数据库备份与恢复代码

以下是一个MySQL数据库备份和恢复的Java代码示例：

备份代码：

public class MySQLBackup {

    public static void backup(String host, String port, String username, String password, String database) {
        try {
            String backupPath = "backup.sql";
            String mysqldumpPath = "mysqldump";
            String command = mysqldumpPath + " -h " + host + " -P " + port + " -u " + username + " -p" + password + " " + database + " > " + backupPath;
            Process process = Runtime.getRuntime().exec(command);
            int exitValue = process.waitFor();
            if (exitValue == 0) {
                System.out.println("Backup succeeded!");
            } else {
                System.out.println("Backup failed!");
            }
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }

}

恢复代码：

public class MySQLRestore {

    public static void restore(String host, String port, String username, String password, String database) {
        try {
            String backupPath = "backup.sql";
            String mysqlPath = "mysql";
            String command = mysqlPath + " -h " + host + " -P " + port + " -u " + username + " -p" + password + " " + database + " < " + backupPath;
            Process process = Runtime.getRuntime().exec(command);
            int exitValue = process.waitFor();
            if (exitValue == 0) {
                System.out.println("Restore succeeded!");
            } else {
                System.out.println("Restore failed!");
            }
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }

}

这个示例使用了Java的Runtime类来执行系统命令，备份和恢复都是通过执行mysqldump和mysql命令来实现的。请注意，在实际应用中需要替换主机名、端口号、用户名、密码、数据库名和备份文件路径等参数。