图片上传 / 图片与简单字段的混合上传

• 描述：一个form表单中同时包含图片上传域和简单的text域
• 依赖：
  • commons-fileupload-1.2.2.jar
  • commons-io-2.4.jar
  • jstl.jar
  • standard.jar
  • servlet-api.jar
• 代码：
  • FileUpload.java

    • package fileupload;
      
      import java.io.File;
      import java.io.IOException;
      import java.util.List;
      import java.util.UUID;
      
      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.FileUploadException;
      import org.apache.commons.fileupload.disk.DiskFileItemFactory;
      import org.apache.commons.fileupload.servlet.ServletFileUpload;
      
      import util.FileUtil;
      
      @WebServlet(urlPatterns = { "/UploadFile" })
      public class FileUpload extends HttpServlet {
          
          private static final long serialVersionUID = 1L;
      
          @SuppressWarnings("unchecked")
          protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
              
              //上传图片的最大大小
              int maxSize = 3;
              //允许的图片类型
              String[] imgTypes = {".jpg",".gif",".bmp",".png",".jpeg",".ico"};
              //上传文件的目录
              String uploadFullPath = FileUtil.UPLOAD_DIR;
              //上传文件的临时目录
              String uploadTempFullPath = FileUtil.UPLOAD_DIR + File.separator + "tmp";
              
              if(!new File(uploadFullPath).isDirectory()){
                  new File(uploadFullPath).mkdirs(); 
              }   
              
              if(!new File(uploadTempFullPath).isDirectory()){   
                  new File(uploadTempFullPath).mkdirs();
              }
              
              DiskFileItemFactory factory = new DiskFileItemFactory();
              //设置最大缓存
              factory.setSizeThreshold(5*1024);
              factory.setRepository(new File(uploadTempFullPath));
          
              ServletFileUpload upload = new ServletFileUpload(factory);
              //设置文件大小上限
              upload.setSizeMax(maxSize*1024*1024);
              
              String filePath = null;
              String simpleField = null;
              
              List<FileItem> fileItems = null;
              try {
                  fileItems = upload.parseRequest(request);
              } catch (FileUploadException e) {
                  e.printStackTrace();
              }
              
              for (FileItem fileItem : fileItems) {
                  
                  if (!fileItem.isFormField()) {
                      String fileName = fileItem.getName().toLowerCase();
                      if (fileName.endsWith(imgTypes[0])
                              || fileName.endsWith(imgTypes[1])
                              || fileName.endsWith(imgTypes[2])
                              || fileName.endsWith(imgTypes[3])
                              || fileName.endsWith(imgTypes[4])
                              || fileName.endsWith(imgTypes[5])) {
                          
                          String uuid = UUID.randomUUID().toString();
                          String generateFullFileName = uuid + fileName.substring(fileName.lastIndexOf("."));
                          filePath = uploadFullPath + File.separator + generateFullFileName;
                          
                          System.out.println("filePath: " + filePath);
                          
                          try {
                              fileItem.write(new File(filePath));
                          } catch (Exception e) {
                              e.printStackTrace();
                          }
                          
                          request.setAttribute("fullFilePath", filePath);
                          request.setAttribute("imgUrl", "/img/" + generateFullFileName);
                          
                      } else {
                          request.setAttribute("failMessage", "上传失败，请确定你选择的文件为图片！");
                      }
                  }
                  
                  if (fileItem.isFormField()) {
                      String fieldName = fileItem.getFieldName();
                      if ("simpleField".equals(fieldName)) {
                          String value = new String(fileItem.getString("utf-8"));
                          if (value != null && value.length() > 0) {
                              simpleField = value;
                              request.setAttribute("simpleField", simpleField);
                          }
                      }
                  }
                  
              }
              
              request.getRequestDispatcher("/fileupload/fileUpload.jsp").forward(request, response);
          }
      
      }
      

  • FileUtil.java

    • package util;
      
      import java.io.File;
      import java.io.FileInputStream;
      import java.io.IOException;
      import java.io.InputStream;
      import java.io.InputStreamReader;
      import java.io.Reader;
      import java.nio.ByteBuffer;
      import java.util.Properties;
      
      public class FileUtil {
      
          public static String UPLOAD_DIR;
          
          static {
              
              Properties properties = new Properties();
              
              InputStream is = FileUtil.class.getResourceAsStream("/project.properties");
              try {
                  properties.load(is);
                  is.close();
              } catch (IOException e) {
                  e.printStackTrace();
                  throw new InternalError(e.getMessage());
              }
              
              String osType = System.getProperty("os.name").toLowerCase();
              
              if (osType.indexOf("win") >= 0) {
                  UPLOAD_DIR = properties.getProperty("WIN_UPLOAD_DIR");
              } else if (osType.indexOf("mac") >= 0) {
                  UPLOAD_DIR = properties.getProperty("MAC_UPLOAD_DIR");
              } else if (osType.indexOf("nix") >= 0 || osType.indexOf("nux") >= 0) {
                  UPLOAD_DIR = properties.getProperty("NIX_UPLOAD_DIR");
              } else if (osType.indexOf("sunos") >= 0) {
                  UPLOAD_DIR = properties.getProperty("SOL_UPLOAD_DIR");
              } else {
                  throw new InternalError("Your system is not supported!");
              }
              
          }
          
          public static byte[] readIntoByteArray(String fileName) throws IOException {
              FileInputStream fis = null;
              
              File file = new File(fileName);
              
              if (Integer.MAX_VALUE <= file.length()) {
                  throw new RuntimeException("File is too big, and length = " + file.length());
              }
              
              try {
                  fis = new FileInputStream(file);
                  ByteBuffer bb = ByteBuffer.allocate((int)file.length());
                  
                  int bytesRead = fis.getChannel().read(bb);
                  
                  if (bytesRead != file.length()) {
                      throw new IOException("Error occurred while reading file, bytes = " + bytesRead);
                  }
                  
                  return bb.array();
              } catch (IOException e) {
                  throw new IOException(e.getLocalizedMessage());
              } finally {
                  if (fis != null) {
                      fis.close();
                  }
              }
              
          }
          
          /*
           * http://stackoverflow.com/questions/326390/how-to-create-a-java-string-from-the-contents-of-a-file
           */
          public static String readIntoString(InputStream is, String encoding) throws IOException {
              final char[] buffer = new char[0x2000];
              
              StringBuilder out = new StringBuilder();
              
              Reader in = new InputStreamReader(is, encoding != null ? encoding : "UTF-8");
              
              int read;
              
              do {
                  read = in.read(buffer, 0, buffer.length);
                  
                  if (read > 0) {
                      out.append(buffer, 0, read);
                  }
                  
              } while (read >= 0);
              
              return out.toString();
          }
          
          public static void deleteDir(String filePath) {
              File file = new File(filePath);
              if (file.exists() && file.isDirectory()) {
                  if (file.listFiles().length == 0) {
                      file.delete();
                  } else {
                      File[] deleteFile = file.listFiles();
                      int i = file.listFiles().length;
                      for (int j = 0; j < i; j ++) {
                          if (deleteFile[j].isDirectory()) {
                              deleteDir(deleteFile[j].getAbsolutePath());
                          }
                          deleteFile[j].delete();
                      }
                      file.delete();
                  }
              }
          }
          
      }
      

  • project.properties

    • WIN_UPLOAD_DIR=C:\\upload\\public
      #MAC_UPLOAD_DIR=
      #NIX_UPLOAD_DIR=
      #SOL_UPLOAD_DIR=

  • fileUpload.jsp

    • <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
      <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
      <!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">
              <link href="../css/global.css" rel="stylesheet" type="text/css"/>
              <title>File Upload</title>
          </head>
          
          <body>
              <div class="headContainer">
                  <div class="header"></div>
              </div>
              
              <div class="mainContainer">
                  <div>
                      <form id="fileUpload" name="fileUpload" method="post" enctype="multipart/form-data" action="/FileUpload/UploadFile">
                          <label>Simple Field : </label><input id="simpleField" name="simpleField" type="text" />
                          <br />
                          <label>Upload Files : </label><input type="file" name="fileUpload" />
                          <br />
                          <input type="submit" value="Submit" />
                          <input type="reset" value="Reset" />
                      </form>
                  </div>
                  <div id="echo">
                      <img src="${imgUrl}" />
                      <br />
                      <span id="fullFilePath">${fullFilePath}</span>
                      <br />
                      <span id="simpleField">${simpleField}</span>
                  </div>
              </div>
              
              <div class="footContainer">
                  <div class="footer"></div>
              </div>
          </body>
      </html>

• PS:
  • Windows下可为上传的图片目录在Application Server专门设置一个虚拟目录，这样client就可以访问图片了
  • 设置虚拟目录方式同设置虚拟开发目录，如：

    <context path="/img" docbase="C:\upload\public" reloadable="true"></context>

  • 设置了虚拟目录，只对该目录下的文件有权限，对该目录下的目录依然是无权限访问的