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很多刚入门的同学,不清楚如何用java、swing去开发出一个系统?

不清楚如何使用java代码去操作数据库进行增删改查一些列操作,不清楚java代码和数据库(mysql、sqlserver)之间怎么联系起来。

一个系统本质上就是一系列的模块组合起来的,只要懂了一个模块的实现,其他的自然而然的也就不难。

今天,我们通过做一个学生管理的一个通俗模块,去给大家演示如何用java+swing+mysql去实现一个学生管理的曾删改查。

1.前期准备工作,开发工具安装,主要包括如下开发工具:

  • jdk,java开发和运行环境,1.7或者1.8的版本都可以。
  • eclispe,java代码编写工具,主要用来写java代码,当然你可以用idea
  • mysql,数据库,主要用来存储数据,5.6以上版本,8.0的版本需要注意驱动的升级
  • navicat for mysql 数据库可视化工具,主要用来操作mysql,简化数据库操作。

2.以上环境准备好之后,接下来可以进行数据库表的设计,我们可以用navicat for mysql创建一个数据库(如何创建,可以自行科普),名字叫做db_demo;

然后再新建一个数据库表t_student,sql语句如下,可自行拷贝然后执行:

DROP TABLE IF EXISTS `t_student`;
CREATE TABLE `t_student` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '学生ID',
  `stuno` varchar(32) DEFAULT NULL COMMENT '学号',
  `name` varchar(32) DEFAULT NULL COMMENT '姓名',
  `grade` varchar(32) DEFAULT NULL COMMENT '班级',
  `create_time` datetime DEFAULT NULL COMMENT '添加时间',
  `update_time` datetime DEFAULT NULL COMMENT '修改时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

这样数据库表,就已经创建好了。数据库表一般对应一个entity实体类,字段互相对应,实体类代码如下:

package com.xiaoniucr.entity;

import java.util.Date;

/**
 * 学生实体类
 * @author Lenovo
 *
 */
public class Student {
	
	/**
	 * 学生ID
	 */
	private Integer id;
	
	/**
	 * 学号
	 */
	private String stuno;
	
	/**
	 * 姓名
	 */
	private String name;
	
	/**
	 * 班级
	 */
	private String grade;
	
	/**
	 * 添加时间
	 */
	private Date creatTime;
	
	/**
	 * 修改时间
	 */
	private Date updateTime;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getStuno() {
		return stuno;
	}

	public void setStuno(String stuno) {
		this.stuno = stuno;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getGrade() {
		return grade;
	}

	public void setGrade(String grade) {
		this.grade = grade;
	}

	public Date getCreatTime() {
		return creatTime;
	}

	public void setCreatTime(Date creatTime) {
		this.creatTime = creatTime;
	}

	public Date getUpdateTime() {
		return updateTime;
	}

	public void setUpdateTime(Date updateTime) {
		this.updateTime = updateTime;
	}
	
	

}

  

3.接下来我们开始写java代码了,首先设计界面,粗略思考一下,包含三个界面:学生列表查询界面,学生信息添加界面,学生信息修改界面,其中添加界面和修改界面差不多的,界面如下:

查询界面:

查询界面设计代码:

package com.xiaoniucr.view;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableModel;

import com.xiaoniucr.dao.StudentDao;
import com.xiaoniucr.entity.Student;

public class UserListView extends JFrame {

	private JPanel contentPane;
	private JTable table;
	private JTextField nameText;

	private StudentDao studentDao = new StudentDao();

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					UserListView frame = new UserListView();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public UserListView() {

		setTitle("学生列表");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 600, 337);
		setLocationRelativeTo(null);
		
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);

		JScrollPane scrollPane = new JScrollPane();
		scrollPane.setBounds(10, 39, 564, 232);
		contentPane.add(scrollPane);

		Object[] columns = { "ID", "学号", "姓名", "年级", "添加时间" };// 字段
		Object[][] data = null;// 需要展示的数据,一般是二维数组
		DefaultTableModel model = new DefaultTableModel(data, columns);
		table = new JTable(model);
		//加载学生数据
		load(null);
		scrollPane.setViewportView(table);

		JLabel lblNewLabel = new JLabel("姓名");
		lblNewLabel.setBounds(10, 10, 42, 15);
		contentPane.add(lblNewLabel);

		nameText = new JTextField();
		nameText.setBounds(44, 8, 115, 21);
		contentPane.add(nameText);
		nameText.setColumns(10);

		//查询按钮
		JButton searchBtn = new JButton("查询");
		searchBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				load(nameText.getText());
			}
		});
		searchBtn.setBounds(169, 8, 63, 23);
		contentPane.add(searchBtn);

		//添加按钮
		JButton addBtn = new JButton("添加");
		addBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				AddView view = new AddView();
				view.setVisible(true);
			}
		});
		addBtn.setBounds(365, 8, 63, 23);
		contentPane.add(addBtn);

		//修改按钮
		JButton updateBtn = new JButton("修改");
		updateBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 获取选中行
				int row = table.getSelectedRow();
				if (row < 0) {
					JOptionPane.showMessageDialog(contentPane, "请选择一条记录", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				int id = Integer.valueOf(table.getValueAt(row, 0).toString());
				UpdateView view = new UpdateView(id);
				view.setVisible(true);
				
			}
		});
		updateBtn.setBounds(438, 8, 63, 23);

		//删除按钮
		JButton deleteBtn = new JButton("删除");
		deleteBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 获取选中行
				int row = table.getSelectedRow();
				if (row < 0) {
					JOptionPane.showMessageDialog(contentPane, "请选择一条记录", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				int result = JOptionPane.showConfirmDialog(contentPane, "确认删除该学生吗?", "提示",
						JOptionPane.YES_NO_OPTION);
				if (result == 0) {
					int id = Integer.valueOf(table.getValueAt(row, 0).toString());
					boolean flag = studentDao.delete(id);
					if(flag){
						JOptionPane.showMessageDialog(contentPane, "删除成功!");
						load(null);
					}else{
						JOptionPane.showMessageDialog(contentPane, "操作失败", "系统提示", JOptionPane.WARNING_MESSAGE);
						
					}
				}
				return;
			}
		});
		deleteBtn.setBounds(511, 8, 63, 23);
		contentPane.add(deleteBtn);
		contentPane.add(updateBtn);
	}

	// 填充表格数据
	public void load(String name){
		List<Student> list = studentDao.queryList(name);
		DefaultTableModel tableModel = (DefaultTableModel) table.getModel();
		tableModel.setRowCount(0);// 清除原有行
		// 填充数据
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		for (Student item : list) {
			String[] arr = new String[5];
			arr[0] = item.getId() + "";
			arr[1] = item.getStuno();
			arr[2] = item.getName();
			arr[3] = item.getGrade();
			arr[4] = sdf.format(item.getCreatTime());
			// 添加数据到表格
			tableModel.addRow(arr);
		}
	}
}

添加界面:

添加界面代码:

package com.xiaoniucr.view;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;

import com.xiaoniucr.dao.StudentDao;
import com.xiaoniucr.entity.Student;

public class AddView extends JFrame {

	private JPanel contentPane;
	private JTextField stunoText;
	private JTextField nameText;
	private JTextField gradeText;
	
	private StudentDao studentDao = new StudentDao();

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					AddView frame = new AddView();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public AddView() {
		setTitle("学生添加");
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setBounds(100, 100, 443, 300);
		setLocationRelativeTo(null);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JLabel lblNewLabel = new JLabel("学号:");
		lblNewLabel.setBounds(112, 50, 43, 15);
		contentPane.add(lblNewLabel);
		
		stunoText = new JTextField();
		stunoText.setBounds(151, 47, 160, 21);
		contentPane.add(stunoText);
		stunoText.setColumns(10);
		
		JLabel lblNewLabel_1 = new JLabel("姓名:");
		lblNewLabel_1.setBounds(112, 93, 43, 15);
		contentPane.add(lblNewLabel_1);
		
		nameText = new JTextField();
		nameText.setBounds(151, 90, 160, 21);
		contentPane.add(nameText);
		nameText.setColumns(10);
		
		JLabel lblNewLabel_2 = new JLabel("班级:");
		lblNewLabel_2.setBounds(111, 134, 43, 15);
		contentPane.add(lblNewLabel_2);
		
		gradeText = new JTextField();
		gradeText.setBounds(151, 131, 160, 21);
		contentPane.add(gradeText);
		gradeText.setColumns(10);
		
		//保存
		JButton saveBtn = new JButton("保存");
		saveBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				
				String stuno = stunoText.getText();
				String name = nameText.getText();
				String grade = gradeText.getText();
				if(stuno == null || "".equals(stuno)){
					JOptionPane.showMessageDialog(contentPane, "请输入学号", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				if(name == null || "".equals(name)){
					JOptionPane.showMessageDialog(contentPane, "请输入姓名", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				if(grade == null || "".equals(grade)){
					JOptionPane.showMessageDialog(contentPane, "请输入班级", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				Student student = new Student();
				student.setStuno(stuno);
				student.setName(name);
				student.setGrade(grade);
				boolean flag = studentDao.save(student);
				if(flag){
					dispose();
					JOptionPane.showMessageDialog(contentPane, "添加成功,刷新可查看!");
				}else{
					JOptionPane.showMessageDialog(contentPane, "操作失败", "系统提示", JOptionPane.WARNING_MESSAGE);
				}
				return;
				
				
			}
		});
		saveBtn.setBounds(151, 180, 74, 23);
		contentPane.add(saveBtn);
		
		//取消
		JButton cancleBtn = new JButton("取消");
		cancleBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				dispose();
			}
		});
		cancleBtn.setBounds(237, 180, 74, 23);
		contentPane.add(cancleBtn);
	}

}

修改界面:

 修改界面代码:

package com.xiaoniucr.view;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;

import com.xiaoniucr.dao.StudentDao;
import com.xiaoniucr.entity.Student;

public class UpdateView extends JFrame {

	private JPanel contentPane;
	private JTextField stunoText;
	private JTextField nameText;
	private JTextField gradeText;
	
	private StudentDao studentDao = new StudentDao();

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					UpdateView frame = new UpdateView(1);
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public UpdateView(final int id) {
		setTitle("学生编辑");
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setBounds(100, 100, 443, 300);
		setLocationRelativeTo(null);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JLabel lblNewLabel = new JLabel("学号:");
		lblNewLabel.setBounds(112, 50, 43, 15);
		contentPane.add(lblNewLabel);
		
		stunoText = new JTextField();
		stunoText.setBounds(151, 47, 160, 21);
		contentPane.add(stunoText);
		stunoText.setColumns(10);
		
		JLabel lblNewLabel_1 = new JLabel("姓名:");
		lblNewLabel_1.setBounds(112, 93, 43, 15);
		contentPane.add(lblNewLabel_1);
		
		nameText = new JTextField();
		nameText.setBounds(151, 90, 160, 21);
		contentPane.add(nameText);
		nameText.setColumns(10);
		
		JLabel lblNewLabel_2 = new JLabel("班级:");
		lblNewLabel_2.setBounds(111, 134, 43, 15);
		contentPane.add(lblNewLabel_2);
		
		gradeText = new JTextField();
		gradeText.setBounds(151, 131, 160, 21);
		contentPane.add(gradeText);
		gradeText.setColumns(10);
		
		//保存
		JButton saveBtn = new JButton("保存");
		saveBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				
				String stuno = stunoText.getText();
				String name = nameText.getText();
				String grade = gradeText.getText();
				if(stuno == null || "".equals(stuno)){
					JOptionPane.showMessageDialog(contentPane, "请输入学号", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				if(name == null || "".equals(name)){
					JOptionPane.showMessageDialog(contentPane, "请输入姓名", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				if(grade == null || "".equals(grade)){
					JOptionPane.showMessageDialog(contentPane, "请输入班级", "系统提示", JOptionPane.WARNING_MESSAGE);
					return;
				}
				Student student = new Student();
				student.setId(id);
				student.setStuno(stuno);
				student.setName(name);
				student.setGrade(grade);
				boolean flag = studentDao.update(student);
				if(flag){
					dispose();
					JOptionPane.showMessageDialog(contentPane, "修改成功,刷新可查看!");
				}else{
					JOptionPane.showMessageDialog(contentPane, "操作失败", "系统提示", JOptionPane.WARNING_MESSAGE);
				}
				return;
				
				
			}
		});
		saveBtn.setBounds(151, 180, 74, 23);
		contentPane.add(saveBtn);
		
		//取消
		JButton cancleBtn = new JButton("取消");
		cancleBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				dispose();
			}
		});
		cancleBtn.setBounds(237, 180, 74, 23);
		contentPane.add(cancleBtn);
		
		//数据回显
		Student student = studentDao.getById(id);
		stunoText.setText(student.getStuno());
		nameText.setText(student.getName());
		gradeText.setText(student.getGrade());
	}

}

4.界面设计完成之后,就是连接数据库了,连接数据库需要依赖一个jar包:mysql-connector-java-5.1.21.jar,数据库连接代码如下:包含数据库的连接和使用完成之后的一些资源释放。

package com.xiaoniucr.util;

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

public class JDBCUtils {

	//数据库连接地址
	public static String URL = "jdbc:mysql://localhost:3306/db_demo?useUnicode=true&characterEncoding=utf8";
	//数据库驱动
	public static String DRIVER = "com.mysql.jdbc.Driver";
	//数据库用户名
	public static String USER = "root";
	//数据库密码
	public static String PWD = "123456";

	/*
	 * 数据库连接
	 */
	public static Connection getConnection() {

		Connection con = null;
		try {
			// 加载驱动
			Class.forName(DRIVER);
			// 获取连接对象
			con = DriverManager.getConnection(URL, USER, PWD);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return con;
	}

	/**
	 * 关闭连接资源
	 * @param con	连接对象
	 * @param pstmt	预编译对象
	 * @param rs	结果集
	 */
	public static void close(Connection con, PreparedStatement pstmt, ResultSet rs) {

		try {
			if (rs != null){
				rs.close();
			}
			if (pstmt != null){
				pstmt.close();
			}
			if (con != null){
				con.close();
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

}

5.数据库连接完成之后,就是数据库的操作了,这里包含三个操作,学生列表的查询,学生信息的添加保存到数据库,和学生信息的修改保存,数据库操作代码如下:

package com.xiaoniucr.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.xiaoniucr.entity.Student;
import com.xiaoniucr.util.JDBCUtils;

/**
 * 学生数据库操作
 * @author Lenovo
 *
 */
public class StudentDao {
	
	
	
	/**
	 * 查询学生列表
	 * @param name 学生姓名
	 * @return
	 */
	public List<Student> queryList(String name){
		
		
		List<Student> list = new ArrayList<Student>();
		Connection con = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			con = JDBCUtils.getConnection();
			List<Object> params = new ArrayList<>();
			StringBuffer sb = new StringBuffer("select * from t_student where 1=1 ");
			if(name != null && !"".equals(name)){
				sb.append("and name like ? ");
				params.add(name);
			}
			sb.append("order by create_time desc");
			pstmt = con.prepareStatement(sb.toString());
			if(params != null && params.size()>0){
				for(int i=0; i<params.size(); i++){
					pstmt.setObject(i, params.get(i));
				}
			}
			rs = pstmt.executeQuery();
			while(rs.next()){
				Student student = new Student();
				student.setId(rs.getInt("id"));
				student.setStuno(rs.getString("stuno"));
				student.setName(rs.getString("name"));
				student.setGrade(rs.getString("grade"));
				student.setCreatTime(rs.getDate("create_time"));
				student.setUpdateTime(rs.getDate("update_time"));
				list.add(student);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			JDBCUtils.close(con, pstmt, rs);
		}
		return list;
		
		
	}
	
	
	/**
	 * 保存学生信息
	 * @param student
	 * @return
	 */
	public boolean save(Student student){
		
		Connection con = null;
		String sql = "insert into t_student(stuno,name,grade,create_time,update_time) values(?,?,?,?,?)";
		PreparedStatement pstmt = null;
		try {
			con = JDBCUtils.getConnection();
			pstmt = con.prepareStatement(sql);
			pstmt.setString(1, student.getStuno());
			pstmt.setString(2, student.getName());
			pstmt.setString(3, student.getGrade());
			Date date = new Date();
			pstmt.setTimestamp(4, new Timestamp(date.getTime()));
			pstmt.setTimestamp(5, new Timestamp(date.getTime()));
			int rows = pstmt.executeUpdate();
			if(rows > 0){
				return true;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			JDBCUtils.close(con, pstmt, null);
		}
		return false;
	
	}
	
	
	
	/**
	 * 修改学生信息
	 * @param student
	 * @return
	 */
	public boolean update(Student student){
		
		Connection con = null;
		String sql = "update t_student set stuno=?,name=?,grade=?,update_time=? where id=?";
		PreparedStatement pstmt = null;
		try {
			con = JDBCUtils.getConnection();
			pstmt = con.prepareStatement(sql);
			pstmt.setString(1, student.getStuno());
			pstmt.setString(2, student.getName());
			pstmt.setString(3, student.getGrade());
			Date date = new Date();
			pstmt.setTimestamp(4, new Timestamp(date.getTime()));
			pstmt.setInt(5, student.getId());
			int rows = pstmt.executeUpdate();
			if(rows > 0){
				return true;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			JDBCUtils.close(con, pstmt, null);
		}
		return false;
	
	}
	
	
	
	
	/**
	 * 删除学生信息
	 * @param student
	 * @return
	 */
	public boolean delete(int id){
		
		Connection con = null;
		String sql = "delete from t_student where id=?";
		PreparedStatement pstmt = null;
		try {
			con = JDBCUtils.getConnection();
			pstmt = con.prepareStatement(sql);
			pstmt.setInt(1, id);
			int rows = pstmt.executeUpdate();
			if(rows > 0){
				return true;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			JDBCUtils.close(con, pstmt, null);
		}
		return false;
	
	}
	
	
	
	/**
	 * 根据ID查询学生
	 * @param id 学生ID
	 * @return
	 */
	public Student getById(int id){
		
		
		Student student = null;
		Connection con = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			con = JDBCUtils.getConnection();
			String sql = "select * from t_student where id = ?";
			pstmt = con.prepareStatement(sql);
			pstmt.setObject(1, id);
			rs = pstmt.executeQuery();
			while(rs.next()){
				student = new Student();
				student.setId(rs.getInt("id"));
				student.setStuno(rs.getString("stuno"));
				student.setName(rs.getString("name"));
				student.setGrade(rs.getString("grade"));
				student.setCreatTime(rs.getDate("create_time"));
				student.setUpdateTime(rs.getDate("update_time"));
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			JDBCUtils.close(con, pstmt, rs);
		}
		return student;
		
		
	}

}

  以上就是全部的代码了,大家可以参考一下,或者直接创建一个项目,然后代码复制进去,基本都可以跑起来。

 

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