Java Servlet上传文件
在网上看好多程序员在找Java文件上传的demo，其实用Servlet3.0(JDK1.6)自身带的API就可以了，Servlet3.0新增了Part接口，HttpServletRequest的getPart()方法取得Part实现对象，以下是实现单文件上传的代码：
1、前端页面代码：
<!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>调用HttpServletRequest的getPart()方法！</h1><br>
<form action="OneFileUpLoadServlet" method="post"
enctype="multipart/form-data">
选择一个要上传的文件：<br>
<input
type="file" name="one-photo"/><br>
<input type="submit"
name="upload" value="Upload">
</form>
</body>
</html>
2、后台Servlet代码：
package com.victory.servlet;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
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;
@MultipartConfig
@WebServlet("/OneFileUpLoadServlet")
public
class OneFileUpLoadServlet extends HttpServlet {
private static final long
serialVersionUID = 1L;
protected void doGet(HttpServletRequest
request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void
doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
request.setCharacterEncoding("UTF-8");
Part part = request.getPart("one-photo");
String fileName =
getFileName(part);
writeTo(fileName, part);
}
private String
getFileName(Part part) throws IOException{
String header =
part.getHeader("Content-Disposition");
String filePath =
header.substring(header.indexOf("filename=\"") + 10, header.lastIndexOf("\""));
String fileName = filePath.substring(filePath.lastIndexOf("\\")+1);
return fileName;
}
//保存到服务器上的C:根目录下
private void
writeTo(String fileName, Part part) throws IOException {
InputStream is =
part.getInputStream();
OutputStream os = new
FileOutputStream("C:/"+fileName);
byte[] buffer = new byte[1024*2];
int
length = -1;
while((length = is.read(buffer)) != -1) {
os.write(buffer,
0, length);
}
is.close();
os.close();
}
}
以下是实现多文件上传：
1、前端页面：
<!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>调用HttpServletRequest的getParts()方法！</h1><br>
<form action="MoreFileUpLoadServlet" method="post"
enctype="multipart/form-data">
选择要上传的文件：<br>
<input
type="file" name="filename1" value="" /><br>
<input type="file"
name="filename2" value="" /><br>
<input type="file"
name="filename3" value="" /><br>
<input type="file"
name="filename4" value="" /><br>
<input type="file"
name="filename5" value="" /><br>
<input type="file"
name="filename6" value="" /><br>
<input type="file"
name="filename7" value="" /><br>
<input type="file"
name="filename8" value="" /><br>
<input type="submit"
name="upload" value="Upload">
</form>
</body>
</html>
2、后台Servlet代码：
package com.victory.servlet;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
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;
@MultipartConfig
@WebServlet("/MoreFileUpLoadServlet")
public
class MoreFileUpLoadServlet extends HttpServlet {
private static final long
serialVersionUID = 1L;
protected void doGet(HttpServletRequest
request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void
doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
request.setCharacterEncoding("UTF-8");
for(Part part:request.getParts()) {
if(part.getName().startsWith("file")) {
String fileName =
getFileName(part);
writeTo(fileName, part);
}
}
}
private String getFileName(Part part) throws IOException{
String
header = part.getHeader("Content-Disposition");
String filePath =
header.substring(header.indexOf("filename=\"") + 10, header.lastIndexOf("\""));
String fileName = filePath.substring(filePath.lastIndexOf("\\")+1);
return fileName;
}
//保存到服务器上的C:根目录下
private void
writeTo(String fileName, Part part) throws IOException {
InputStream is =
part.getInputStream();
OutputStream os = new
FileOutputStream("C:/"+fileName);
byte[] buffer = new byte[1024*2];
int
length = -1;
while((length = is.read(buffer)) != -1) {
os.write(buffer,
0, length);
}
is.close();
os.close();
}
}
