我有一个程序,它从给定的根开始探索文件系统。该程序从根点递归地探索所有目录并对 tiff 文件执行处理。事实上,它合并了每两个 tiff 文件。我使用 ExecutorService 和 ThreadPoolExecutor 来处理合并功能。
ExecutorService exec = Executors.newFixedThreadPool(threadsNumber);
inputDirectoryProcess( inputDir );
exec.shutdown();
try {
exec.awaitTermination(Long.MAX_VALUE, TimeUnit.DAYS);
} catch (InterruptedException e) {
e.printStackTrace();
}
对于我使用的每个合并函数,如下:
exec.submit(new MultipageTask( a, Integer.toString( intDetector(directoryFiles.get(i + 1).getName())/2 ), out) );
以下是 MultipageTask 类:
public void run() {
Thread thread = Thread.currentThread();
System.out.println("start by " + thread.getName() + " (" + thread.getId() + ")");
Integer[] resoulutions = null;
try {
BufferedImage image[] = new BufferedImage[tifImages.length];
for (int i = 0; i < tifImages.length; i++) {
resoulutions = getsize(tifImages[i].getPath());
SeekableStream ss = null;
ss = new FileSeekableStream(tifImages[i]);
ImageDecoder decoder = ImageCodec.createImageDecoder("tiff", ss, null);
PlanarImage op = null;
op = new NullOpImage(decoder.decodeAsRenderedImage(0),
null, OpImage.OP_IO_BOUND, null);
image[i] = op.getAsBufferedImage();
}
TIFFField[] fields = new TIFFField[3];
// ResolutionUnit
TIFFField fieldResUnit = new TIFFField(296, TIFFField.TIFF_SHORT, 1,
(Object) new char[] { 2 });
fields[0] = fieldResUnit;
// XResolution
TIFFField fieldXRes = new TIFFField(282, TIFFField.TIFF_RATIONAL, 1,
(Object) new long[][] { { resoulutions[0], 1 } });
fields[1] = fieldXRes;
// YResolution
TIFFField fieldYRes = new TIFFField(283, TIFFField.TIFF_RATIONAL, 1,
(Object) new long[][] { { resoulutions[1], 1 } });
fields[2] = fieldYRes;
TIFFEncodeParam params = new TIFFEncodeParam();
params.setCompression( TIFFEncodeParam.COMPRESSION_GROUP4 );
params.setExtraFields( fields );
OutputStream out = new FileOutputStream(outDir + "\\" + image_name + ".tif");
ImageEncoder encoder = ImageCodec.createImageEncoder("tiff", out, params);
Vector vector = new Vector();
for (int i = 1; i < tifImages.length; i++) {
vector.add(image[i]);
}
params.setExtraImages(vector.iterator());
encoder.encode(image[0]);
out.close();
System.out.println("end by " + thread.getName() + " (" + thread.getId() + ")");
} catch (IOException e) {
e.printStackTrace();
}
increasetCount();
}
}
public synchronized void increasetCount() {
convertCount = convertCount + 2;
updateBar( convertCount );
}
程序终止后,我注意到有些文件尚未处理。所以我记录了线程的进入和退出,如上所示。在控制台中我看到以下几行:
start by pool-2-thread-4 (30)
end by pool-2-thread-2 (28)
start by pool-2-thread-2 (28)
start by pool-2-thread-4 (30)
start by pool-2-thread-2 (28)
start by pool-2-thread-1 (27)
start by pool-2-thread-1 (27)
start by pool-2-thread-4 (30)
end by pool-2-thread-1 (27)
end by pool-2-thread-2 (28)
start by pool-2-thread-1 (27)
start by pool-2-thread-2 (28)
正如您看到的一些线程,例如 28 个开头,但没有结束。这会导致丢失一些合并进程并且程序无法处理所有 tiff 文件。
注意:我应该提到,当我增加threadsNumber时,丢失的会增加!!
我该如何解决这个问题?我想确保每个线程完成运行过程。
感谢并抱歉英语不好。
最佳答案
如果您没有共享资源并且它不是死锁/活锁,请尝试使用 try/catch 包围您的代码
public class MultipageTask implements Runnable {
private File[] tifImages;
private String image_name;
private String outDir;
public MultipageTask(File[] tifImages, String image_name, String outDir) {
this.tifImages = tifImages;
this.image_name = image_name;
this.outDir = outDir;
}
@Override
public void run() {
Thread thread = Thread.currentThread();
System.out.println("start by " + thread.getName() + " (" + thread.getId() + ")");
try{
// doing merge process
}catch(Exception e){
e.printStackTrace();
}
System.out.println("end by " + thread.getName() + " (" + thread.getId() + ")");
}
}
关于java:线程没有完全完成run()方法?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26098927/