Question

我正在尝试学习JSP / Servlets ......我设法编写了一个备份整个数据库的函数......

package com.functions;

import java.io.*;
import java.io.IOException;
//import java.sql.Connection;
//import java.sql.PreparedStatement;
//import java.sql.ResultSet;
//import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//import com.functions.utility.DBConnector;

public class addMarks3 extends HttpServlet {

    private static final long serialVersionUID = 8097085789553030042L;

    protected void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {       

        System.out.println("--------------------");
        System.out.println(" On Backup.java ");
        System.out.println("--------------------");

            fetchDataFromDB(request,response);
    }

    private void fetchDataFromDB(HttpServletRequest request,HttpServletResponse response){


        try {
            Runtime runtime = Runtime.getRuntime();
            File backupFile = new File("C:/Users/Rohan/Desktop/LMS/backup.sql");
            FileWriter fw = new FileWriter(backupFile);
            Process child = runtime.exec("C:/Program Files (x86)/MySQL/MySQL Server 5.5/bin/mysqldump --user=root --password=root --lock-all-tables --opt dummy");
            InputStreamReader irs = new InputStreamReader(child.getInputStream());
            BufferedReader br = new BufferedReader(irs);

            String line;
            while( (line=br.readLine()) != null ) {
                fw.write(line + "\n");
            }
            fw.close();
            irs.close();
            br.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }

    }
}

我仍然无法弄清楚如何验证备份是否成功.. ?? 如何检查备份是否成功。

PS：每次运行文件时都会填充文件....

Answer 1

好吧，如果每次都填充文件，这是否意味着备份成功了？

您是否考虑过将流程流传输到响应流？

Answer 2

尝试这样。检查文件大小。

 File backupFile = new File("C:/Users/Rohan/Desktop/LMS/backup.sql");
 int len1=backupFile.length();
 FileWriter fw = new FileWriter(backupFile);

 Process child = runtime.exec("C:/Program Files (x86)/MySQL/MySQL Server 5.5/bin/mysqldump --user=root --password=root --lock-all-tables --opt dummy");
        InputStreamReader irs = new InputStreamReader(child.getInputStream());
        BufferedReader br = new BufferedReader(irs);
        String line;
        while( (line=br.readLine()) != null ) {
            fw.write(line + "\n");
        }
        fw.close();
        irs.close();
        br.close(); 

       int len2=backupFile.length();

       int compare=len2-len1;

          if(compare>0)
          {
            System.out.println("-- Backup done---");
          }

检查备份已创建

2 个答案: