关于字典：使用json字符串创建java映射

Create a java map using json string

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{
"userType":"I",
"classList": [
{
"id": 1,
"name":"c1"
},
{
"id": 2,
"name":"c2"
},
{
"id": 3,
"name":"c3"
}
]
}

如何向上面的示例示例声明和放置值？

使用杰克逊图书馆，

1 2	HashMap<String,Object> map = new ObjectMapper().readValue(jsonString, HashMap.class);

对maven使用此依赖项，

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<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
jackson-core</artifactId>
<version>2.8.7</version>
</dependency>

您需要创建一个Map，并将map和List放入第一个Map：

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public Map<String, Object> createMap() {
Map<String, Object> map = new HashMap<String, Object>();
map.put("userType","I");
List<Map<String, Object>> classList = new ArrayList<Map<String, Object>>();
Map<String, Object> class1 = new HashMap<String, Object>();
class1.put("id", 1);
class1.put("name","c1");
classList.add(class1);

Map<String, Object> class2 = new HashMap<String, Object>();
class1.put("id", 2);
class1.put("name","c2");
classList.add(class2);

Map<String, Object> class3 = new HashMap<String, Object>();
class1.put("id", 3);
class1.put("name","c3");
classList.add(class3);

map.put("classList", classList);
return map;
}