我需要在图像magick工具的帮助下使用流程构建器在文件夹中进行图像转换。我需要在转换后删除原始文件，但是当我使用等待它需要很长时间才能完成。我使用了以下代码
for (int h = 0; h < convimagefolder.size(); h++) {
/* CMYK conversion for jpg and tiff and also .psd conversion*/
destpathfinalconvs = new File(tempdir + "/" + convimagefolder.get(h));
// JOptionPane.showMessageDialog(null, "CMYK jpg conversion - folder assign");
ProcessBuilder pb = new ProcessBuilder("mogrify", "-colorspace", "RGB", destpathfinalconvs.toString() + "\\" + "*.jpg");
pb.redirectErrorStream(true);
try {
Process p = pb.start();
System.out.println("CMYK to RGB jpg done for "+convimagefolder.get(h));
// try {
// p.waitFor();
// } catch (InterruptedException ex) {
// Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
// }
} catch (IOException ex) {
Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
}
// JOptionPane.showMessageDialog(null, "tif conversion - folder assign");
ProcessBuilder pb1 = new ProcessBuilder("mogrify", "-colorspace", "RGB", destpathfinalconvs.toString() + "\\" + "*.tif");
pb1.redirectErrorStream(true);
try {
Process p1 = pb1.start();
System.out.println("cmyk tif to rgb done " + convimagefolder.get(h));
// try {
// p1.waitFor();
// } catch (InterruptedException ex) {
// Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
// }
} catch (IOException ex) {
Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
}
// JOptionPane.showMessageDialog(null, "psd conversion - folder assign");
ProcessBuilder pb2 = new ProcessBuilder("mogrify", "-format", "jpg", destpathfinalconvs.toString() + "\\" + "*.psd[0]");
pb2.redirectErrorStream(true);
try {
Process p2 = pb2.start();
System.out.println("psd to jpg done" + convimagefolder.get(h));
// try {
// p2.waitFor();
// } catch (InterruptedException ex) {
// Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
// }
} catch (IOException ex) {
Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
}
/* CMYK conversion for jpg and tiff and also .psd conversion*/
/* tif to jpg conversion*/
ProcessBuilder pb3 = new ProcessBuilder("mogrify", "-format", "jpg", destpathfinalconvs.toString() + "\\" + "*.tif");
pb3.redirectErrorStream(true);
try {
Process p3 = pb3.start();
// try {
// p3.waitFor();
// } catch (InterruptedException ex) {
// Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
// }
System.out.println(".tif to jpg done successfully"+ convimagefolder.get(h));
} catch (IOException ex) {
Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
JOptionPane.showMessageDialog(null, "Error in tif to jpg conversion " + ex.toString());
}
/* pdf to jpg*/
ProcessBuilder pb4 = new ProcessBuilder("mogrify", "-format", "jpg", destpathfinalconvs.toString() + "\\" + "*.pdf");
pb4.redirectErrorStream(true);
try {
Process p4 = pb4.start();
// try {
// p4.waitFor();
// } catch (InterruptedException ex) {
// Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
// }
System.out.println(".pdf to jpg done successfully"+ convimagefolder.get(h));
} catch (IOException ex) {
Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
JOptionPane.showMessageDialog(null, "Error in tif to jpg conversion " + ex.toString());
}
/* image size reduction*/
ProcessBuilder pb5 = new ProcessBuilder("mogrify", "-strip", "-quality", "50%", destpathfinalconvs.toString() + "\\" + "*.jpg");
// ProcessBuilder pb5 = new ProcessBuilder("mogrify", "-path ", destinationpath.toString(), "-strip", "-quality", "50%", destinationpath.toString() + "\\" + "*.jpg");
pb5.redirectErrorStream(true);
try {
Process p5 = pb5.start();
// try {
// p5.waitFor();
// } catch (InterruptedException ex) {
// Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
// }
System.out.println("image conversion done successfully"+ convimagefolder.get(h));
} catch (IOException ex) {
Logger.getLogger(DefineTask.class.getName()).log(Level.SEVERE, null, ex);
JOptionPane.showMessageDialog(null, "Error in jpg compression " + ex.toString());
}
}
JOptionPane.showMessageDialog(null, "Image compression and conversion done using Image Magick");
是否可以通过线程执行此操作。请建议缩短转换时间
答案 0 :(得分：2)
我会看看Executors，这将允许您汇集一系列任务并让它们自动在一个或多个线程中执行...
例如......
ExecutorService service = Executors.newFixedThreadPool(7);
for (int h = 0; h < convimagefolder.size(); h++) {
/* CMYK conversion for jpg and tiff and also .psd conversion*/
destpathfinalconvs = new File(tempdir + "/" + convimagefolder.get(h));
service.submit(new ProcessTask(
"CMYK to RGB jpg done for " + convimagefolder.get(h),
new String[]{
"mogrify", "-colorspace", "RGB", destpathfinalconvs.toString() + "\\" + "*.jpg"}
));
service.submit(new ProcessTask(
"CMYK to RGB jpg done for " + convimagefolder.get(h),
new String[]{
"mogrify", "-colorspace", "RGB", destpathfinalconvs.toString() + "\\" + "*.jpg"}
));
service.submit(new ProcessTask(
"cmyk tif to rgb done " + convimagefolder.get(h),
new String[]{
"mogrify", "-colorspace", "RGB", destpathfinalconvs.toString() + "\\" + "*.tif"}
));
service.submit(new ProcessTask(
"psd to jpg done" + convimagefolder.get(h),
new String[]{
"mogrify", "-format", "jpg", destpathfinalconvs.toString() + "\\" + "*.psd[0]"}
));
service.submit(new ProcessTask(
".tif to jpg done successfully" + convimagefolder.get(h),
new String[]{
"mogrify", "-format", "jpg", destpathfinalconvs.toString() + "\\" + "*.tif"
}
));
service.submit(new ProcessTask(
".pdf to jpg done successfully" + convimagefolder.get(h),
new String[]{
"mogrify", "-format", "jpg", destpathfinalconvs.toString() + "\\" + "*.pdf"
}
));
service.submit(new ProcessTask(
"image conversion done successfully" + convimagefolder.get(h),
new String[]{
"mogrify", "-strip", "-quality", "50%", destpathfinalconvs.toString() + "\\" + "*.jpg"}
));
}
实际Callable任务......
public class ProcessTask implements Callable<Integer> {
private String cmds[];
private String name;
public ProcessTask(String name, String[] cmds) {
this.cmds = cmds;
this.name = name;
}
@Override
public Integer call() throws Exception {
System.out.println("Started " + name);
ProcessBuilder pb = new ProcessBuilder(cmds);
pb.redirectErrorStream(true);
Process p5 = pb.start();
p5.waitFor();
System.out.println("Completed " + name);
return p5.exitValue();
}
}
现在，如果您想等到所有任务完成并检查其状态（查看谁成功完成以及谁失败了），您可以将所有Callable添加到List并使用ExecutorService#invokeAll(List)，它会阻止，直到Callable中的所有List都已完成。然后，您可以遍历返回的List并查看是否有任何Callable失败（调用Callable#get将返回Callable返回的值或抛出{{} 1}} Exception提出......）
另一种方法可能是，不是在单个Callable内执行流程，而是创建一个Callable，其中引用Callable，将这些添加到File并使用引用的ExecutorService执行Callable中的每个步骤，等待每个步骤完成...
这样，当你走到尽头时，你可以删除该文件。这将允许您并行处理每个文件......