Json字符串到Hashmap.Java[重复]

Question

我试图使用com.fasterxml.jackson.databind.ObjectMapper将json字符串转换为hashmap。

String str = "{\"key\":\"[{\"one\":\"value\"}]\"}";
ObjectMapper mapper = new ObjectMapper();
try {
    HashMap<String, String> map = mapper.readValue(str, HashMap.class);
    System.out.println(map);
} catch (JsonMappingException e) {
    e.printStackTrace();
} catch (JsonProcessingException e) {
    e.printStackTrace();
}

但是得到下面的错误，

com.fasterxml.jackson.core.JsonParseException: Unexpected character ('o' (code 111)): was expecting comma to separate Object entries
 at [Source: (String)"{"key": "[{"one":"value"}]"}"; line: 1, column: 14]
    at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:2391)
    at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:735)
    at com.fasterxml.jackson.core.base.ParserMinimalBase._reportUnexpectedChar(ParserMinimalBase.java:659)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._skipComma(ReaderBasedJsonParser.java:2382)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser.nextFieldName(ReaderBasedJsonParser.java:947)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer._readAndBindStringKeyMap(MapDeserializer.java:594)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:437)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:32)
    at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:323)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4674)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3629)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3597)
    at com.sample.quick.check.one.App.main(App.java:15)

在json字符串中，我希望键和值作为字符串并将它们存储到hashMap中。我不想将值解析为jsonArray。

Answer 1

JSON 字符串无效。如果 key 的值是字符串，则需要转义 \”。这意味着您需要告诉“Java”来转义\字符。

将字符串更改为String str = "{\"key\"：\"[{\\\"one\\\"：\\\"value\\\"}]\"}"；

这意味着：

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.HashMap;

class Scratch {
    public static void main(String[] args) {
        String str = "{\"key\":\"[{\\\"one\\\":\\\"value\\\"}]\"}";
        ObjectMapper mapper = new ObjectMapper();
        try {
            HashMap<String, String> map = mapper.readValue(str, HashMap.class);
            System.out.println(map);
        } catch (JsonMappingException e) {
            e.printStackTrace();
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}