JDBC数据连接之增删改查MVC

每天叫醒自己的不是闹钟，而是梦想

conn层

package conn;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.mysql.jdbc.Statement;

public class Conn {
	/*Statement stmt;
	 * 该对象用于执行静态SQL语句并返回它产生的结果。

默认情况下，只有一个ResultSet对象每Statement对象可以同时打开。因此，如果一个ResultSet对象的阅读是交错的另一个阅读，每个人都必须有不同的Statement对象产生。在Statement接口的所有执行方法隐式关闭的声明，目前ResultSet对象如果打开一个存在。
简单来说，就是一个结果对应一个Statement
本次实现增删改查。需要4个返回结果，所以定义4个Statement对象
*/
	Statement stmt;
	Statement stmt1;
	Statement stmt2;
	Statement stmt3;

	public Conn()  //本段代码块构造函数，初始化连接数据库
	{
		try {
			Class.forName("com.mysql.jdbc.Driver");//加载jdbc驱动
			String url = "jdbc:mysql://localhost:3306/test?user=root&password=password&useUnicode=true&characterEncoding=utf8&autoReconnect=true&failOverReadOnly=false";
			Connection con=DriverManager.getConnection(url);//连接数据库
			stmt =(Statement) con.createStatement();
			stmt1 =(Statement) con.createStatement();
			stmt2 =(Statement) con.createStatement();
			stmt3 =(Statement) con.createStatement();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}
	public boolean insert(String sql) //插入。Statement对象调用executeupdate方法执行sql语句。  成功与否返回布尔型。
	{
		boolean flag=true;  //flag标识
		try {
			stmt.executeUpdate(sql);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			flag=false;//捕获到异常。执行失败。返回false；
		}
		return flag;
	}
	public boolean update(String sql)
	{
		boolean flag=true;
		try {
			stmt1.executeUpdate(sql);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			flag=false;
		}
		return flag;
	}
	public boolean delect(String sql)
	{
		boolean flag=true;
		try {
			stmt2.executeUpdate(sql);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			flag=false;
		}
		return flag;
	}
	public ResultSet select(String sql) throws Exception
	{

			return stmt3.executeQuery(sql);

	}
}

　　dao层

package dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import com.mysql.jdbc.ResultSetImpl;

import bean.Student;
import conn.Conn;
/*本类中拼接sql语句  本类为实现接口方法
 * 用于用户调用
 * 传入conn连接数据库类
 * 节后的实现后缀用impl
 *
 * */
public class StudentDao implements IStudentDao {
	Conn conn=new Conn();
	@Override
	public boolean insertStudent(Student student) {
		// TODO Auto-generated method stub
		String name=student.getName();
		int age=student.getAge();
		int sex=student.getSex();
		String sql = "INSERT INTO student(`name`,`age`,`sex`) VALUES('"+name+"',"+age+","+sex+");";

		return conn.insert(sql);
	}

	@Override
	public boolean updateStudent(Student student) {
		int id=student.getId();
		String name=student.getName();
		int age=student.getAge();
		int sex=student.getSex();
		String sql = "UPDATE student set `name`='"+name+"',age="+age+",sex="+sex+" WHERE id="+id+"";
	   // String sql = "UPDATE student SET `name`='"+name+"'"+",age="+age+",sex="+sex+" WHERE id="+id;
		return conn.update(sql);
	}

	@Override
	public boolean delectStudent(Student student) {
		// TODO Auto-generated method stub
		int id=student.getId();
		String sql = "DELETE FROM student where id="+id;
		return conn.delect(sql);
	}

	@Override
	public ArrayList<Student> selectStudent() {
		// TODO Auto-generated method stub
		String sql="select *from student;";
		ResultSet set=null;
		ArrayList<Student> list=new ArrayList<>();
		try {
			set=conn.select(sql);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		try {
			while(set.next())
			{
				Student student=new Student();
				student.setId(set.getInt("id"));
				student.setName(set.getString("name"));
				student.setAge(set.getInt("age"));
				student.setSex(set.getInt("sex"));
				list.add(student);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return list;
	}

}

　　

package dao;

import java.util.ArrayList;

import bean.Student;

public interface IStudentDao {
/*本接口写方法。用于其他类继承调用
 * 使用其他包类是。需要先导入
 * 查询结果返回数组
 * 接口
 *
 * */
public boolean insertStudent(Student student);
public boolean updateStudent(Student student);
public boolean delectStudent(Student student);
public ArrayList<Student> selectStudent();
}

　　server

package server;

import java.util.ArrayList;

import bean.Student;

public interface IStudentServer {
	public boolean insertStudent(Student student);
	public boolean deleteStudent(Student student);
	public boolean updateStudent(Student student);
	public ArrayList<Student> selectAllStudent();

}

　

package serverImpl;

import java.util.ArrayList;

import bean.Student;
import dao.StudentDao;
import server.IStudentServer;

public class ServerStudent implements IStudentServer{
		StudentDao studentDao= new StudentDao();

	@Override
	public boolean insertStudent(Student student) {
		// TODO Auto-generated method stub
		return studentDao.insertStudent(student);
	}

	@Override
	public boolean deleteStudent(Student student) {
		// TODO Auto-generated method stub
		return studentDao.delectStudent(student);
	}

	@Override
	public boolean updateStudent(Student student) {
		// TODO Auto-generated method stub
		return studentDao.updateStudent(student);
	}

	@Override
	public ArrayList<Student> selectAllStudent() {
		// TODO Auto-generated method stub
		return studentDao.selectStudent();
	}

}

　　action

package action;

import java.util.ArrayList;

import bean.Student;
import serverImpl.ServerStudent;

public class StudentAction {
ServerStudent serverStudent =new ServerStudent();
public String insertStudent(Student student)
{
	boolean flag=serverStudent.insertStudent(student);
	if(flag==true)
		return "插入成功";
	else
		return "插入失败";
}
public String delectStudent(Student  student)
{	boolean flag=serverStudent.deleteStudent(student);
	if(flag==true)
	return "刪除成功";
else
	return "刪除失败";
	}
public String updateStudent(Student student)
{	boolean flag=serverStudent.updateStudent(student);
if(flag==true)
	return "修改成功";
else
	return "修改失败";
	}
public String selectStudent()
{
	ArrayList<Student> student=serverStudent.selectAllStudent();
	String ss = "";
	for(Student chaoba:student) {
		ss += "id："+chaoba.getId();
		ss += " name:"+chaoba.getName();
		ss += " age:" + chaoba.getAge();
		ss += " sex:" + (chaoba.getSex()==1?"男":"女");
		ss += "\r\n";
	}
	return ss;
	}
}

　　

bean 业务实体

package bean;
/*Student类。用做业务实体，
 * 进行复制。传递获取
 *
 *
 *
 *
 * */
public class Student {
private int id;
private String name;
private int age;
private int sex;
public int getId() {
	return id;
}
public void setId(int id) {
	this.id = id;
}
public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}
public int getAge() {
	return age;
}
public void setAge(int age) {
	this.age = age;
}
public int getSex() {
	return sex;
}
public void setSex(int sex) {
	this.sex = sex;
}

}

　　

　*-------------------------------------------*
By:暮雪超霸博客：http://www.cnblogs.com/chaoba/
　*-------------------------------------------*