使用Java代码还原数据库-程序无响应 [英] Database restoring with java code - program not responding

问题描述

我正在尝试使用Java程序还原备份的.sql文件。我在下面发布方法。但是，当我执行此程序时，程序会暂停很长时间。然后，我在命令行（Windows）中执行了相同的mysql命令，它的工作原理十分迷人。

I'm trying to restore a backed up .sql file using Java program. I'm posting the method below. But when I execute this the program halts for a long time. Then I executed same mysql command in command line(Windows) it's works charmingly.

我错过的地方感到困惑。你怎么看 ？

Puzzled where I missed. What do you think ?

            File file;
         final JFileChooser fc = new JFileChooser();
         int returnVal = fc.showOpenDialog(this);

   if (returnVal == JFileChooser.APPROVE_OPTION) {
                 file = fc.getSelectedFile();

         try {
             System.out.println(file.getCanonicalPath());

        String executeCmd = "mysql -u " + username + " -p" + password +" " + dbName+" < "+" \" "+file.getCanonicalPath()+"\" " ;
         Process runtimeProcess;
           runtimeProcess = Runtime.getRuntime().exec(executeCmd);
         int processComplete = runtimeProcess.waitFor();
         if (processComplete == 0) {

            JOptionPane.showMessageDialog(Interface.mainFrame, "Database Backup restored successfully.", "Netmetering", 1);     
        } else {
            System.out.println("Could not restore the backup");
        }
    } catch (IOException | InterruptedException ex) {}

。 。

推荐答案

String executeCmd = "mysql -u " + username + " -p" + password +" " + dbName+" < "+" \" "+file.getCanonicalPath()+"\" " ;
Process runtimeProcess = Runtime.getRuntime().exec(executeCmd);
InputStream is = runtimeProcess.getInputStream();

// Do one OR the other, but not both ;)

// If you don't care about the output, but I think it's a bit of waste personally...
while (is.read() != -1) {}

// I'd at least dump the output to the console...
int byteRead = -1;
while ((byteRead = is.read()) != -1) {
    System.out.print((char)byteRead );
}

int processComplete = runtimeProcess.waitFor();
if (processComplete == 0) {...}

我也建议使用 ProcessBuilder 像这样手动创建 Process ，它可以更好地处理参数-IMHO

I would also recommend using ProcessBuilder over creating the Process manually like this, it handles the parameters better - IMHO

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