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libcurl上传文件实例

.

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header. You can disable this header with CURLOPT_HTTPHEADER as usual.

When setting CURLOPT_HTTPPOST, it will automatically set CURLOPT_NOBODY to 0 (since 7.14.1).


CURLOPT_POST   --application/x-www-form-urlencoded形式

A non-zero parameter tells the library to do a regular HTTP post. This will also make the library use the a "Content-Type: application/x-www-form-urlencoded" header. (This is by far the most commonly used POST method).

Use one of CURLOPT_POSTFIELDS or CURLOPT_COPYPOSTFIELDS options to specify what data to post and CURLOPT_POSTFIELDSIZE or CURLOPT_POSTFIELDSIZE_LARGE to set the data size.

Optionally, you can provide data to POST using the CURLOPT_READFUNCTION and CURLOPT_READDATA options but then you must make sure to not set CURLOPT_POSTFIELDS to anything but NULL. When providing data with a callback, you must transmit it using chunked transfer-encoding or you must set the size of the data with the CURLOPT_POSTFIELDSIZE or CURLOPT_POSTFIELDSIZE_LARGE option. To enable chunked encoding, you simply pass in the appropriate Transfer-Encoding header, see the post-callback.c example.

You can override the default POST Content-Type: header by setting your own with CURLOPT_HTTPHEADER.

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header. You can disable this header with CURLOPT_HTTPHEADER as usual.

If you use POST to a HTTP 1.1 server, you can send data without knowing the size before starting the POST if you use chunked encoding. You enable this by adding a header like "Transfer-Encoding: chunked" with CURLOPT_HTTPHEADER. With HTTP 1.0 or without chunked transfer, you must specify the size in the request.

When setting CURLOPT_POST to a non-zero value, it will automatically set CURLOPT_NOBODY to 0 (since 7.14.1).

If you issue a POST request and then want to make a HEAD or GET using the same re-used handle, you must explicitly set the new request type using CURLOPT_NOBODY or CURLOPT_HTTPGET or similar.


以上是两种POST方式,具体代码如下:
    ALLUPLOADFILES::iterator iter = allFiles.begin();
    
//如果含有文件 //name="files"; filename="file1.txt"    
    if( bFileFlag ) //以form-dataf方式post
    {
        
for (;iter != allFiles.end();iter++)
        
{
            
if ( iter->isFile )
            
{
                my_bytestr_url_encode(iter
->fileName);
                curl_formadd(
&post, &last, CURLFORM_COPYNAME , iter->contrlID.c_str(),
                    CURLFORM_BUFFER, iter
->fileName.c_str(),
                    CURLFORM_BUFFERPTR,iter
->data.c_str(),
                    CURLFORM_END);    
            }

            
else
            
{
                curl_formadd(
&post, &last, CURLFORM_COPYNAME , iter->contrlID.c_str(),
                    CURLFORM_COPYCONTENTS,iter
->data.c_str(),
                    CURLFORM_END);    
            }

        }

    }

    
else //以application/x-www-form-urlencoded方式post
    {
        
for (;iter != allFiles.end();iter++)
        
{
            my_bytestr_url_encode(iter
->contrlID);
            my_bytestr_url_encode(iter
->data);
            postbuffer 
+= iter->contrlID;
            postbuffer 
+= "=";
            postbuffer 
+= iter->data;
            postbuffer 
+= "&";
        }

    }



    
if (bFileFlag) 
        curl_easy_setopt(curl, CURLOPT_HTTPPOST,post);
    
else 
    
{
        curl_easy_setopt(curl, CURLOPT_POST,
1);
        curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS  , postbuffer.c_str());
    }


    code 
= curl_easy_perform(curl);


对于返回页面,我们可以和上一篇文章所说那样,设置write的回调函数,写入文件即可:
    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 
1);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writer);

long writer(void
*data, int size, int nmemb, string &content)
{
    long sizes 
= size * nmemb;
    string temp(data,sizes);
    printf(
"receive data(%d bytes):\r\n%s",  sizes, (char*)data );
    content 
+= temp; 
    
return sizes;
}

测试:
我们可以用tomcat写一个jsp上传代码测试一下,其中使用到了smartUpload组件,代码如下:upload.html
<form action="upload.jsp" method="post" ENCTYPE="multipart/form-data">

输入名称:
<input type="type" name="name"><br>

选择要上传的图片:

<input type="file" name="pic">

<input type="submit" value="上传">

</form>
upload.jsp如下:
<jsp:useBean id="smart" scope="page" class="org.lxh.smart.SmartUpload"/>

<%
       
//上传初始化
       smart.initialize(pageContext);
       
//准备上传
       smart.upload();     
       
//保存上传的文件
       
//smart.save("/upload");
       
//取得文件的扩展名称
       String ext = smart.getFiles().getFile(0).getFileExt();
%>
<%
       
//String name=request.getParameter("name"); 表单被封装了,不能用这种方法取值.
       String name=smart.getRequest().getParameter("name");
%> 

       
//<%=name+"."+ext%>
<%       //保存文件,包括改名.
       smart.getFiles().getFile(0).saveAs("/upload/"+name+"."+ext);
%>

经测试用libcurl POST文件成功。以上是简单的测试,比较深入的问题还有待进一步研究。
由于我对HTTP协议,WEB这块不是太熟,如果有错误理解不当的地方,还请指正,欢迎大家和我探讨,谢谢!

posted on 2008-07-03 16:49 浪迹天涯 阅读(12870) 评论(3)  编辑 收藏 引用 所属分类: Lib

评论

# re: libcurl上传文件实例 2008-07-03 21:15 企业即时通讯

容(提交失败后,可以通过“恢复上次提交”恢复刚刚提交的内容)   回复  更多评论   

# re: libcurl上传文件实例 2008-09-11 13:40 浪迹天涯

你说的是断点续传的问题,目前libcurl好像并不支持!  回复  更多评论   

# re: libcurl上传文件实例 2014-01-08 21:08 ]]]]

''''  回复  更多评论   


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