Software Training For Free: 2021

Sunday, December 26, 2021

Jsp and servlet Select a data from database

step 1

To Create a Jsp Page for select.jsp

Click the Project Folder-----go to src folder----main folder----web app ---right click the web app---new

----jsp---select.jsp

select.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<!DOCTYPE html>

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<form action="select" method="post">

<input type="text" name="n1" placeholder="Username"><br><br>

<input type="submit"><br><br>

</form>

</body>

</html>

Create a Servlet Page

goto src/main/java then right click new---sevlet---class name---select----finish

select.java

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.sql.*;

/**

* Servlet implementation class register

@WebServlet("/select")

public class select extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

PrintWriter pw=response.getWriter();

try

{

String a=request.getParameter("n1");

Class.forName("com.mysql.jdbc.Driver");

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/example","root","");

Statement st=con.createStatement();

ResultSet rs=st.executeQuery("select * from ex where username='"+a+"' ");

while(rs.next())

{

pw.println("the user password is "+rs.getString(2));

}

catch(Exception e)

{

pw.println(e);

}

connect the jar files

right click the project build path----configure build path---add external jars---add mysqlconnector.jar

Note : download the mysqlconnector.jar in google

also copy the jar file paste into ----src---main---web app---WEB-INF---lib-----mysql-connector.jar

Run

Right click the jsp page----run as ---run an server--finish

Jsp Servlet Delete the data in database

step 1

Eclipse---File ----New----Dynamic Web Project----ProjectName----Finish

step 2

To Create a Jsp Page for delete.jsp

Click the Project Folder-----go to src folder----main folder----web app ---right click the web app---new

----jsp---delete.jsp

delete.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<!DOCTYPE html>

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<form action="delete" method="post">

<input type="text" name="n1" placeholder="Username"><br><br>

<input type="submit"><br><br>

</form>

</body>

</html>

Create a Servlet Page

goto src/main/java then right click new---sevlet---class name---delete----finish

delete.java

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.sql.*;

/**

* Servlet implementation class register

@WebServlet("/delete")

public class delete extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

PrintWriter pw=response.getWriter();

try

{

String a=request.getParameter("n1");

Class.forName("com.mysql.jdbc.Driver");

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/example","root","");

Statement st=con.createStatement();

st.executeUpdate("delete from ex where username='"+a+"' ");

pw.println("delete successfully");

}

catch(Exception e)

{

pw.println(e);

}

connect the jar files

right click the project build path----configure build path---add external jars---add mysqlconnector.jar

Note : download the mysqlconnector.jar in google

also copy the jar file paste into ----src---main---web app---WEB-INF---lib-----mysql-connector.jar

Run

Right click the jsp page----run as ---run an server--finish

Jsp and Servlet Update the data in database

step 1

Eclipse---File ----New----Dynamic Web Project----ProjectName----Finish

step 2

To Create a Jsp Page for update.jsp

Click the Project Folder-----go to src folder----main folder----web app ---right click the web app---new

----jsp---update.jsp

Update.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<!DOCTYPE html>

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<form action="update" method="post">

<input type="password" name="n1" placeholder="old password"><br><br>

<input type="password" name="n2" placeholder="new password"><br><br>

<input type="submit"><br><br>

</form>

</body>

</html>

Create a Servlet Page

goto src/main/java then right click new---sevlet---class name---update----finish

update.java

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.sql.*;

/**

* Servlet implementation class register

@WebServlet("/update")

public class update extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

PrintWriter pw=response.getWriter();

try

{

String a=request.getParameter("n1");

String b=request.getParameter("n2");

Class.forName("com.mysql.jdbc.Driver");

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/example","root","");

Statement st=con.createStatement();

st.executeUpdate("update ex set password='"+b+"' where password='"+a+"' ");

pw.println("update successfully");

}

catch(Exception e)

{

pw.println(e);

}

connect the jar files

right click the project build path----configure build path---add external jars---add mysqlconnector.jar

Note : download the mysqlconnector.jar in google

also copy the jar file paste into ----src---main---web app---WEB-INF---lib-----mysql-connector.jar

Run

Right click the jsp page----run as ---run an server--finish

Jsp and Servlet insert data into database

step 1

Create a Data Base

Start---Xampp Control Panel---Start Apache and MySql

step 2

create database

Query : create database Example;

create table

Query : create table ex(username varchar(50),password varchar(50));

step 3

Eclipse---File ----New----Dynamic Web Project----ProjectName----Finish

step 4

To Create a Jsp Page for register.jsp

Click the Project Folder-----go to src folder----main folder----web app ---right click the web app---new

----jsp---register.jsp

Register.jsp

in register.jsp create a register form design

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<!DOCTYPE html>

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<form action="register" method="post">

<input type="text" name="n1" placeholder="username"><br><br>

<input type="password" name="n2" placeholder="password"><br><br>

<input type="submit"><br><br>

</form>

</body>

</html>

Create a Servlet Page

goto src/main/java then right click new---sevlet---class name---register----finish

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.sql.*;

/**

* Servlet implementation class register

@WebServlet("/register")

public class register extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

PrintWriter pw=response.getWriter();

try

{

String a=request.getParameter("n1");

String b=request.getParameter("n2");

Class.forName("com.mysql.jdbc.Driver");

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/example","root","");

Statement st=con.createStatement();

st.executeUpdate("insert into ex values('"+a+"','"+b+"')");

pw.println("insert successfully");

}

catch(Exception e)

{

pw.println(e);

}

connect the jar files

right click the project build path----configure build path---add external jars---add mysqlconnector.jar

Note : download the mysqlconnector.jar in google

also copy the jar file paste into ----src---main---web app---WEB-INF---lib-----mysql-connector.jar

Run

Right click the jsp page----run as ---run an server--finish

MYSQL

Tuesday, May 11, 2021

Matplotlib Tutorial

Matplotlib:

It is a library to create graph plotting in data science.

Import Matplotlib:

Import matplotlib

This line used to import matplotlib.

Find Version:

import matplolib

print(matplotlib.__version__)

This line used to find matplotlib version.

Pyplot:

Most commonly used utility is pyplot.

Import Pyplot:

import matplotlib. pyplot as plt

This line used to import the pyplot module.

Example:

import matplotlib.pyplot as plt

       import numpy as np
       xpoints = np.array([0, 5])
       ypoints = np.array([0, 100])
     plt.plot(xpoints, ypoints)
       plt.show()

Output:

Set Position:

Example:

import matplotlib.pyplot as plt

       import numpy as np
     xpoints = np.array([1, 5])
       ypoints = np.array([4, 10])
       plt.plot(xpoints, ypoints, 'o')

plt.show()

Output:

It shows only the position of the x,y points by using plt.plot(xpoints, ypoints, 'o')

Multiple Points:

import matplotlib.pyplot as plt

           import numpy as np
         xpoints = np.array([2,4,7,9])
           ypoints = np.array([6,3,8,1])
           plt.plot(xpoints, ypoints)
           plt.show()

Output:

Default X Points:

import matplotlib.pyplot as plt

           import numpy as np
           ypoints = np.array([3, 8, 1, 10, 5, 7])
                      plt.plot(ypoints)
           plt.show()

Output:

Markers:

import matplotlib.pyplot as plt

       import numpy as np
       ypoints = np.array([1,4,6,3])
       plt.plot(ypoints, marker = 'o')

plt.show()

Output:

Point the position by the markers code plt.plot(ypoints, marker = 'o')

Marker own symbol:

import matplotlib.pyplot as plt

       import numpy as np
       ypoints = np.array([1,4,6,3])
       plt.plot(ypoints, marker = '*')

plt.show()

Output:

Line Style:

import matplotlib.pyplot as plt

       import numpy as np
     ypoints = np.array([3, 8, 1, 10])
       plt.plot(ypoints, linestyle = 'dotted')
       plt.show()

Output:

We have more line style like this dashed(), dashdot().

Line Color:

import matplotlib.pyplot as plt

       import numpy as np
       ypoints = np.array([3, 8, 1, 10])
       plt.plot(ypoints, color = 'pink')
       plt.show()

Output:

we can use ,ore colors by using plt.plot(ypoints, color = 'pink')

Line Width:

       import matplotlib.pyplot as plt
       import numpy as np
       ypoints = np.array([3, 8, 1, 10])
       plt.plot(ypoints, linewidth = '25.0')
       plt.show()

Output:

Labels:

        import numpy as np
       import matplotlib.pyplot as plt
       x = np.array([80, 85, 90, 95, 100, 105, 110, 115, 120, 125])
       y = np.array([240, 250, 260, 270, 280, 290, 300, 310, 320, 330])
       plt.plot(x, y)
       plt.title("Income")
       plt.xlabel("Average ")
       plt.ylabel("Days")
       plt.show()

Output:

We can add labels like this.

Grid Lines:

import sys

import matplotlib

matplotlib.use('Agg')

import numpy as np

import matplotlib.pyplot as plt

x = np.array([80, 85, 90, 95, 100, 105, 110, 115, 120, 125])

y = np.array([240, 250, 260, 270, 280, 290, 300, 310, 320, 330])

plt.title("Income")

plt.xlabel("Average")

plt.ylabel("Days")

plt.plot(x, y)

plt.grid()

plt.show()

Output:

We can add horizontal and vertical lines only by using plt.grid(axis = 'x'),

plt.grid(axis = 'y')

Bar Chart:

import matplotlib.pyplot as plt

       import numpy as np
       x = np.array(["A", "B", "C", "D"])
       y = np.array([3, 8, 1, 10])
       plt.bar(x,y)
       plt.show()

Output:

Histograms:

import sys

import matplotlib

matplotlib.use('Agg')

import matplotlib.pyplot as plt

import numpy as np

x = np.random.normal(150,50,230)

plt.hist(x)

plt.show()

Output:

Pie Chart:

       import matplotlib.pyplot as plt
       import numpy as np
       y = np.array([35, 25, 25, 15])
       plt.pie(y)
       plt.show()

Output:

Software Training For Free

Sunday, December 26, 2021

Jsp and servlet Select a data from database

Jsp Servlet Delete the data in database

Jsp and Servlet Update the data in database

Jsp and Servlet insert data into database

Tuesday, May 11, 2021

Matplotlib Tutorial

Matplotlib:

Python Technical Interview Questions

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