Jsp 如何在多部分post请求中传递参数 Servlet代码 HTML代码 文件上载表格 文件上载： 选择要上载的文件：

我的问题是：如何在多部分post请求中传递

fname

参数？

简短回答：您将在请求的

部分找到
fname

长答案：对于多部分类型的请求，即使是简单的
字段值也会放在部分中。您必须迭代
HttpServletRequest.getParts（）
返回的
Part
对象，并根据它们的
名称
属性处理它们：

for( Part p : request.getParts() ) {
    if( "fname".equals(p.getName()) ) {
        ...
    }
    else if( "file".equals(p.getName()) ) {
        ...
    }
}

为了使事情进一步复杂化，该部件的内容可用作
InputStream
-
part.getInputStream（）
-因此您必须对流进行一些转换→ <代码>字节[]

→ <代码>字符串获取值。

链接每个程序
Link Each Programms
------------------------------------------------------

import java.sql.*;
import java.io.*;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import java.util.Hashtable;
import java.util.List;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.ParameterParser;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;


/**
 * Servlet implementation class Recent
 */
@WebServlet("/Recent")
@MultipartConfig
public class Recent extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Recent() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // TODO Auto-generated method stub
         Sample  s1=new Sample();
         final String UPLOAD_DIRECTORY = "/home/pradeep/Documents/pradeep/WebContent/Images";
         if(ServletFileUpload.isMultipartContent(request)){
                try {
         List<FileItem> multiparts = new 
                            ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);

                    for(FileItem item : multiparts){
                        if(!item.isFormField())
                        {
                            String name = new File(item.getName()).getName();
                            item.write( new File(UPLOAD_DIRECTORY + File.separator + name));
                            String Path= "/home/pradeep/Documents/pradeep/WebContent/Images/" +name;


                          s1.connecting(Path);


                        }
                    }

                        request.setAttribute("message", "File Uploaded Successfully");
                } catch (Exception ex) {
                   request.setAttribute("message", "File Upload Failed due to " + ex);
                }          

            }else{
                request.setAttribute("message",
                                     "Sorry this Servlet only handles file upload request");
            }



                request.getRequestDispatcher("/Result.jsp").forward(request, response);




    }

}
-------------------------------------------------------------------------------------------
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import dbconnections.Connections;



public class Sample {
    Connections con=new Connections();

    public void connecting(String Path)
    {
        Connection conn=con.Connect();

        PreparedStatement pst;
        String query="INSERT INTO Student1 (Path) values (?)";
       try {

            pst=conn.prepareStatement(query);
            pst.setString(1,Path);
            pst.executeUpdate();

        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // TODO Auto-generated method stub
    }


}
-------------------------------------------------------------------------------------
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<div>
            <h3> Choose File to Upload in Server </h3>          
           <form action="Recent" method="post" enctype="multipart/form-data">

            <input type="file" name="file" />
            <input type="submit" value="upload" />
            </form>          
        </div>


</body>
</html>

------------------------------------------------------
导入java.sql.*；
导入java.io.*；
导入javax.servlet.ServletException；
导入javax.servlet.annotation.MultipartConfig；
导入javax.servlet.annotation.WebServlet；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入javax.servlet.http.Part；
导入javax.servlet.annotation.MultipartConfig；
导入javax.servlet.annotation.WebServlet；
导入java.util.Hashtable；
导入java.util.List；
导入org.apache.commons.fileupload.FileItem；
导入org.apache.commons.fileupload.ParameterParser；
导入org.apache.commons.fileupload.disk.DiskFileItemFactory；
导入org.apache.commons.fileupload.servlet.ServletFileUpload；
/**
*最近的Servlet实现类
*/
@WebServlet（“/最近”）
@多重配置
公共类最近扩展了HttpServlet{
私有静态最终长serialVersionUID=1L；
/**
*@参见HttpServlet#HttpServlet（）
*/
公众近期{
超级（）；
//TODO自动生成的构造函数存根
}
/**
*@请参阅HttpServlet#doPost（HttpServletRequest请求，HttpServletResponse响应）
*/
受保护的void doPost（HttpServletRequest请求、HttpServletResponse响应）引发ServletException、IOException{
//TODO自动生成的方法存根
样本s1=新样本（）；
最终字符串UPLOAD_DIRECTORY=“/home/pradeep/Documents/pradeep/WebContent/Images”；
if（ServletFileUpload.isMultipartContent（请求））{
试一试{
列表多部分=新建
ServletFileUpload（新的DiskFileItemFactory（））.parseRequest（请求）；
用于（文件项：多部分）{
如果（！item.isFormField（））
{
字符串名称=新文件（item.getName（））.getName（）；
item.write（新文件（UPLOAD_DIRECTORY+File.separator+name））；
字符串路径=“/home/pradeep/Documents/pradeep/WebContent/Images/”+名称；
s1.连接（路径）；
}
}
request.setAttribute（“消息”，“文件上传成功”）；
}捕获（例外情况除外）{
request.setAttribute（“消息”，“文件上载因“+ex”而失败）；
}          
}否则{
request.setAttribute（“消息”，
“抱歉，此Servlet仅处理文件上载请求”）；
}
request.getRequestDispatcher（“/Result.jsp”）.forward（请求，响应）；
}
}
-------------------------------------------------------------------------------------------
导入java.sql.Connection；
导入java.sql.DriverManager；
导入java.sql.PreparedStatement；
导入java.sql.ResultSet；
导入java.sql.SQLException；
导入dbconnections.Connections；
公共类样本{
连接con=新连接（）；
公共无效连接（字符串路径）
{
连接conn=con.Connect（）；
编制报表pst；
String query=“插入Student1（路径）值（？”；
试一试{
pst=conn.prepareStatement（查询）；
pst.setString（1，路径）；
pst.executeUpdate（）；
}捕获（SQLE异常）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}
//TODO自动生成的方法存根
}
}
-------------------------------------------------------------------------------------
在此处插入标题
选择要在服务器中上载的文件

然后使用类型“fname”不存在。有关可飞行类型，请参见。服务器端“名称”中的Alse也不存在。您应该使用request.getparameter（“fname”）。我已经更正了。仍然不工作。可能操作是UploadServlet.jsp？request.getParts（）。。。不存在……好吧，Javadocs说它可以在他们的网站上找到，但它不存在于我的HttpServletRequest中。我找到了解决方案。如果您也有这个问题，请将javax.servlet.api升级到3.0.1

for( Part p : request.getParts() ) {
    if( "fname".equals(p.getName()) ) {
        ...
    }
    else if( "file".equals(p.getName()) ) {
        ...
    }
}

Link Each Programms
------------------------------------------------------

import java.sql.*;
import java.io.*;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import java.util.Hashtable;
import java.util.List;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.ParameterParser;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;


/**
 * Servlet implementation class Recent
 */
@WebServlet("/Recent")
@MultipartConfig
public class Recent extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Recent() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // TODO Auto-generated method stub
         Sample  s1=new Sample();
         final String UPLOAD_DIRECTORY = "/home/pradeep/Documents/pradeep/WebContent/Images";
         if(ServletFileUpload.isMultipartContent(request)){
                try {
         List<FileItem> multiparts = new 
                            ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);

                    for(FileItem item : multiparts){
                        if(!item.isFormField())
                        {
                            String name = new File(item.getName()).getName();
                            item.write( new File(UPLOAD_DIRECTORY + File.separator + name));
                            String Path= "/home/pradeep/Documents/pradeep/WebContent/Images/" +name;


                          s1.connecting(Path);


                        }
                    }

                        request.setAttribute("message", "File Uploaded Successfully");
                } catch (Exception ex) {
                   request.setAttribute("message", "File Upload Failed due to " + ex);
                }          

            }else{
                request.setAttribute("message",
                                     "Sorry this Servlet only handles file upload request");
            }



                request.getRequestDispatcher("/Result.jsp").forward(request, response);




    }

}
-------------------------------------------------------------------------------------------
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import dbconnections.Connections;



public class Sample {
    Connections con=new Connections();

    public void connecting(String Path)
    {
        Connection conn=con.Connect();

        PreparedStatement pst;
        String query="INSERT INTO Student1 (Path) values (?)";
       try {

            pst=conn.prepareStatement(query);
            pst.setString(1,Path);
            pst.executeUpdate();

        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // TODO Auto-generated method stub
    }


}
-------------------------------------------------------------------------------------
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<div>
            <h3> Choose File to Upload in Server </h3>          
           <form action="Recent" method="post" enctype="multipart/form-data">

            <input type="file" name="file" />
            <input type="submit" value="upload" />
            </form>          
        </div>


</body>
</html>