java操作数据库定时备份与还原

Posted 2020-09-28 磕磕碰碰后才知道如何改变

mysql每天23:00自动备份

1. public class DatabaseBackup {  
2.     /** 
3.      *  
4.      * @param dbdir mysql数据库安装路径 
5.      * @param dbname  数据库的名称 
6.      * @param backdir 备份的目录 
7.      */  
8.     public static void backup(String dbdir, String dbname, String backdir) {  
9.         Calendar calendar = Calendar.getInstance();  
10.         SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy_MM_dd_HHmmss");  
11.         String currentTime = dateFormat.format(calendar.getTime());  
12.         try {  
13.             long startTime = System.currentTimeMillis();  
14.             Runtime rt = Runtime.getRuntime();  
15.             Process child = rt  
16.                     .exec(dbdir + "/bin/mysqldump --default-character-set=utf8 -uroot -p123456 " + dbname);  
17.             InputStream in = child.getInputStream();  
18.             InputStreamReader xx = new InputStreamReader(in, "utf8");  
19.   
20.             FileOutputStream fout = new FileOutputStream(new File(backdir, dbname + "_" + currentTime + ".bak"));  
21.             OutputStreamWriter writer = new OutputStreamWriter(fout, "utf8");  
22.   
23.             dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
24.   
25.             writer.write("-- Dump by Microsoul at " + dateFormat.format(calendar.getTime()) + "\r\n");  
26.   
27.             String inStr;  
28.             BufferedReader br = new BufferedReader(xx);  
29.             // 这样实时写入文件很重要，网上有很多是将读取的存入字符串中，最后再写成文件，这样会导致Java的堆栈内存溢出。  
30.             while ((inStr = br.readLine()) != null) {  
31.                 writer.write(inStr);  
32.                 writer.write("\r\n");  
33.             }  
34.   
35.             writer.write("\r\n-- Use " + (System.currentTimeMillis() - startTime) + "ms\r\n");  
36.   
37.             writer.flush();  
38.             in.close();  
39.             xx.close();  
40.             br.close();  
41.             writer.close();  
42.             fout.close();  
43.         } catch (Exception e) {  
44.             PrintStream print = null;  
45.             try {  
46.                 print = new PrintStream(new File(backdir, currentTime + "_backup_err.log"));  
47.                 dateFormat.applyPattern("yyyy-MM-dd HH:mm:ss");  
48.                 currentTime = dateFormat.format(calendar.getTime());  
49.                 print.println(currentTime + "  backup failed.");  
50.                 e.printStackTrace(print);  
51.                 print.flush();  
52.             } catch (IOException e2) {  
53.   
54.             } finally {  
55.                 if (print != null) {  
56.                     print.close();  
57.                 }  
58.             }  
59.         }  
60.   
61.     }  
62. }  

 以上是备份的代码；

Java代码  

1. public class Test {  
2.     public static void main(String[] args) {  
3.         Calendar twentyOne = Calendar.getInstance();  
4.         twentyOne.set(Calendar.HOUR_OF_DAY, 23);  
5.         twentyOne.set(Calendar.MINUTE, 0);  
6.         twentyOne.set(Calendar.SECOND, 0);  
7.   
8.         new Timer().schedule(new TimerTask() {  
9.             @Override  
10.             public void run() {  
11.                 DatabaseBackup.backup("/usr/local/mysql", "test", "/home/xtiger/db/");  
12.             }  
13.         }, twentyOne.getTime(), 24 * 3600 * 1000);  
14.     }  
15. }