JAVA基础篇—文件上传下载
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/index.jsp
<%@ 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> <script type="text/javascript" src="/web-ajax/js/jquery.min.js"></script> </head> <body> <form action="${pageContext.request.contextPath}/FileServlet" enctype="multipart/form-data" method="post"> 用户： <input type="text" name="username"/><br> <input type="file" name="photo"/><br> <input type="file" name="photo1"/><br> <input type="file" name="photo2"/><br> <input type="submit" value="起飞"/> </form> </body> </html>
/downlode.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <a href="${pageContext.request.contextPath}/DownServlet">下载吧</a> </body> </html>
/class FileServlet
package com.neuedu.servlet;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.UUID;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
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.FileUploadBase.FileSizeLimitExceededException;
import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
@WebServlet("/FileServlet")
public class FileServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//工厂类，用于构建一个解析器实例。
DiskFileItemFactory factory=new DiskFileItemFactory();
//创建对象，完成上传
ServletFileUpload fileupload=new ServletFileUpload(factory);
fileupload.setSizeMax(1024*1500);
ServletContext servletContext = request.getServletContext();
String realPath = servletContext.getRealPath("/upload");
File file=new File(realPath);
if (!file.exists()) {
file.mkdir();
}
try {
List<FileItem>filelist=fileupload.parseRequest(request);
for (FileItem fileItem : filelist) {
if (fileItem.isFormField()) {
String name = fileItem.getFieldName();
String value = fileItem.getString("utf8");
System.out.println(name+":"+value);
}else {
long size = fileItem.getSize();
if(size ==0){
continue;
}
String contentType = fileItem.getContentType();
String name = fileItem.getName();
if(name.contains("\\\\")){
name = name.substring(name.lastIndexOf("\\\\")+1);
}
//uuid_name.jpg
String prefix = UUID.randomUUID().toString();
prefix = prefix.replace("-","");
String fileName = prefix+"_"+name;
// String fieldName = fileItem.getFieldName();
System.out.println(size+":"+contentType+":--------"+name+":"+fileName);
fileItem.write(new File(realPath+"\\\\"+fileName));
}
}
}catch(FileSizeLimitExceededException e){
System.out.println("文件大小不可以超过500K");
}catch(SizeLimitExceededException e){
System.out.println("总大小不可以超过1500k");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/class DownServlet
package com.neuedu.servlet;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.IOUtils;
@WebServlet("/DownServlet")
public class DownServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ServletContext servletContext = request.getServletContext();
String fileName="风吹麦浪.mp3";
String path = servletContext.getRealPath("/风吹麦浪.mp3");
File file=new File(path);
String type = servletContext.getMimeType(path);
InputStream in=new FileInputStream(file);
response.setContentType(type);
fileName = new String(fileName.getBytes("gbk"),"iso8859-1");
response.setHeader("Content-Disposition", "attachment; filename="+fileName);
ServletOutputStream out=response.getOutputStream();
IOUtils.copy(in, out);
in.close();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
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