Attempted read from closed stream 问题以及解决方案

  DefaultHttpClient httpClient = new DefaultHttpClient();
		        HttpPost httpPost = new HttpPost(url);
		        httpPost.setEntity(new UrlEncodedFormEntity(paramList, Consts.UTF_8));
		        HttpResponse response = httpClient.execute(httpPost);
		        HttpEntity entity = response.getEntity();
		        
		        InputStream in = entity.getContent();//获取数据流
	         
		        // 保存流
		        ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
		        BufferedInputStream br = new BufferedInputStream(in); 
		        byte[] b = new byte[1024]; 
		        for (int c = 0; (c = br.read(b)) != -1;) 
		        { 
		            bos.write(b, 0, c); 
		        } 
		        b = null; 
		        br.close(); 
		        
		        
		        in = new ByteArrayInputStream(bos.toByteArray());
		        // 第一次读流
		        StringBuffer out = new StringBuffer();
		        byte[] b1 = new byte[1024]; 
		        for (int n; (n = in.read(b1)) != -1;) {
		             out.append(new String(b1, 0, n));  //这个可以用来读取文件内容 并且文件内容有中文读取出来也不会乱码
		        }
		        // 判断文件是否存在
		        String resultHtml = out.toString();
		        int firstIndex = resultHtml.indexOf("\n");
		        if(firstIndex < 0){
		        	logger.info("文件不存在或异常"+resultHtml);
		        	return false;
		        }
		        // 重置游标
		        in.reset();
		        
		        // 输出到文件
        	    FileOutputStream fos = new FileOutputStream(new File(req.getFilePath()));
                BufferedOutputStream  bos1 = new BufferedOutputStream(fos,2048);
              	// 第二次读流
              	int len;
	   		    byte [] bytes = new byte[2048];
	   		    while((len=in.read(bytes,0,2048)) != -1){
	   		    	bos1.write(bytes,0,len);
	   		    }
	   		    bos1.flush();
		        bos1.close();