Department of Information Science and
Engineering
1
Department of Information Science
and Engineering
JAVA AND J2EE LAB
[18IS6DLJVA ]
Faculty : Mrs.Radhika T V
Assistant Professor , Dept of ISE
DSCE
2
Course OutcomesJAVA AND J2EE LAB
[18IS6DLJVA ]
CO1 - Write, compile and execute java programs.
CO2- Apply the basic concepts of object oriented
programming in writing java programs.
CO3-Design and use classes, packages and interfaces
CO4-Analyze and implement exception handling, event
handling
CO5-Develop graphical user interface using swings
CO6-Construct web applications using Servlets and JSP
Program 1
a) Write a Java program to implement
linear search.
Linear Search
•It is also known as sequential search- A method for finding an
element within a list.
• Given a list of elements in an array, a[]
•We need to search given element x in a[]
Input and output statements in Java
• In Java we need to use special methods to perform i/o.
• Every class has
– Properties (variables)
– Actions(Methods)
• In order to access members of class, we need object.
• Input and output functions in java are called through class name.
• In Java, there are 3 main I/O streams. All these streams are attached
with the console.
1) System.in: standard input stream
2) System.out: standard output stream
3) System.err: standard error stream
• All the above I/O streams are available in Java.lang package
• import.java.lang.*
Cntd..
• Following are the output statements in java
– System.out.print
– System.out.println
– System.out.printf
• Input functions are used to read lines of input at runtime
• To do this following classes are used
– Scanner
– Buffer Reader
Scanner Class in Java
• Scanner is a class in Java used to read input from keyboard.
• java.util package used for obtaining the input of the primitive types
like int, double, etc. and strings.
• Make use of -import java.util.scanner
-import java.util.*
• To access methods of Scanner class –create object.
• Methods available are
–
–
–
–
next()
next Int()
next Float()
next Double()
• Syntax for reading input through Scanner class:
Classname objectname=new constructor();
Ex: Scanner sc=new Scanner(System.in);
Program 1)a
import java.util.Scanner;
Class LinearS
{
Public static void main(String args[])
{
int counter, num, item, array[];
Scanner input =new Scanner(System.in);
System.out.println("Enter number of elements");
num =input.nextInt();
array = new int[num];
System.out.println("Enter "+ num +" integers");
for(counter =0; counter < n; counter++)
array[counter]=input.nextInt();
System.out.println("Enter the search value");
item=input.nextInt();
Program 1)a cntd..
for(counter =0; counter < n; counter++)
{
if(array[counter]== item)
{
System.out.println(item +" is present at location
"+(counter+1));
break;
}
}
if(counter == num)
System.out.println(item +" is not present in array.");
}
}
Output:
Enter the number of
elements 4
Enter 4 integer 20 52 17
92
Enter search value 17
17 is present at location
3
Buffer Reader
• Java BufferedReader class is used to read the text from a
character-based input stream.
• Reads input through keyboard or via existing file
• Following classes are used
– InputstreamReader (System.in)
– FileReader
•
•
•
•
Need to include IOException
Buffer Reader class is available in java.io package
Import java.io.*
Methods available in BufferReader Class are
– read()
– readLine()
Cntd..
• For type casting following methods are used
– Integer.parseInt()
– Float.parseFloat()
• Syntax for reading bytes and converting to character set:
(i) InputStreamReader ir=new InputStreamReader(System.in)
• To read character set data from buffer
(ii)BufferReader br=new BufferReader(ir)
• compareToIgnoreCase() - compares two strings lexicographically
Program 1)b
Write a java program for sorting a given list of names.
import java.io.*;
class SortingNames
{
public static void main(String[] args) throws IOException
{
BufferedReader br = new BufferedReader(new
InputStreamReader(System.in));
System.out.print("\nEnter The number of Names :");
int n = Integer.parseInt(br.readLine());
String names[] = new String[n];
System.out.println();
for (int i = 1; i <= n; i++)
{
System.out.print("Enter Name " + i + ":");
names[i-1] = br.readLine();
}
Cntd..
System.out.println("\nNames in Ascending Order");
System.out.println();
for (int j = 0; j < names.length; j++)
Output:
{
Enter the number of
for (int i = j + 1; i < names.length; i++)
names:3
{
Enter name 1: ab
if (names[i].compareToIgnoreCase(names[j]) < 0) Enter name 2: abc
{
Enter name 3:a
String temp = names[j];
Names in Ascending Order
names[j] = names[i];
a
names[i] = temp;
ab
}
abc
}
System.out.println(names[j]);
}
}
}