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Servlet 3.0 File Upload Example
服务端代码（Servlet）：
package in.co.javatutorials;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
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;
/**
* @author javatutorials.co.in
*/
@MultipartConfig // indicates that request MIME type is multipart/form-data
@WebServlet("/upload")
public class FileUploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String responseMessage = "File Upload Successfull!!";
// Get file part using HttpServletRequest抯 getPart() method
Part filePart = request.getPart("file");
// Extract file name from content-disposition header of file part
String fileName = getFileName(filePart);
String basePath = "C:" + File.separator + "temp" + File.separator;
System.out.println("***** fileName: " + fileName);
// Copy input file to destination path
InputStream inputStream = null;
OutputStream outputStream = null;
try {
File outputFilePath = new File(basePath + fileName);
System.out.println("***** outputFilePath: " + outputFilePath.getAbsolutePath());
inputStream = filePart.getInputStream();
outputStream = new FileOutputStream(outputFilePath);
int read = 0;
final byte[] bytes = new byte[1024];
while ((read = inputStream.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}
} catch (FileNotFoundException fne) {
fne.printStackTrace();
responseMessage = "File Upload Failed!!";
} finally {
if (outputStream != null) {
outputStream.close();
}
if (inputStream != null) {
inputStream.close();
}
}
// create and return response to client web browser
response.setContentType("text/html;UTF-8");
PrintWriter writer = response.getWriter();
writer.write("<html>");
writer.write("<head>");
writer.write("<title>Servlet 3.0 File Upload Example </title>");
writer.write("</head>");
writer.write("<body>");
writer.write("<h3>" + responseMessage + "</h3>");
writer.write("</body>");
writer.write("</html>");
writer.close();
}
// Extract file name from content-disposition header of file part
private String getFileName(Part part) {
final String partHeader = part.getHeader("content-disposition");
System.out.println("***** partHeader: " + partHeader);
for (String content : part.getHeader("content-disposition").split(";")) {
if (content.trim().startsWith("filename")) {
return content.substring(content.indexOf('=') + 1).trim()
.replace("\"", "");
}
}
return null;
}
}
客户端代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Servlet 3.0 File Upload Example</title>
</head>
<body>
<form method="post" action="/FileUploadExample/upload" enctype="multipart/form-data">
File<input type="file" name="file">
<input type="submit" value="submit">
</form>
</body>
</html>
