Java 使用jackson反序列化为自定义对象的HashMap

我有以下课程:

import org.codehaus.jackson.annotate.JsonIgnoreProperties;

import org.codehaus.jackson.annotate.JsonProperty;

import java.io.Serializable;

import java.util.HashMap;

@JsonIgnoreProperties(ignoreUnknown = true)

public class Theme implements Serializable {

@JsonProperty

private String themeName;

@JsonProperty

private boolean customized;

@JsonProperty

private HashMap<String, String> descriptor;

//...getters and setters for the above properties

}

当我执行以下代码时:

    HashMap<String, Theme> test = new HashMap<String, Theme>();

Theme t1 = new Theme();

t1.setCustomized(false);

t1.setThemeName("theme1");

test.put("theme1", t1);

Theme t2 = new Theme();

t2.setCustomized(true);

t2.setThemeName("theme2");

t2.setDescriptor(new HashMap<String, String>());

t2.getDescriptor().put("foo", "one");

t2.getDescriptor().put("bar", "two");

test.put("theme2", t2);

String json = "";

ObjectMapper mapper = objectMapperFactory.createObjectMapper();

try {

json = mapper.writeValueAsString(test);

} catch (IOException e) {

e.printStackTrace();

}

产生的json字符串如下所示:

{

"theme2": {

"themeName": "theme2",

"customized": true,

"descriptor": {

"foo": "one",

"bar": "two"

}

},

"theme1": {

"themeName": "theme1",

"customized": false,

"descriptor": null

}

}

我的问题是让上面的json字符串反序列化回一个

HashMap<String, Theme> 

宾语。

我的反序列化代码如下所示:

HashMap<String, Themes> themes =

objectMapperFactory.createObjectMapper().readValue(json, HashMap.class);

它使用正确的键反序列化为HashMap,但不会为这些值创建Theme对象。我不知道在readValue()方法中要指定什么而不是“ HashMap.class”。

任何帮助,将不胜感激。

回答:

你应该创建特定的Map类型并将其提供给反序列化过程:

TypeFactory typeFactory = mapper.getTypeFactory();

MapType mapType = typeFactory.constructMapType(HashMap.class, String.class, Theme.class);

HashMap<String, Theme> map = mapper.readValue(json, mapType);

以上是 Java 使用jackson反序列化为自定义对象的HashMap 的全部内容, 来源链接: utcz.com/qa/431306.html

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