java - 通过Java套接字下载图像时需要编码规范吗？

该程序应从闪烁下载指定的图像。这是一个作业问题，我必须使用套接字。我的程序成功发出了http请求并收到了响应。我消除了标头并将字节写入jpg文件。但是，当我想使用图像查看器程序打开它时，它说：


解释JPEG图像文件时出错（对JPEG库的调用不正确
状态200


因此，我分别下载了该图像并在文本编辑器中将其打开，似乎其中的某些部分未转换。

原始文件：


\ FF \ D8 \ FF \ E0 \ 00 JFIF \ 00 \ 00 \ 00 \ 00 \ 00 \ 00 \ FF \ E2 \ A0ICC_PROFILE


下载文件：


\ 00 JFIF \ 00 \ 00 \ 00 \ 00 \ 00 \ 00 \00ￜￜￜICC_PROFILE


这是关于字符编码的吗？如果是，我应该如何指定编码？或者我该怎么做才能真正获取jpeg文件？

public class ImageReceiver {
public static void main(String[] args) {
    String imglink = "https://farm2.staticflickr.com/1495/26290635781_138da3fed8_m.jpg";
    String flicker = "farm2.staticflickr.com";

    Socket socket = null;
    DataOutputStream out;

    try {
        socket = new Socket(flicker, 80);
        out = new DataOutputStream(socket.getOutputStream());

        out.writeBytes("GET "+ imglink +" HTTP/1.1\r\n");
        out.writeBytes("Host: "+ flicker +":80\r\n\r\n");
        out.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }

    DataInputStream in = null;
    OutputStream output = null;

    try {
        in = new DataInputStream(socket.getInputStream());
        output = new FileOutputStream("chair.txt");

        System.out.println("input connection is established");

        byte[] bytes = new byte[2048];
        int length;
        boolean eohFound = false;

        while ((length = in.read(bytes)) != -1) {
            if(!eohFound){
                String string = new String(bytes, 0, length);
                int indexOfEOH = string.indexOf("\r\n\r\n");
                if(indexOfEOH != -1) {
                    System.out.println("index: " + indexOfEOH);
                    length = length - indexOfEOH - 4;
                    System.out.println(length);
                    bytes = string.substring(indexOfEOH + 4).getBytes();
                    eohFound = true;
                } else {
                    length = 0;
                }
            }
            output.write(bytes, 0, length);
            output.flush();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }


    try {
        in.close();
        output.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.out.println("Image is downloaded");

}

}

最佳答案

在EJP的帮助下，我重新编写了代码。这里只修改了一部分。我先读Line（）直到得到新行，然后再读取为字节并写入文件：

    try {
        in = new DataInputStream(socket.getInputStream());
        output = new FileOutputStream("chair.jpg");

        byte[] bytes = new byte[2048];
        int length;

        String inputLine;

        //Get rid of headers...
        while ((inputLine = in.readLine()) != null){
            if(inputLine.equals(""))
                break;
        }


        while ((length = in.read(bytes)) != -1) {
            output.write(bytes, 0, length);
            output.flush();
        }

    } catch (IOException e) {
        e.printStackTrace();
    }

关于java - 通过Java套接字下载图像时需要编码规范吗？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/36558857/