How to use JavaWeb to display mysql database data
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EMS- employee Information Management system
Summary of the basic Operation of MySQL Learning
Summary of the basic commands of MySQL Learning
Create ems library show databases; create database ems; use ems; create user table create table user (id int primary key auto_increment, name varchar (50), salary double, age int)
Insert tabular data: insert into user values (1); insert into user values (2); insert into user values (3); insert into user values (4)
Create UserListServlets
Connect to the database using JDBC
Copy the jar package to the lib folder
/ / use JDBC to connect to the mysql database, process the output query in the user table, ResultSet result=null; Connection con=null; try {/ / (1) register the load driver Class.forName ("com.mysql.jdbc.Driver"); / / (2) get the link to the database / / (1). Connect to the url address of mysql String url= "jdbc:mysql://localhost:3306/ems"; / / (2). The user name String username= "root" to connect to mysql; / / (3). Password for connecting to mysql String pwd= "123456"; con=DriverManager.getConnection (url, username, pwd); / / (3) precompiled sql statement System.out.println ("MySQL connected successfully!" + con); / / 3. Precompile the SQL statement String sql= "select * from user"; PreparedStatement prep=con.prepareStatement (sql); / / (4) execute the sql statement result=prep.executeQuery (); / / (5) close con.close ();} catch (Exception e) {e.printStackTrace ();} package EMS Import java.io.IOException;import java.io.PrintWriter;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse / / Servletpublic class UserListServlets extends HttpServlet {public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException of employee information query, IOException {/ / use JDBC to connect to the mysql database, and process the output query in the user table to ResultSet result=null; Connection con=null Try {/ / (1) register the load driver Class.forName ("com.mysql.jdbc.Driver"); / / (2) get the link to the database / / (1). Connect to the url address of mysql String url= "jdbc:mysql://localhost:3306/ems"; / / (2). The user name String username= "root" to connect to mysql; / / (3). Password for connecting to mysql String pwd= "123456"; con=DriverManager.getConnection (url, username, pwd); / / (3) precompiled sql statement System.out.println ("MySQL connected successfully!" + con); / / 3. Precompile the SQL statement String sql= "select * from user"; PreparedStatement prep=con.prepareStatement (sql); / / (4) execute the sql statement result=prep.executeQuery () } catch (Exception e) {e.printStackTrace () } / / use response to obtain the character output stream PrintWriter, and output the query results to the browser side / / set format encoding response.setContentType ("text/html;charset=utf-8") / / output a table PrintWriter pw=response.getWriter (); pw.println ("); pw.println (" employee Information Table "); pw.println ("); pw.println ("Job ID name, salary Age") to the browser Pw.println ("") Try {while (result.next ()) {pw.println ("" + result.getInt ("id") + "+ result.getString (" name ") +"+ result.getDouble (" salary ") +" + result.getInt ("age") + "") System.out.println (result.getInt ("id") + "-" + result.getString ("name") + "-" + result.getDouble ("salary") + "-" + result.getInt ("age")) } catch (SQLException e) {/ / TODO Auto-generated catch block e.printStackTrace ();} pw.println ("") / / shut down try {con.close ();} catch (SQLException e) {/ / TODO Auto-generated catch block e.printStackTrace ();}} deployment server
Redeploy server referenc
Visit the website: http://localhost:8080/Servlet/lists
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