Java EE (Java Enterprise Edition) General Discussion

The page is located at web/test/test.jsp and the java as below
Is there anything still need to add to test.jsp?

DB.java (web/classes/DB/db.class)
------------------------------------------------------------------------------
package DB;
import java.sql.*;

public class db
{
String db_url="jdbc:mysql://localhost:3306/DB";
String db_user="root";
String db_password="123456";
private ResultSet r=null;
static private ResultSet res=null;
int staff_Id=0;

/** Creates a new instance of db */

public int getRetrieveId()
{
try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
}
catch (Exception E)
{
E.printStackTrace();
}
try{
Connection C = DriverManager.getConnection(db_url,db_user,db_password);
Statement S = C.createStatement();
r = S.executeQuery("select max(staff_Id) from staff");
while(r.next()){
staff_Id=r.getInt(1);
}
S.close();
C.close();

}
catch(Exception e)
{
e.printStackTrace();
}
return staff_Id;
}

public static boolean getSearch(String s)
{
String search_db_url="jdbc:mysql://localhost:3306/DB";
String search_db_user="root";
String search_db_password="123456";
String str=null;
boolean result=false;

try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
}
catch (Exception E)
{
E.printStackTrace();
}
try{
Connection C = DriverManager.getConnection(search_db_url,search_db_user,search_db_password);
Statement S = C.createStatement();
res = S.executeQuery(s);
while(res.next()){
str=res.getString(1);
}
if(!str.equals(null))
{
result=true;
}
S.close();
C.close();

}
catch(Exception e)
{
e.printStackTrace();
}
return result;
}


public void setUpdate(String str)
{
try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
}
catch (Exception E)
{
E.printStackTrace();
}
try{
Connection C = DriverManager.getConnection(db_url,db_user,db_password);
Statement S = C.createStatement();
int r = S.executeUpdate(str);
S.close();
C.close();

}
catch(Exception e)
{
e.printStackTrace();
}
}

}