JSON to HashMap Recursively and JSON to Object in Java | Code Factory
2 min readApr 16, 2020
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JSON to HashMap Recursively
JsonToHashMap.java
package com.codeFactory;import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;import org.codehaus.jettison.json.JSONArray;
import org.codehaus.jettison.json.JSONObject;/**
* @author code.factory
*
*/
public class JsonToHashMap {public static void main(String args[]) throws Exception {
JSONObject jsonObject = new JSONObject(
"{\"A\":\"M1\",\"Data\":[ {\"B\":[{ \"B1\":\"111\",\"B2\":\"Warning \"},{ \"B1\":\"222\",\"B2\":\"Warning \"}],\"C\":[{\"c1\":\"IL2\",\"c2\":\"[0.750183,0.00933380975964486]\"},{\"c1\":\"IL1b\",\"c2\":\"[0.750183,-1.5216938335421]\"}]}]}");
System.out.println(getMap(jsonObject));
}private static Map getMap(JSONObject object) {
Map<String, Object> map = new HashMap<String, Object>();Object jsonObject = null;
String key = null;
Object value = null;try {
Iterator<String> keys = object.keys();
while (keys.hasNext()) {key = null;
value = null;key = keys.next();if (null != key && !object.isNull(key)) {
value = object.get(key);
}if (value instanceof JSONObject) {
map.put(key, getMap((JSONObject) value));
continue;
}if (value instanceof JSONArray) {
JSONArray array = ((JSONArray) value);
List list = new ArrayList();
for (int i = 0; i < array.length(); i++) {
jsonObject = array.get(i);
if (jsonObject instanceof JSONObject) {
list.add(getMap((JSONObject) jsonObject));
} else {
list.add(jsonObject);
}
}
map.put(key, list);
continue;
}map.put(key, value);
}
} catch (Exception e) {
System.out.println(e);
}
return map;
}
}
JSON to Object
JsonToObject.java
package com.codeFactory;import java.io.IOException;
import java.util.ArrayList;
import java.util.List;import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.type.TypeFactory;/**
* @author code.factory
*
*/
public class JsonToObject {public static void main(String[] args) {String json = "[{\"fName\": \"Code\",\"lName\": \"Factory\"},{\"fName\": \"Emp Fname\",\"lName\": \"Emp Lname\"}]";
ObjectMapper mapper = new ObjectMapper();
List<Employee> list = new ArrayList<Employee>();
try {
list = mapper.readValue(json, TypeFactory.defaultInstance().constructCollectionType(List.class, Employee.class));
} catch (JsonParseException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}System.out.println(list);
}}
Employee.java
package com.codeFactory;/**
* @author code.factory
*
*/
public class Employee {private String fName;
private String lName;public String getfName() {
return fName;
}public void setfName(String fName) {
this.fName = fName;
}public String getlName() {
return lName;
}public void setlName(String lName) {
this.lName = lName;
}@Override
public String toString() {
return "Author [fName : " + fName + ", lName : " + lName + "]";
}
}