第十四周课程总结&实验报告

简易记事本

（一）实验代码：

package A;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;

import javax.swing.*;

public class TextPad implements ActionListener {
    JFrame frame;
    JMenuBar bar;
    JMenu fileMenu, editMenu;
    ImageIcon newIcon, openIcon, saveIcon, closeIcon;
    JMenuItem newItem, openItem, saveItem, closeItem;
    JTextArea area;
    JScrollPane scroll;
    File file;

    public TextPad() {
        frame = new JFrame("HNC");
        bar = new JMenuBar();
        fileMenu = new JMenu("文件");
        area = new JTextArea();
        scroll = new JScrollPane(area);

        newIcon = new ImageIcon("d:" + File.separator + "tupian" + File.separator + "1.jpg");
        openIcon = new ImageIcon("d:" + File.separator + "tupian" + File.separator + "2.jpg");
        saveIcon = new ImageIcon("d:" + File.separator + "tupian"+ File.separator + "3.jpg");
        closeIcon = new ImageIcon("d:" + File.separator + "tupian" + File.separator + "4.jpg");
        newItem = new JMenuItem("新建(N)", newIcon);
        openItem = new JMenuItem("打开(O)", openIcon);
        saveItem = new JMenuItem("保存(S)", saveIcon);
        closeItem = new JMenuItem("关闭(C)", closeIcon);

        newItem.setMnemonic(KeyEvent.VK_N);
        openItem.setMnemonic(KeyEvent.VK_O);
        saveItem.setMnemonic(KeyEvent.VK_S);
        closeItem.setMnemonic(KeyEvent.VK_C);

        newItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N,
                InputEvent.CTRL_MASK));
        openItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,
                InputEvent.CTRL_MASK));
        saveItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,
                InputEvent.CTRL_MASK));
        closeItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,
                InputEvent.CTRL_MASK));

        newItem.addActionListener(this);
        openItem.addActionListener(this);
        saveItem.addActionListener(this);
        closeItem.addActionListener(this);
        bar.add(fileMenu);
        fileMenu.add(newItem);
        fileMenu.add(openItem);
        fileMenu.add(saveItem);
        fileMenu.add(closeItem);
        frame.add(scroll);
        frame.setJMenuBar(bar);
        frame.setSize(400, 300);
        frame.setLocation(300, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }


    public void actionPerformed(ActionEvent event) {
        Object obj = event.getSource();
        if (obj instanceof JMenuItem) {
            JMenuItem item = (JMenuItem) obj;
            if (item == newItem) {
                new TextPad();
            } else if (item == openItem) {
                JFileChooser chooser = new JFileChooser();
                chooser.showOpenDialog(null);
                file = chooser.getSelectedFile();
                try {
                    FileInputStream fis = new FileInputStream(file);
                    byte[] b = new byte[fis.available()];
                    fis.read(b);
                    area.append(new String(b));
                    fis.close();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else if (item == saveItem) {
                JFileChooser chooser = new JFileChooser();
                chooser.showSaveDialog(null);
                file = chooser.getSelectedFile();
                if (!file.exists()) {
                    try {
                        PrintStream out = new PrintStream(new FileOutputStream(file));
                        out.print(area.getText());
                        out.close();
                    } catch (FileNotFoundException e1) {
                        e1.printStackTrace();
                    }
                }
            } else if (item == closeItem) {
                System.exit(0);
            }
        }

    }
}

实验结果：

　 JDBC驱动程序分为四类： 1）JDBC-ODBC桥驱动； 2）JDBA本地驱动； 3）JDBC网络驱动； 4）本地协议纯JDBC驱动；

JDBC的连接地址实际上是由以下的3个部分组成。
（1）jabc 协议：JDBC URL 中的协议总是 jdbc。
（2）子协议：驱动程序名或数据库连接机制（这种机制可由一个或多个驱动程序支持）的名称，如
MySQL。
（3）子名称： 种标识数据库的方法。必须遵循“//主机名：端口/子协议”的标准URL 命名约定,
如//localhost:3306/mldn

加载驱动程序：

Class.forName(driverClass)
//加载MySql驱动
Class.forName("com.mysql.jdbc.Driver")
//加载Oracle驱动
Class.forName("oracle.jdbc.driver.OracleDriver")

获得数据库连接：

DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/imooc", "root", "root");

创建StatementPreparedStatement对象：

conn.createStatement();
conn.prepareStatement(sql);

完整实例：

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

public class DbUtil {

    public static final String URL = "jdbc:mysql://localhost:3306/imooc";
    public static final String USER = "liulx";
    public static final String PASSWORD = "123456";

    public static void main(String[] args) throws Exception {
        //1.加载驱动程序
        Class.forName("com.mysql.jdbc.Driver");
        //2. 获得数据库连接
        Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
        //3.操作数据库，实现增删改查
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("SELECT user_name, age FROM imooc_goddess");
        //如果有数据，rs.next()返回true
        while(rs.next()){
            System.out.println(rs.getString("user_name")+" 年龄："+rs.getInt("age"));
        }
    }
}