依赖jar
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency> <dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
示例如下:
1. 新建Maven项目 upload
war 类型
2. pom.xml
<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.java</groupId>
<artifactId>upload</artifactId>
<version>1.0.0</version>
<packaging>war</packaging> <dependencies> <dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency> <dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency> </dependencies> <build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin> </plugins>
</build>
</project>
3. UploadFileServlet.java
package com.java.servlet; import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map; 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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FileUtils; /**
* 原生Servlet上传文件
*
*/
public class UploadFileServlet extends HttpServlet { private static final long serialVersionUID = -755404037178760784L; /**
* 设置字符集为UTF-8
*/
private static final String ENCODING = "UTF-8"; @Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if (ServletFileUpload.isMultipartContent(request)) {
try {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
List<FileItem> items = upload.parseRequest(request); // 存储普通表单参数
Map<String, String> paramMap = new HashMap<>(); // 存储文件参数
Map<String, FileItem> fileMap = new HashMap<>(); /* 解析表单参数 */
for (FileItem item : items) { // 普通表单参数
if (item.isFormField()) {
paramMap.put(item.getFieldName(), item.getString(ENCODING));
} // 文件参数
else {
fileMap.put(item.getFieldName(), item);
}
} /* 从参数集合中获取需要的参数 */
String uploadPath = paramMap.get("uploadPath");
FileItem fileItem = fileMap.get("file");
String fileName = fileItem.getName(); File outFile = new File(uploadPath, fileName);
if (outFile.exists()) {
FileUtils.forceDelete(outFile);
}
fileItem.write(outFile); write(response, "上传完成:" + outFile.getAbsolutePath());
} catch (FileUploadException e) {
e.printStackTrace();
write(response, e.getMessage());
} catch (Exception e) {
e.printStackTrace();
write(response, e.getMessage());
}
} // 请求Content-type设置错误时给出提示
else {
write(response, "非multipart类型,检查Content-type");
} } private void write(HttpServletResponse response, String message) {
response.setContentType("text/html; charset=UTF-8");
PrintWriter writer = null;
try {
writer = response.getWriter();
writer.write(message);
writer.flush();
} catch (IOException e) {
e.printStackTrace();
} finally {
writer.close();
}
} }
4. web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5"> <display-name>upload</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list> <servlet>
<servlet-name>uploadFile</servlet-name>
<servlet-class>com.java.servlet.UploadFileServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>uploadFile</servlet-name>
<url-pattern>/uploadFile</url-pattern>
</servlet-mapping>
</web-app>
5. 新建页面文件 src/main/webapp/index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%> <!DOCTYPE html>
<html> <head>
<title>上传文件</title>
<base href="<%=basePath%>">
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
</head> <body> <form action="uploadFile" enctype="multipart/form-data" method="post">
<table>
<tr>
<th>选择上传文件:</th>
<td><input name="file" type="file" /></td>
</tr>
<tr>
<th>上传服务器路径:</th>
<td><input name="uploadPath" type="text" placeholder="上传服务器路径" /></td>
</tr>
<tr>
<td colspan="2"><button type="submit">上传</button></td>
</tr>
</table>
</form> </body> </html>
部署到tomcat下,启动
浏览器输入 http://localhost:8080/upload/
如下所示:
选择文件,输入上传路径 G:\Temp\Test 如下所示:
单击【上传】,返回信息如下:
上传完成:G:\Temp\Test\fastjson-1.2.49.jar
查看G:\Temp\Test,文件已上传成功!
.