日期:2014-05-20  浏览次数:21027 次

[急]java.net.SocketException: Connection reset by peer: socket write error
要从一个被屏蔽的网站上下载一些东西,于是写了一个Servlet,将它传到了一台境外的服务器上.
让这台服务器去下载指定的资源,然后再回传给我.相当于一个代理吧.

Java code
public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String url = request.getParameter("url"); //得到要下载的资源的URL.

        if (!StringUtils.isNullOrEmpty(url)) {
            System.out.println(url);
            URL u = new URL(url);
            URLConnection conn = u.openConnection();

            try { ///把响应头设置成一样的.
                for (Map.Entry<String, List<String>> m : conn.getHeaderFields()
                        .entrySet()) {
                    if (m != null && m.getKey() != null && m.getValue() != null
                            && m.getValue().size() > 0) {
                        response.setHeader(m.getKey(), m.getValue().get(0));
                    }
                }
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
                CommonLog.log.warn(e);
            }

            InputStream in = conn.getInputStream(); //从 connection得到inputstream
            OutputStream out = response.getOutputStream(); //得到向客户端的输出流
            try {
                IOUtils
                        .write(conn.getInputStream(), response
                                .getOutputStream()); //写数据.
            } catch (Exception e) {
                e.printStackTrace();
                // TODO: handle exception
                CommonLog.log.warn(e);
                if (in != null) {
                    in.close();
                }
                if (out != null) {
                    out.close();
                }
            }
        }
    }


IOUtils.write()代码如下:

Java code
    /**
     * 从input里面读取数据然后写入output,读完后自动关闭流。
     * @param input inputStream
     * @param output outputStream
     * */
    public static void write(InputStream input, OutputStream output)
            throws IOException {
        write(input,output,true);
    }

    /**
     * 自动从inputstream里面读数据,然后写到outputstream里面去。
     * @param input inputstream
     * @param output outputstream
     * @param close 读完后是否自动关闭流。
     * */
    public static void write(InputStream input, OutputStream output,boolean close)
            throws IOException {
        byte[] b = new byte[1024];
        int len = input.read(b);
        while (len != -1) {
            output.write(b, 0, len);
            len = input.read(b);
        }
        
        output.flush();
        if (close) {
            input.close();    
            output.close();
        }
    }


将程序传到服务器上以后,在服务器上访问
http://localhost:8080/test/down?url=http://www.xxx.com/z.zip
可以下载成功.

但是当远程访问的时候,就会出现
java.net.SocketException: Connection reset by peer: socket write error

假设服务器IP是2.2.2.2吧.

访问
http://2.2.2.2:8080/test/down?url=http://www.xxx.com/z.zip
就会出现上面的那个错误.
注意,我并没有关闭浏览器或者按停止按钮.只要一打上那个地址就会出错.


错误发生在:

Java code
output.write(b, 0, len);//执行这行代码的时候.


具体的错误信息如下:


Java code
ClientAbortExceptionjava.net.SocketException: Connection reset by peer: socket write error 
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:366)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:432)
at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:347)
at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:392)