我使用Java,我有一个JSON字符串:

{
"name" : "abc" ,
"email id " : ["abc@gmail.com","def@gmail.com","ghi@gmail.com"]
}

然后是我的Java地图:

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

我想把所有来自JSONObject的数据存储在那个HashMap中。

有人能为此提供代码吗?我想用org。json库。


当前回答

如果你想要无库版本,这里是与regex的解决方案:

public static HashMap<String, String> jsonStringToMap(String inputJsonString) {
    final String regex = "(?:\\\"|\\')(?<key>[\\w\\d]+)(?:\\\"|\\')(?:\\:\\s*)(?:\\\"|\\')?(?<value>[\\w\\s-]*)(?:\\\"|\\')?";
    HashMap<String, String> map = new HashMap<>();
    final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
    final Matcher matcher = pattern.matcher(inputJsonString);

    while (matcher.find()) {
        for (int i = 1; i <= matcher.groupCount(); i++) {
            map.put(matcher.group("key"), matcher.group("value"));
        }
    }
    return map;
}

其他回答

试试下面的代码:

 Map<String, String> params = new HashMap<String, String>();
                try
                {

                   Iterator<?> keys = jsonObject.keys();

                    while (keys.hasNext())
                    {
                        String key = (String) keys.next();
                        String value = jsonObject.getString(key);
                        params.put(key, value);

                    }


                }
                catch (Exception xx)
                {
                    xx.toString();
                }

简单实用:

/**
 * @param jsonThing can be a <code>JsonObject</code>, a <code>JsonArray</code>,
 *                     a <code>Boolean</code>, a <code>Number</code>,
 *                     a <code>null</code> or a <code>JSONObject.NULL</code>.
 * @return <i>Appropriate Java Object</i>, that may be a <code>Map</code>, a <code>List</code>,
 * a <code>Boolean</code>, a <code>Number</code> or a <code>null</code>.
 */
public static Object jsonThingToAppropriateJavaObject(Object jsonThing) throws JSONException {
    if (jsonThing instanceof JSONArray) {
        final ArrayList<Object> list = new ArrayList<>();

        final JSONArray jsonArray = (JSONArray) jsonThing;
        final int l = jsonArray.length();
        for (int i = 0; i < l; ++i) list.add(jsonThingToAppropriateJavaObject(jsonArray.get(i)));
        return list;
    }

    if (jsonThing instanceof JSONObject) {
        final HashMap<String, Object> map = new HashMap<>();

        final Iterator<String> keysItr = ((JSONObject) jsonThing).keys();
        while (keysItr.hasNext()) {
            final String key = keysItr.next();
            map.put(key, jsonThingToAppropriateJavaObject(((JSONObject) jsonThing).get(key)));
        }
        return map;
    }

    if (JSONObject.NULL.equals(jsonThing)) return null;

    return jsonThing;
}

谢谢@Vikas Gupta。

你也可以使用Jackson API:

    final String json = "....your json...";
    final ObjectMapper mapper = new ObjectMapper();
    final MapType type = mapper.getTypeFactory().constructMapType(
        Map.class, String.class, Object.class);
    final Map<String, Object> data = mapper.readValue(json, type);

使用Gson,你可以做以下事情:

Map<String, Object> retMap = new Gson().fromJson(
    jsonString, new TypeToken<HashMap<String, Object>>() {}.getType()
);

以下是移植到JSR 353的Vikas代码:

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.json.JsonArray;
import javax.json.JsonException;
import javax.json.JsonObject;

public class JsonUtils {
    public static Map<String, Object> jsonToMap(JsonObject json) {
        Map<String, Object> retMap = new HashMap<String, Object>();

        if(json != JsonObject.NULL) {
            retMap = toMap(json);
        }
        return retMap;
    }

    public static Map<String, Object> toMap(JsonObject object) throws JsonException {
        Map<String, Object> map = new HashMap<String, Object>();

        Iterator<String> keysItr = object.keySet().iterator();
        while(keysItr.hasNext()) {
            String key = keysItr.next();
            Object value = object.get(key);

            if(value instanceof JsonArray) {
                value = toList((JsonArray) value);
            }

            else if(value instanceof JsonObject) {
                value = toMap((JsonObject) value);
            }
            map.put(key, value);
        }
        return map;
    }

    public static List<Object> toList(JsonArray array) {
        List<Object> list = new ArrayList<Object>();
        for(int i = 0; i < array.size(); i++) {
            Object value = array.get(i);
            if(value instanceof JsonArray) {
                value = toList((JsonArray) value);
            }

            else if(value instanceof JsonObject) {
                value = toMap((JsonObject) value);
            }
            list.add(value);
        }
        return list;
    }
}