如何使用Jackson将JSON对象转换为Java HashMap?
我的JSON结构如下:如何使用Jackson将JSON对象转换为Java HashMap?,java,json,hashmap,jackson,Java,Json,Hashmap,Jackson,我的JSON结构如下: { "person": { "name": "snoop", "age": "22", "sex": "male" } } public class Person { HashMap<String,String> map; //getters and setters } 像这样的豆子: { "person": { "na
{
"person":
{
"name": "snoop",
"age": "22",
"sex": "male"
}
}
public class Person {
HashMap<String,String> map;
//getters and setters
}
像这样的豆子:
{
"person":
{
"name": "snoop",
"age": "22",
"sex": "male"
}
}
public class Person {
HashMap<String,String> map;
//getters and setters
}
计划是:
String jsonString = "{\"type\": \"Extends\", \"target\": \"application\", \"ret\":\"true\" }";
ObjectMapper mapper = new ObjectMapper();
try {
Map<String, Object> carMap = mapper.readValue(jsonString, new TypeReference<Map<String, Object>>() {
});
for (Entry<String, Object> entry : carMap.entrySet()) {
System.out.println("key=" + entry.getKey() + " and value=" + entry.getValue());
}
} catch (Exception e) {
e.printStackTrace();
}
它不起作用,当Hashmap为空时,会给出NullPointerException
有没有任何方法可以使用Jackson API在Person类中填充Hashmap。在这里使用
JsonAnyGetter
和JsonAnySetter
注释
例如:
Perosn等级:
@JsonRootName("person")
class Person {
HashMap<String, String> map = new HashMap<>();
@JsonAnyGetter
public Map<String, String> getMap() {
return map;
}
@JsonAnySetter
public void setMap(String name, String value) {
map.put(name, value);
}
}
在这里使用
JsonAnyGetter
和JsonAnySetter
注释
例如:
Perosn等级:
@JsonRootName("person")
class Person {
HashMap<String, String> map = new HashMap<>();
@JsonAnyGetter
public Map<String, String> getMap() {
return map;
}
@JsonAnySetter
public void setMap(String name, String value) {
map.put(name, value);
}
}
“不工作”具体如何?它给出空的hasmap值。尝试此链接:可能重复的“不工作”具体如何?它给出空的hasmap值。尝试此链接:可能重复的