How to get all node names from XML in java

This code logic will help to get all the node names including child nodes from the XML file.

Parsing a below sample XML file:

<USER>
<NAME>Gopal Aggarwal</NAME>
<AGE>26</AGE>

<ADDRESS>
        <CITY> Bangalore</CITY>
        <STATE>Karnataka</STATE>
</ADDRESS>
</USER>

I am create a Set of unique node and print the output in the end.

package com.info.gopal.xml.parsing;

import java.io.File;
import java.io.IOException;

import java.util.LinkedHashSet;
import java.util.Set;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import org.xml.sax.SAXException;


public class ReadAndParse {


    public static void main(String[] args) throws ParserConfigurationException,
                                                  SAXException, IOException {
        File inputFile = new File("File Location");
        DocumentBuilderFactory dbfact = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder = dbfact.newDocumentBuilder();
        Document doc = dBuilder.parse(inputFile);
        doc.getDocumentElement().normalize();
        NodeList list = doc.getDocumentElement().getChildNodes();
        //Set with node names
        Set<String> nodeSet = new LinkedHashSet<String>();
        nodeSet = getAllNodeName(list,nodeSet); 
        //Printing node name
        for(String node : nodeSet){
            System.out.println(node);
        }
    }

    private static Set<String> getAllNodeName(NodeList list,Set<String> nodeSet) {
        for (int i = 0; i < list.getLength(); i++) {
            Node node = list.item(i);
            if (node.getNodeType() == node.ELEMENT_NODE && node.getNodeType() != node.COMMENT_NODE) {
                nodeSet.add(node.getNodeName());
                if(node.getChildNodes().getLength() > 1){
                    nodeSet = getAllNodeName(node.getChildNodes(),nodeSet);
                }
            }
        }
        return nodeSet;
    }
}


Output :

NAME
AGE
ADDRESS
CITY
STATE

*Comments and feedback are most welcomed, Thanks.

Create and Parse JSON using jackson in java

Required JSON String with Array:

{"NAME":"USER","AGE":25,"COUNTRY":"INDIA",
  "ADDRESS": [{"STREET":"xys","CITY":"Bangalore","POSTAL CODE":54321}]
}


CreateJson class having logic for creating and parsing JSON

import java.util.ArrayList;
import java.util.List;

public class CreateJson {

    public static void main(String[] args) {

        UserBean userData = new UserBean();
        userData.setName("USER");
        userData.setAge(25);
        userData.setCountry("INDIA");

        AddressBean address = new AddressBean();
        address.setCity("Bangalore");
        address.setPostalCode(54321);
        address.setStreet("xys");
        List<AddressBean> addressList = new ArrayList<AddressBean>();
        addressList.add(address);
       
        userData.setAddressList(addressList);
        String jsonString = JsonUtil.getJSONString(userData);
        System.out.println(jsonString);
       
        //Method Call to Parse JsonString
        parseMyJsonString(jsonString);

    }

    private static void parseMyJsonString(String jsonString) {
        UserBean userBean = JsonUtil.fromJsonToObject(jsonString);
        System.out.println(userBean.getAge());
        List<AddressBean> addressList = userBean.getAddressList();

        for (AddressBean list : addressList) {
            System.out.println("City " + list.getCity());
            System.out.println("Postal Code " + list.getPostalCode());
        }
    }
}

1. Create AddressBean.java


import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.map.annotate.JsonSerialize;

@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL)
public class AddressBean {
   
    @JsonProperty("STREET")
    private String street = null;
    @JsonProperty("CITY")
    private String city = null;
    @JsonProperty("POSTAL CODE")
    private int postalCode;
   
    public AddressBean(){
       
    }

    public void setStreet(String street) {
        this.street = street;
    }

    public String getStreet() {
        return street;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getCity() {
        return city;
    }

    public void setPostalCode(int postalCode) {
        this.postalCode = postalCode;
    }

    public int getPostalCode() {
        return postalCode;
    }
}

2. Create a UserBean.java


import java.util.List;
import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.map.annotate.JsonSerialize;

@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL)
public class UserBean {
  
   @JsonProperty("NAME")
   private String name = null;
    @JsonProperty("AGE")
   private int age = 0;
    @JsonProperty("COUNTRY")
   private String country = null;
   //List of AddressBean
   @JsonProperty("ADDRESS")
   private List<AddressBean> addressList = null;
  
   public UserBean(){
      
   }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getAge() {
        return age;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String getCountry() {
        return country;
    }

    public void setAddressList(List<AddressBean> addressList) {
        this.addressList = addressList;
    }

    public List<AddressBean> getAddressList() {
        return addressList;
    }
}

3. Create a Util Class having logic for parsing and creating JSON of UserBean object

import java.io.IOException;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;

public final class JsonUtil {

    /**
     * Creates a JSON String
     * @param bean
     * @return String
     */
    public static String getJSONString(UserBean bean) {
        String jsonString = null;
        try {
            jsonString = createObjectMapper().writeValueAsString(bean);
        } catch (JsonGenerationException e) {
            e.printStackTrace();
        } catch (JsonMappingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return jsonString;
    }

    /**
     * Parse Json string to UserBean Object
     * @param json
     * @return UserBean
     */
    public static UserBean fromJsonToObject(String json) {
        UserBean responseObj = null;
        try {
            responseObj = createObjectMapper().readValue(json, UserBean.class);
        } catch (Exception exception) {
            exception.printStackTrace();
        }

        return responseObj;
    }

    /**
     * @return ObjectMapper
     */
    private static ObjectMapper createObjectMapper() {
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationConfig.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY,
                         true);
        mapper.configure(DeserializationConfig.Feature.USE_JAVA_ARRAY_FOR_JSON_ARRAY,
                         true);
        mapper.configure(DeserializationConfig.Feature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT,
                         true);
        mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS,
                         true);

        return mapper;
    }
}

*Using jackson-all-1.9.0.jar

*Comments and feedback are most welcomed, Thanks.

Creating and parsing JSON using Json-simple

1. Simple JSON string creation.

Requirement: {"NAME":"USER","AGE":25,"COUNTRY":"INDIA"}

    public static void main(String[] args) {
        JSONObject createUserJson = new JSONObject();
        createUserJson.put("NAME", "GOPAL");
        createUserJson.put("AGE", 25);
        createUserJson.put("COUNTRY", "INDIA");
       
        String jsonString =  JSONValue.toJSONString(createUserJson);
        System.out.println(jsonString);       
    }

2. JSON creation with Array

Requirement:  
{"NAME":"USER","AGE":25,"COUNTRY":"INDIA",
    "ADDRESS" : [ {"STREET":"xyz", "POSTAL CODE":"654321","CITY":"BANGALORE"} ,
                               {"STREET":"abc", "POSTAL CODE":"987654","CITY":"BANGALORE"}
                             ]                              
}


public static void main(String[] args) {
        JSONObject createUserJson = new JSONObject();
        createUserJson.put("NAME", "GOPAL");
        createUserJson.put("AGE", 25);
        createUserJson.put("COUNTRY", "INDIA");
        
        List<Map> jsonArray = new ArrayList<Map>();
        Map<String, String> streetXYZ = new HashMap<String, String>();
        streetXYZ.put("STREET", "xyz");
        streetXYZ.put("POSTAL CODE", "654321");
        streetXYZ.put("CITY", "BANGALORE");

        Map<String, String> streetABC = new HashMap<String, String>();
        streetABC.put("STREET", "xyz");
        streetABC.put("POSTAL CODE", "654321");
        streetABC.put("CITY", "BANGALORE");

        jsonArray.add(streetXYZ);
        jsonArray.add(streetABC);
        createUserJson.put("ADDRESS", jsonArray);
 
        String jsonString =  JSONValue.toJSONString(createUserJson);
        System.out.println(jsonString);       
    }

3. Parsing JSON String - Example is parsing above JSON created.

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

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

private static void parsingJsonString(String jsonString) {
        JSONParser parser = new JSONParser();
        try {
            JSONObject jsonObject = (JSONObject)parser.parse(jsonString);
            String name = (String)jsonObject.get("NAME");
            System.out.println(name);
           
            JSONArray addressArray = (JSONArray)jsonObject.get("ADDRESS");
            for (int i = 0; i < addressArray.size(); i++) {
                Object arrayObj = parser.parse(addressArray.get(i).toString());
                JSONObject jsonArrayObject = (JSONObject)arrayObj;
                System.out.println("Street " + jsonArrayObject.get("STREET"));
                System.out.println("Postal Code " +
                                   jsonArrayObject.get("POSTAL CODE"));
                System.out.println("City " + jsonArrayObject.get("CITY"));
                System.out.println("-------------------------------------");
            }

        } catch (ParseException e) {
            e.getMessage();
        }  
}

*Using Json-simple-1.1.1.jar

*Comments and feedback are most welcomed, Thanks.