alexandreaquiles/UploadArquivoServlet.java

## formUpload.html
<html>
	<body>
		<form action="upload" method="post" enctype="multipart/form-data">
			<input type="text" name="texto">
			<input type="file" name="arquivo">
			<input type="submit" value="Upload">
		</form>
	</body>
</html>

## UploadArquivoServlet.java
package upload;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebInitParam;
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;

@WebServlet(urlPatterns = "/upload", initParams = { @WebInitParam(name = "diretorio", value = "/home/alexandre/uploads") })
@MultipartConfig
public class UploadArquivoServlet extends HttpServlet {

	private static final String FILENAME_REGEX = ".*filename=\"(.*)\".*";
	private File diretorio;

	@Override
	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		String path = config.getInitParameter("diretorio");
		diretorio = new File(path);
		diretorio.mkdirs();
	}

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		PrintWriter out = response.getWriter();

		try {
			for (Part part : request.getParts()) {
				String fileName = obtainFileName(part);
				if (fileName != null) {
					if (part.getSize() <= 0) {
						out.println("<h1>Voce não enviou um arquivo!</h1>");
						return;
					}
					processUploadedFile(part, fileName);
				} else {
					// para inputs que nao sao 'file', fileName é null
					String nomeDoCampo = part.getName();
					String valorDoCampo = request.getParameter(nomeDoCampo);
					System.out.println(nomeDoCampo + ": " + valorDoCampo);
				}
			}
			out.println("<h1>Arquivo gravado!</h1>");
		} catch (Exception ex) {
			ex.printStackTrace();
			out.println("<h1>Erro ao escrever no arquivo!</h1>");
			return;
		}
	}

	private void processUploadedFile(Part part, String fileName) throws Exception {
		InputStream inputStream = part.getInputStream();
		File uploadedFile = new File(diretorio, fileName);
		Files.copy(inputStream, uploadedFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
	}

	private String obtainFileName(Part part) {
		String contentDisposition = part.getHeader("content-disposition");
		Pattern regex = Pattern.compile(FILENAME_REGEX);
		Matcher matcher = regex.matcher(contentDisposition);
		if (matcher.find()) {
			return matcher.group(1);
		}
		return null;
	}

}
	<html>
	<body>
	<form action="upload" method="post" enctype="multipart/form-data">
	<input type="text" name="texto">
	<input type="file" name="arquivo">
	<input type="submit" value="Upload">
	</form>
	</body>
	</html>
	package upload;

	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.PrintWriter;
	import java.nio.file.Files;
	import java.nio.file.StandardCopyOption;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import javax.servlet.ServletConfig;
	import javax.servlet.ServletException;
	import javax.servlet.annotation.MultipartConfig;
	import javax.servlet.annotation.WebInitParam;
	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;

	@WebServlet(urlPatterns = "/upload", initParams = { @WebInitParam(name = "diretorio", value = "/home/alexandre/uploads") })
	@MultipartConfig
	public class UploadArquivoServlet extends HttpServlet {

	private static final String FILENAME_REGEX = ".filename=\"(.)\".*";
	private File diretorio;

	@Override
	public void init(ServletConfig config) throws ServletException {
	super.init(config);
	String path = config.getInitParameter("diretorio");
	diretorio = new File(path);
	diretorio.mkdirs();
	}

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	PrintWriter out = response.getWriter();

	try {
	for (Part part : request.getParts()) {
	String fileName = obtainFileName(part);
	if (fileName != null) {
	if (part.getSize() <= 0) {
	out.println("<h1>Voce não enviou um arquivo!</h1>");
	return;
	}
	processUploadedFile(part, fileName);
	} else {
	// para inputs que nao sao 'file', fileName é null
	String nomeDoCampo = part.getName();
	String valorDoCampo = request.getParameter(nomeDoCampo);
	System.out.println(nomeDoCampo + ": " + valorDoCampo);
	}
	}
	out.println("<h1>Arquivo gravado!</h1>");
	} catch (Exception ex) {
	ex.printStackTrace();
	out.println("<h1>Erro ao escrever no arquivo!</h1>");
	return;
	}
	}

	private void processUploadedFile(Part part, String fileName) throws Exception {
	InputStream inputStream = part.getInputStream();
	File uploadedFile = new File(diretorio, fileName);
	Files.copy(inputStream, uploadedFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
	}

	private String obtainFileName(Part part) {
	String contentDisposition = part.getHeader("content-disposition");
	Pattern regex = Pattern.compile(FILENAME_REGEX);
	Matcher matcher = regex.matcher(contentDisposition);
	if (matcher.find()) {
	return matcher.group(1);
	}
	return null;
	}

	}