error for Importing sql file to mysql database using java in windows

Question

here is my code

try{   
String logf = "mysql -p -h localhost ruralcdn<E:\\data\\DBServer\\"+FileName;
System.out.println("Command"+logf);
Runtime rt = Runtime.getRuntime();

Process pr = rt.exec(logf); 
int lm = pr.waitFor();
System.out.println("lm"+lm);

System.out.println("!!Done!!");
}catch(Exception ex){
System.out.println("!!error!!");                

}

when i compile the above code, it hangs for infinite period of time and no entry updated in my database. when i tried using the method given below

Connection conn = dbConnectionSource.getConnection();
Statement stmt = conn.createStatement();
stmt.execute(FileUtils.readFileToString(new File("./some-sql-file")));

console displayed error:you have an error in your sql syntex

please help me so that i can do things correctly.

Thanks -A

when i tried second method and my file containing only one sql query then it works fine but when sql file have more than one sql query it shows error!! — user1376689
– user1376689, Commented May 5, 2012 at 14:51

Stephen C · Accepted Answer · 2012-05-06 08:09:29Z

4

Your command (in logf) includes a redirection of standard input. Unfortunately, you can't do it that way because the Process.exec(String) method doesn't understand how to do command redirection, quoting and sso on. It only understands how to execute a simple command with arguments separated by spaces.

You've got two choices:

You can open the file in Java, and write it to the process object's output stream so that it show up on the commands standard input.
You can tell Java to run the mysql command in a shell / command interpretter that can take care of the redirection and so on.

Your code should look something like this:

String[] command = new String{
        "cmd",
        "/c",
        "mysql -p -h localhost ruralcdn < E:\\data\\DBServer\\" + fileName;

ProcessBuilder pb = new ProcessBuilder(command);
Process p = pb.start();
p.waitFor();

The other thing that your code should do is to read and display (or discard) the standard output / error from the command. If you don't read it:

you won't know if it contains any error messages, and
there is the possibility that the mysql command will block because it can't write any more to the pipe that you haven't reading.

console displayed error:you have an error in your sql syntex

It is probably telling the truth ...

By the way, the reason that the mysql command currently hangs for ever is that it is waiting for the Java process to send it data on its standard input. And that ain't going to happen because your Java code doesn't write anything to it.

edited May 6, 2012 at 8:09

answered May 5, 2012 at 14:59

Stephen C

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user1376689 Over a year ago

Thank u for your help,but still i am not able to solve my problem.

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