Recommendation::Main.java

最新推荐文章于 2023-09-01 00:52:28 发布
原创最新推荐文章于 2023-09-01 00:52:28 发布 · 578 阅读
0 ·
CC 4.0 BY-SA版权
MySQL数据库专栏收录该内容
5 篇文章
订阅专栏
本文介绍了如何使用MySQL数据库进行用户信息插入，并实现基于用户兴趣的推荐系统，通过交互式输入获取用户偏好并生成个性化推荐。
摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >
package pA;

import java.util.Scanner;
import java.util.Arrays;
import java.util.Random;
import java.math.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Main {
	public static Recommend[] arr;
	public static Pair[] arrp;
	public static Scanner input;
	public static Recommend A;
	public static int n;
	public static int num;
	public static int information;
	
	//JDBC的协议、主机名（此处是本地机）、端口号、需要连接的数据库等信息
    public static String url = "jdbc:mysql://localhost:3306/recommend";
    public static String user = "root";                   //登录用户名
    public static String password = "123456";             //登录密码
    
    public static Connection con;
    public static Statement stmt;
	
	public static void main(String[] args) {
		setup();
		loop();
	}
	
	public static void setup() {
		
        try {
        	Class.forName("com.mysql.jdbc.Driver"); //指定MySQL驱动。
            con = DriverManager.getConnection(url, user, password);  //连接MySQL数据库
            System.out.println("连接数据库服务器成功。");
            stmt = con.createStatement();
        } catch (ClassNotFoundException e) {    //捕获没有找到驱动的异常，是forName()方法抛出的。
            System.out.println("没有找到MySQL驱动。");
        } catch (SQLException e) {              //捕获连接失败的异常，是Connection对象抛出的。
            System.out.println("连接数据库服务器失败。");
        }
        
        
        
        
        String chars = "abcdefghijklmnopqrstuvwxyz";	//!!!here
        //String sql1 = "INSERT INTO user VALUES(0,1,2,3,4,5,6,7,'Zhangsan')";
        String sql1 = "INSERT INTO user VALUES("+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		"'"+
        		"Zhangsan"+	//单字母用户
        		"')";
        try {
        	int cnt1 = stmt.executeUpdate(sql1);//执行UPDATE语句，返回更新的记录数。  
        	if (cnt1 != 0) {  
        		System.out.println("INSERT语句执行成功。");
        	}
        } catch (SQLException e) {              //捕获连接失败的异常，是Connection对象抛出的。
            System.out.println("连接数据库服务器失败。");
        }
        
        
        //again
        Random random = new Random();
        
        //System.out.println(chars.charAt((int)(Math.random() * 26)));
        for (int i = 0; i < 10; i++) {
        	String tmp = "INSERT INTO user VALUES("+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		"'"+
        		chars.charAt((int)(Math.random() * 26))+	//用户
        		chars.charAt((int)(Math.random() * 26))+
        		"')";
        	try {
            	int cnt1 = stmt.executeUpdate(tmp);//执行UPDATE语句，返回更新的记录数。  
            	if (cnt1 != 0) {  
            		System.out.println("INSERT语句执行成功。");
            	}
            } catch (SQLException e) {              //捕获连接失败的异常，是Connection对象抛出的。
                System.out.println("连接数据库服务器失败。");
            }	
        }
        
        //again1
        for (int i = 0; i < 10; i++) {
        	String tmp = "INSERT INTO feature VALUES("+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		Math.random()+","+
        		"'"+
        		chars.charAt((int)(Math.random() * 26))+	//商品名
        		chars.charAt((int)(Math.random() * 26))+
        		"')";
        	try {
            	int cnt1 = stmt.executeUpdate(tmp);//执行UPDATE语句，返回更新的记录数。  
            	if (cnt1 != 0) {  
            		System.out.println("INSERT语句执行成功。");
            	}
            } catch (SQLException e) {              //捕获连接失败的异常，是Connection对象抛出的。
                System.out.println("连接数据库服务器失败。");
            }
        }
        
        
        
        
		System.out.println("Please input the number of features of one vector.");
		input = new Scanner(System.in);
		n = input.nextInt();
		
		System.out.println("Please input the considering vector.");
		A = new Recommend(n);
				
		System.out.println("Please input the number of comparing vectors.");
		num = input.nextInt();
		System.out.println("Please input these vectors.");
		arr = new Recommend[num];
		for (int i = 0; i < num; i++) {
			arr[i] = new Recommend(n);
		}
		//Recommend B = new Recommend(n);
		//double s = A.getSimiliar(B);
		//System.out.print("The similiar factor is ");
		//System.out.println(s);
		
		arrp = new Pair[num];
	}
	
	public static void loop() {
		while (true) {
			catchInfo();
			//dealWithInfo();
		}
	}
	
	public static void catchInfo() {
		System.out.println("Please input the kind of information.");
		System.out.println("1 for update; 2 for output to screen.");
		information = input.nextInt();
		switch (information) {
		case 1:
			update();
			break;
		case 2:
			outputToScreen();
		}
	}
	
	//public static void dealWithInfo() {
		
	//}
	
	public static void outputToScreen() {
		System.out.println("Input recommend mode:");
		System.out.println("0 for all; 1 for part; 2 for this user's preference.");
		int mode = input.nextInt();
		if (mode == 0) {
			for (int i = 0; i < num; i++) {
				arrp[i] = new Pair(i, A.getSimiliar(arr[i]));
			}
		} else if (mode == 1) {
			System.out.println("Input the part of recommend.");
			int index = input.nextInt();
			for (int i = 0; i < num; i++) {
				arrp[i] = new Pair(i, A.getSimiliarPartOf(arr[i], index));
			}
		} else if (mode == 2) {
			for (int i = 0; i < num; i++) {
				arrp[i] = new Pair(i, A.getThisUsersPrefer(arr[i]));
			}
		}
		
		Arrays.sort(arrp, new PairCmp());
		//System.out.println("The pre " + num + " number of goods and the recommend rates are:");
		System.out.println("The pre " + num + " number of goods are:");
		for (int i = 0; i < num; i++) { //输出前num个物品，推荐度依次降低
			//System.out.println((int)arrp[i].first + " " + arrp[i].second);
			System.out.println((int)arrp[i].first);
		}
	}
	
	public static void update() {
		System.out.println("Please input the way which the customer view or buy.");
		System.out.println("1 for view; 2 for buy.");
		int w = input.nextInt();
		if (w == 1) {
			A.rate[0] += 1;
			A.maintainRate();
			for (int i = 0; i < n; i++) {
				A.feature[i] = A.rate[i];
			}
		} else if (w == 2) {
			A.rate[0] += 3;
			A.maintainRate();
			for (int i = 0; i < n; i++) {
				A.feature[i] = A.rate[i];
			}
		} else {
			System.out.println("Input wrong.");
		}
	}
}