如何在Java代码中运行mysqldump命令？

Question

I want to test to run mysqldump command in my function but I could not create aaadumpdb.sql file. My code is below:

@Test
public void dumpDB() {
    Process p = null;
    try {
        Runtime runtime = Runtime.getRuntime();
        p = runtime
                .exec("mysqldump -u root -padmin --add-drop-database aaa_db "
                        + "D:\\backupdenemeaaa " + "aaadumpdb.sql");
        // change the dbpass and dbname with your dbpass and dbname
        int processComplete = p.waitFor();

        if (processComplete == 0) {

            System.out.println("Backup created successfully!");

        } else {
            JOptionPane.showMessageDialog(new JDialog(),
                    "Could not create the backup");
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    File f = new File("aaadumpdb.sql");

    assertTrue(f.exists());
}

Can anybody give me some advice about it? Thank you.

I did some edit in my code but when I run, my code enter into else structure. What can be the problem?

My editted code is below:

    @Test
public void dumpDB() {
    Process p = null;
    try {
        Runtime runtime = Runtime.getRuntime();
        String mysqldumpExecutable = "C:\\Program Files\\MySQL\\MySQL Server 5.6\\bin\\mysqldump.exe";
        p = runtime.exec(mysqldumpExecutable + " -uroot -padmin --add-drop-database -B aaa_db -r" + "D:\\backupdenemeaaa " + "\\aaadumpdb.sql");
        // change the dbpass and dbname with your dbpass and dbname
        int processComplete = p.waitFor();

        if (processComplete == 0) {

            System.out.println("Backup created successfully!");

        } else {
            JOptionPane.showMessageDialog(new JDialog(),
                    "Could not create the backup");
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    File f = new File("aaadumpdb.sql");

    assertTrue(f.exists());

How can I solve this problem? Thank you.

Answer 1

Add the below snippet to find what exactly is happening

try
        {
            InputStreamReader isr = new InputStreamReader(process.getErrorStream());
            BufferedReader br = new BufferedReader(isr,4094);
            String line=null;
            while ( (line = br.readLine()) != null)
                System.out.println(type + "> " + line);    
            } catch (IOException ioe)
              {
                ioe.printStackTrace();  
              }
    }

You will be aware of the the exceptions and errors that might occur in that Process execution

Answer 2

The stacktrace would really help to debug it, but I believe you can check if "mysqldump" is in your PATH or the application will simple not find the executable. If you don't want to mess around with your PATH you can hardcode the path to the executable like below:

String mysqldumpExecutable = "C:\\apps\\mysql\\mysqldump.exe";
runtime.exec(mysqldumpExecutable + "-u root -padmin --add-drop-database aaa_db (.....));

When you say you can't create the file what exactly does that mean? Are you getting an error? Nothing happens? Help us help you.