struts2 input file多文件同时通过ajax提交

<input type="file" name="files" multiple="multiple">
必须是multiple才可以上传多个文件。

<form id= "uploadForm">
      <p >
      <input type="text" name="fileIndex" id="fileIndex" />
      <input type="text" name="fileSize" id="fileSize" />
      上传文件： <input type="file" name="files" id="files" multiple="multiple">  </ p>
      <input type="button" value="上传" onclick="doUpload()" />
</form>
<script>
function doUpload() {
    var files = document.getElementById("files").files;;
    var fileIndex = "";
    for(var i = 0; i < files.length; i++){
        if(files[i].value != ""){
            fileIndex = fileIndex+i+",";
        }
    }
    $("#fileIndex").val(fileIndex.substring(0,fileIndex.length-1));
    $("#fileSize").val(files.length);
    
     var formData = new FormData($( "#uploadForm" )[0]);
     $.ajax({
          url: '/uploadFiles.html' ,
          type: 'POST',
          data: formData,
          async: false,
          cache: false,
          contentType: false,
          processData: false,
          success: function (returndata) {
              alert(returndata);
          },
          error: function (returndata) {
              alert(returndata);
          }
     });
}
</script>

@Action("/uploadFiles")
    public void uploadFiles() throws Exception {
        imgsUpload();
    }

private File[] files;
private String[] filesFileName;    

    public void setFiles(File[] files) {
        this.files = files;
    }
        public File[] getFiles() {
        return files;
    }

    public String[] getFilesFileName() {
        return filesFileName;
    }

    public void setFilesFileName(String[] filesFileName) {
        this.filesFileName = filesFileName;
    }

/**
     * 上传多图片
     * @return 图片路径数组
     * @throws IOException if has error
     */
    protected String[] imgsUpload() throws IOException {
        String fileIndex = paramString("fileIndex");
        int fileSize = paramInt("fileSize");
        String[] indexs = fileIndex.split(",");
        String[] picPath = new String[fileSize];
        if (files != null && files[0] != null) {
            for (int i = 0; i < files.length; i++) {
                if (!ImageUtil.fileIsImage(files[i])) {
                    printResult("您上传的图片无效，请重新上传！", true);
                } else {
                    int index = Integer.parseInt(indexs[i]);
                    Operator oper = getOperator();
                    Date d = DateUtil.getNow();
                    String upfiesDir = ServletActionContext.getServletContext().getRealPath("/data/upfiles/images/");
                    String realPath = ServletActionContext.getServletContext().getRealPath("");
                    String destFileName = upfiesDir + DateUtil.dateStr2(d) + "/" + oper.getId()
                            + entityClass.getSimpleName() + "/" + DateUtil.dateStr(d, "HHmmss") + i
                            + filesFileName[i].substring(filesFileName[i].lastIndexOf("."));
                    File imageFile = new File(destFileName);
                    FileUtils.copyFile(files[i], imageFile);
                    picPath[index] = destFileName.replace(realPath, "").replace(File.separator, "/");
                }
            }
        }
        return picPath;
    }

package com.rd.p2p.common.util;

import java.awt.AlphaComposite;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.ImageProducer;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;

import org.apache.log4j.Logger;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import com.sun.jimi.core.Jimi;
import com.sun.jimi.core.JimiWriter;
import com.sun.jimi.core.options.JPGOptions;

/**
 * 工具类-图片处理
 * */
@SuppressWarnings("restriction")
public class ImageUtil {

    private static final Logger LOGGER= Logger.getLogger(ImageUtil.class);
    private static FileInputStream fis;

    /**
     * 校验文件是否是图片，是:true，否:false
     * 
     * @param file 需要验证的File文件
     * @return true or false
     */
    @SuppressWarnings("resource")
    public static boolean fileIsImage(File file) {
        InputStream is = null;
        BufferedReader reader = null;
        try {
            // 将文件转换成输入流
            is = new FileInputStream(file);
            // 用image IO读取文件，如果文件file不是图片，则为null
            BufferedImage image = ImageIO.read(is);
            if (image != null) { // 如果image不为空，则说明file文件是图片
                reader = new BufferedReader(new FileReader(file));
                String exits = null;
                while ((exits = reader.readLine()) != null) {
                    exits = shiftD(exits);
                    if (exits.indexOf("eval(") > 0 || exits.indexOf("<?php") > 0 || exits.indexOf("eval") > 0) {
                        return false;
                    }
                }
                return true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (is != null) {
                    is.close();
                }
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return false;
    }

    /**
     * 
     * @param str
     * @return
     */
    public static String shiftD(String str) {
        int size = str.length();
        char[] chs = str.toCharArray();
        for (int i = 0; i < size; i++) {
            if (chs[i] <= 'Z' && chs[i] >= 'A') {
                chs[i] = (char) (chs[i] + 32);
            }
        }
        return new String(chs);
    }

    /**
     * 将附加图片合并到底图的正中央
     * 
     * @param negativeImagePath 底图路径
     * @param addImage 附加图片
     * @param toPath 合成图片写入路径
     * @throws IOException
     */
    public static void mergeBothImageCenter(String negativeImagePath, BufferedImage addImage, String toPath)
        throws IOException {
        InputStream is = null;
        OutputStream os = null;
        try {
            is = new FileInputStream(negativeImagePath);
            BufferedImage image = ImageIO.read(is);
            Graphics g = image.getGraphics();
            g.drawImage(addImage, image.getWidth() / 2 - addImage.getWidth() / 2,
                    image.getHeight() / 2 - addImage.getHeight() / 2, null);
            os = new FileOutputStream(toPath);
            JPEGImageEncoder enc = JPEGCodec.createJPEGEncoder(os);
            enc.encode(image);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (os != null) {
                os.close();
            }
            if (is != null) {
                is.close();
            }
        }
    }

    /**
     * 创建图片放大图(等比放大)
     * 
     * @param src 源图片文件完整路径
     * @param dist 目标图片文件完整路径
     * @param width 放大的宽度
     * @param height 放大的高度
     */
    public static void createThumbnail(String src, String dist, int width, int height) {
        try {
            File srcfile = new File(src);
            if (!srcfile.exists()) {
                LOGGER.error("文件不存在");
                return;
            }
            BufferedImage image = ImageIO.read(srcfile);
            BufferedImage bfImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            bfImage.getGraphics().drawImage(image.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0, null);

            FileOutputStream os = new FileOutputStream(dist);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(os);
            encoder.encode(bfImage);
            os.close();
        } catch (Exception e) {
            LOGGER.error("创建缩略图发生异常", e);
        }
    }

    /**
     * 创建图片缩略图(等比缩放)
     * 
     * @param src 源图片文件完整路径
     * @param dist 目标图片文件完整路径
     * @param width 缩放的宽度
     * @param height 缩放的高度
     */
    public static void createThumbnailSmall(String src, String dist, float width, float height) {
        try {
            File srcfile = new File(src);
            if (!srcfile.exists()) {
                LOGGER.error("文件不存在");
                return;
            }
            BufferedImage image = ImageIO.read(srcfile);

            // 获得缩放的比例
            double ratio = 1.0;
            // 判断如果高、宽都不大于设定值，则不处理
            if (image.getHeight() > height || image.getWidth() > width) {
                if (image.getHeight() > image.getWidth()) {
                    ratio = height / image.getHeight();
                } else {
                    ratio = width / image.getWidth();
                }
            }
            // 计算新的图面宽度和高度
            int newWidth = (int) (image.getWidth() * ratio);
            int newHeight = (int) (image.getHeight() * ratio);

            BufferedImage bfImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);
            bfImage.getGraphics().drawImage(image.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH), 0, 0,
                    null);

            FileOutputStream os = new FileOutputStream(dist);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(os);
            encoder.encode(bfImage);
            os.close();
        } catch (Exception e) {
            LOGGER.error("创建缩略图发生异常", e);
        }
    }

    /**
     * 防止处理图片变色
     * 
     * @param image
     * @return
     */
    public static BufferedImage toBufferedImage(Image image) {
        if (image instanceof BufferedImage) {
            return (BufferedImage) image;
        }

        image = new ImageIcon(image).getImage();
        BufferedImage bimage = null;
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        try {
            int transparency = Transparency.OPAQUE;
            GraphicsDevice gs = ge.getDefaultScreenDevice();
            GraphicsConfiguration gc = gs.getDefaultConfiguration();
            bimage = gc.createCompatibleImage(image.getWidth(null), image.getHeight(null), transparency);
        } catch (HeadlessException e) {// linux没有专门处理图片的图形界面,但是不会影响正常的图片处理。此处不用补货异常
        }

        if (bimage == null) {
            int type = BufferedImage.TYPE_INT_RGB;
            bimage = new BufferedImage(image.getWidth(null), image.getHeight(null), type);
        }

        Graphics g = bimage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        return bimage;
    }

    /**
     * 添加图片水印,添加完成之后，默认覆盖原有图片，另，在对图片处理时，要防止图片变色
     * 
     * @param targetImg 目标图片路径
     * @param waterImg 水印图片路径
     * @param x 水印图片距离目标图片左侧的偏移量，如果x<0, 则在正中间
     * @param y 水印图片距离目标图片上侧的偏移量，如果y<0, 则在正中间
     * @param alpha 透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明)
     */
    public final static void pressImage(String targetImg, String waterImg, String imageType, int x, int y, float alpha) {
        try {
            File file = new File(targetImg);
            Image image = ImageIO.read(file);
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = bufferedImage.createGraphics();
            g.drawImage(image, 0, 0, width, height, null);

            Image waterImage = ImageIO.read(new File(waterImg)); // 水印文件
            int width_1 = waterImage.getWidth(null);
            int height_1 = waterImage.getHeight(null);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));

            int widthDiff = width - width_1;
            int heightDiff = height - height_1;
            if (x < 0) {
                x = widthDiff / 2;
            } else if (x > widthDiff) {
                x = widthDiff;
            }
            if (y < 0) {
                y = heightDiff / 2;
            } else if (y > heightDiff) {
                y = heightDiff;
            }
            g.drawImage(waterImage, x, y, width_1, height_1, null); // 水印文件结束
            g.dispose();
            ImageIO.write(bufferedImage, imageType, file);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * @param source
     * @param dest
     * @param quality 图片质量,最好不要设置为100 。 0<quality<100 图片格式转换
     */
    public static void toJpg(String source, int quality) {
        // 0<quality<100
        if (quality < 0 || quality > 100 || (quality + "") == null || (quality + "").equals("")) {// 图片质量,如果为空，则默认为75
            quality = 75;
        }

        String outfile = getFileName(source) + getFileTypeOne(source);
        try {
            JPGOptions options = new JPGOptions();
            options.setQuality(quality);
            ImageProducer image = Jimi.getImageProducer(source);
            JimiWriter writer = Jimi.createJimiWriter(outfile);
            writer.setSource(image);
            // 加入属性设置，非必要
            // /*
            writer.setOptions(options);
            // */
            writer.putImage(outfile);
        } catch (Exception je) {
            je.printStackTrace();
        }
    }

    /**
     * 上传文件名称
     * 
     * @param file
     * @return
     */
    public static String getFileName(String file) {
        return file.substring(0, file.lastIndexOf("."));
    }

    /**
     * 提取上传文件类型名。如23424234.gif，返回".gif"
     * 
     * @param file
     * @return
     */
    public static String getFileTypeOne(String file) {
        return file.substring(file.lastIndexOf("."));
    }

    /**
     * 提取上传文件类型名。如23424234.gif，返回"gif"
     * 
     * @param file
     * @return
     */
    public static String getFileTypeTwo(String file) {
        return file.substring(file.lastIndexOf(".") + 1);
    }
    
    /**
     * 获取文件大小
     * @param filePath
     */
    public static int getFileByte(File file){
        try{   
            fis = new FileInputStream(file);   
            try{    
                return fis.available();   
            }catch(IOException e1){   
                e1.printStackTrace();   
            }   
         }catch(FileNotFoundException e2){   
             e2.printStackTrace();   
         }   
        return 0;
    }
}