springmvc图片上传（兼容ie8以上，实时预览）

html代码：

<form id="uploadform" method="post" enctype="multipart/form-data">
            <table>
                <tr>
                    <td><span class="need">&nbsp;&nbsp;&nbsp;</span>新闻图片:</td>
                    <td width="100" align="right"><input type="file"
                        onchange="preview(this)" name="newsImages" id="newsImages" /></td>
                </tr>
                <tr>
                    <td colspan="2">
                        <div id="preview"></div>
                    </td>
                </tr>
            </table>
        </form>

js：

<script type="text/javascript" src="resource/js/jquery-1.9.1.min.js"></script>
<script src="http://malsup.github.io/jquery.form.js"></script>
function preview(file) {
            var prevDiv = document.getElementById(‘preview‘);
            if (file.files && file.files[0]) {
                var reader = new FileReader();
                reader.onload = function(evt) {
                    prevDiv.innerHTML = ‘<img src="‘ + evt.target.result + ‘" />‘;
                }
                reader.readAsDataURL(file.files[0]);
            } else {
                prevDiv.innerHTML = ‘<div class="img" style="filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src=\‘‘ + file.value + ‘\‘"></div>‘;
            }
            uploadPhoto();
        }
        function uploadPhoto() {
            var imagePath = $("#newsImages").val();
            if (imagePath == "") {
                alert("please upload image file");
                return false;
            }
            var strExtension = imagePath.substr(imagePath.lastIndexOf(‘.‘) + 1);
            if (strExtension != ‘jpg‘ && strExtension != ‘gif‘
                    && strExtension != ‘png‘ && strExtension != ‘bmp‘) {
                alert("please upload file that is a image");
                return false;
            }
            $("#uploadform").ajaxSubmit({
                type : ‘POST‘,
                url : ‘news/upload‘,
                data : {
                    imgPath : $("#newsImages").val()
                },
                success : function(data) {
                    $("input[name=‘newsImage‘]").val(data);
                },
                error : function() {
                    alert("上传失败，请检查网络后重试");
                }
            });

        }

controller:

@Controller
@RequestMapping(value = "/news")
public class NewsController {

/**
     * 处理上传的file文件的图片
     * @author zhangyn
     * @param map
     * @param request
     * @param newsImages
     * @return
     */
    @RequestMapping(value = "/upload")
    @ResponseBody
    public String upload(ModelMap map, HttpServletRequest request,
            @RequestParam(value = "newsImages", required = false) MultipartFile newsImages) {
        String pic_path = request.getSession().getServletContext().getRealPath("/")+"upload";//保存在项目下的upload文件夹下。
        String fileName = newsImages.getOriginalFilename();
        Date date=new Date();
        long time = date.getTime();
        File targetFile = new File(pic_path, time+fileName);//重命名的考虑是按照一定的格式存储利于查找，且避免了相同名称的覆盖。
        if (!targetFile.exists()) {
            targetFile.mkdirs();
        }
        try {
            newsImages.transferTo(targetFile);
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return "upload/"+time+fileName;
    }
}

spring-mvc.xml

    <!-- 上传文件拦截，设置最大上传文件大小 10M=10*1024*1024(B)=10485760 bytes -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="10485760" />
    </bean>