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import java.io.File;
import com.artifex.gsjava.GSInstance;
import com.artifex.gsjava.callbacks.DisplayCallback;
import com.artifex.gsjava.util.*;
import com.artifex.gsjava.callbacks.*;
import java.io.IOException;
import java.util.Arrays;
import static com.artifex.gsjava.GSAPI.*;
/**
* Handles running a separate instance of Ghostscript.
*/
public class Worker implements Runnable {
// Whether to use Java-implemented standard input/output
public static final boolean USE_CUSTOM_STDIO = true;
// Whether stdout is enabled (effective only if USE_CUSTOM_STDIO = true)
public static final boolean USE_STDOUT = false;
private static int ID = 0; // Next thread ID
private final File inPS, outPDF; // Input and output files
private final Thread thread; // The thread running this worker
/**
* Create a worker thread to convert a postscript file
* to a pdf file.
*
* @param inPS The postscript file.
* @param outPDF The output PDF file.
*/
public Worker(String inPS, String outPDF) {
this.inPS = new File(inPS);
this.outPDF = new File(outPDF);
this.thread = new Thread(this);
this.thread.setName("Worker-" + ID++);
}
/**
* Starts this worker
*/
public void start() {
System.out.println("Start: " + thread.getName());
thread.start();
}
@Override
public void run() {
System.out.println("Started worker: " + thread.getName());
GSInstance gsInstance = null;
try {
gsInstance = createGSInstance();
// If we want to use the IO functions StdIO, set them
if (USE_CUSTOM_STDIO) {
StdIO io = new StdIO();
gsInstance.set_stdio(io, USE_STDOUT ? io : null, io);
}
// Create the output file if it doesn't exist
if (!outPDF.exists())
outPDF.createNewFile();
// Ghostscript arguments to use with init_with_args
String[] args = {
"gs",
"-sDEVICE=pdfwrite",
"-o", outPDF.getPath(),
inPS.getPath()
};
// init_with_args will perform all the conversions
int code = gsInstance.init_with_args(args);
if (code != GS_ERROR_OK)
throw new IllegalStateException("Failed to init with args (code = " + code + ")");
System.out.println("Worker " + thread.getName() + " completed.");
} catch (Exception e) {
System.err.println("Worker " + thread.getName() + " threw exception: " + e);
} finally {
if (gsInstance != null)
gsInstance.delete_instance();
}
}
// Creates a new Ghostscript inistance
private GSInstance createGSInstance() {
GSInstance gsInstance = new GSInstance();
int code;
code = gsInstance.set_arg_encoding(1);
if (code != GS_ERROR_OK) {
gsInstance.delete_instance();
throw new IllegalStateException("Failed to set arg encoding (code = " + code + ")");
}
return gsInstance;
}
// Handles standard input/output
private static class StdIO implements IStdOutFunction, IStdErrFunction, IStdInFunction {
public int onStdOut(long callerHandle, byte[] str, int len) {
System.out.println(new String(str));
return len;
}
public int onStdErr(long callerHandle, byte[] str, int len) {
System.err.println(new String(str));
return len;
}
public int onStdIn(long callerHandle, byte[] buf, int len) {
try {
return System.in.read(buf, 0, len);
} catch (IOException e) {
return 0;
}
}
}
}
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