结果为：

把json数据转换为Map<String, Object>：

private String nine() {Gson gson2 = new GsonBuilder().enableComplexMapKeySerialization().create();Map<String, ToJsonBeanOne> map = new LinkedHashMap<String, ToJsonBeanOne>();map.put("key1", new ToJsonBeanOne(1, "小熊1", 21));map.put("key2", new ToJsonBeanOne(2, "小熊2", 21));map.put("key3", new ToJsonBeanOne(3, "小熊3", 21));String jsonString = gson2.toJson(map);Type type = new TypeToken<Map<String, ToJsonBeanOne>>() {}.getType();Map<String, ToJsonBeanOne> map2 = gson.fromJson(jsonString, type);String showString = "";for (String keyString : map2.keySet()) {showString += "key:\n" + keyString + "\nvalue:\n" + map2.get(keyString).toString() + "-----\n";}showString += "----------------------\n";return showString;}

结果为：

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