JavaEE MVC

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🌈目录

🎄建立接口
🎨团队开发命名规范解决方案
📦封装属性
💰完成 insert 功能
🎰插入测试
🧿完善 return 0
🔮修改 select 返回值类型
🎲完成 select 功能
🎯查询测试

🎄建立接口

interfacer.java

package cc.cnix.ShoppingSystem.interfacer;

import cc.cnix.ShoppingSystem.manager.user_manager;

public interface interfacer {
    
    /**
     * 插入学生信息
     * @param um    学生信息对象
     * @return    -2 数据库异常        -1 值存在        0 插入失败    >0 插入成功
     */
    public int insertUser(user_manager um);    //import user_manager
    
    public void selectUser(user_manager um);
}

🎨团队开发命名规范解决方案

contorl_user.java

package cc.cnix.ShoppingSystem.control;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

//团队开发，规范化命名
import cc.cnix.ShoppingSystem.interfacer.interfacer;
import cc.cnix.ShoppingSystem.jdbc.JdbcUnit;
import cc.cnix.ShoppingSystem.manager.user_manager;

public class control_user implements interfacer {

    @Override
    public void insertUser(user_manager um) {
        // TODO Auto-generated method stub
    }

    @Override
    public void selectUser(user_manager um) {
        // TODO Auto-generated method stub
    }

}

要修改本身的东西需要在接口文件( interfacer.java )修改
eg : 文档注释

📦封装属性

user_manager.java

Getter and Setters

package cc.cnix.ShoppingSystem.manager;
//对参数进行封装，以后只调用一个就好
public class user_manager {

    private String S_id = "";
    private String S_Number = "";
    private String S_Name = "";
    private String S_Sex = "";
    
    public String getS_id() {
        return S_id;
    }
    public void setS_id(String s_id) {
        S_id = s_id;
    }
    public String getS_Number() {
        return S_Number;
    }
    public void setS_Number(String s_Number) {
        S_Number = s_Number;
    }
    public String getS_Name() {
        return S_Name;
    }
    public void setS_Name(String s_Name) {
        S_Name = s_Name;
    }
    public String getS_Sex() {
        return S_Sex;
    }
    public void setS_Sex(String s_Sex) {
        S_Sex = s_Sex;
    }

}

💰完成 insert 功能

删除 control_user.java 错误地方，重新导入

略

control_user.java

    @Override
    public int insertUser(user_manager um) {
        // TODO Auto-generated method stub
        Connection con = JdbcUnit.openDb();    //打开数据库
        
        ResultSet rs = JdbcUnit.dbSelect(con, "si_user", "s_id = " + um.getS_id());
        
        //利用指针下移判断是否有数据
        try {
            if (rs.next()) {
                return -1;    //利用数字定义个人协议
                
            }else {
                
                int w = JdbcUnit.dbInsert(con, "si_user", "" + um.getS_id() + ",'" + um.getS_Number() + "','" + um.getS_Name() + "','" + um.getS_Sex() + "'");
                
                if (w > 0) {
                    return w;
                }else {
                    return 0;
                }
                                
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            
            return -2;    //定义异常的返回值
        }
        
    }

🎰插入测试

UnitTest.java

@Test
public void test() {
    control_user cu = new control_user();    //import control_user
    user_manager um = new user_manager();

    um.setS_id("1");
    um.setS_Number("11789");
    um.setS_Name("wriprin");
    um.setS_Sex("male");

    int h = cu.insertUser(um);

    if (h == -2) {
        System.out.println("服务器异常");
    }else if (h == -1) {
        System.out.println("所插入数据已存在，请修改后重新插入");
    }else if (h == 0) {
        System.out.println("程序bug，请联系管理人员修改");
    }else {
        System.out.println("注册成功");
    }

}

🧿完善 return 0

学习使用数字定义个人协议，而非 boolean（只能表示真假两条件）

control_user.java

try {
    if (rs.next()) {
        return -1;    //利用数字定义个人协议

    }else {

        int w = JdbcUnit.dbInsert(con, "si_user", "" + um.getS_id() + ",'" + um.getS_Number() + "','" + um.getS_Name() + "','" + um.getS_Sex() + "'");

        if (w > 0) {
            return w;
        }else {
            return 0;
        }

    }

🔮修改 select 返回值类型

interfacer.java

public ArrayList<user_manager> selectUser(user_manager um);    //返回值改为 ArrayList

🎲完成 select 功能

control_user.java

    @Override
    public ArrayList<user_manager> selectUser(user_manager um) {
        // TODO Auto-generated method stub
        
        Connection con = JdbcUnit.openDb();    //打开数据库
        
        ResultSet rs = JdbcUnit.dbSelect(con, "si_user", "s_id = " + um.getS_id());
        
        ArrayList<user_manager> al = new ArrayList<user_manager>();
        user_manager dw = new user_manager();
        
        try {
            if (rs.next()) {
                dw.setS_id(rs.getString(1).toString());
                dw.setS_Number(rs.getString(1).toString());
                dw.setS_Name(rs.getString(1).toString());
                dw.setS_Sex(rs.getString(1).toString());
                al.add(dw);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        
        return null;
    }

🥏查询测试

UnitTest.java

@Test
public void testSelect() {
    control_user cu = new control_user();    //import control_user
    user_manager um = new user_manager();

    um.setS_id("1");

    ArrayList<user_manager> al = cu.selectUser(um);

    if (al.size() > 0) {
        System.out.println(al.get(0).getS_id());
        System.out.println(al.get(0).getS_Number());
        System.out.println(al.get(0).getS_Name());
        System.out.println(al.get(0).getS_Sex());
    }else {
        System.out.println("无内容");
    }

}

🧵完成 delete 功能

interfacer.java

public int deleteUser(user_manager um);

public int deleteUserAll();

public int updateUser(user_manager um);

control_user.java 追加新添加的方法

完成删除方法

@Override
public int deleteUser(user_manager um) {
    // TODO Auto-generated method stub

    Connection con = JdbcUnit.openDb();
    int h = JdbcUnit.dbDelete(con, "si_user", "s_id = " + um.getS_id());

    if (h >= 0) {
        return 1;
    }else {
        return 0;
    }

}

@Override
public int deleteUserAll() {
    // TODO Auto-generated method stub

    Connection con = JdbcUnit.openDb();
    int h = JdbcUnit.dbDelete(con, "si_user");

    return 0;
}

🎡完成 update 功能

@Override
public int updateUser(user_manager um) {
    // TODO Auto-generated method stub
    String value = "";
    Connection con = JdbcUnit.openDb();

    if (um.getS_Name().equals("") == false) {
        value = value + "S_Name = '" + um.getS_Name() + "'";
    }


    if (um.getS_Number().equals("") == false) {
        if (value.equals("") == true) {
            value = value + "S_Number = '" + um.getS_Number() + "'";
        }else {
            value = value + ",S_Number = '" + um.getS_Number() + "'";
        }
    }

    if (um.getS_Sex().equals("") == false) {
        if (value.equals("") == true) {
            value = value + "S_Sex = '" + um.getS_Sex() + "'";
        }else {
            value = value + ",S_Sex = '" + um.getS_Sex() + "'";
        }
    }

    int h = JdbcUnit.dbUpdate(con, "si_user", value, "S_id = " + um.getS_id());

    if (h > 0) {
        return 1;
    }else {
        return 0;
    }
}

🎯关闭数据库连接

如果有 try catch 就写在 catch 后面，如果没有 try catch 就写在数据库连接后面。

control_user.java

finally{
    JdbcUnit.dbClose(con, null, null);
}

eg1 : (有 try catch)

@Override
public int insertUser(user_manager um) {
    // TODO Auto-generated method stub
    Connection con = JdbcUnit.openDb();    //打开数据库
    
    ResultSet rs = JdbcUnit.dbSelect(con, "si_user", "s_id = " + um.getS_id());
    
    //利用指针下移判断是否有数据
    try {
        if (rs.next()) {
            return -1;    //利用数字定义个人协议
            
        }else {
            
            int w = JdbcUnit.dbInsert(con, "si_user", "" + um.getS_id() + ",'" + um.getS_Number() + "','" + um.getS_Name() + "','" + um.getS_Sex() + "'");
            
            if (w > 0) {
                return w;
            }else {
                return 0;
            }
                            
        }
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        
        return -2;    //定义异常的返回值
    }
    
    finally{
        JdbcUnit.dbClose(con, null, null);
    }
    
}

eg 2 : (无 try catch)

@Override
public int deleteUser(user_manager um) {
    // TODO Auto-generated method stub

    Connection con = JdbcUnit.openDb();
    int h = JdbcUnit.dbDelete(con, "si_user", "s_id = " + um.getS_id());

    JdbcUnit.dbClose(con, null, null);

    if (h >= 0) {
        return 1;
    }else {
        return 0;
    }

}

JavaEE MVC

Wriprin

🎄建立接口

🎨团队开发命名规范解决方案

📦封装属性

💰完成 insert 功能

🎰插入测试

🧿完善 return 0

🔮修改 select 返回值类型

🎲完成 select 功能

🥏查询测试

🧵完成 delete 功能

🎡完成 update 功能

🎯关闭数据库连接

文章目录