Sorting Map Based on the Value(value contains Bean, sorting map based on the Bean's property value)

A map contains values as bean's object, if one wants to sort map based on the value of the bean's property.

Following code snippet demonstrate the way to sort a map based on the value having bean object having property as name. There is a bean named TestBean having properties like name, age and address. A map contains value as object of TestBean. This map is sorted based on the value of bean's name property.


import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;


public class BeanUtility{


public static void main(String [] args){

//Creating map object.
 Map mapObj=new HashMap();
 
//Create bean object and put it into the map.
 TestBean bean=new TestBean();
 bean.setName("Bac");
 bean.setAge(25);
 bean.setAddress("delhi");
 mapObj.put("one", bean); 

 TestBean bean2=new TestBean();
 bean2.setName("Cab");
 bean2.setAge(24);
 bean2.setAddress("NCR");
 mapObj.put("two", bean2); 
 
 TestBean bean3=new TestBean();
 bean3.setName("Aac");
 bean3.setAge(23);
 bean3.setAddress("Gurgaon");
 mapObj.put("three", bean3); 

//Sort Map
 Map sortedMap=sortMapByValue(mapObj);
 

//Print Map Values
 printMap(sortedMap);
}

// Method to sort Map.
private static Map<String, TestBean> sortMapByValue(Map<String, TestBean> unsortMap) {
   
//Convert Map to LinkList
      List<Map.Entry<String, TestBean>> listObj = new LinkedList<Map.Entry<String, TestBean>>        (unsortMap.entrySet());

// Sort list with comparator
       Collections.sort(listObj, new Comparator<Map.Entry<String, TestBean>>() {
public int compare(Map.Entry<String, TestBean> object1, Map.Entry<String, TestBean> object2) {
//compare name property's value.
    return ((TestBean) object1.getValue()).getName().compareTo(((TestBean) object2.getValue()).getName());
}
});

//Fill sorted list into LinkedHashMap.
    Map<String, TestBean> objLinkHashMap = new LinkedHashMap<String, TestBean>();
    for (Iterator<Map.Entry<String, TestBean>> itrator = listObj.iterator(); itrator.hasNext();) {
Map.Entry<String, TestBean> entry = itrator.next();
objLinkHashMap.put(entry.getKey(), entry.getValue());
}
return objLinkHashMap;
}

// Method to print Map Values.
private static void printMap(Map objMap){

Collection<TestBean> collection=objMap.values();
Iterator<TestBean> itr=collection.iterator();
while(itr.hasNext()){
TestBean bean=itr.next();
System.out.println("name: "+bean.getName()+"  Address: "+bean.getAddress()+"  age: "+bean.getAge());
}
}
}


// Bean 
class TestBean{

private String name ;
private String address;
private int age;

public String getName() {
return name;
}

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

public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
}

public int getAge() {
return age;
}

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

public TestBean(){

}
}


OUTPUT: