View difference between Paste ID: 91WrwCk8 and HrP1kDmQ

 package com.example.javaqui;
 
-import java.awt.GridBagConstraints;
+import java.io.BufferedReader;
-import java.awt.GridBagLayout;
+import java.io.BufferedWriter;
-import java.awt.event.ActionEvent;
+import java.io.File;
-import java.awt.event.ActionListener;
+import java.io.FileInputStream;
 import java.io.FileOutputStream;
-import javax.swing.JButton;
+import java.io.FileReader;
-import javax.swing.JFrame;
+import java.io.FileWriter;
-import javax.swing.JLabel;
+import java.io.IOException;
-import javax.swing.JOptionPane;
+import java.io.InputStreamReader;
-import javax.swing.JPanel;
+import java.io.ObjectInputStream;
-import javax.swing.JPasswordField;
+import java.io.ObjectOutputStream;
-import javax.swing.JTextField;
+import java.sql.Connection;
 import java.sql.DriverManager;
-public class login implements ActionListener
+import java.sql.PreparedStatement;
 import java.sql.ResultSet;
-	JFrame myframe;
+import java.sql.SQLException;
-	JPanel mypanel;
+import java.sql.Statement;
-	JLabel lblusername,lblpassword;
+import java.util.ArrayList;
-	JTextField tusername,tpassword;
+
-	JButton btnlogin;
+public class studentslist
-	GridBagLayout g;
+
-	GridBagConstraints gbc;
+	String datasource;
-	public login()
+	ArrayList<student> students;
 	BufferedReader reader;
-		//initializations
+	int choice;
-		myframe=new JFrame("Login");
+	int filereadtoken;
-		mypanel=new JPanel();
+	//1 is for file,2 is for serialized data,3 is for database
-		lblusername=new JLabel("User Name");
+	//for database only
-		lblpassword=new JLabel("Password");
+	private Connection con=null;
-		tusername=new JTextField(15);
+	private Statement st=null;
-		tpassword=new JPasswordField(15);
+	ResultSet rs=null;
-		btnlogin=new JButton("L O G I N");
+	String query=null;
-		g=new GridBagLayout();
+	String constring="jdbc:mysql://localhost/test?user=root&password=";
-		gbc=new GridBagConstraints();
+
 	public studentslist()
-		//placements
+
-		mypanel.setLayout(g);
+		datasource="Not Choosen";
 		filereadtoken=0;
-		gbc.anchor=GridBagConstraints.NORTHWEST;
+		reader=new BufferedReader(new InputStreamReader(System.in));
-		gbc.gridx=1;
+		showmenu();
-		gbc.gridy=5;
+
-		g.setConstraints(lblusername,gbc);
+	public void showmenu()
-		mypanel.add(lblusername);
+
 		while(true){
-		gbc.anchor=GridBagConstraints.NORTHWEST;
+		clearscreen();
-		gbc.gridx=5;
+		System.out.println("Data Source Choosen : "+ datasource);
-		gbc.gridy=5;
+		System.out.println("1. Choose plain text as data source");
-		g.setConstraints(tusername,gbc);
+		System.out.println("2. Choose serialized text as data source");
-		mypanel.add(tusername);
+		System.out.println("3. Choose db as data source");
 		System.out.println("4. Add Student");
-		gbc.anchor=GridBagConstraints.NORTHWEST;
+		System.out.println("5. List Students");
-		gbc.gridx=1;
+		System.out.println("Enter your choice [1,2,3,4,5]");
-		gbc.gridy=10;
+		try
-		g.setConstraints(lblpassword,gbc);
+
-		mypanel.add(lblpassword);
+			choice=Integer.parseInt(reader.readLine());
 			switch(choice)
-		gbc.anchor=GridBagConstraints.NORTHWEST;
+
-		gbc.gridx=5;
+				case 1:
-		gbc.gridy=10;
+				{
-		g.setConstraints(tpassword,gbc);
+					datasource="PlainText";
-		mypanel.add(tpassword);
+					filereadtoken=1;
 					break;
-		gbc.anchor=GridBagConstraints.NORTHWEST;
+				}
-		gbc.gridx=5;
+				case 2:
-		gbc.gridy=15;
+				{
-		g.setConstraints(btnlogin,gbc);
+					datasource="Serialization";
-		mypanel.add(btnlogin);
+					filereadtoken=2;
 					if(deserializedata()==null)
-		btnlogin.addActionListener(this);
+						students=new ArrayList<student>();
-		tpassword.addActionListener(this);
+					else
 						students=deserializedata();
-		myframe.getContentPane().add(mypanel);
+					break;
-		myframe.setSize(400, 400);
+				}
-		myframe.setVisible(true);
+				case 3:
 				{
 					datasource="Database";
 					filereadtoken=3;
-		new login();
+					break;
 				}
-	@Override
+				case 4:
-	public void actionPerformed(ActionEvent e)
+				{
 					if(checkdatasource())
-		Object obj=e.getSource();
+						getstudentdetails();
-		String username=tusername.getText().toString();
+					break;
-		String password=tpassword.getText().toString();
+				}
-		if(obj==btnlogin)
+				case 5:
-		{
+				{
-			if(username.length()==0 || password.length() ==0)
+					if(checkdatasource())
 					{
-				JOptionPane.showMessageDialog(myframe, "Incomplete Data");
+						if(filereadtoken==1)
 							readfromfile();
-			else
+						else if(filereadtoken==2)
 							printstudentdetails();
-				checklogin(username,password);
+						else if(filereadtoken==3)
 							printstudentsdb();
 					}
 					break;
-		if(obj==tpassword)
+				}
 				default:
-			checklogin(username,password);
+				{
 					System.out.println("Invalid Choice");
 					break;
-	private void checklogin(String username, String password)
+				}
 			}
-		dboperations operation1=new dboperations();
+		}
-		operation1.makecon();
+		catch (IOException e)
-		if(operation1.validateuser(username, password))
+
 			e.printStackTrace();
-			new menu();
+
-			myframe.setVisible(false);
+
 	}
 	public ArrayList<student> deserializedata()
 	{
-			JOptionPane.showMessageDialog(myframe, "Not Validated !");
+		FileInputStream fileIn=null;
-		}
+		ObjectInputStream inStream=null;
 		try
 		{
 			fileIn=new FileInputStream("data");
 			inStream=new ObjectInputStream(fileIn);
 			students=(ArrayList<student>) inStream.readObject();
 			return students;
 		}
 		catch(IOException e)
 		{
 			//e.printStackTrace();
 			System.out.println(e.getMessage());
 			return null;
 		}
 		catch(ClassNotFoundException c)
 		{c.printStackTrace();return null;}
 		finally
 		{
 
 			try
 			{
 				fileIn.close();
 				inStream.close();
 			}
 			catch(Exception e)
 			{
 				return null;
 			}
 		}
 	}
 	public void serializedata()
 	{
 		FileOutputStream fileOut=null;
 		ObjectOutputStream outStream=null;
 		try
 		{
 			fileOut=new FileOutputStream("data");
 			outStream=new ObjectOutputStream(fileOut);
 			outStream.writeObject(students);
 		}
 		catch(IOException e)
 		{
 			e.printStackTrace();
 		}
 		finally
 		{
 			try {
 				fileOut.close();
 				outStream.close();
 			} catch (IOException e) {
 				// TODO Auto-generated catch block
 				e.printStackTrace();
 			}
 
 		}
 	}
 	public void readfromfile()
 	{
 		File file;
 		FileReader fileReader=null;
 		BufferedReader bufferedReader=null;
 		try
 		{
 			file=new File("file.txt");
 			fileReader=new FileReader(file);
 			bufferedReader=new BufferedReader(fileReader);
 			String line;
 			while((line=bufferedReader.readLine())!=null)
 			{
 				System.out.println(line);
 			}
 			String dummy=reader.readLine();
 		}
 		catch(IOException e)
 		{e.printStackTrace();}
 		finally
 		{
 			try{
 				if(fileReader!=null)
 					fileReader.close();
 				if(bufferedReader!=null)
 					bufferedReader.close();
 			}catch(IOException e){;}
 		}
 	}
 	public void writetofile(ArrayList<String> data)
 	{
 		String student=data.get(0)+","+data.get(1)+","+data.get(2)+","+data.get(3);
 		try
 		{
 			File file=new File("file.txt");
 			FileWriter filewriter=new FileWriter(file.getName(),true);
 			//BufferedWriter bufferedwriter=new BufferedWriter(filewriter);
 			filewriter.write("\n");
 			filewriter.write(student);
 			filewriter.close();
 		}
 		catch(IOException e)
 		{
 			e.printStackTrace();
 		}
 	}
 	public Boolean checkdatasource()
 	{
 		if(filereadtoken==0)
 		{
 			System.out.println("Please choose data source to proceed !");
 			try
 			{
 				String dummy=reader.readLine();
 			}
 			catch(IOException e)
 			{e.printStackTrace();}
 			return false;
 		}
 		else
 			return true;
 	}
 	public void clearscreen()
 	{
 		for(int clear=0;clear<1000;clear++)
 		{
 			System.out.println("");
 		}
 	}
 	public void getstudentdetails()
 	{
 		try{
 		clearscreen();
 		System.out.println("Enter Student Number");
 		String sno=reader.readLine();
 		System.out.println("Enter Student Name");
 		String sname=reader.readLine();
 		System.out.println("Enter Subject Code");
 		String sbcode=reader.readLine();
 		System.out.println("Enter Subject Name");
 		String sbname=reader.readLine();
 		if(filereadtoken==1)
 		{
 			ArrayList<String> data=new ArrayList<String>();
 			data.add(sno);
 			data.add(sname);
 			data.add(sbcode);
 			data.add(sbname);
 			writetofile(data);
 		}
 		else if(filereadtoken==2)
 		{
 			student s=new student(sno,sname,sbcode,sbname);
 			students.add(s);
 			serializedata();
 
 		}
 		else if(filereadtoken==3)
 		{
 			student s=new student(sno,sname,sbcode,sbname);
 			writetodb(s);
 
 		}
 		else
 			System.out.println("Data source not choosen");
 		}
 		catch(IOException e)
 		{
 			System.out.println(e.getMessage());
 		}
 	}
 	public void printstudentdetails()
 	{
 		clearscreen();
 		for(student s:students)
 		{
 			System.out.println(s.snumber);
 			System.out.println(s.sname);
 			System.out.println(s.sbcode);
 			System.out.println(s.sbname);
 		}
 		try
 		{
 			reader.readLine();
 		}
 		catch(IOException e)
 		{
 			e.printStackTrace();
 		}
 	}
 	public void makecon()
 	{
 		try
 		{
 			Class.forName("com.mysql.jdbc.Driver");
 			con=DriverManager.getConnection(constring);
 			//st=con.createStatement();
 		}
 		catch (Exception e)
 		{
 			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
 
 	}
 	public Boolean writetodb(student s)
 	{
 		try
 		{
 			makecon();
 			query="insert into students(studentno,studentname,subjectcode,subjectname) values(?,?,?,?)";
 			PreparedStatement ps=con.prepareStatement(query);
 			ps.setString(1,s.snumber);
 			ps.setString(2,s.sname);
 			ps.setString(3,s.sbcode);
 			ps.setString(4,s.sbname);
 			//System.out.println(query);
 			ps.executeUpdate();
 			System.out.println("student inserted !");
 				return true;
 		}
 		catch(Exception e)
 		{
 			System.out.println(e);
 			return false;
 		}
 		finally
 		{
 			try {
 				con.close();
 			} catch (SQLException e) {
 				// TODO Auto-generated catch block
 				System.out.print(e.getMessage());
 			}
 		}
 	}
 	public void printstudentsdb()
 	{
 		try
 		{
 			makecon();
 			query="select * from students";
 			PreparedStatement ps=con.prepareStatement(query);
 			ResultSet rs=ps.executeQuery();
 			while(rs.next())
 			{
 				System.out.print(rs.getString(1));
 				System.out.print(",");
 				System.out.print(rs.getString(2));
 				System.out.print(",");
 				System.out.print(rs.getString(3));
 				System.out.print(",");
 				System.out.print(rs.getString(4));
 				System.out.println();
 			}
 			reader.readLine();
 		}
 		catch(Exception e)
 		{
 			System.out.println(e.getMessage());
 		}
 	}
 	public static void main(String args[])
 	{
 		new studentslist();
 	}
 }