java - 如何使用java流从网络获取PDF文件

Question

我需要从网络下载 PDF 文件，例如 http://www.math.uni-goettingen.de/zirkel/loesungen/blatt15/loes15.pdf 此链接。我必须使用 Streams 来做到这一点。对于图像，它对我来说效果很好:

public static void main(String[] args) {
        try {           
                //get the url page from the arguments array
                String arg = args[0];
                URL url = new URL("https://cs7065.vk.me/c637923/v637923205/25608/AD8WhOSx1ic.jpg");

                try{
                    //jpg
                    InputStream in = new BufferedInputStream(url.openStream());
                    ByteArrayOutputStream out = new ByteArrayOutputStream();
                    byte[] buf = new byte[131072];
                    int n = 0;
                    while (-1!=(n=in.read(buf)))
                    {
                       out.write(buf, 0, n);
                    }
                    out.close();
                    in.close();
                    byte[] response = out.toByteArray();
                    FileOutputStream fos = new FileOutputStream("borrowed_image.jpg");
                    fos.write(response);
                    fos.close();
                 }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

但是对于 PDF，它不起作用。可能是什么问题？

Answer 1

我对您的代码进行了少量编辑以修复语法错误，这似乎有效(如下)。考虑将 close() 语句放在 finally block 中。

package org.snb;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;

public class PdfTester {
    public static void main(String[] args) {
        //get the url page from the arguments array

        try{
            //String arg = args[0];
            URL url = new URL("http://www.pdf995.com/samples/pdf.pdf");
            //jpg
            InputStream in = new BufferedInputStream(url.openStream());
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            byte[] buf = new byte[131072];
            int n = 0;
            while (-1!=(n=in.read(buf)))
            {
               out.write(buf, 0, n);
            }
            out.close();
            in.close();
            byte[] response = out.toByteArray();
            FileOutputStream fos = new FileOutputStream("/tmp/bart.pdf");
            fos.write(response);
            fos.close();
         }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}