10 steps to teach you to learn simple MVC architecture for Java programs (for beginners)

Suitable for novice, big good under mercy, thank you!

1th Step: Install the Oracle database, the installation process does not repeat;

2nd step: Create a new account Zwp_test

Creating a temporary tablespace create temporary tablespace zwp_test_temp   tempfile ' F:\app\Administrator\oradata\zwp_test_temp.dbf '  size 50m   autoextend on   next 50m maxsize 20480m   extent management local;//creating data table space Create Tablespace ZWP_ Test_data   logging   datafile ' F:\app\Administrator\oradata\zwp_test_data.dbf '  size 50m   autoextend On   next 50m maxsize 20480m   extent management local;//creating user Create users Zwp_test identified by Zwp_testdefault Tabl Espace zwp_test_datatemporary tablespace zwp_test_temp;//grants permission grant CONNECT,RESOURCE,DBA to Zwp_test;

3rd Step: Create a new users table

CREATE TABLE Users (  userid   varchar2 (8) NOT NULL primary key, username VARCHAR2 (TEN) not NULL, password VARCHAR2 (2 0) Default ' NOT NULL, age      int default ' is not NULL, sex      varchar2 (+) NOT null) tablespace zwp_test_data;

4th step: Inserting data

Insert into users (userid,username,password,age,sex) VALUES (' 001 ', ' zhouwp ', ' 123 ', ' n ', ' man ');

5th step: Build the environment, I will not repeat, can Baidu, Google

Function Description:

The ability to do a user query

Resource structures such as:

6th step: Display Interface jsp

<%@ page language= "java" import= "java.util.*" pageencoding= "GB18030"%><%@ page import= "com.web.zwp.*"%> <%@ page import= "java.util.*"%>
 7th step: Link Database 
 
Package Com.web.db;import Java.sql.connection;import Java.sql.drivermanager;import java.sql.PreparedStatement; Import Java.sql.resultset;import Java.sql.sqlexception;public class db {private DB () {}/** * get connection * @return */publ IC static Connection getconnection () {Connection conn = null;try {class.forname ("oracle.jdbc.driver.OracleDriver"); conn = Drivermanager.getconnection ("Jdbc:oracle:thin: @localhost: 1521:drp", "Zwp_test", "Zwp_test");} catch (ClassNotFoundException e) {//Todo auto-generated catch Blocke.printstacktrace ();} catch (SQLException e) {//TODO Auto-generated catch Blocke.printstacktrace ();} Return conn;} public static void Close (PreparedStatement pstmt) {if (pstmt! = null) {try {pstmt.close ()} catch (SQLException e) {//TOD O auto-generated catch Blocke.printstacktrace ();}}} public static void Close (Connection conn) {if (conn! = null) {try {conn.close ()} catch (SQLException e) {//TODO Auto-gen Erated catch Blocke.printstacktrace ();}}} public static void Close (ResultSetRS) {if (rs! = null) {try {rs.close ();} catch (SQLException e) {//TODO auto-generated catch Blocke.printstacktrace ();}}} public static void Main (string[] args) {db.getconnection ();}}
8th step: Create the User object class
Package Com.web.zwp;public class User {private string Userid;private string Username;private string Password;private int< C0/>age;private string Sex;public string GetUserName () {return UserName;} public void Setusername (String userName) {userName = UserName;} Public String GetPassword () {return PassWord;} public void SetPassword (String passWord) {PassWord = PassWord;} public int getage () {return age;} public void Setage (int.) {age = age;} Public String Getsex () {return Sex;} public void Setsex (String sex) {sex = sex;} Public String GetUserId () {return UserId;} public void Setuserid (String userId) {userid = userid;}}
9th step: Create a new user management class Usermanager, implement the Query method in the class
Package Com.web.zwp;import Java.sql.*;import Com.web.db.db;import Com.web.zwp.user;public class UserManager {private Static Usermanager instance = new Usermanager (); Usermanager () {}public static Usermanager getinstance () {return instance;} /* * Query all */public User findalluser () {String sql = "SELECT * from users"; Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; User User = null;try {conn = db.getconnection ();p stmt = conn.preparestatement (sql); rs = Pstmt.executequery (); if (Rs.next ( ) {user = new user (), User.setuserid (rs.getstring ("userid")), User.setusername (rs.getstring ("username")); User.setpassword (rs.getstring ("password")), User.setage (Rs.getint ("Age")), User.setsex (rs.getstring ("Sex"));}} catch (SQLException e) {e.printstacktrace ();} Finally {Db.close (RS);D b.close (pstmt);D b.close (conn);} return user;} /* * Query by ID */public User Findalluserbyid (String userId) {String sql = "SELECT * from Users where userid=?"; Connection conn = null; PreparedStatement pstmt = null; ResUltset rs = null; User User = null;try {conn = db.getconnection ();p stmt = conn.preparestatement (sql);p stmt.setstring (1, userId); rs = pstmt. ExecuteQuery (), if (Rs.next ()) {user = new user (), User.setuserid (rs.getstring ("userid")), User.setusername ( Rs.getstring ("username")), User.setpassword (rs.getstring ("password")), User.setage (Rs.getint ("Age")); user.setsex (Rs.getstring ("Sex"));}} catch (SQLException e) {e.printstacktrace ();} Finally {Db.close (RS);D b.close (pstmt);D b.close (conn);} return user;}
 10th step: Implement the Control section by Httpservet m 
 
 
Package Com.web.zwp;import Java.io.ioexception;import Java.util.arraylist;import java.util.list;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class ShowUsers extends HttpServlet {/** * *///private static final long serialversionuid = 3434710866509057630l;public void DoPost (httpservletre Quest request, HttpServletResponse response) throws Servletexception, IOException {String userid=request.getparameter ( "UserID"); if (Userid==null | | Userid.trim (). Length () ==0) {User user=usermanager.getinstance (). Findalluser (); list<user> userlist = new arraylist<user> (); Userlist.add (User); Request.setattribute ("UserList", userlist) Request.getrequestdispatcher ("/showusers.jsp"). Forward (request, response);} Else{user user=usermanager.getinstance (). Findalluserbyid (userid); list<user> userlist = new arraylist<user> (); Userlist.add (user);//Get data from the database to User in the Request objectThe List property is forwarded to the foreground Jsprequest.setattribute ("UserList", userlist); Request.getrequestdispatcher ("/showusers.jsp"). Forward (request, response);}} public void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { This.dopost (request, Response);}}

Final Display Interface style:





  
10 steps to teach you to learn simple MVC architecture for Java programs (for beginners)