Java Useful Program

How to search user defined object from a List by using binary search using comparator

package com.java2novice.collections;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

public class MyListBinarySearch

{

public static void main(String a[])

{

        List empList = new ArrayList();

        empList.add(new Emp(12,"Dinesh",50000));

        empList.add(new Emp(146,"Tom",20000));

        empList.add(new Emp(201,"John",40000));

        empList.add(new Emp(302,"Krish",44500));

        empList.add(new Emp(543,"Abdul",10000));

        Emp searchKey = new Emp(201,"John",40000);

        int index = Collections.binarySearch(empList, searchKey, new EmpComp());

        System.out.println("Index of the searched key: "+index);

    }

}

class EmpComp implements Comparator

{

 public int compare(Emp e1, Emp e2)

{

        if(e1.getEmpId() == e2.getEmpId())

       {

            return 0;

        }

        else  

       {

            return -1;

        }

    }

}

class Emp

{

    private int empId;

    private String empName;

    private int empSal;

 public Emp(int id, String name, int sal)

{

        this.empId = id;

        this.empName = name;

        this.empSal = sal;

 }

 public int getEmpId()

{

        return empId;

 }

 public void setEmpId(int empId)

{

        this.empId = empId;

 }

public String getEmpName()

{

        return empName;

  }

 public void setEmpName(String empName)

{

        this.empName = empName;

 }

 public int getEmpSal()

{

        return empSal;

 }

 public void setEmpSal(int empSal)

{

        this.empSal = empSal;

 }

 public String toString()

 {

        return empId+" : "+empName+" : "+empSal;

    }

}

Write for Collections.checked Collection() method

package com.java2novice.collections;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.List;

public class MyCheckedCollection

{

public static void main(String a[])

{

        List myList = new ArrayList();

        myList.add("one");

        myList.add("two");

        myList.add("three");

        myList.add("four");

        Collection chkList = Collections.checkedCollection(myList, String.class);

        System.out.println("Checked list content: "+chkList);

        myList.add(10);

        chkList.add(10);

    }

}

Write  for Collections.checkedList() method

package com.java2novice.collections;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class MyCheckedList

{

public static void main(String a[])

{

        List myList = new ArrayList();

        myList.add("one");

        myList.add("two");

        myList.add("three");

        myList.add("four");

        List chkList = Collections.checkedList(myList, String.class);

        System.out.println("Checked list content: "+chkList);

        myList.add(10);

        chkList.add(10);

    }

}