Console grab binary output

Question

I'm playing around with a small app that will save mysqldump output to file.
I managed to get it working, except when there's binary data on blob fields.
So, if I run from a console:
mysqldump -h server -u uni testdb > /tmp/test.1sql
and then the program listed below, I get excessive garbage in the binary fields and file sizes grow up:
-rw-r--r-- 1 nobody nobody 4535097 Aug 20 14:36 /tmp/test1.sql
-rw-r--r-- 1 nobody nobody 6493448 Aug 20 14:51 /tmp/test.sql
So, I tried executing with the --hex-blob flag in the mysqldump command, but in this case I've to pay the extra size cost:
-rw-r--r-- 1 nobody nobody 7131966 Aug 20 14:47 /tmp/test1.sql
As you will see, I'm grabbing the contents through an InputStreamReader
and then I write they with OutputStreamWriter. I didn't choose execute the command and save the file by the console 'cause I would prefer know what's going on, count bytes, showing a progress or whatever...
I would like to know how could I grab the binary output of the command ?...
It seems like the sh command is not binary...
Thank you!
This is the code:
class StreamGobbler extends Thread
InputStream is;
String type;
String Filename;
StreamGobbler(InputStream is, String type,String Filename)
this.is = is;
this.type = type;
this.Filename=Filename;
public void run()
try
PrintWriter out;
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
if (type=="ERROR") {
FileWriter outFile = new FileWriter("/tmp/error.log");
out = new PrintWriter(outFile);
String line=null;
while ( (line = br.readLine()) != null)
if (type=="ERROR") {
System.out.println(type + ">" + line);
out.println(line);
} else {
out.println(line);
out.close();
} else {
// FileWriter outFile = new FileWriter(Filename);
// out = new PrintWriter(outFile);
FileOutputStream fos = new FileOutputStream(new File(Filename));
OutputStreamWriter outs = new OutputStreamWriter(fos,"UTF8");
int len = 512;
char buf[] = new char[len];
int numRead;
while ((numRead = isr.read(buf, 0, len)) != -1)
outs.write(buf, 0, numRead);
outs.close();
} catch (IOException ioe)
ioe.printStackTrace();
public class mxdump {
public mxdump(String Cmd) {
try {
Cmd="/bin/bash /usr/bin/mysqldump -h server -u uni testdb";
/* String cmd[]={"sh", "-c",Cmd,""} ; //"mysqldump";
ProcessBuilder pb=new ProcessBuilder(cmd);
System.out.println("Start");
pb.start();
System.out.println("Termino"); */
String cmd[]={"sh", "-c",Cmd,""} ;
Runtime rt = Runtime.getRuntime();
System.out.println("Execing " + cmd[0] + " " + cmd[1]
+ " " + cmd[2]);
Process proc = rt.exec(cmd);
// any error message?
StreamGobbler errorGobbler = new
StreamGobbler(proc.getErrorStream(), "ERROR","");
StreamGobbler outputGobbler = new
StreamGobbler(proc.getInputStream(), "OUTPUT","/tmp/test.sql" );
// kick them off
errorGobbler.start();
outputGobbler.start();
// any error???
int exitVal = proc.waitFor();
System.out.println("ExitValue: " + exitVal);
catch(Throwable t)
//System.out.println(e);
t.printStackTrace();
}

Answer 1

Don't use Readers and Writers on binary data. Use Streams.