Bulletin Board – Implementation
Introduction:
Bulletin
Board application provides group communication between different group members.
Here we are maintaining different groups, and each group is having two or more
members. With in a particular group any member can post the message which can
be read by all the group members and can read the message posted by other group
members. Here we are maintaining separate message table for every group.
Implementation:
à Create the
database and tables as shown below.
à
Establish the connection to the database using JDBC from the program.
à
Insert al the messages posted by particular group members into its
corresponding table.
à
If any group member want to read the message, extract all messages from its
group table and display
them.
Create
a database called “BULLETIN” and then create the following tables in it:
bulletin.java
import
java.io.*;
import
java.sql.*;
public
class bulletin {
static Connection con;
static Statement st;
static ResultSet rs;
public static void main(String[] args)throws
IOException {
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
con=DriverManager.getConnection("jdbc:odbc:BULLETIN");
st=con.createStatement();
}
catch(ClassNotFoundException ex) {
ex.printStackTrace();
}
catch(SQLException ex) {
ex.printStackTrace();
}
if(con!=null) {
System.out.println("Connected
to server...\n");
System.out.println("Please
Enter your group name: \n");
try
{
rs=st.executeQuery("Select * from groups");
while(rs.next()) {
System.out.println(rs.getString("Group"));
}
}
catch(SQLException ex) {
ex.printStackTrace();
}
String grpname;
BufferedReader br=new
BufferedReader(new InputStreamReader(System.in));
grpname=br.readLine();
System.out.println("Enter
username: \t");
String usr=br.readLine();
System.out.println("\nEnter
password: \t");
String pass=br.readLine();
try
{
String query="select * from "+grpname.trim()+"Mem where
Member='"+usr+"'";
System.out.println(query);
rs=st.executeQuery(query);
while(rs.next()) {
if(rs.getString("passwd").equals(pass)) {
System.out.println("Login
Successful!!!HAVE A NICE DAY!!!");
while(true) {
System.out.println("Enter your choice:
\n");
System.out.println("1. Read messages
\n");
System.out.println("2. Write messages
\n");
System.out.println("3. Logout
\n");
int option=Integer.parseInt(br.readLine());
switch(option) {
case 1:
query="select
* from "+grpname+ "Msg";
System.out.println(query);
rs=st.executeQuery(query);
while(rs.next())
System.out.println(rs.getString("user")+":"+rs.getString("Message")+"\n\n");
break;
case 2:
System.out.println("Enter
your message: \n");
String
msg=br.readLine();
query="insert
into "+grpname+"Msg"+"values('"+msg+"','"+usr+"')";
System.out.println(query);
st.executeUpdate(query);
break;
case 3:
System.exit(1);
default:
System.out.println("Choose
a valid option!!! \n");
break;
}
}
}
else {
System.out.println("Please
login again!!!\n");
System.exit(1);
}
}
}
catch(SQLException ex)
{
ex.printStackTrace(); }
}
}
}
Bulletin Board:
OUTPUT
C:\Documents and
Settings\cse4y>e:
E:\>cd Lab
E:\Lab>cd bulletin
E:\Lab\bulletin>javac
*.java
E:\Lab\bulletin>java
bulletin
Connected to server...
Please Enter your group
name:
Group1
Group2
Group1
Enter username:
abc
Enter password:
abc123
select * from Group1Mem
where Member='abc'
Login successful!!!HAVE
A NICE DAY!!!
Enter your choice:
1. Read mesages
2. Write message
3. Logout
1
select * from Group1Msg
abc:Hello
xyz:Hi all!
