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1 文件上传
* common-fileupload
* http://commons.apache.org/proper/commons-fileupload/download_fileupload.cgi
* form：enctype="multipart/form-data"
* input： type=“file”
* 下载common-fileupload和导包
* http://commons.apache.org/proper/commons-fileupload/download_fileupload.cgi
* 常见的API
* ServletFileUpload（核心）
* 构建的时候，需要DiskFileItemFactory
* DiskFileItemFactory
* FileItem
* Hello 文件上传
* 导入jar
<%@ 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>
<h1>文件上传</h1>
<form action="${pageContext.request.contextPath }/upload" method="post" enctype="multipart/form-data">
<input type="text" name="username"/><br>
<input type="file" name="file1"/><br>
<input type="file" name="file2"/><br>
<input type="submit" value="提交"/>
</form>
</body>
</html>protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1 获取存储文件上传路径，假如不存在就创建
String realPath = request.getServletContext().getRealPath("/WEB-INF/upload");
File saveDir = new File(realPath);
if (!saveDir.exists() || !saveDir.isDirectory()) {
saveDir.mkdir();
}
// 2 构建DiskFileItemFactory
DiskFileItemFactory dfif = new DiskFileItemFactory();
// 3 构建ServletFileUpload
ServletFileUpload upload = new ServletFileUpload(dfif);
// 4 设置编码
upload.setHeaderEncoding("UTF-8");
// 6 通过请求获取FileItem的列表
InputStream is = null;
FileOutputStream out = null;
try {
List<FileItem> items = upload.parseRequest(request);
for (FileItem item : items) {
// 判断是文件上传还是普通文本域
if (item.isFormField()) {
String fieldName = item.getFieldName();
String value = item.getString("UTF-8");
System.out.println(fieldName + ":" + value);
continue;
}
// 得到上传的文件名称，
String filename = item.getName();
System.out.println(filename);
if (filename == null || filename.trim().equals("")) {
continue;
}
// 注意：不同的浏览器提交的文件名是不一样的，有些浏览器提交上来的文件名是带有路径的，如： c:\a\b\1.txt，而有些只是单纯的文件名，如：1.txt
// 处理获取到的上传文件的文件名的路径部分，只保留文件名部分
filename = filename.substring(filename.lastIndexOf("\\") + 1);
is = item.getInputStream();
out = new FileOutputStream(saveDir + "\\" + filename);
IOUtils.copy(is, out, 1024 * 8);
}
} catch (FileUploadException e) {
e.printStackTrace();
} finally {
if (is != null) {
is.close();
}
if (out != null) {
out.close();
}
}
}
1.5 Servlet3.0 文件上传
* 在Servlet2.5中，我们要实现文件上传功能时，一般都需要借助第三方开源组件，例如Apache的commons-fileupload组件，在Servlet3.0中提供了对文件上传的原生支持，我们不需要借助任何第三方上传组件，直接使用Servlet3.0提供的API就能够实现文件上传功能了。
* @MultipartConfig
* Collection<Part> parts=request.getParts();
/**
* Servlet implementation class UploadServlet
*/
@WebServlet(name = "upload3", urlPatterns = { "/upload3" })
@MultipartConfig
public class UploadServlet3 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public UploadServlet3() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
// 1 获取存储文件上传路径，假如不存在就创建
String realPath = request.getServletContext().getRealPath("/WEB-INF/upload");
File saveDir = new File(realPath);
if (!saveDir.exists() || !saveDir.isDirectory()) {
saveDir.mkdir();
}
Collection<Part> parts = request.getParts();
for (Part part : parts) {
String header = part.getHeader("content-disposition");
System.out.println(header);
String filename = getFileName(header);
System.out.println(filename);
part.write(realPath + File.separator + filename);
}
PrintWriter out = response.getWriter();
out.println("上传成功");
out.flush();
out.close();
}
/**
* 根据请求头解析出文件名 请求头的格式：火狐和google浏览器下：form-data; name="file";
* filename="snmp4j--api.zip" IE浏览器下：form-data; name="file";
* filename="E:\snmp4j--api.zip"
*
* @param header
* 请求头
* @return 文件名
*/
public String getFileName(String header) {
/**
* String[] tempArr1 = header.split(";");代码执行完之后，在不同的浏览器下，tempArr1数组里面的内容稍有区别
* 火狐或者google浏览器下：tempArr1={form-data,name="file",filename="snmp4j--api.zip"}
* IE浏览器下：tempArr1={form-data,name="file",filename="E:\snmp4j--api.zip"}
*/
String[] tempArr1 = header.split(";");
/**
* 火狐或者google浏览器下：tempArr2={filename,"snmp4j--api.zip"}
* IE浏览器下：tempArr2={filename,"E:\snmp4j--api.zip"}
*/
String[] tempArr2 = tempArr1[2].split("=");
// 获取文件名，兼容各种浏览器的写法
String fileName = tempArr2[1].substring(tempArr2[1].lastIndexOf("\\") + 1).replaceAll("\"", "");
return fileName;
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}