diff --git a/CMakeLists.txt b/CMakeLists.txt
index d9645d47..edeae6a9 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -129,6 +129,7 @@ set(DROGON_SOURCES
     lib/src/HttpAppFrameworkImpl.cc
     lib/src/HttpClientImpl.cc
     lib/src/HttpControllersRouter.cc
+    lib/src/HttpFileImpl.cc
     lib/src/HttpFileUploadRequest.cc
     lib/src/HttpRequestImpl.cc
     lib/src/HttpRequestParser.cc
diff --git a/examples/simple_example/api_Attachment.cc b/examples/simple_example/api_Attachment.cc
index b979b1ad..3aa6c292 100644
--- a/examples/simple_example/api_Attachment.cc
+++ b/examples/simple_example/api_Attachment.cc
@@ -17,7 +17,7 @@ void Attachment::upload(const HttpRequestPtr &req,
     if (fileUpload.parse(req) == 0)
     {
         // LOG_DEBUG << "upload good!";
-        auto files = fileUpload.getFiles();
+        auto &files = fileUpload.getFiles();
         // LOG_DEBUG << "file num=" << files.size();
         for (auto const &file : files)
         {
diff --git a/lib/inc/drogon/MultiPart.h b/lib/inc/drogon/MultiPart.h
index 6979158a..460d6b3d 100644
--- a/lib/inc/drogon/MultiPart.h
+++ b/lib/inc/drogon/MultiPart.h
@@ -14,36 +14,32 @@
 
 #pragma once
 
+#include <drogon/HttpRequest.h>
 #include <map>
 #include <string>
 #include <vector>
+#include <memory>
 
 namespace drogon
 {
+class HttpFileImpl;
+/**
+ * @brief This class represents a uploaded file by a HTTP request.
+ *
+ */
 class HttpFile
 {
   public:
+    HttpFile(std::shared_ptr<HttpFileImpl> &&implPtr);
     /// Return the file name;
-    const std::string &getFileName() const
-    {
-        return fileName_;
-    };
+    const std::string &getFileName() const;
 
-    /// Set the file name
-    void setFileName(const std::string &filename)
-    {
-        fileName_ = filename;
-    };
+    /// Set the file name, usually called by the MultiPartParser parser.
+    void setFileName(const std::string &filename);
 
-    /// Set the contents of the file, usually called by the FileUpload parser.
-    void setFile(const std::string &file)
-    {
-        fileContent_ = file;
-    };
-    void setFile(std::string &&file)
-    {
-        fileContent_ = std::move(file);
-    }
+    /// Set the contents of the file, usually called by the MultiPartParser
+    /// parser.
+    void setFile(const char *data, size_t length);
 
     /// Save the file to the file system.
     /**
@@ -70,38 +66,16 @@ class HttpFile
     int saveAs(const std::string &filename) const;
 
     /// Return the file length.
-    int64_t fileLength() const noexcept
-    {
-        return fileContent_.length();
-    };
-    /// Return the file content.
-    char *fileData() noexcept
-    {
-#if __cplusplus >= 201703L || (defined _MSC_VER && _MSC_VER > 1900)
-        return fileContent_.data();
-#else
-        return (char *)(fileContent_.data());
-#endif
-    }
-    const char *fileData() const noexcept
-    {
-        return fileContent_.data();
-    }
-    std::string &fileContent() noexcept
-    {
-        return fileContent_;
-    }
-    const std::string &fileContent() const noexcept
-    {
-        return fileContent_;
-    }
+    size_t fileLength() const noexcept;
+
+    /// Return the file data.
+    const char *fileData() const noexcept;
+
     /// Return the md5 string of the file
     std::string getMd5() const;
 
-  protected:
-    int saveTo(const std::string &pathAndFilename) const;
-    std::string fileName_;
-    std::string fileContent_;
+  private:
+    std::shared_ptr<HttpFileImpl> implPtr_;
 };
 
 /// A parser class which help the user to get the files and the parameters in
@@ -113,7 +87,7 @@ class MultiPartParser
     ~MultiPartParser(){};
     /// Get files, This method should be called after calling the parse()
     /// method.
-    const std::vector<HttpFile> &getFiles();
+    const std::vector<HttpFile> &getFiles() const;
 
     /// Get parameters, This method should be called after calling the parse ()
     /// method.
@@ -125,8 +99,11 @@ class MultiPartParser
   protected:
     std::vector<HttpFile> files_;
     std::map<std::string, std::string> parameters_;
-    int parse(const HttpRequestPtr &req, const std::string &boundary);
+    int parse(const HttpRequestPtr &req,
+              const char *boundaryData,
+              size_t boundaryLen);
     int parseEntity(const char *begin, const char *end);
+    HttpRequestPtr requestPtr_;
 };
 
 /// In order to be compatible with old interfaces
diff --git a/lib/inc/drogon/utils/Utilities.h b/lib/inc/drogon/utils/Utilities.h
index b7075636..26b2f32a 100644
--- a/lib/inc/drogon/utils/Utilities.h
+++ b/lib/inc/drogon/utils/Utilities.h
@@ -98,7 +98,11 @@ std::string urlEncode(const std::string &);
 std::string urlEncodeComponent(const std::string &);
 
 /// Get the MD5 digest of a string.
-std::string getMd5(const std::string &originalString);
+std::string getMd5(const char *data, const size_t dataLen);
+inline std::string getMd5(const std::string &originalString)
+{
+    return getMd5(originalString.data(), originalString.length());
+}
 
 /// Commpress or decompress data using gzip lib.
 /**
diff --git a/lib/src/HttpFileImpl.cc b/lib/src/HttpFileImpl.cc
new file mode 100644
index 00000000..be6b0e26
--- /dev/null
+++ b/lib/src/HttpFileImpl.cc
@@ -0,0 +1,161 @@
+/**
+ *
+ *  HttpFileImpl.cc
+ *  An Tao
+ *
+ *  Copyright 2018, An Tao.  All rights reserved.
+ *  https://github.com/an-tao/drogon
+ *  Use of this source code is governed by a MIT license
+ *  that can be found in the License file.
+ *
+ *  Drogon
+ *
+ */
+
+#include "HttpFileImpl.h"
+#include "HttpAppFrameworkImpl.h"
+#include <drogon/MultiPart.h>
+#include <fstream>
+#include <iostream>
+
+using namespace drogon;
+
+int HttpFileImpl::save(const std::string &path) const
+{
+    assert(!path.empty());
+    if (fileName_ == "")
+        return -1;
+    std::string filename;
+    auto tmpPath = path;
+    if (path[0] == '/' ||
+        (path.length() >= 2 && path[0] == '.' && path[1] == '/') ||
+        (path.length() >= 3 && path[0] == '.' && path[1] == '.' &&
+         path[2] == '/') ||
+        path == "." || path == "..")
+    {
+        // Absolute or relative path
+    }
+    else
+    {
+        auto &uploadPath = HttpAppFrameworkImpl::instance().getUploadPath();
+        if (uploadPath[uploadPath.length() - 1] == '/')
+            tmpPath = uploadPath + path;
+        else
+            tmpPath = uploadPath + "/" + path;
+    }
+
+    if (utils::createPath(tmpPath) < 0)
+        return -1;
+
+    if (tmpPath[tmpPath.length() - 1] != '/')
+    {
+        filename = tmpPath + "/";
+        filename.append(fileName_.data(), fileName_.length());
+    }
+    else
+        filename = tmpPath.append(fileName_.data(), fileName_.length());
+
+    return saveTo(filename);
+}
+int HttpFileImpl::save() const
+{
+    return save(HttpAppFrameworkImpl::instance().getUploadPath());
+}
+int HttpFileImpl::saveAs(const std::string &filename) const
+{
+    assert(!filename.empty());
+    auto pathAndFileName = filename;
+    if (filename[0] == '/' ||
+        (filename.length() >= 2 && filename[0] == '.' && filename[1] == '/') ||
+        (filename.length() >= 3 && filename[0] == '.' && filename[1] == '.' &&
+         filename[2] == '/'))
+    {
+        // Absolute or relative path
+    }
+    else
+    {
+        auto &uploadPath = HttpAppFrameworkImpl::instance().getUploadPath();
+        if (uploadPath[uploadPath.length() - 1] == '/')
+            pathAndFileName = uploadPath + filename;
+        else
+            pathAndFileName = uploadPath + "/" + filename;
+    }
+    auto pathPos = pathAndFileName.rfind('/');
+    if (pathPos != std::string::npos)
+    {
+        std::string path = pathAndFileName.substr(0, pathPos);
+        if (utils::createPath(path) < 0)
+            return -1;
+    }
+    return saveTo(pathAndFileName);
+}
+int HttpFileImpl::saveTo(const std::string &pathAndFilename) const
+{
+    LOG_TRACE << "save uploaded file:" << pathAndFilename;
+    std::ofstream file(pathAndFilename);
+    if (file.is_open())
+    {
+        file.write(fileContent_.data(), fileContent_.size());
+        file.close();
+        return 0;
+    }
+    else
+    {
+        LOG_ERROR << "save failed!";
+        return -1;
+    }
+}
+std::string HttpFileImpl::getMd5() const
+{
+    return utils::getMd5(fileContent_.data(), fileContent_.size());
+}
+
+const std::string &HttpFile::getFileName() const
+{
+    return implPtr_->getFileName();
+}
+
+void HttpFile::setFileName(const std::string &filename)
+{
+    implPtr_->setFileName(filename);
+}
+
+void HttpFile::setFile(const char *data, size_t length)
+{
+    implPtr_->setFile(data, length);
+}
+
+int HttpFile::save() const
+{
+    return implPtr_->save();
+}
+
+int HttpFile::save(const std::string &path) const
+{
+    return implPtr_->save(path);
+}
+
+int HttpFile::saveAs(const std::string &filename) const
+{
+    return implPtr_->saveAs(filename);
+}
+
+size_t HttpFile::fileLength() const noexcept
+{
+    return implPtr_->fileLength();
+}
+
+const char *HttpFile::fileData() const noexcept
+{
+    return implPtr_->fileData();
+}
+
+std::string HttpFile::getMd5() const
+{
+    return implPtr_->getMd5();
+}
+
+HttpFile::HttpFile(std::shared_ptr<HttpFileImpl> &&implPtr)
+    : implPtr_(std::move(implPtr))
+{
+}
diff --git a/lib/src/HttpFileImpl.h b/lib/src/HttpFileImpl.h
new file mode 100644
index 00000000..8e0cb36e
--- /dev/null
+++ b/lib/src/HttpFileImpl.h
@@ -0,0 +1,100 @@
+/**
+ *
+ *  HttpFileImpl.h
+ *  An Tao
+ *
+ *  Copyright 2018, An Tao.  All rights reserved.
+ *  https://github.com/an-tao/drogon
+ *  Use of this source code is governed by a MIT license
+ *  that can be found in the License file.
+ *
+ *  Drogon
+ *
+ */
+
+#pragma once
+#include <drogon/utils/string_view.h>
+#include <drogon/HttpRequest.h>
+
+#include <map>
+#include <string>
+#include <vector>
+#include <memory>
+namespace drogon
+{
+class HttpFileImpl
+{
+  public:
+    /// Return the file name;
+    const std::string &getFileName() const
+    {
+        return fileName_;
+    };
+
+    /// Set the file name, usually called by the MultiPartParser parser.
+    void setFileName(const std::string &filename)
+    {
+        fileName_ = filename;
+    };
+
+    /// Set the contents of the file, usually called by the MultiPartParser
+    /// parser.
+    void setFile(const char *data, size_t length)
+    {
+        fileContent_ = string_view{data, length};
+    };
+
+    /// Save the file to the file system.
+    /**
+     * The folder saving the file is app().getUploadPath().
+     * The full path is app().getUploadPath()+"/"+this->getFileName()
+     */
+    int save() const;
+
+    /// Save the file to @param path
+    /**
+     * @param path if the parameter is prefixed with "/", "./" or "../", or is
+     * "." or "..", the full path is path+"/"+this->getFileName(),
+     * otherwise the file is saved as
+     * app().getUploadPath()+"/"+path+"/"+this->getFileName()
+     */
+    int save(const std::string &path) const;
+
+    /// Save the file to file system with a new name
+    /**
+     * @param filename if the parameter isn't prefixed with "/", "./" or "../",
+     * the full path is app().getUploadPath()+"/"+filename, otherwise the file
+     * is saved as the filename
+     */
+    int saveAs(const std::string &filename) const;
+
+    /// Return the file length.
+    size_t fileLength() const noexcept
+    {
+        return fileContent_.length();
+    };
+
+    const char *fileData() const noexcept
+    {
+        return fileContent_.data();
+    }
+
+    const string_view &fileContent() const noexcept
+    {
+        return fileContent_;
+    }
+
+    /// Return the md5 string of the file
+    std::string getMd5() const;
+    int saveTo(const std::string &pathAndFilename) const;
+    void setRequest(const HttpRequestPtr &req)
+    {
+        requestPtr_ = req;
+    }
+
+  private:
+    std::string fileName_;
+    string_view fileContent_;
+    HttpRequestPtr requestPtr_;
+};
+}  // namespace drogon
\ No newline at end of file
diff --git a/lib/src/MultiPart.cc b/lib/src/MultiPart.cc
index ff90e1dc..9d733570 100644
--- a/lib/src/MultiPart.cc
+++ b/lib/src/MultiPart.cc
@@ -15,6 +15,7 @@
 #include "HttpRequestImpl.h"
 #include "HttpUtils.h"
 #include "HttpAppFrameworkImpl.h"
+#include "HttpFileImpl.h"
 #include <drogon/MultiPart.h>
 #include <drogon/utils/Utilities.h>
 #include <drogon/config.h>
@@ -29,7 +30,7 @@
 
 using namespace drogon;
 
-const std::vector<HttpFile> &MultiPartParser::getFiles()
+const std::vector<HttpFile> &MultiPartParser::getFiles() const
 {
     return files_;
 }
@@ -60,9 +61,9 @@ int MultiPartParser::parse(const HttpRequestPtr &req)
     pos = contentType.find("boundary=");
     if (pos == std::string::npos)
         return -1;
-    std::string boundary = contentType.substr(pos + 9);
-
-    return parse(req, boundary);
+    return parse(req,
+                 contentType.data() + (pos + 9),
+                 contentType.size() - (pos + 9));
 }
 
 int MultiPartParser::parseEntity(const char *begin, const char *end)
@@ -95,20 +96,26 @@ int MultiPartParser::parseEntity(const char *begin, const char *end)
         auto pos1 = std::search(pos, end, quotationMark, quotationMark + 1);
         if (pos1 == end)
             return -1;
-        HttpFile file;
-        file.setFileName(std::string(pos, pos1));
+        auto filePtr = std::make_shared<HttpFileImpl>();
+        filePtr->setRequest(requestPtr_);
+        filePtr->setFileName(std::string(pos, pos1));
         pos1 = std::search(pos1, end, CRLF, CRLF + 4);
         if (pos1 == end)
             return -1;
-        file.setFile(std::string(pos1 + 4, end));
-        files_.push_back(std::move(file));
+        filePtr->setFile(pos1 + 4, static_cast<size_t>(end - pos1 - 4));
+        files_.push_back(std::move(HttpFile(std::move(filePtr))));
         return 0;
     }
 }
 
 int MultiPartParser::parse(const HttpRequestPtr &req,
-                           const std::string &boundary)
+                           const char *boundaryData,
+                           size_t boundaryLen)
 {
+    string_view boundary{boundaryData, boundaryLen};
+    if (boundary.size() > 2 && boundary[0] == '\"')
+        boundary = boundary.substr(1, boundary.size() - 2);
+    requestPtr_ = req;
     string_view::size_type pos1, pos2;
     pos1 = 0;
     auto content = static_cast<HttpRequestImpl *>(req.get())->bodyView();
@@ -134,92 +141,3 @@ int MultiPartParser::parse(const HttpRequestPtr &req,
     }
     return 0;
 }
-
-int HttpFile::save(const std::string &path) const
-{
-    assert(!path.empty());
-    if (fileName_ == "")
-        return -1;
-    std::string filename;
-    auto tmpPath = path;
-    if (path[0] == '/' ||
-        (path.length() >= 2 && path[0] == '.' && path[1] == '/') ||
-        (path.length() >= 3 && path[0] == '.' && path[1] == '.' &&
-         path[2] == '/') ||
-        path == "." || path == "..")
-    {
-        // Absolute or relative path
-    }
-    else
-    {
-        auto &uploadPath = HttpAppFrameworkImpl::instance().getUploadPath();
-        if (uploadPath[uploadPath.length() - 1] == '/')
-            tmpPath = uploadPath + path;
-        else
-            tmpPath = uploadPath + "/" + path;
-    }
-
-    if (utils::createPath(tmpPath) < 0)
-        return -1;
-
-    if (tmpPath[tmpPath.length() - 1] != '/')
-    {
-        filename = tmpPath + "/" + fileName_;
-    }
-    else
-        filename = tmpPath + fileName_;
-
-    return saveTo(filename);
-}
-int HttpFile::save() const
-{
-    return save(HttpAppFrameworkImpl::instance().getUploadPath());
-}
-int HttpFile::saveAs(const std::string &filename) const
-{
-    assert(!filename.empty());
-    auto pathAndFileName = filename;
-    if (filename[0] == '/' ||
-        (filename.length() >= 2 && filename[0] == '.' && filename[1] == '/') ||
-        (filename.length() >= 3 && filename[0] == '.' && filename[1] == '.' &&
-         filename[2] == '/'))
-    {
-        // Absolute or relative path
-    }
-    else
-    {
-        auto &uploadPath = HttpAppFrameworkImpl::instance().getUploadPath();
-        if (uploadPath[uploadPath.length() - 1] == '/')
-            pathAndFileName = uploadPath + filename;
-        else
-            pathAndFileName = uploadPath + "/" + filename;
-    }
-    auto pathPos = pathAndFileName.rfind('/');
-    if (pathPos != std::string::npos)
-    {
-        std::string path = pathAndFileName.substr(0, pathPos);
-        if (utils::createPath(path) < 0)
-            return -1;
-    }
-    return saveTo(pathAndFileName);
-}
-int HttpFile::saveTo(const std::string &pathAndFilename) const
-{
-    LOG_TRACE << "save uploaded file:" << pathAndFilename;
-    std::ofstream file(pathAndFilename);
-    if (file.is_open())
-    {
-        file << fileContent_;
-        file.close();
-        return 0;
-    }
-    else
-    {
-        LOG_ERROR << "save failed!";
-        return -1;
-    }
-}
-std::string HttpFile::getMd5() const
-{
-    return utils::getMd5(fileContent_);
-}
diff --git a/lib/src/Utilities.cc b/lib/src/Utilities.cc
index e5819ce1..dd72b104 100644
--- a/lib/src/Utilities.cc
+++ b/lib/src/Utilities.cc
@@ -1144,17 +1144,17 @@ std::string brotliDecompress(const char *data, const size_t ndata)
 }
 #endif
 
-std::string getMd5(const std::string &originalString)
+std::string getMd5(const char *data, const size_t dataLen)
 {
 #ifdef OpenSSL_FOUND
     MD5_CTX c;
     unsigned char md5[16] = {0};
     MD5_Init(&c);
-    MD5_Update(&c, originalString.c_str(), originalString.size());
+    MD5_Update(&c, data, dataLen);
     MD5_Final(md5, &c);
     return utils::binaryStringToHex(md5, 16);
 #else
-    return Md5Encode::encode(originalString);
+    return Md5Encode::encode(data, dataLen);
 #endif
 }
 
diff --git a/lib/src/ssl_funcs/Md5.cc b/lib/src/ssl_funcs/Md5.cc
index 2330e7ff..411d7ef4 100644
--- a/lib/src/ssl_funcs/Md5.cc
+++ b/lib/src/ssl_funcs/Md5.cc
@@ -320,7 +320,7 @@ std::string Md5Encode::getHexStr(uint32_t numStr)
 // function: Encode
 // @param srcInfo: the string to be encoded.
 // return : the string after encoding
-std::string Md5Encode::encode(const std::string &srcInfo)
+std::string Md5Encode::encode(const char *data, const size_t dataLen)
 {
     ParamDynamic param;
     param.ua_ = kA;
@@ -334,7 +334,7 @@ std::string Md5Encode::encode(const std::string &srcInfo)
 
     std::string result;
     char *outDataPtr = nullptr;
-    int totalByte = fillData(srcInfo.c_str(), srcInfo.length(), &outDataPtr);
+    int totalByte = fillData(data, dataLen, &outDataPtr);
 
     for (int i = 0; i < totalByte / (BIT_OF_GROUP / BIT_OF_BYTE); ++i)
     {
diff --git a/lib/src/ssl_funcs/Md5.h b/lib/src/ssl_funcs/Md5.h
index 07bee842..e65117e4 100644
--- a/lib/src/ssl_funcs/Md5.h
+++ b/lib/src/ssl_funcs/Md5.h
@@ -58,7 +58,7 @@ class Md5Encode
     };
 
   public:
-    static std::string encode(const std::string &srcInfo);
+    static std::string encode(const char *data, const size_t dataLen);
 
   protected:
     static uint32_t cycleMoveLeft(uint32_t srcNum, int bitNumToMove);