Ich verwende Java und habe einen String, der JSON ist:

{
"name" : "abc" ,
"email id " : ["[email protected]","[email protected]","[email protected]"]
}

Dann meine Karte in Java:

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

Ich möchte alle Daten aus dem JSONObject in dieser HashMap speichern.

Kann jemand Code dafür bereitstellen? Ich möchte die org.jsonBibliothek nutzen.

Ich habe diesen Code vor einigen Tagen durch Rekursion geschrieben.

public static Map<String, Object> jsonToMap(JSONObject json) throws JSONException {
    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.keys();
    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) throws JSONException {
    List<Object> list = new ArrayList<Object>();
    for(int i = 0; i < array.length(); 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;
}

Mit GSon können Sie Folgendes tun:

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

Hoffe das wird funktionieren, versuche das:

import com.fasterxml.jackson.databind.ObjectMapper;
Map<String, Object> response = new ObjectMapper().readValue(str, HashMap.class);

str, dein JSON String

So einfach ist das, wenn Sie eine E-Mail-Adresse wünschen:

String emailIds = response.get("email id").toString();

Hier ist Vikas Code, der auf JSR 353 portiert ist:

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;
    }
}

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

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;


public class JsonUtils {

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

        if(json != null) {
            retMap = toMap(json);
        }
        return retMap;
    }

    public static Map<String, Object> toMap(JSONObject object) {
        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;
    }
}

Versuchen Sie diesen Code:

 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();
                }

Konvertieren eines JSON-Strings in Map

public static Map<String, Object> jsonString2Map( String jsonString ) throws JSONException{
        Map<String, Object> keys = new HashMap<String, Object>(); 

        org.json.JSONObject jsonObject = new org.json.JSONObject( jsonString ); // HashMap
        Iterator<?> keyset = jsonObject.keys(); // HM

        while (keyset.hasNext()) {
            String key =  (String) keyset.next();
            Object value = jsonObject.get(key);
            System.out.print("\n Key : "+key);
            if ( value instanceof org.json.JSONObject ) {
                System.out.println("Incomin value is of JSONObject : ");
                keys.put( key, jsonString2Map( value.toString() ));
            }else if ( value instanceof org.json.JSONArray) {
                org.json.JSONArray jsonArray = jsonObject.getJSONArray(key);
                //JSONArray jsonArray = new JSONArray(value.toString());
                keys.put( key, jsonArray2List( jsonArray ));
            } else {
                keyNode( value);
                keys.put( key, value );
            }
        }
        return keys;
    }

Konvertieren des JSON-Arrays in eine Liste

public static List<Object> jsonArray2List( JSONArray arrayOFKeys ) throws JSONException{
        System.out.println("Incoming value is of JSONArray : =========");
        List<Object> array2List = new ArrayList<Object>();
        for ( int i = 0; i < arrayOFKeys.length(); i++ )  {
            if ( arrayOFKeys.opt(i) instanceof JSONObject ) {
                Map<String, Object> subObj2Map = jsonString2Map(arrayOFKeys.opt(i).toString());
                array2List.add(subObj2Map);
            }else if ( arrayOFKeys.opt(i) instanceof JSONArray ) {
                List<Object> subarray2List = jsonArray2List((JSONArray) arrayOFKeys.opt(i));
                array2List.add(subarray2List);
            }else {
                keyNode( arrayOFKeys.opt(i) );
                array2List.add( arrayOFKeys.opt(i) );
            }
        }
        return array2List;      
    }

JSON in einem beliebigen Format anzeigen

public static void displayJSONMAP( Map<String, Object> allKeys ) throws Exception{
        Set<String> keyset = allKeys.keySet(); // HM$keyset
        if (! keyset.isEmpty()) {
            Iterator<String> keys = keyset.iterator(); // HM$keysIterator
            while (keys.hasNext()) {
                String key = keys.next();
                Object value = allKeys.get( key );
                if ( value instanceof Map ) {
                    System.out.println("\n Object Key : "+key);
                        displayJSONMAP(jsonString2Map(value.toString()));                   
                }else if ( value instanceof List ) {
                    System.out.println("\n Array Key : "+key);
                    JSONArray jsonArray = new JSONArray(value.toString());
                    jsonArray2List(jsonArray);
                }else {
                    System.out.println("key : "+key+" value : "+value);
                }
            }
        }   

    }

Google.gson zu HashMap.

Sie können auch die Jackson API dafür verwenden:

    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);

Sie können jede konvertieren JSONzu mapmithilfe von Jackson Bibliothek wie folgt:

String json = "{\r\n\"name\" : \"abc\" ,\r\n\"email id \" : [\"[email protected]\",\"[email protected]\",\"[email protected]\"]\r\n}";
ObjectMapper mapper = new ObjectMapper();
Map<String, Object> map = new HashMap<String, Object>();
// convert JSON string to Map
map = mapper.readValue(json, new TypeReference<Map<String, Object>>() {});
System.out.println(map);

Maven-Abhängigkeiten für Jackson :

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.5.3</version>
    <scope>compile</scope>
</dependency>

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.5.3</version>
    <scope>compile</scope>
</dependency>

Hoffe das wird helfen. Viel Spaß beim Codieren :)

Mit Jackson konvertieren:

JSONObject obj = new JSONObject().put("abc", "pqr").put("xyz", 5);

Map<String, Object> map = new ObjectMapper().readValue(obj.toString(), new TypeReference<Map<String, Object>>() {});

Sie können die Google Gson-Bibliothek verwenden, um ein JSON-Objekt zu konvertieren.

https://code.google.com/p/google-gson/

Andere Bibliotheken wie Jackson sind ebenfalls verfügbar.

Dadurch wird es nicht in eine Karte konvertiert. Aber Sie können alles tun, was Sie wollen.

Wenn Sie Rekursion hassen - verwenden Sie einen Stack und javax.json, um einen Json-String in eine Liste von Maps zu konvertieren:

import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Stack;
import javax.json.Json;
import javax.json.stream.JsonParser;

public class TestCreateObjFromJson {
    public static List<Map<String,Object>> extract(InputStream is) {
        List extracted = new ArrayList<>();
        JsonParser parser = Json.createParser(is);

        String nextKey = "";
        Object nextval = "";
        Stack s = new Stack<>();
        while(parser.hasNext()) {
            JsonParser.Event event = parser.next();
            switch(event) {
                case START_ARRAY :  List nextList = new ArrayList<>();
                                    if(!s.empty()) {
                                        // If this is not the root object, add it to tbe parent object
                                        setValue(s,nextKey,nextList);
                                    }
                                    s.push(nextList);
                                    break;
                case START_OBJECT : Map<String,Object> nextMap = new HashMap<>();
                                    if(!s.empty()) {
                                        // If this is not the root object, add it to tbe parent object
                                        setValue(s,nextKey,nextMap);
                                    }
                                    s.push(nextMap);
                                    break;
                case KEY_NAME : nextKey = parser.getString();
                                break;
                case VALUE_STRING : setValue(s,nextKey,parser.getString());
                                    break;
                case VALUE_NUMBER : setValue(s,nextKey,parser.getLong());
                                    break;
                case VALUE_TRUE :   setValue(s,nextKey,true);
                                    break;
                case VALUE_FALSE :  setValue(s,nextKey,false);
                                    break;
                case VALUE_NULL :   setValue(s,nextKey,"");
                                    break;
                case END_OBJECT :   
                case END_ARRAY  :   if(s.size() > 1) {
                                        // If this is not a root object, move up
                                        s.pop(); 
                                    } else {
                                        // If this is a root object, add ir ro rhw final 
                                        extracted.add(s.pop()); 
                                    }
                default         :   break;
            }
        }

        return extracted;
    }

    private static void setValue(Stack s, String nextKey, Object v) {
        if(Map.class.isAssignableFrom(s.peek().getClass()) ) ((Map)s.peek()).put(nextKey, v);
        else ((List)s.peek()).add(v);
    }
}

Kurz und nützlich:

/**
 * @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;
}

Vielen Dank an @Vikas Gupta .

Ich habe gerade Gson benutzt

HashMap<String, Object> map = new Gson().fromJson(json.toString(), HashMap.class);

Der folgende Parser liest eine Datei, analysiert sie JsonElementmithilfe der Google- JsonParser.parseMethode in eine generische und konvertiert dann alle Elemente im generierten JSON in ein natives Java List<object>oder Map<String, Object>.

Hinweis : Der folgende Code basiert weg von Vikas Gupta ‚s Antwort .

GsonParser.java

import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import com.google.gson.GsonBuilder;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonPrimitive;

public class GsonParser {
    public static void main(String[] args) {
        try {
            print(loadJsonArray("data_array.json", true));
            print(loadJsonObject("data_object.json", true));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void print(Object object) {
        System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(object).toString());
    }

    public static Map<String, Object> loadJsonObject(String filename, boolean isResource)
            throws UnsupportedEncodingException, FileNotFoundException, JsonIOException, JsonSyntaxException, MalformedURLException {
        return jsonToMap(loadJson(filename, isResource).getAsJsonObject());
    }

    public static List<Object> loadJsonArray(String filename, boolean isResource)
            throws UnsupportedEncodingException, FileNotFoundException, JsonIOException, JsonSyntaxException, MalformedURLException {
        return jsonToList(loadJson(filename, isResource).getAsJsonArray());
    }

    private static JsonElement loadJson(String filename, boolean isResource) throws UnsupportedEncodingException, FileNotFoundException, JsonIOException, JsonSyntaxException, MalformedURLException {
        return new JsonParser().parse(new InputStreamReader(FileLoader.openInputStream(filename, isResource), "UTF-8"));
    }

    public static Object parse(JsonElement json) {
        if (json.isJsonObject()) {
            return jsonToMap((JsonObject) json);
        } else if (json.isJsonArray()) {
            return jsonToList((JsonArray) json);
        }

        return null;
    }

    public static Map<String, Object> jsonToMap(JsonObject jsonObject) {
        if (jsonObject.isJsonNull()) {
            return new HashMap<String, Object>();
        }

        return toMap(jsonObject);
    }

    public static List<Object> jsonToList(JsonArray jsonArray) {
        if (jsonArray.isJsonNull()) {
            return new ArrayList<Object>();
        }

        return toList(jsonArray);
    }

    private static final Map<String, Object> toMap(JsonObject object) {
        Map<String, Object> map = new HashMap<String, Object>();

        for (Entry<String, JsonElement> pair : object.entrySet()) {
            map.put(pair.getKey(), toValue(pair.getValue()));
        }

        return map;
    }

    private static final List<Object> toList(JsonArray array) {
        List<Object> list = new ArrayList<Object>();

        for (JsonElement element : array) {
            list.add(toValue(element));
        }

        return list;
    }

    private static final Object toPrimitive(JsonPrimitive value) {
        if (value.isBoolean()) {
            return value.getAsBoolean();
        } else if (value.isString()) {
            return value.getAsString();
        } else if (value.isNumber()){
            return value.getAsNumber();
        }

        return null;
    }

    private static final Object toValue(JsonElement value) {
        if (value.isJsonNull()) {
            return null;
        } else if (value.isJsonArray()) {
            return toList((JsonArray) value);
        } else if (value.isJsonObject()) {
            return toMap((JsonObject) value);
        } else if (value.isJsonPrimitive()) {
            return toPrimitive((JsonPrimitive) value);
        }

        return null;
    }
}

FileLoader.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Scanner;

public class FileLoader {
    public static Reader openReader(String filename, boolean isResource) throws UnsupportedEncodingException, FileNotFoundException, MalformedURLException {
        return openReader(filename, isResource, "UTF-8");
    }

    public static Reader openReader(String filename, boolean isResource, String charset) throws UnsupportedEncodingException, FileNotFoundException, MalformedURLException {
        return new InputStreamReader(openInputStream(filename, isResource), charset);
    }

    public static InputStream openInputStream(String filename, boolean isResource) throws FileNotFoundException, MalformedURLException {
        if (isResource) {
            return FileLoader.class.getClassLoader().getResourceAsStream(filename);
        }

        return new FileInputStream(load(filename, isResource));
    }

    public static String read(String path, boolean isResource) throws IOException {
        return read(path, isResource, "UTF-8");
    }

    public static String read(String path, boolean isResource, String charset) throws IOException {
        return read(pathToUrl(path, isResource), charset);
    }

    @SuppressWarnings("resource")
    protected static String read(URL url, String charset) throws IOException {
        return new Scanner(url.openStream(), charset).useDelimiter("\\A").next();
    }

    protected static File load(String path, boolean isResource) throws MalformedURLException {
        return load(pathToUrl(path, isResource));
    }

    protected static File load(URL url) {
        try {
            return new File(url.toURI());
        } catch (URISyntaxException e) {
            return new File(url.getPath());
        }
    }

    private static final URL pathToUrl(String path, boolean isResource) throws MalformedURLException {
        if (isResource) {
            return FileLoader.class.getClassLoader().getResource(path);
        }

        return new URL("file:/" + path);
    }
}

Dies ist eine alte Frage und bezieht sich vielleicht immer noch auf jemanden. Angenommen
, Sie haben die Zeichenfolge HashMap hashund JsonObject jsonObject.

1) Definieren Sie die Schlüsselliste.
Beispiel:

ArrayList<String> keyArrayList = new ArrayList<>();  
keyArrayList.add("key0");   
keyArrayList.add("key1");  

2) Erstellen Sie foreach - Schleife, fügen Sie hashaus jsonObjectmit:

for(String key : keyArrayList){  
    hash.put(key, jsonObject.getString(key));
}

Das ist mein Ansatz, hoffe es beantwortet die Frage.

Stellen Sie sich vor, Sie haben eine Liste mit E-Mails wie unten. nicht auf eine Programmiersprache beschränkt,

emailsList = ["[email protected]","[email protected]","[email protected]"]

Es folgt nun JAVA-Code - zum Konvertieren von json in map

JSONObject jsonObj = new JSONObject().put("name","abc").put("email id",emailsList);
Map<String, Object> s = jsonObj.getMap();

Mit json-simple Sie Daten JSON in Map und Map in JSON konvertieren.

try
{
    JSONObject obj11 = new JSONObject();
    obj11.put(1, "Kishan");
    obj11.put(2, "Radhesh");
    obj11.put(3, "Sonal");
    obj11.put(4, "Madhu");

    Map map = new  HashMap();

    obj11.toJSONString();

    map = obj11;

    System.out.println(map.get(1));


    JSONObject obj12 = new JSONObject();

    obj12 = (JSONObject) map;

    System.out.println(obj12.get(1));
}
catch(Exception e)
{
    System.err.println("EROR : 01 :"+e);
}