java ajax异步上传文件（文档、图片都可以）

在写项目的时候，经常用到图片上传啊什么的，这儿提供一个方法，万能，咋都能用。

ajax

$(".save-head").click(function () {                var formData = new FormData();                 formData.append('file', $('#upload')[0].files[0]);                 formData.append('school', '${userCenterJson.teacher.schoolCode }');                 formData.append('teacherCode', '${userCenterJson.teacher.teacherCode }');                 $.ajax({             url : '<%=SignAndMd5.uploadimg %>',             scriptCharset : "UTF-8",             contentType : "application/x-www-form-urlencoded; charset=UTF-8",             type : 'POST',             cache : false,             data : formData,             processData : false,             contentType : false,             }).done(function(data) {             alert("上载成功");             $("#headImg").val(data.trim());             $("#headform").submit();             }).fail(function(res) {             console.log(res.responseText);             });                 }); 

这边对formData做一个解释，其实这就是一个载体，有点像json一样，用来传数据的，但是他可以放着文件信息传到后台

我这边传了两个值，用于动态拼装文件路径，后台获取的代码这里放一下：

String school = "";        String teacherCode = "";                while (iter.hasNext()) {        FileItem item = (FileItem) iter.next();            item.getString("UTF-8");                        if (item.getFieldName().equals("school")) {            school = item.getString();            filePath += school + "//";            filePath += "TeacherHeadPic//";            }            if (item.getFieldName().equals("teacherCode")) {            teacherCode = item.getString();            }        }

我的ajax url为了方便直接是一个jsp，随取随用。

<%@page import="java.awt.Color"%><%@page import="com.kids.image.ImageUtils"%><%@page import="com.kids.picWork.ImgHandel"%><%@ page contentType="text/html; charset=utf-8" language="java" import="java.sql.*" errorPage=""%><%@ page import="java.util.List"%><%@ page import="java.io.*"%><%@ page import="java.util.Iterator"%><%@ page import="org.apache.commons.fileupload.FileItem"%><%@ page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%><%@ page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%><%request.setCharacterEncoding("UTF-8");    String filePath = request.getRealPath("/SchoolCenter/") + "//";    try {        DiskFileItemFactory fu = new DiskFileItemFactory();        fu.setSizeThreshold(2 * 1024 * 1024);        fu.setSizeThreshold(4096);        ServletFileUpload upload = new ServletFileUpload(fu);        upload.setHeaderEncoding("UTF-8");        List fileItems = upload.parseRequest(request);         Iterator iter = fileItems.iterator();        String TextDate = "";                String school = "";        String teacherCode = "";                while (iter.hasNext()) {        FileItem item = (FileItem) iter.next();            item.getString("UTF-8");                        if (item.getFieldName().equals("school")) {            school = item.getString();            filePath += school + "//";            filePath += "TeacherHeadPic//";            }            if (item.getFieldName().equals("teacherCode")) {            teacherCode = item.getString();            }        }        Iterator iter2 = fileItems.iterator();        while (iter2.hasNext()) {        FileItem item = (FileItem) iter2.next();            item.getString("UTF-8");            //忽略其他不是文件域的所有表单信息                        if (!item.isFormField()) {                            String name1 = item.getName();//获取上传的文件名                               long size = item.getSize();//获取上传的文件大小(字节为单位)                if ((name1 == null || name1.equals("")) && size == 0) {                    continue;//跳到while检查条件                }                int end = name1.length();                int begin = name1.lastIndexOf("\\");                String newname = name1.substring(begin + 1, end);                TextDate = newname;                if (TextDate.length() == 0) {                    System.out.println("上传文件导入异常，请重新上传...");                } else {                    try {                        //保存文件                        newname = teacherCode + "." + newname.split("\\.")[1];                                                System.out.println(newname);                                                File savedFile = new File(filePath, newname);//用原文件名，作为上传文件的文件名。                        item.write(savedFile);                        item.delete();                                                new ImgHandel().thumbnailImage(filePath + newname, 150, 150, "thumb_", false);                                        File f = new File(filePath + newname);                ImageUtils.fromFile(f)                .scale(1)                .rotate(90)//旋转角度                .quality(1)                .bgcolor(Color.white)                .toFile(new File(filePath + newname));                                                out.println(newname);        out.flush();        out = pageContext.pushBody();                    } catch (Exception e) {                        out.println(e);                    }                }            }        }            } catch (Exception e) {        e.printStackTrace();    }%>

这里的ajax对图片有两个处理，

一个是生成缩略图，

new ImgHandel().thumbnailImage(filePath + newname, 150, 150, "thumb_", false);

一个是旋转上传的图片

 new ImgHandel().thumbnailImage(filePath + newname, 150, 150, "thumb_", false);                                        File f = new File(filePath + newname);                ImageUtils.fromFile(f)                .scale(1)                .rotate(90)//旋转角度                .quality(1)                .bgcolor(Color.white)                .toFile(new File(filePath + newname));

如果不需要，直接删除即可。

这两个操作在另外文章中。