package cc.openhome;import java.io.Serializable;public class Message implements Serializable {private Long id;private String name;private String email;private String msg;public Message() {}public Message(String name, String email, String msg) {this.name = name;this.email = email;this.msg = msg;}public String getEmail(){return email;}public void setEmail(String email) {this.email = email;}public Long getId() {return id;}public void setId(Long id) {this.id = id;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}public String getName() {return name;}public void setName(String name) {this.name = name;}
}

package cc.openhome;import java.sql.*;
import java.util.*;public class MessageDAO {private String url;private String user;private String passwd;public MessageDAO(String url, String user, String passwd) {this.url = url;this.user = user;this.passwd = passwd;}public void add(Message message) {try {Connection conn = DriverManager.getConnection(url, user, passwd);Statement statement = conn.createStatement();statement.executeUpdate("INSERT INTO t_message(name, email, msg) VALUES('"+ message.getName() + "', '"+ message.getEmail() + "', '"+ message.getMsg() + "')");} catch (SQLException e) {throw new RuntimeException(e);}}public List<Message> get() {List<Message> messages = null;try {Connection conn = DriverManager.getConnection(url, user, passwd);Statement statement = conn.createStatement();ResultSet result = statement.executeQuery("SELECT * FROM t_message");messages = new ArrayList<Message>();while(result.next()) {Message message = new Message();message.setId(result.getLong(1));message.setName(result.getString(2));message.setEmail(result.getString(3));message.setMsg(result.getString(4));messages.add(message);}} catch (SQLException e) {throw new RuntimeException(e);}return messages;}}

package cc.openhome;import java.util.Scanner;public class MessageDAODemo {public static void main(String args[]) throws Exception {Scanner scanner = new Scanner(System.in);MessageDAO dao = new MessageDAO("jdbc:mysql://1.2.3.4:3306/demo?" +"useUnicode=true&characterEncoding=UTF8","user", "pwd");while (true) {System.out.print("(1) Show Message (2) Add Message: ");switch(Integer.parseInt(scanner.nextLine())) {case 1:for (Message message : dao.get()) {System.out.printf("%d\t%s\t%s\t%s%n",message.getId(),message.getName(),message.getEmail(),message.getMsg());}break;case 2:System.out.print("Name: ");String name = scanner.nextLine();System.out.print("Email: ");String email = scanner.nextLine();System.out.print("Message: ");String msg = scanner.nextLine();dao.add(new Message(name, email, msg));}}}
}