Struts2+DAO层实现实例02——搭建DAO基本框架并与Struts2组合

实例内容

• 　　创建DAO（Data Access Oject）接口：BaseDAO
• 　　创建其实例化类：UserDAO　　用于获取数据库struts中的userinfo表中的内容
• 　　创建User的Java Bean类，含有username和password，以及其get和set方法
• 　　修改Action中的验证用户名机制，将验证通过DAO层与数据库进行通信判别。

实例代码

　　BaseDAO:

package UserBlock;

import java.util.ArrayList;
import java.util.Collection;

/**
 * DAO(Data Access Oject)接口
 * Created by Richard on 2017/6/16.
 */
public interface BaseDAO {

    public boolean insert(String username,String password) throws  Exception;

    public Collection select() throws  Exception;

    public boolean delete(String username) throws  Exception;

    public ArrayList up_select(String username) throws  Exception;

    public boolean update(String username,String password) throws  Exception;
}

　　UserDAO:

package UserBlock;

import javax.xml.transform.Result;
import java.sql.*;
import java.util.ArrayList;
import java.util.Collection;

/**
 * Created by Richard on 2017/6/16.
 */
public class UserDao implements BaseDAO {
    private String url = "jdbc:mysql://localhost:3306/struts";
    private String user = "root";
    private String password = "root";

    @Override
    public boolean insert(String username,String upassword) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        String sql = "insert into userinfo(username,password)Values(?,?)";
        Connection conn = DriverManager.getConnection(url, user, password);
        PreparedStatement pst = conn.prepareStatement(sql);
        pst.setString(1, username);
        pst.setString(2, upassword);
        int i = pst.executeUpdate();
        if (i >= 1) {
            return true;
        } else {
            return false;
        }
    }

    @Override
    public Collection select() throws Exception {
        ArrayList al = new ArrayList();
        Class.forName("com.mysql.jdbc.Driver");
        String sql = "select * from userinfo";
        Connection conn = DriverManager.getConnection(url, user, password);
        Statement st = conn.createStatement();
        ResultSet rs = st.executeQuery(sql);
        if (rs.next()) {
            User Get = new User();
            Get.setUsername(rs.getString("username"));
            Get.setPassword(rs.getString("password"));
            al.add(Get);
        }
        return al;
    }

    @Override
    public boolean delete(String username) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        String sql = "delete from userinfo where username=?";
        Connection conn = DriverManager.getConnection(url, user, password);
        PreparedStatement pst = conn.prepareStatement(sql);
        pst.setString(1, username);
        int i = pst.executeUpdate();
        if (i >= 1) {
            return true;
        } else {
            return false;
        }

    }

    @Override
    public ArrayList up_select(String username) throws Exception {
        ArrayList al = new ArrayList();
        Class.forName("com.mysql.jdbc.Driver");
        String sql = "select * from userinfo where username=?";
        Connection conn = DriverManager.getConnection(url, user, password);
        PreparedStatement pst = conn.prepareStatement(sql);
        pst.setString(1,username);
        ResultSet rs = pst.executeQuery();
        if (rs.next()) {
            User Get = new User();
            Get.setUsername(rs.getString("username"));
            Get.setPassword(rs.getString("password"));
            al.add(Get);
        }
        return al;
    }

    @Override
    public boolean update(String username,String upassword) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        String sql = "update userinfo set password=? where username=?";
        Connection conn = DriverManager.getConnection(url, user, password);
        PreparedStatement pst = conn.prepareStatement(sql);
        pst.setString(1,upassword);
        pst.setString(2,username);
        int i = pst.executeUpdate();
        if (i >= 1) {
            return true;
        } else {
            return false;

        }
    }
}

　　新修改的Action：

package UserBlock;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

import java.util.ArrayList;
import java.util.Map;
import java.util.logging.LogManager;

/**
 * Created by Richard on 2017/6/16.
 * 继承ActionSupport实现一个Action
 * 登陆界面通过loginuser.action调用login()方法来处理数据
 *          login()方法中通过ActionContext调用Session对象，存入输入错误的数据
 *          通过addActionMessage()方法向页面输出相关信息
 * 注册页面通过reguser.action调用reg()方法来处理数据
 */
public class UserAction extends ActionSupport {
    private String INDEX="index";
    private String LOGIN="login";
    private  String REG="register";
    private String username;
    private String password;

    public String getCompassword() {
        return compassword;
    }

    public void setCompassword(String compassword) {
        this.compassword = compassword;
    }

    private String compassword;
    private UserDao user;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String login(){
        try{
            user=new UserDao();
            ArrayList result=user.up_select(username);
            if(result.size()>0){
                User aim= (User) result.get(0);
                if(aim.getPassword().equals(password)){
                    /*登陆成功*/
                    return INDEX;
                }else{
                    ActionContext applicton=ActionContext.getContext();
                    Map session=applicton.getSession();
                    int count;
                    if(session.get("count")==null){
                        count=0;
                    }else{
                        count= (int) session.get("count");
                    }
                    if(count>=3){
                        addActionMessage("错误次数过多");
                        count=0;
                        session.put("count",count);
                        return LOGIN;
                    }else{
                        count++;
                        addActionMessage("您输入的用户名或密码错误"+count);
                        session.put("count",count);
                        return LOGIN;
                    }

                }
            }else{
                addActionMessage("该用户不存在，已经跳转到注册页面");
                return REG;
            }
        }catch (Exception e){
            addActionError(e.getMessage());
            System.out.println(e.getMessage());
            e.printStackTrace();
            return LOGIN;
        }
    }

    public String reg(){
        try{
            user=new UserDao();
            ArrayList result=user.up_select(username);
            if(result.size()>0)
            {
                addActionMessage("该用户已经存在");
                return REG;
            }
            else{
                if(user.insert(username,password)){
                    return INDEX;
                }else{
                    addActionMessage("发生未知错误，请重试！");
                    return REG;
                }

            }
        }catch (Exception e){
                addActionError(e.getMessage());
                return REG;
        }
    }
}

项目代码

Git项目源代码，持续更新