1、创建数据库连接类：
package com.db.mvp;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
//数据库连接类
public class DatabaseManager {
private static DatabaseManager instance;
private Connection connection;
private DatabaseManager() {
// 私有构造函数，禁止外部直接创建实例
}
public static synchronized DatabaseManager getInstance() {
if (instance == null) {
instance = new DatabaseManager();
}
return instance;
}
public Connection getConnection() throws SQLException {
if (connection == null || connection.isClosed()) {
// 数据库连接配置
String url = "jdbc:mysql://localhost:3306/test_data";
String username = "root";
String password = "admin";
connection = DriverManager.getConnection(url, username, password);
}
return connection;
}
}2、创建Model的实体类：
package com.db.mvp;
//实体类
public class WordsInfo {
private int id;
private String engName;
private String chiVal;
private String lastUsedTime;
private int usedTimes;
private String createdTime;
private int priority;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getEngName() {
return engName;
}
public void setEngName(String engName) {
this.engName = engName;
}
public String getChiVal() {
return chiVal;
}
public void setChiVal(String chiVal) {
this.chiVal = chiVal;
}
public String getLastUsedTime() {
return lastUsedTime;
}
public void setLastUsedTime(String lastUsedTime) {
this.lastUsedTime = lastUsedTime;
}
public int getUsedTimes() {
return usedTimes;
}
public void setUsedTimes(int usedTimes) {
this.usedTimes = usedTimes;
}
public String getCreatedTime() {
return createdTime;
}
public void setCreatedTime(String createdTime) {
this.createdTime = createdTime;
}
public int getPriority() {
return priority;
}
public void setPriority(int priority) {
this.priority = priority;
}
}3、创建Model类：
package com.db.mvp;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import com.db.daomodule.DatabaseManager;
//Model层
public class WordsInfoModel {
private Connection connection;
public List<WordsInfo> getAllWordsInfo() {
List<WordsInfo> wordsInfoList = new ArrayList<>();
try {
connection = DatabaseManager.getInstance().getConnection();
Statement statement = connection.createStatement();
String sql = "SELECT * FROM words_info";
ResultSet resultSet = statement.executeQuery(sql);
while (resultSet.next()) {
WordsInfo wordsInfo = new WordsInfo();
wordsInfo.setId(resultSet.getInt("id"));
wordsInfo.setEngName(resultSet.getString("eng_name"));
wordsInfo.setChiVal(resultSet.getString("chi_val"));
wordsInfo.setLastUsedTime(resultSet.getString("last_used_time"));
wordsInfo.setUsedTimes(resultSet.getInt("used_times"));
wordsInfo.setCreatedTime(resultSet.getString("created_time"));
wordsInfo.setPriority(resultSet.getInt("priority"));
wordsInfoList.add(wordsInfo);
}
resultSet.close();
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
return wordsInfoList;
}
public void insertWordsInfo(WordsInfo wordsInfo) {
try {
connection = DatabaseManager.getInstance().getConnection();
String sql = "INSERT INTO words_info (eng_name, chi_val, last_used_time, used_times, created_time, priority) VALUES (?, ?, ?, ?, ?, ?)";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, wordsInfo.getEngName());
statement.setString(2, wordsInfo.getChiVal());
statement.setString(3, wordsInfo.getLastUsedTime());
statement.setInt(4, wordsInfo.getUsedTimes());
statement.setString(5, wordsInfo.getCreatedTime());
statement.setInt(6, wordsInfo.getPriority());
statement.executeUpdate();
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void updateWordsInfo(WordsInfo wordsInfo) {
try {
connection = DatabaseManager.getInstance().getConnection();
String sql = "UPDATE words_info SET eng_name=?, chi_val=?, last_used_time=?, used_times=?, created_time=?, priority=? WHERE id=?";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, wordsInfo.getEngName());
statement.setString(2, wordsInfo.getChiVal());
statement.setString(3, wordsInfo.getLastUsedTime());
statement.setInt(4, wordsInfo.getUsedTimes());
statement.setString(5, wordsInfo.getCreatedTime());
statement.setInt(6, wordsInfo.getPriority());
statement.setInt(7, wordsInfo.getId());
statement.executeUpdate();
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void deleteWordsInfo(int id) {
try {
connection = DatabaseManager.getInstance().getConnection();
String sql = "DELETE FROM words_info WHERE id=?";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setInt(1, id);
statement.executeUpdate();
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}4、创建Presenter层：
package com.db.mvp;
import java.util.List;
//Presenter层,同时持有Model对象和View对象。
public class WordsInfoPresenter {
private WordsInfoModel model;
private WordsInfoView view;
public WordsInfoPresenter(WordsInfoView view) {
this.view = view;
model = new WordsInfoModel();
}
public void getAllWordsInfo() {
List<WordsInfo> wordsInfoList = model.getAllWordsInfo();
view.showWordsInfo(wordsInfoList);
}
public void insertWordsInfo(WordsInfo wordsInfo) {
model.insertWordsInfo(wordsInfo);
getAllWordsInfo(); // 刷新数据显示
}
public void updateWordsInfo(WordsInfo wordsInfo) {
model.updateWordsInfo(wordsInfo);
getAllWordsInfo(); // 刷新数据显示
}
public void deleteWordsInfo(int id) {
model.deleteWordsInfo(id);
getAllWordsInfo(); // 刷新数据显示
}
}5、创建View层：
package com.db.mvp;
import java.util.List;
//View层
public interface WordsInfoView {
void getAllWordsInfo();
void showWordsInfo(List<WordsInfo> wordsInfoList);
}
6、创建UserView类实现View层接口，并进行测试：
package com.db.mvp;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
//在MVP模式中，View层负责与用户交互和展示数据的内容，
//Presenter层负责处理业务逻辑并更新View层，
//Model层负责存储和管理数据。
//MVC与MVP模式的主要区别如下：
//职责分配：
//在MVC模式中，Model负责管理应用程序的数据和业务逻辑，View负责呈现数据给用户，Controller负责接受用户的输入并作出响应。
//在MVP模式中，Model同样负责管理数据和业务逻辑，View负责呈现数据给用户，
//Presenter作为中间人负责处理用户的输入，将输入与Model交互，并更新View。
//数据流：
//在MVC模式中，数据流是双向的。用户的输入通过Controller传递给Model进行处理，处理后的数据通过View呈现给用户。
//同时，Model也可以直接更新View。
//在MVP模式中，数据流是单向的。用户的输入通过View传递给Presenter进行处理，Presenter将数据交给Model进行处理，
//处理完成后，Model将结果交给Presenter，再由Presenter更新View。
//单向依赖：
//在MVC模式中，View依赖于Controller和Model，Controller依赖于View和Model，Model独立存在。
//在MVP模式中，View只依赖于Presenter，Presenter依赖于View和Model，Model独立存在。
//可测试性：
//在MVC模式中，由于Controller处理用户的输入和输出，因此可以很容易地对Controller进行单元测试。
//在MVP模式中，由于Presenter处理用户的输入和输出，因此可以很容易地对Presenter进行单元测试。
public class UserView implements WordsInfoView {
private WordsInfoPresenter presenter;
//this关键字指的是当前类的实例，即Main类的实例。
//在Main类的构造方法中，实例化一个WordsInfoPresenter对象，并将this作为参数传递给它。
//这样做的目的是将WordsInfoView接口的实现传递给WordsInfoPresenter，
//以便在WordsInfoPresenter中调用WordsInfoView接口的方法。
//通过将this传递给WordsInfoPresenter，
//WordsInfoPresenter就可以调用Main类中实现的showWordsInfo方法，以便在控制台上显示单词信息。
public UserView() {
presenter = new WordsInfoPresenter(this);
}
public static void main(String[] args) {
// 获取当前时间
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String currentTime = dateFormat.format(new Date());
UserView userView = new UserView();
userView.getAllWordsInfo();
WordsInfo wordsInfo = new WordsInfo();
wordsInfo.setEngName("test");
wordsInfo.setChiVal("测试");
wordsInfo.setLastUsedTime(currentTime);
wordsInfo.setUsedTimes(1);
wordsInfo.setCreatedTime(currentTime);
wordsInfo.setPriority(0);
//presenter作为中间人负责处理用户的输入，将输入与Model交互，并更新View。
userView.presenter.insertWordsInfo(wordsInfo);
userView.presenter.getAllWordsInfo();
userView.presenter.updateWordsInfo(wordsInfo);
userView.presenter.getAllWordsInfo();
userView.presenter.deleteWordsInfo(98);
userView.presenter.getAllWordsInfo();
}
@Override
public void showWordsInfo(List<WordsInfo> wordsInfoList) {
for (WordsInfo wordsInfo : wordsInfoList) {
System.out.println(wordsInfo.getEngName() + " - " + wordsInfo.getChiVal());
}
}
@Override
public void getAllWordsInfo() {
}
}