接口
{
final ResultMessage message =new ResultMessage();
message.setErrno(ErrorNumConsts.OPERATION_ERROR);
message.setErrmsg("upload failed");
try {
DiskFileItemFactory factory =new DiskFileItemFactory(10240, new File(TEMP_PATH));
ServletFileUpload upload =new ServletFileUpload(factory);
upload.setHeaderEncoding("UTF-8");
List items = upload.parseRequest(request);
if (items.size() ==0) {
message.setErrno(ErrorNumConsts.PARAM_ERROR);
message.setErrmsg("file not be null");
return message.toString();
}
items.forEach(fileItem -> {
if (!fileItem.isFormField()) {
InputStream in =null;
try {
in = fileItem.getInputStream();
}catch (IOException e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
}
if (in ==null) {
return;
}
ByteArrayOutputStream baos =new ByteArrayOutputStream();
try {
IOUtils.copy(in, baos);
}catch (IOException e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
ResultMessageUtil.setErrorResultMessage(message, ErrorNumConsts.OPERATION_ERROR,
"流拷贝异常");
return;
}
try {
Long total = FileUtil.getFileLineNum(new ByteArrayInputStream(baos.toByteArray()));
if (total >NUM_TOTAL) {
ResultMessageUtil.setErrorResultMessage(message, ErrorNumConsts.PARAM_ERROR,
"上传文件行数超过" + (NUM_TOTAL -1) +"行限制");
return;
}
}catch (Exception e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
ResultMessageUtil.setErrorResultMessage(message, ErrorNumConsts.OPERATION_ERROR,
"判断文件记录条数异常");
return;
}
String fileName = fileItem.getName();
// different browser different file name
fileName = fileName.substring(fileName.lastIndexOf("\\") +1).trim();
String taskId =null;
try {
taskId = getTaskId();
}catch (Exception e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
return;
}
fileName = taskId +"-" + fileName;
String key = UUIDUtil.getUUID();
try {
RedisFacade redisFacade = RedisFacade.getInstance();
String reidsKey =PRE_FIX + fileName;
redisFacade.set(reidsKey, key);
redisFacade.expire(reidsKey, TIME_PERIOD);
}catch (Exception e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
ResultMessageUtil.setErrorResultMessage(message, ErrorNumConsts.OPERATION_ERROR,
"redis error");
return;
}
try {
GIFT gift = GIFTUtil.upLoad(UPLOAD_URL, key, fileName,new
ByteArrayInputStream(baos.toByteArray()));
if (gift !=null) {
ResultMessageUtil.setErrorResultMessage(message, ErrorNumConsts.SUCCESS,
"upload file success");
JSONObject object =new JSONObject();
object.put("taskId", taskId);
object.put("fileName", fileName);
message.setData(object);
}
}catch (Exception e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
ResultMessageUtil.setErrorResultMessage(message, ErrorNumConsts.OPERATION_ERROR,
"upload failed");
}
try {
in.close();
}catch (IOException e) {
logger.warn("close input stream failed");
}
fileItem.delete();
}
});
}catch (FileUploadException e) {
logger.warn(ExceptionUtils.getExceptionStackTrace(e));
}
return message.toString();
}
GiftUtil.upload
public static GIFTupLoad(String url, String key, String fileName, InputStream stream)throws Exception {
checkParams(url,key,fileName,stream);
CloseableHttpClient client = HttpClients.createDefault();
HttpPost post =new HttpPost(getUrl(url,key));
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.setCharset(Charset.forName("UTF-8"));//设置请求的编码格式
builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
//1,form key 2,file input strem ,3,content-type; 4,file name
builder.addBinaryBody("filecontent",stream, ContentType.MULTIPART_FORM_DATA,fileName);
HttpEntity entity = builder.build();
post.setEntity(entity);
HttpResponse response =null;
try {
response = client.execute(post);
if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
String data = EntityUtils.toString(response.getEntity());
return JSONObject.parseObject(data,GIFT.class);
}
throw new Exception("upload failed["+response.getStatusLine().getStatusCode()+"]:" + response.getStatusLine().getReasonPhrase());
}finally {
if(response !=null){
((CloseableHttpResponse) response).close();
}
}
}
具体步骤如下：
１、创建DiskFileItemFactory对象，设置缓冲区大小和临时文件目录
２、使用DiskFileItemFactory 对象创建ServletFileUpload对象，并设置上传文
件的大小限制。
３、调用ServletFileUpload.parseRequest方法解析request对象，得到一个保
存了所有上传内容的List对象。
４、对list进行迭代，每迭代一个FileItem对象，调用其isFormField方法判断
是否是上传文件
5、 为普通表单字段，则调用getFieldName、getString方法得到字段名和字段
值
6、 为上传文件，则调用getInputStream方法得到数据输入流，从而读取上传
数据。
注： 我们这里调用giftUtil.upLoad实现http上传，即使用MultipartEntityBuilder。
一个小细节即：
ByteArrayOutputStream baos = newByteArrayOutputStream();
IOUtils.copy(in, baos);
将字符输入流转成byte数组流，因为输入流只能用一次，这里转成byte数组流可以复用，但这个接口并未复用。