java - 进程在 waitFor() 中挂起

Question

我正在尝试运行 mysql 来执行来自 java 的一些文件。输入是从文件中读取的，应该通过管道传输到 mysql 进程中，一切似乎都正常，但是行

int exitCode = proc.waitFor(); 

永不返回。

private boolean runScript(String path, String cmd, File file) throws IOException, InterruptedException {
        Runtime rt = Runtime.getRuntime();
        Process proc = rt.exec( path + File.separatorChar + cmd );
        OutputStream procOS = proc.getOutputStream();
        InputStream procES = proc.getErrorStream();
        InputStream procIS = proc.getInputStream();
        OutputStreamWriter procStdIn = new OutputStreamWriter( procOS );

        FileInputStream fis = new FileInputStream( file );
        BufferedReader reader = new BufferedReader( new InputStreamReader( fis ) );
        String send;

        while ( ( send = reader.readLine() ) != null ) {
            procStdIn.write( send );
            System.out.println( send );
            copyStream( procES, System.err );
            copyStream( procIS, System.out );
        }
        procStdIn.write( "\r\nexit\r\n" );
        int exitCode = proc.waitFor();
        return exitCode == 0;
    }

    private void copyStream(InputStream is, PrintStream err) throws IOException {
        byte b[] = new byte[ 1024 ];
        int length;
        while ( is.available() > 0 && ( length = is.read( b ) ) > 0 ) {
            err.write( b, 0, length );
        }

Answer 1

我怀疑您正在阻止读取 stdout 和 stderr。参见 this answer了解更多详情。