使用 Java 对 mysql 数据库进行简单备份和恢复

Question

如何从 java 代码备份 mysql 数据库，例如：

1. 它的保存路径是动态分配的。
2. Path 中的空格不会产生问题。
3. 路径是使用执行的 jar 文件生成的。
4. DBname、DBusername 或 DBpass 是动态分配的。
5. 创建一个专门的文件夹来保存备份文件。

Answer 1

注意：下面给出的代码是解决问题的一种方法，可能不是最好的方法。 代码中的一切都是可变的。 如果环境变量中没有mysql，则在mysqldump和mysql之前添加路径（例如对于XAMPP，C:\xampp\mysql\bin\mysqldump）

（希望这能解决您的问题。我花了一天时间完全弄清楚所有事情并正确实施它们）

备份方法：

public static void Backupdbtosql() {
    try {

        /*NOTE: Getting path to the Jar file being executed*/
        /*NOTE: YourImplementingClass-> replace with the class executing the code*/
        CodeSource codeSource = YourImplementingClass.class.getProtectionDomain().getCodeSource();
        File jarFile = new File(codeSource.getLocation().toURI().getPath());
        String jarDir = jarFile.getParentFile().getPath();


        /*NOTE: Creating Database Constraints*/
        String dbName = "YourDBName";
        String dbUser = "YourUserName";
        String dbPass = "YourUserPassword";

        /*NOTE: Creating Path Constraints for folder saving*/
        /*NOTE: Here the backup folder is created for saving inside it*/
        String folderPath = jarDir + "\\backup";

        /*NOTE: Creating Folder if it does not exist*/
        File f1 = new File(folderPath);
        f1.mkdir();

        /*NOTE: Creating Path Constraints for backup saving*/
        /*NOTE: Here the backup is saved in a folder called backup with the name backup.sql*/
         String savePath = "\"" + jarDir + "\\backup\\" + "backup.sql\"";

        /*NOTE: Used to create a cmd command*/
        String executeCmd = "mysqldump -u" + dbUser + " -p" + dbPass + " --database " + dbName + " -r " + savePath;

        /*NOTE: Executing the command here*/
        Process runtimeProcess = Runtime.getRuntime().exec(executeCmd);
        int processComplete = runtimeProcess.waitFor();

        /*NOTE: processComplete=0 if correctly executed, will contain other values if not*/
        if (processComplete == 0) {
            System.out.println("Backup Complete");
        } else {
            System.out.println("Backup Failure");
        }

    } catch (URISyntaxException | IOException | InterruptedException ex) {
        JOptionPane.showMessageDialog(null, "Error at Backuprestore" + ex.getMessage());
    }
}

还原方法：

public static void Restoredbfromsql(String s) {
        try {
            /*NOTE: String s is the mysql file name including the .sql in its name*/
            /*NOTE: Getting path to the Jar file being executed*/
            /*NOTE: YourImplementingClass-> replace with the class executing the code*/
            CodeSource codeSource = YourImplementingClass.class.getProtectionDomain().getCodeSource();
            File jarFile = new File(codeSource.getLocation().toURI().getPath());
            String jarDir = jarFile.getParentFile().getPath();

            /*NOTE: Creating Database Constraints*/
             String dbName = "YourDBName";
             String dbUser = "YourUserName";
             String dbPass = "YourUserPassword";

            /*NOTE: Creating Path Constraints for restoring*/
            String restorePath = jarDir + "\\backup" + "\\" + s;

            /*NOTE: Used to create a cmd command*/
            /*NOTE: Do not create a single large string, this will cause buffer locking, use string array*/
            String[] executeCmd = new String[]{"mysql", dbName, "-u" + dbUser, "-p" + dbPass, "-e", " source " + restorePath};

            /*NOTE: processComplete=0 if correctly executed, will contain other values if not*/
            Process runtimeProcess = Runtime.getRuntime().exec(executeCmd);
            int processComplete = runtimeProcess.waitFor();

            /*NOTE: processComplete=0 if correctly executed, will contain other values if not*/
            if (processComplete == 0) {
                JOptionPane.showMessageDialog(null, "Successfully restored from SQL : " + s);
            } else {
                JOptionPane.showMessageDialog(null, "Error at restoring");
            }


        } catch (URISyntaxException | IOException | InterruptedException | HeadlessException ex) {
            JOptionPane.showMessageDialog(null, "Error at Restoredbfromsql" + ex.getMessage());
        }

    }

Answer 2

如果Hibernate配置正确，这是小菜一碟：

Session session = HibernateUtil.getSessionFactory().openSession();
// for every table, have the bean implement Serializable and use the next 4 lines
List <TblBean> tblCollection = session.createCriteria(TblBean.class).list();
FileOutputStream backup = new FileOutputStream("backupOf"+TblBean.getClass().getName()+".dat");
ObjectOutputStream backupWriter = new ObjectOutputStream(backup);
backupWriter.write(tblCollection);

Answer 3

public static String getData(String host, String port, String user, String password, String db,String table) throws Exception {

    //an "C:/xampp/mysql/bin/mysqldump" ---- location ito han mysqldump

    Process run = Runtime.getRuntime().exec(
            "C:/xampp/mysql/bin/mysqldump --host="  + host + " --port=" + port + 
            " --user=" + user + " --password=" + password +
            " --compact --databases --add-drop-table --complete-insert --extended-insert " +
            "--skip-comments --skip-triggers "+ db+" --tables "+table);

    InputStream in = run.getInputStream(); 
    BufferedReader br = new BufferedReader(new InputStreamReader(in));
    StringBuffer temp = new StringBuffer();
    int count;
    char[] cbuf = new char[BUFFER];

    while ((count = br.read(cbuf, 0, BUFFER)) != -1)
        temp.append(cbuf, 0, count);

    br.close();
    in.close();

    return temp.toString();
}

Answer 4

除了 chettyharish 的回答，如果您的服务器操作系统是 ubuntu，则路径应该有前斜杠 '/' 而不是反斜杠 '\' 例如/path/to/your/file

例如： String savePath = "\"" + jarDir + "\\backup\\" + "backup.sql\"";

将是： String savePath="/"+jarDir+"/backup/backup.sql"