JSP-使用apachecommons上传文件

为什么我的文件上传代码不起作用

我正在使用“commons-fileupload-1.1.1.jar”

此外，我还看到NetBeans 6.1中“isMultipartContent”的第二行有一个删除线

    // Check that we have a file upload request  
>>>>    boolean isMultipart = FileUpload.isMultipartContent(request);  

// Create variables for path, filename and extension  
appPath = application.getRealPath("\\");

// Create a factory for disk-based file items  
FileItemFactory factory = new DiskFileItemFactory();  

// Create a new file upload handler  
ServletFileUpload upload = new ServletFileUpload(factory);  

// Parse the request and Extract request items  
>>>>>    List items = upload.parseRequest(request);

// create an Iterator to iterate through request items  
Iterator iter = items.iterator();

//Form fields
//out.println("<br><br>While loop started");

while (iter.hasNext())
{  
  FileItem item = (FileItem) iter.next();

  if(item.isFormField())
  {
    String name = item.getFieldName();  
    String value = item.getString();  

    if(name.equals("txtUsername")) 
    {
      _USERNAME_ = value;

      Class.forName("org.gjt.mm.mysql.Driver");

      try
      {
        connection = DriverManager.getConnection("jdbc:mysql://localhost/ict");
        statement = connection.createStatement();
        recordset = statement.executeQuery("SELECT * FROM registered_students WHERE username=\'" + _USERNAME_ + "\'");

        while(recordset.next())
        {
          roll = recordset.getString(4);

          _ROLL_ = roll;
        }

        recordset.close();
        recordset=null;

        statement.close();
        statement=null;
      }
      finally
      {
        if(connection!=null)
        {
          connection.close();
        }
      }
    }
  }
}

---

因为commons fileupload依赖于。把它添加到你的类路径中。

只是一个注释-你的数据库查询让我有点畏缩。如果语句和ResultSet对象未关闭，则可能会发生内存泄漏，并且由于您将输入直接复制到查询中，因此可能会发生注入攻击

PreparedStatement select = null;
ResultSet rs = null;

try { con.prepareStatement("SELECT * FROM registered_students WHERE username = ?");
    select.setString(1, username);
    rs = select.executeQuery();
} finally {
    if (select != null) select.close();
    if (rs != null) rs.close();
}

PreparedStatement select = null;
ResultSet rs = null;

try { con.prepareStatement("SELECT * FROM registered_students WHERE username = ?");
    select.setString(1, username);
    rs = select.executeQuery();
} finally {
    if (select != null) select.close();
    if (rs != null) rs.close();
}