In this post, we will learn How to Sort Map based on Values in java?
Here I have shown a couple of cases, In the first case, Map values are Strings, and second case Map values are Custom objects.
Finally, We will also look at Sort Map based on Keys Using Java 8 stream API and Lambda.
Sorting Map based on Values, when Values contains Strings:
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package com.kkjavatutorials.client; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; /** * Sort Map based on Values in java * @author KK JavaTutorials * */ public class SortMapBasedOnValues { public static void main(String[] args) { Map<Integer,String> employeeIdandNameMap = new HashMap<>(); employeeIdandNameMap.put(10234, "Sean"); employeeIdandNameMap.put(10033, "KK"); employeeIdandNameMap.put(11004, "MARK"); employeeIdandNameMap.put(11724, "ANTONY"); employeeIdandNameMap.put(12004, "WEST"); employeeIdandNameMap.put(13234, "BEAN"); employeeIdandNameMap.put(10004, "AK"); System.out.println("Original Map::::"); employeeIdandNameMap.forEach((k,v)->System.out.println(k+"\t"+v)); Set<Entry<Integer, String>> entrySet = employeeIdandNameMap.entrySet(); List<Entry<Integer, String>> list = new ArrayList<>(entrySet); Collections.sort(list, (o1, o2) -> o1.getValue().compareTo(o2.getValue())); System.out.println("Map sorted based on Values::::"); list.forEach(s->{ System.out.println(s.getKey()+"\t"+s.getValue()); }); } } |
Output of the above program:
Original Map::::
10033 KK
13234 BEAN
12004 WEST
10004 AK
10234 Sean
11004 MARK
11724 ANTONY
Map sorted based on Values::::
10004 AK
11724 ANTONY
13234 BEAN
10033 KK
11004 MARK
10234 Sean
12004 WEST
Sorting Map based on Values, when Values contains Custom Objects:
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package com.kkjavatutorials.client; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import com.kkjavatutorials.model.Employee; /** * Sort Map based on Values(Custom Object) in java * @author KK JavaTutorials * */ public class SortMapBasedOnValuesWithCustomObjects { public static void main(String[] args) { Map<Integer,Employee> employeeIdandNameMap = new HashMap<>(); employeeIdandNameMap.put(12301, new Employee(12301, "Sean", "IT", 30000.0)); employeeIdandNameMap.put(12303, new Employee(12303, "Abhay", "Finance", 10000.0)); employeeIdandNameMap.put(10304, new Employee(10304, "West", "Admin", 20000.0)); employeeIdandNameMap.put(10005, new Employee(10005, "Sam", "Finance", 40000.0)); employeeIdandNameMap.put(11106, new Employee(11106, "Frank", "Risk", 10000.0)); employeeIdandNameMap.put(11009, new Employee(11009, "Lussy", "Surveillance", 70000.0)); employeeIdandNameMap.put(10007, new Employee(10007, "Hamid", "Asset Management", 80000.0)); System.out.println("Original Map::::"); employeeIdandNameMap.forEach((k,v)->System.out.println(k+"\t"+v)); Set<Entry<Integer, Employee>> entrySet = employeeIdandNameMap.entrySet(); List<Entry<Integer, Employee>> list = new ArrayList<>(entrySet); Collections.sort(list, (o1, o2) -> o1.getValue().getEmployeeName().compareTo(o2.getValue().getEmployeeName())); System.out.println("Map sorted based on Values::::"); list.forEach(e->{ System.out.println(e.getKey()+"\t"+e.getValue()); }); } } |
Sort Map based on Keys Using Java 8 stream API and Lambda.
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package com.kkjavatutorials.client; import java.util.HashMap; import java.util.LinkedHashMap; import java.util.Map; import java.util.stream.Collectors; import com.kkjavatutorials.model.Employee; /** * Sort Map based on Keys Using Java 8 stream API and Lambda Expression. * @author KK JavaTutorials * */ public class SortMapBasedOnValuesWithCustomObjects2 { public static void main(String[] args) { Map<Integer,Employee> employeeIdandNameMap = new HashMap<>(); employeeIdandNameMap.put(12301, new Employee(12301, "Sean", "IT", 30000.0)); employeeIdandNameMap.put(12303, new Employee(12303, "Abhay", "Finance", 10000.0)); employeeIdandNameMap.put(10304, new Employee(10304, "West", "Admin", 20000.0)); employeeIdandNameMap.put(10005, new Employee(10005, "Sam", "Finance", 40000.0)); employeeIdandNameMap.put(11106, new Employee(11106, "Frank", "Risk", 10000.0)); employeeIdandNameMap.put(11009, new Employee(11009, "Lussy", "Surveillance", 70000.0)); employeeIdandNameMap.put(10007, new Employee(10007, "Hamid", "Asset Management", 80000.0)); System.out.println("Original Map::::"); employeeIdandNameMap.forEach((k,v)->System.out.println(k+"\t"+v)); System.out.println("Map sorted based on Values::::"); LinkedHashMap<Integer, Employee> mapSortedBasedOnKeys = employeeIdandNameMap.entrySet().stream().sorted((e1,e2)-> e1.getValue().getEmployeeName().compareTo(e2.getValue().getEmployeeName())). collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, (e1,e2)->e1, LinkedHashMap::new)); mapSortedBasedOnKeys.forEach((k,v)->System.out.println(k+"\t"+v)); } } |
Output of the above program:
Original Map::::
10304 Employee [employeeId=10304, employeeName=West, deptName=Admin, salary=20000.0]
11009 Employee [employeeId=11009, employeeName=Lussy, deptName=Surveillance, salary=70000.0]
11106 Employee [employeeId=11106, employeeName=Frank, deptName=Risk, salary=10000.0]
10005 Employee [employeeId=10005, employeeName=Sam, deptName=Finance, salary=40000.0]
10007 Employee [employeeId=10007, employeeName=Hamid, deptName=Asset Management, salary=80000.0]
12301 Employee [employeeId=12301, employeeName=Sean, deptName=IT, salary=30000.0]
12303 Employee [employeeId=12303, employeeName=Abhay, deptName=Finance, salary=10000.0]
Map sorted based on Values::::
12303 Employee [employeeId=12303, employeeName=Abhay, deptName=Finance, salary=10000.0]
11106 Employee [employeeId=11106, employeeName=Frank, deptName=Risk, salary=10000.0]
10007 Employee [employeeId=10007, employeeName=Hamid, deptName=Asset Management, salary=80000.0]
11009 Employee [employeeId=11009, employeeName=Lussy, deptName=Surveillance, salary=70000.0]
10005 Employee [employeeId=10005, employeeName=Sam, deptName=Finance, salary=40000.0]
12301 Employee [employeeId=12301, employeeName=Sean, deptName=IT, salary=30000.0]
10304 Employee [employeeId=10304, employeeName=West, deptName=Admin, salary=20000.0]
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