Modify as per your needs in example:
Create a Employee Class as below
package com.myapp.test.collection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class Employee implements Comparable<Object> {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int getSalary() {
return salary;
}
public void setSalary(int salary) {
this.salary = salary;
}
private int age;
private int salary;
@Override
public int compareTo(Object arg0) {
if (this.name.hashCode() > arg0.hashCode())
return 1;
else if (this.name.hashCode() < arg0.hashCode())
return -1;
else
return 0;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((name == null) ? 0 : name.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Employee other = (Employee) obj;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
return true;
}
public static void main(String[] args) {
List<String> datas = new ArrayList<String>();
datas.add("xyz");
datas.add("bcd");
datas.add("abc");
for (String string : datas) {
System.out.println(string);
}
Collections.sort(datas);
for (String string : datas) {
System.out.println(string);
}
System.out.println("======================");
List<Employee> employees = new ArrayList<Employee>();
Employee employee = new Employee();
employee.setName("xyz");
employee.setAge(20);
employee.setSalary(10000);
employees.add(employee);
Employee employee1 = new Employee();
employee1.setName("bcd");
employee1.setAge(20);
employee1.setSalary(10000);
employees.add(employee1);
Employee employee2 = new Employee();
employee2.setName("abc");
employee2.setAge(20);
employee2.setSalary(10000);
employees.add(employee2);
for (Employee localEmployee : employees) {
System.out.println(localEmployee.getName());
}
Collections.sort(employees);
for (Employee localEmployee : employees) {
System.out.println(localEmployee.getName());
}
}
}
Create a Comparator as below:
package com.myapp.test.collection;
import java.text.CollationKey;
import java.text.Collator;
import java.util.Comparator;
import java.util.Locale;
//This comparator class is use full when Employee Object has name with special character then want to sort the name with special character
public class ComparatorExample implements Comparator<Employee> {
public int compare(Employee employeeClass, Employee anotherEmployeeClass) {
Collator usCollator = Collator.getInstance(Locale.US);
usCollator.setStrength(Collator.PRIMARY);
if ((employeeClass != null && employeeClass instanceof Employee)
&& (anotherEmployeeClass != null && anotherEmployeeClass instanceof Employee)) {
String name1 = ((Employee) employeeClass).getName();
String name2 = ((Employee) anotherEmployeeClass).getName();
CollationKey key1 = usCollator.getCollationKey(name1.toUpperCase());
CollationKey key2 = usCollator.getCollationKey(name2.toUpperCase());
return key1.compareTo(key2);
}
return 1;
}
}
Create a class where your main method should exist as write below main method code as:
public static void main(String[] args) {
List<Employee> employeeList = new ArrayList<Employee>();
Employee employee = new Employee();
employee.setName("abc");
employee.setAge(20);
employee.setSalary(2000);
employeeList.add(employee);
Employee employee2 = new Employee();
employee2.setName("xyz");
employee2.setAge(20);
employee2.setSalary(2000);
employeeList.add(employee2);
Employee employee3 = new Employee();
employee3.setName("def");
employee3.setAge(20);
employee3.setSalary(2000);
employeeList.add(employee3);
Collections.sort(employeeList, new ComparatorExample());
for (Iterator iterator = employeeList.iterator(); iterator.hasNext();) {
Employee empl = (Employee) iterator.next();
System.out.println(empl.getName());
}
}
