纯jsp servlet 实现 upload file功能

xfxlch

浏览: 168150 次
性别:
来自: 杭州

最近访客更多访客>>

remote_silence

liufengfan666

zhao12138

yhcc_0817

博主相关

博客

微博

相册

留言

关于我

文章分类

社区版块

存档分类

博客分类：

Java

本篇主要是简单的实现jsp servlet 的上传文件的功能，基于servlet 2.5。
jar依赖：
commons-fileupload/commons-io/servlet-api（commons-fileupload 自动依赖common-io）
pom.xml文件的内容如下：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.luchenghao.demo</groupId>
	<artifactId>gridconfig</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<org.springframework.version>4.1.5.RELEASE</org.springframework.version>
	</properties>
	
	<dependencies>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>servlet-api</artifactId>
			<version>2.5</version>
		</dependency>
		
		<dependency>
			<groupId>commons-fileupload</groupId>
			<artifactId>commons-fileupload</artifactId>
			<version>1.3</version>
		</dependency>
		
	</dependencies>
</project>

form 表单的内容：
要点： method必须是post方法，get是不支持文件上传的。
enctype 属性值为：multipart/form-data。
action 的名字可以取了humanable的值就好了。
input的type要设为file，以支持文件类型。
代码如下：

<!DOCTYPE title 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=ISO-8859-1">
		<title>File Uploading Form</title>
	</head>
	<h3>File Upload:</h3>
	Select a file to upload: <br/>
	<form action="UploadServlet" method="post" enctype="multipart/form-data">
		<input type="file" name="file" size="50" />
		<br />
		<input type="Submit" value="Upload"/>
	</form>
</html>

为了能把上传的文件保存起来，我们配置一个保存的路径c:\temp\data，这个路径必须是真是存在，如果不存在就手动去创建该目录（in web.xml）如下：

<context-param> 
		<description>Location to store uploaded file</description> 
		<param-name>file-upload</param-name> 
		<param-value>
         c:\temp\data\
		</param-value> 
	</context-param>

整个web.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" version="2.5">
	<context-param> 
		<description>Location to store uploaded file</description> 
		<param-name>file-upload</param-name> 
		<param-value>
         c:\temp\data\
		</param-value> 
	</context-param>

	<servlet>
		<servlet-name>upload</servlet-name>
		<servlet-class>com.statestreetgx.fcm.core.controller.UploadController</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>upload</servlet-name>
		<url-pattern>/UploadServlet</url-pattern>
	</servlet-mapping>
</web-app>

后台的servlet代码如下：

package com.statestreetgx.fcm.core.controller;

import java.io.File;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

/**
 * 
 * @author a574539
 */
public class UploadController extends HttpServlet {

    /**
     * serialVersionUID
     */
    private static final long serialVersionUID = -3218211616591116540L;
    private boolean isMultipart;
    private String filePath;
    private int maxFileSize = 50 * 1024;
    private int maxMemSize = 4 * 1024;
    private File file;

    public void init() {
        // Get the file location where it would be stored.
        filePath = getServletContext().getInitParameter("file-upload");
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException {
        // Check that we have a file upload request
        isMultipart = ServletFileUpload.isMultipartContent(request);
        response.setContentType("text/html");
        java.io.PrintWriter out = response.getWriter();
        if (!isMultipart) {
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet upload</title>");
            out.println("</head>");
            out.println("<body>");
            out.println("<p>No file uploaded</p>");
            out.println("</body>");
            out.println("</html>");
            return;
        }
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // maximum size that will be stored in memory
        factory.setSizeThreshold(maxMemSize);
        // Location to save data that is larger than maxMemSize.
        factory.setRepository(new File("c:\\temp"));

        // Create a new file upload handler
        ServletFileUpload upload = new ServletFileUpload(factory);
        // maximum file size to be uploaded.
        upload.setSizeMax(maxFileSize);

        try {
            // Parse the request to get file items.
            List fileItems = upload.parseRequest(request);

            // Process the uploaded file items
            Iterator i = fileItems.iterator();

            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet upload</title>");
            out.println("</head>");
            out.println("<body>");
            while (i.hasNext()) {
                FileItem fi = (FileItem) i.next();
                if (!fi.isFormField()) {
                    // Get the uploaded file parameters
                    String fieldName = fi.getFieldName();
                    String fileName = fi.getName();
                    String contentType = fi.getContentType();
                    boolean isInMemory = fi.isInMemory();
                    long sizeInBytes = fi.getSize();
                    // Write the file
                    if (fileName.lastIndexOf("\\") >= 0) {
                        file = new File(filePath + fileName.substring(fileName.lastIndexOf("\\")));
                    } else {
                        file = new File(filePath + fileName.substring(fileName.lastIndexOf("\\") + 1));
                    }
                    fi.write(file);
                    out.println("Uploaded Filename: " + fileName + "<br>");
                }
            }
            out.println("</body>");
            out.println("</html>");
        } catch (Exception ex) {
            System.out.println(ex);
        }
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException {

        throw new ServletException("GET method used with " + getClass().getName() + ": POST method required.");
    }

//    @RequestMapping(value = "upload")
//    @ResponseBody
//    public void upload() {
//        System.out.println("hello");
//    }
}

参考链接：http://www.tutorialspoint.com/servlets/servlets-file-uploading.htm

--EOF--

分享到：

程序员好悲伤 | jenkins 配置findbugs

2015-08-17 20:35
浏览 760
评论(0)
分类:编程语言
查看更多

发表评论

您还没有登录,请您登录后再发表评论

最近访客更多访客>>

博主相关

文章分类

社区版块

存档分类

最新评论

纯jsp servlet 实现 upload file功能

评论

发表评论

相关推荐

最近访客 更多访客>>

博主相关

文章分类

社区版块

存档分类

最新评论

纯jsp servlet 实现 upload file功能

评论

发表评论

相关推荐

eclipse project .setting

jar命令工具

Java的按值传递

Mac OS 安装java 开发环境

记一次Java Rest Service Hang住的经历

一个String字符串的问题2

我读重构这本书

系统log的编写

CAS 授权问题

Caused by: java.lang.UnsupportedOperationException 解决方案

LogBack 框架里log-access的使用

how to fix "org.hamcrest.CoreMatchers.containsString cannot be resolved"

java 打印金字塔

dos 命令窗口執行java 命令，帶包路徑

tomcat 远程调试

使用android studio 来开发hello world app的时候，遇到的一些坑。

ThreadLocal

Hibernate Interceptor(拦截器)

eclipse 加入tomcat 包

Transforming XML with XSLT

最近访客更多访客>>