java实现上传图片进行切割的方法

本文实例讲述了java实现上传图片进行切割的方法。分享给大家供大家参考。具体分析如下：

为什么我要进行上传的图片进行切割呢，我这个项目的图片是部门logo，每个部门都可以选择不同的logo，但是要应对浏览器的兼容以及拉伸，我选择了把一张图片切成左、中、右和剩下的部分，因为左边和中变可能会有图案或者字所以不能拉伸，拉伸的只是右边的部分，剩下的部分自适应就可以了。所以用了javax的ImageReader来操作。最后以blob类型保存数据库中。
首先要在form表单里面写上enctype="multipart/form-data"
复制代码代码如下:

下面在表单中写上上传组件
复制代码代码如下:

     上传Logo：








     （图片格式：jpg,jpeg,bmp,gif,png;

     推荐大小：1120×80像素）

图片检查的checkFile()方法用于检查图片是否以规定格式结尾以及是否没有选择
复制代码代码如下:function checkFile(){

        var value = $("#logoFile").val();
        if(!value){
            alert("请选择您要上传的图片！");
            return false;
        }else{
            if(value.lastIndexOf(".jpg") != -1){
                $("#suffix").val("jpg");
                return true;
            }else if(value.lastIndexOf(".jpeg") != -1){
                $("#suffix").val("jpeg");
                return true;
            }else if(value.lastIndexOf(".gif") != -1){
                $("#suffix").val("gif");
                return true;
            }else if(value.lastIndexOf(".bmp") != -1){
                $("#suffix").val("bmp");
                return true;
            }else if(value.lastIndexOf(".png") != -1){
                $("#suffix").val("png");
                return true;
            }else{
                alert("对不起，您上传文件格式有误，请选择指定格式的图片文件上传");
                return false;
            }
        }
}

下面就是进行后台的save操作了。
复制代码代码如下:public String save() throws Exception {
        HttpServletRequest request = ServletActionContext.getRequest() ;
        String departId = request.getParameter("id") ;
        String departName = request.getParameter("name") ;
        String companyId = request.getParameter("companyId") ;
        //图片后缀
        String suffix = request.getParameter("suffix");
        List

listMenu = new ArrayList() ;
        Company company = new Company() ;
        company.setId(Long.valueOf(companyId)) ;
        if(this.logoFile != null && departName != null && companyId != null && suffix != null){
            //获取解析图片的ImageReader
            Iterator imageReaders = ImageIO.getImageReadersByFormatName(suffix);
            ImageReader imageReader = imageReaders.next();
            //把图片以字节流的形式传入
            InputStream logoStream = new BufferedInputStream(new FileInputStream(this.logoFile));
            //转为图片输入流
            ImageInputStream imageInputStream = ImageIO.createImageInputStream(logoStream);
            imageReader.setInput(imageInputStream, true);
            int imageWidth = imageReader.getWidth(0);
            //固定高度80
            int imageHeight = 80;
            //设置左中右和剩下的宽度
            int leftWidth = imageWidth / 2;
            int middleWidth = (imageWidth - leftWidth) / 3;
            int rightWidth = 5;
            int retainWidth = imageWidth - leftWidth -middleWidth - 5;

            ImageReadParam readParam = imageReader.getDefaultReadParam();
            BufferedImage bImage = null;
            //裁剪左半部分
            //根据宽和高获得矩形
            Rectangle leftImageRectangle = new Rectangle(0, 0, leftWidth, imageHeight);
            readParam.setSourceRegion(leftImageRectangle);
            bImage = imageReader.read(0, readParam);
            //字节数组输出流
            ByteArrayOutputStream leftByteArrayOutputStream = new ByteArrayOutputStream();
            ImageIO.write(bImage, suffix, leftByteArrayOutputStream);
            //获得字节数组
            byte[] leftImageData = leftByteArrayOutputStream.toByteArray();
            leftByteArrayOutputStream.close();
            //Hibernate创建一个blob类型
            Blob leftBlob = Hibernate.createBlob(leftImageData, this.departmentManager.getSession());

            //裁剪中部部分
            Rectangle middleImageRectangle = new Rectangle(leftWidth, 0 , middleWidth, imageHeight);
            readParam.setSourceRegion(middleImageRectangle);
            bImage = imageReader.read(0, readParam);

            ByteArrayOutputStream middleArrayOutputStream = new ByteArrayOutputStream();
            ImageIO.write(bImage, suffix, middleArrayOutputStream);
            byte[] middleImageData = middleArrayOutputStream.toByteArray();
            middleArrayOutputStream.close();
            Blob middleBlob = Hibernate.createBlob(middleImageData, this.departmentManager.getSession());

            //裁剪右半部分
            Rectangle rightImageRectangle = new Rectangle(leftWidth + middleWidth, 0, rightWidth, imageHeight);
            readParam.setSourceRegion(rightImageRectangle);
            bImage = imageReader.read(0, readParam);

            ByteArrayOutputStream rightArrayOutputStream = new ByteArrayOutputStream();
            ImageIO.write(bImage, suffix, rightArrayOutputStream);
            byte[] rightImageData = rightArrayOutputStream.toByteArray();
            rightArrayOutputStream.close();
            Blob rightBlob = Hibernate.createBlob(rightImageData, this.departmentManager.getSession());

            //保留部分
            Rectangle retainRectangle = new Rectangle(leftWidth + middleWidth + rightWidth, 0, retainWidth, imageHeight);
            readParam.setSourceRegion(retainRectangle);
            bImage = imageReader.read(0, readParam);

            ByteArrayOutputStream retainArrayOutputStream = new ByteArrayOutputStream();
            ImageIO.write(bImage, suffix, retainArrayOutputStream);
            byte[] retainImageData = retainArrayOutputStream.toByteArray();
            retainArrayOutputStream.close();
            Blob retainBlob = Hibernate.createBlob(retainImageData, this.departmentManager.getSession());

            if(!departId.equals("") && departId!=null){
                Department d = this.departmentManager.findById(Long.valueOf(departId)) ;
                if(this.checkedAuthIds != null){
                    for(int i=0;i                         Menu menu = new Menu() ;
                        menu.setId(checkedAuthIds.get(i)) ;
                        listMenu.add(menu) ;
                    }
                    d.setMenus(listMenu) ;
                }
                d.getDepartmentLogo().setLeftPartImage(leftBlob);
                d.getDepartmentLogo().setMiddlePartImage(middleBlob);
                d.getDepartmentLogo().setRightPartImage(rightBlob);
                d.getDepartmentLogo().setRetainPartImage(retainBlob);
                d.getDepartmentLogo().setCreateTime(new Date());
                d.getDepartmentLogo().setSuffix(suffix);
                d.setName(departName) ;
                d.setParentId(0L) ;
                d.setNodeType(1) ;
                d.setGrade(1) ;
                d.setCompany(company) ;
                this.departmentManager.save(d) ;
            }else{
                Integer parentNodeType = 0 ;
                Department dd = new Department() ;
                if(this.checkedAuthIds!=null && this.checkedAuthIds.size() != 0){
                    for(int i=0;i                         Menu menu = new Menu() ;
                        menu.setId(checkedAuthIds.get(i)) ;
                        listMenu.add(menu) ;
                    }
                    dd.setMenus(listMenu) ;
                }else{
                    dd.setMenus(null) ;
                }
                DepartmentLogo departmentLogo = new DepartmentLogo() ;
                departmentLogo.setCreateTime(new Date());
                departmentLogo.setLeftPartImage(leftBlob);
                departmentLogo.setMiddlePartImage(middleBlob);
                departmentLogo.setRightPartImage(rightBlob);
                departmentLogo.setRetainPartImage(retainBlob);
                departmentLogo.setSuffix(suffix);
                dd.setDepartmentLogo(departmentLogo);
                dd.getDepartmentLogo().setDepartment(dd);
                dd.setId(this.departmentManager.findMaxId()+1) ;
                dd.setName(departName) ;
                dd.setParentId(0L) ;
                dd.setNodeType(1) ;
                dd.setGrade(1) ;
                dd.setOrderType(0) ;
                dd.setCompany(company) ;
                dd.setFlag(0) ;
                this.departmentManager.save(dd) ;
            }
        }
        return "reload";
}

下面就是显示了，我是用的qui，所以在top.jsp上面的css中进行动态显示
复制代码代码如下:
.welcome-hide{width: 210px;white-space: nowrap;overflow: hidden;text-overflow: ellipsis;}
#leftLogo{background: url(${ctx }/admin/department-logo!showLogo.action?position=left) no-repeat;width: ${leftWidth}px;height: 80px;}
#middleLogo{background: url(${ctx }/admin/department-logo!showLogo.action?position=middle) no-repeat;width: ${middleWidth}px;height: 80px;}
#rightLogo,#topTableStyle{background: url(${ctx }/admin/department-logo!showLogo.action?position=right) repeat-x;height: 80px;}
#retainLogo{background: url(${ctx }/admin/department-logo!showLogo.action?position=retain) no-repeat;width: ${retainWidth}px;height: 80px;}

department-logo!showLogo.action中的showLogo方法就是加载图片的方法
复制代码代码如下:public String showLogo() {

        HttpServletRequest request = ServletActionContext.getRequest();
        LoginUser loginUser = (LoginUser)((SecurityContext)request.getSession().
                getAttribute("SPRING_SECURITY_CONTEXT")).getAuthentication().getPrincipal();
        List logos = this.logoManager.findAll();
        for (DepartmentLogo departmentLogo : logos) {
            if (loginUser.getUser().getDepartment().getId().equals(departmentLogo.getDepartment().getId())) {
                String param = request.getParameter("position");
                Blob blob = null;
                if (param != null) {
                    try {
                        if (param.equals("left")) {
                            blob = departmentLogo.getLeftPartImage();
                            imageLogo = blob.getBinaryStream();
                            return "showLogo";
                        }else if (param.equals("middle")) {
                            blob = departmentLogo.getMiddlePartImage();
                            imageLogo = blob.getBinaryStream();
                            return "showLogo";
                        }else if (param.equals("right")) {
                            blob = departmentLogo.getRightPartImage();
                            imageLogo = blob.getBinaryStream();
                            return "showLogo";
                        }else if (param.equals("retain")) {
                            blob = departmentLogo.getRetainPartImage();
                            imageLogo = blob.getBinaryStream();
                            return "showLogo";
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return null;
}

当然返回的地址应该选择struts2中的type="stream"
复制代码代码如下:@Results({
    @Result(name = "showLogo", type = "stream", params = {"contentType", "image/jpeg,"
            + "image/bmp,image/png,image/gif,image/jpeg",
            "inputName", "imageLogo", "bufferSize", "4096"})
})

那么top.jsp中的width是怎么得到的呢？
实在加载菜单的时候得到的，下面是menu中的方法
复制代码代码如下:HttpServletRequest request = ServletActionContext.getRequest();
List logos = this.logoManager.findAll();
for (DepartmentLogo departmentLogo : logos) {
    if (user.getDepartment().getId().equals(departmentLogo.getDepartment().getId())) {
request.setAttribute("leftWidth", ImageIO.read(departmentLogo.
  getLeftPartImage().getBinaryStream()).getWidth());
request.setAttribute("middleWidth", ImageIO.read(departmentLogo.
  getMiddlePartImage().getBinaryStream()).getWidth());
request.setAttribute("retainWidth", ImageIO.read(departmentLogo.
  getRetainPartImage().getBinaryStream()).getWidth());
break;
    }
}

这样就完成了一个上传显示功能。

这个就是我上传的测试图片。

希望本文所述对大家的Java程序设计有所帮助。

java实现上传图片进行切割的方法

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