刚刚用java编写了一个客户端-服务器程序。 目前,程序的全部工作是:客户端发送屏幕截图,压缩图像,将其发送到服务器,服务器将图像保存在目录中。
由于某种原因,服务器保存的图片是部分的,也就是说服务器端并没有保存所有的截图。
客户端截图
相关代码:
private static void screenshot(){
try {
BufferedImage image = new Robot().createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
File compressedImageFile = new File("C:\\Gilad\\Screenshots\\compress.jpg");
OutputStream os = new FileOutputStream(compressedImageFile);
Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpg");
ImageWriter writer = (ImageWriter) writers.next();
ImageOutputStream ios = ImageIO.createImageOutputStream(os);
writer.setOutput(ios);
ImageWriteParam param = writer.getDefaultWriteParam();
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
param.setCompressionQuality(1f);
writer.write(null, new IIOImage(image, null, null), param);
os.close();
ios.close();
writer.dispose();
Path path = Paths.get("C:\\Images\\Screenshots\\compress.jpg");
byte[] compressedImage = Files.readAllBytes(path);
serverThread.sendOutput(compressedImage); //serverThread is object of type ThreadForServer
} catch (HeadlessException | AWTException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
从 ThreadForServer 类发送图像:
outputThread = new Thread(new Runnable(){
@Override
public void run() {
byte[] imageAr;
//ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
int len;
byte[] lenAr;
try{
while(true){
if(outputs.isEmpty()) Thread.sleep(10);
else{
imageAr = outputs.remove();
len = imageAr.length;
System.out.println("length: " + len);
lenAr = ByteBuffer.allocate(4).putInt(len).array();
System.out.println("length array: " + lenAr + " " + System.currentTimeMillis());
socketOutput.write(lenAr);
System.out.println("Image array: " + imageAr + " " + System.currentTimeMillis());
socketOutput.write(imageAr);
socketOutput.flush();
System.out.println("Flushed: " + System.currentTimeMillis());
}
}
}catch(InterruptedException | IOException e){ e.printStackTrace(); }
}
});
服务器端的InputThread:
inputThread = new Thread(new Runnable(){
@Override
public void run() {
byte[] imageAr;
byte[] lenAr = new byte[4];
int len;
try{
while(running){
System.out.println("Server input thread: " + System.currentTimeMillis());
socketInput.read(lenAr);
len = ByteBuffer.wrap(lenAr).asIntBuffer().get();
System.out.println("length: " + len);
imageAr = new byte[len];
socketInput.read(imageAr);
inputs.add(imageAr);
break;
}
}catch(IOException e){
e.printStackTrace();
}
}
});
服务器保存图像:
private static void startClientThreadHandler(ThreadForClient clientThread){
new Thread(new Runnable(){
@Override
public void run() {
try{
while(true){
byte[] image = clientThread.getInput();
if(image == null){
Thread.sleep(10);
continue;
}
ByteArrayInputStream in = new ByteArrayInputStream(image);
BufferedImage buffImage = ImageIO.read(in);
ImageIO.write(buffImage, "jpg", new File(IMAGE_DESTINATION + "\\image" + counter));
++counter;
}
}catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();;
}
提前致谢!
最佳答案
这里存在许多潜在的问题。然而,最有可能的是从套接字输入读取时:
imageAr = new byte[len];
socketInput.read(imageAr);
InputStream.read(byte[])
不保证填充提供的byte[]
。相反,它返回读取了多少字节。可能需要多次调用 read 才能读取所有字节。
https://docs.oracle.com/javase/8/docs/api/java/io/InputStream.html#read-byte:A-
关于java - 仅保存图像的一部分而不是整个图像,我应该修复什么?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41143452/