Google框架-Gson

Android 4.0

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Google框架-Gson

Gson的Jar包：

源码：

文档：

Gson核心类
创建：
1、Gson创建一个类
Gson gson = new Gson(); // Or use new GsonBuilder().create();

2、GsonBuilder创建一个可选的类

Gson gson = new GsonBuilder()

.registerTypeAdapter(Id.class, new IdTypeAdapter())

.enableComplexMapKeySerialization()

.serializeNulls()

.setDateFormat(DateFormat.LONG)

.setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE)

.setPrettyPrinting()

.setVersion(1.0)

.create();

3、没有参数化的类型序列化和反序列化

Gson gson = new Gson(); // Or use new GsonBuilder().create();

MyType target = new MyType();

String json = gson.toJson(target); // serializes target to Json

MyType target2 = gson.fromJson(json, MyType.class); // deserializes json into target2

4、有参数化的序列化和反序列化

Type listType = new TypeToken<List<String>>() {}.getType();

List<String> target = new LinkedList<String>();

target.add("blah");

Gson gson = new Gson();

String json = gson.toJson(target, listType);

List<String> target2 = gson.fromJson(json, listType);

一、Gson序列化：把Java对象转化成JSON格式的文本

类型一：JavaBean

类型二：List<JavaBean>

类型三:List<String>

类型四:List<Map<String,Object>>

Gson将上面的四种数据对象转换成json字符串的方法都是一样的

public static String toJson(Object obj){

Gson gson = new Gson();

String json = gson.toJson(obj);

return json;

}

二、Gson反序列化：
1、类型一：JavaBean：Gson将json字符串转化成JavaBean对象

//这里将javabean转化成json字符串

Person person = new Person("香港","刘德华",1001);

String jsonString = gson.toJson(person);

//这里将json字符串转化成javabean对象,

Gson gson = new Gson();

person = gson.fromJson(jsonString,Person.class);

2、类型二：List<JavaBean>：将json字符串转化成List<JavaBean>对象

Person person1 = new Person("香港","刘德华",1001);

Person person2 = new Person("韩国","宋慧乔",1002);

List<Person> persons = new ArrayList<Person>();

persons.add(person1);

persons.add(person2);

//这里将lsit<javabean>转化成json字符串

String jsonString = gson.toJson(persons);

//解析json字符串

Gson gson = new Gson();

List<Person> persons2 = gson.fromJson(jsonString, new TypeToken<List<Person>>(){}.getType());

3、类型三：List<String>：将json字符串转化成List<String>对象

List<String> list = new ArrayList<String>();

list.add("gson1");

list.add("gson2");

list.add("gson3");

String jsonString = gson.toJson(list);

//解析json字符串

Gson gson = new Gson();

List<String> list2 = gson.fromJson(jsonString, new TypeToken<List<String>>(){}.getType());

4、类型四：List<Map<String,Object>>：将json字符串转化成List<Map<String,Object>>对象

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

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

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

Map<String,Object> map2 = new HashMap<String,Object>();

map2.put("key1", 1);

map2.put("key2", 2);

List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();

list.add(map);

list.add(map2);

Gson gson = new Gson();

String jsonString = gson.toJson(list);

//解析json字符串

List<Map<String,Object>> list2 = gson.fromJson(jsonString, new TypeToken<List<Map<String,Object>>>(){}.getType());

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