使用HttpClient下载图片常用代码，以及下载失败原因

最近一直在完善云相册项目，寻找各种bug，昨天突然发现，图片上传经常出现错误，错误有可能与网速有关，但是这种错误却是致命的，我们不能保证所有人的网速都很稳定，于是我就仔细看了下代码，发现异常都是在此处response = httpClient.execute(post);执行上传动作的时候出的错。先对代码做一点说明吧，UploaderParam是一个实体类对象，里面存放的是下载信息（包括本地图片地址），别的部分只要懂httpClient应该都能明白的。（修改：唉，好像还是和网速有点关联啊，大家仅参考下代码吧）

[代码]java代码：

public String uploadFile(UploaderParam uploaderParam) {
Log.d(TAG, "uploadFile ... ");
HttpResponse response = null;
BufferedReader reader = null;
StringBuilder builder = new StringBuilder();
final String fileNameIn = uploaderParam.getFileName();
Log.i(TAG, "upload fileName: "+ fileNameIn);
try {
String epgUri = assembleEPGUrl(uploaderParam);
HttpPost post = new HttpPost(epgUri);
Log.i(TAG, "httpPost uri: " + epgUri);
//HttpPost post = new HttpPost("http://10.0.64.132:8001/upload?sid=2&skey=23837391433022");
MultipartEntity multipartEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
//读取本地图片，以流的形式
FileInputStream inputStream = new FileInputStream(new File(uploaderParam.getFileName()));
//final byte[] data = IOUtils.toByteArray(inputStream);
final int length = inputStream.available();
Log.i(TAG, "Length is: " + Integer.toString(length));
InputStreamBody isb = new InputStreamBody(inputStream, "uploaderFile") {
@Override
public long getContentLength() {
return length;
}
@Override
public String getFilename() {
return fileNameIn;
}
};
multipartEntity.addPart("uploaderFile", isb);
post.setEntity(multipartEntity);
System.out.println(" 悲了个剧啊"+post.getURI());
Log.d("uploadFile", "uploaderParam.getFileName() is : " + uploaderParam.getFileName());
Thread.sleep(1000);
try{
response = httpClient.execute(post);
}catch(Exception e){
System.out.println("try again!!");
Thread.sleep(1000);
try{
response = httpClient.execute(post);
}catch(Exception e1){
System.out.println("again 失败");
return null;
}
}

Log.d(TAG, "uploadFile .......................................................... ");
Log.d(TAG, "1" + response.getStatusLine().getStatusCode());
Log.d(TAG, "2" + response.getStatusLine().getReasonPhrase());
if(response == null){
System.out.println("response is null");
}
if(response.getStatusLine().getStatusCode() != HttpStatus.SC_OK){
System.out.println("response.getStatusLine().getStatusCode() != HttpStatus.SC_OK");
}
//by LLH
if(response != null && response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
Log.d(TAG, "uploadFile success .......................................................... ");
HttpEntity entity = response.getEntity();
reader = new BufferedReader(new InputStreamReader(entity.getContent()));
String line = null;
while((line = reader.readLine()) != null) {
builder.append(line);
}
reader.close();
}
else
{
Log.e(TAG, "execute() return null");
}
//EntityUtils.toString(response.getEntity());

Log.d(TAG, "uploadFile result is : " + builder.toString());
} catch (Throwable e) {
e.printStackTrace();
}
return builder.toString();
}

代码已经贴出来了，不过仅供参考，真正解决下载失败的其实是包问题，我们都知道，httpclient是封装好的协议，远比使用httpconnection方便很多，但是同时也会有很多问题，我们项目一开始引用的就是httpmime-4.0.1.jar，这个包真的拥有不小的问题，下载时很容易出错。于是我重下了个4.2版本，错误就不再产生了。希望我的这篇文章能帮助你们。

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

以上文章是12年写的，现在基本都是4.0系统，不提倡使用HttpClient，google官方也已经不维护了吧，不管从哪个角度来讲HttpConnection才是现在最好的选择。