java后台中处理图片辅助类汇总(上传图片到服务器,从服务器下载图片保存到本地,缩放图片,copy图片,往图片添加水印图片或者文字,生成二维码,删除图片等)

最近工作中处理小程序宝箱活动,需要java画海报,所以把这块都快百度遍了,记录一下处理的方法,百度博客上面也有不少坑!

获取本地图片路径:

String bgPath = Thread.currentThread().getContextClassLoader().getResource("/").getPath().replaceAll("WEB-INF/classes/","")+"assets/img/01.jpg";
这里主要是java里面获取资源路径,需要其他的可以百度就好

上传图片到服务器

/**
     * 上传图片,返回图片地址
     * @param file 上传的文件
     * @param wxcid 参数
     * @return
     */
    public static String decaptcha(File file,String wxcid) {
        CloseableHttpClient client = HttpClients.createDefault();
        HttpPost post = new HttpPost("http://"+wxcid); //请求接口,接口接受参数是MultipartFile就可以用这个
        RequestConfig config = RequestConfig.custom().setSocketTimeout(30000).setConnectTimeout(20000).build();
        post.setConfig(config);
　　　　　//这里除了httpclient之外还需要一个依赖httpmime,我用的4.5.2没问题,版本坑也很多,注意选择
        FileBody fileBody = new FileBody(file, ContentType.DEFAULT_BINARY);
        MultipartEntityBuilder builder = MultipartEntityBuilder.create();
        builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
        builder.addPart("uploadfile", fileBody);
        // 相当于 <input type="file" class="file" name="file">,匹配@RequestParam("file")
        // .addPart()可以设置模拟浏览器<input/>的表单提交
        HttpEntity entity = builder.build();
        post.setEntity(entity);
        String result = "";
        try {
            CloseableHttpResponse e = client.execute(post);
            HttpEntity resEntity = e.getEntity();
            if(entity != null) {
                result = EntityUtils.toString(resEntity);
                System.out.println("response content:" + result);
            }
        } catch (IOException var10) {
            log.error("请求解析验证码io异常",var10);
            var10.printStackTrace();
        }
        return result;
    }

　　

缩放图片

　　//缩放图片: 目标文件路径,缩放后保存的路径,缩放的宽高,这里都是根据本地路径来的,可以根据需求适当自己修改
    public static void reduceImg(String imgsrc, String imgdist, int widthdist,
                                 int heightdist,boolean isCir) {//是否设置成圆形
        try {
            File srcfile = new File(imgsrc);
            if (!srcfile.exists()) {
                return;
            }
            Image src = javax.imageio.ImageIO.read(srcfile);
            BufferedImage tag= new BufferedImage((int) widthdist, (int) heightdist,
                    BufferedImage.TYPE_4BYTE_ABGR);
            //Graphics graphics = tag.getGraphics();
            Graphics2D graphics = tag.createGraphics();
            // 设置“抗锯齿”的属性(这里好像不管用,很蛋疼)
            graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            //设置成圆形
            if(isCir){
                Ellipse2D.Double shape = new Ellipse2D.Double(0, 0, 50, 50);
                graphics.setClip(shape);
            }
            graphics.drawImage(src.getScaledInstance(widthdist, heightdist,  Image.SCALE_SMOOTH), 0, 0,  null);
            graphics.dispose();
            FileOutputStream out = new FileOutputStream(imgdist);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(tag);
            out.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

　　

copy图片

　　// 拷贝图片
    public static void copyFile(String srcPath, String destPath) throws IOException {
        // 打开输入流
        FileInputStream fis = new FileInputStream(srcPath);
        // 打开输出流
        FileOutputStream fos = new FileOutputStream(destPath);

        // 读取和写入信息
        int len = 0;
        while ((len = fis.read()) != -1) {
            fos.write(len);
        }
        // 关闭流  先开后关  后开先关
        fos.close(); // 后开先关
        fis.close(); // 先开后关
    }

　　

往图片上添加水印

添加文字:

/**
     * 打印文字水印图片
     *
     * @param pressText
     *            --文字
     * @param targetImg --
     *            目标图片
     * @param fontName --
     *            字体名
     * @param fontStyle --
     *            字体样式
     * @param color --
     *            字体颜色
     * @param fontSize --
     *            字体大小
     * @param x --
     *            偏移量
     * @param y
     */

    public static void pressText(String pressText, String targetImg,
                                 String fontName, int fontStyle, Color color, int fontSize, int x,
                                 int y) {
        try {
            File _file = new File(targetImg);
            Image src = ImageIO.read(_file);
            int wideth = src.getWidth(null);
            int height = src.getHeight(null);
            BufferedImage image = new BufferedImage(wideth, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics2D g = image.createGraphics();
            // 设置“抗锯齿”的属性
            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            g.drawImage(src, 0, 0, wideth, height, null);
            g.setColor(color);
            AttributedString ats = new AttributedString(pressText);
            Font font = new Font(fontName, fontStyle, fontSize);
            g.setFont(font);
            ats.addAttribute(TextAttribute.FONT, font, 0, pressText.length());
            AttributedCharacterIterator iter = ats.getIterator();
            /* 添加水印的文字和设置水印文字出现的内容 ----位置 */
            g.drawString(iter, x, y);
            g.dispose();
            FileOutputStream out = new FileOutputStream(targetImg);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(image);
            out.close();
        } catch (Exception e) {
            System.out.println(e);
        }
    }

　　

添加图片:

/**
     * 把图片印刷到图片上
     *
     * @param pressImg --
     *            水印文件
     * @param targetImg --
     *            目标文件
     * @param x
     *            --x坐标
     * @param y
     *            --y坐标
     */
    public final static void pressImage(String pressImg, String targetImg,
                                        int x, int y) {
        try {
            //目标文件
            File _file = new File(targetImg);
            Image src = ImageIO.read(_file);
            int wideth = src.getWidth(null);
            int height = src.getHeight(null);
            BufferedImage image = new BufferedImage(wideth, height,
                    BufferedImage.TYPE_INT_RGB);
            //Graphics g = image.createGraphics();
            Graphics2D g = image.createGraphics();
            // 设置“抗锯齿”的属性
            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            g.drawImage(src, 0, 0, wideth, height, null);
            //水印文件
            File _filebiao = new File(pressImg);
            Image src_biao = ImageIO.read(_filebiao);
            g.drawImage(src_biao, x, y, null);
            //水印文件结束
            g.dispose();
            FileOutputStream out = new FileOutputStream(targetImg);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(image);
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

　　注意的是,这里得抗锯齿好像都不管用

删除图片

/**
     * 根据路径删除图片
     * @param path
     */
    public static void deleteFile(String path){
        File file= new File(path);
        if(file.exists()){
            log.debug("del:"+file.delete());
        }
    }

　　

从服务器下载图片到本地

    /*
     *  根据;;链接下载图片到本地,链接(http://.....)
     */
    public static String downloadByPath(String urlpath,String filename){
        InputStream mainis = null;
        String logoPath="";
        try {
            URL url = new URL(urlpath);
            // 打开连接
            URLConnection con = url.openConnection();
            //设置请求超时为5s
            con.setConnectTimeout(5*1000);
            // 输入流
            mainis = con.getInputStream();
            //通过JPEG图象流创建JPEG数据流解码器
            JPEGImageDecoder jpegDecoder = JPEGCodec.createJPEGDecoder(mainis);
            //解码当前JPEG数据流，返回BufferedImage对象
            BufferedImage buffImg = jpegDecoder.decodeAsBufferedImage();
　　　　　　　// 保存到本地的地址
            logoPath = Thread.currentThread().getContextClassLoader().getResource("/").getPath() + "/" + new String(new Date().getTime() + filename+".jpg");
            OutputStream os = new FileOutputStream(logoPath);
            //创键编码器，用于编码内存中的图象数据。
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            en.encode(buffImg);
            mainis.close();
            os.close();
            return logoPath;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

　　这里有个坑,如果服务器上图片是png或者其他格式,就会报异常 Not a JPEG格式文件,所以一般用下面这种就好:

public static String downloadByPath(String urlpath,String filename) {
		String logoPath ="";
		try {
			URL url = new URL(urlpath);
			URLConnection conn = null;
			conn =url.openConnection();
			//设置超时间为3秒
			conn.setConnectTimeout(3*1000);
			//防止屏蔽程序抓取而返回403错误
			conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

			//得到输入流
			InputStream inputStream = conn.getInputStream();
			//获取自己数组
			byte[] getData = readInputStream(inputStream);
			logoPath = Thread.currentThread().getContextClassLoader().getResource("/").getPath() + "/" + new String(new Date().getTime()+urlpath.substring(urlpath.length()-4));
			//文件保存位置
			File file = new File(logoPath);
			FileOutputStream fos = new FileOutputStream(file);
			fos.write(getData);
			if(fos!=null){
				fos.close();
			}
			if(inputStream!=null){
				inputStream.close();
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return logoPath;
}

　　这种可以适应所有的格式!

生成一般二维码

/**
     * 生成二维码
     * @param createPath  生成二维码路径
     * @param exurl 扫码跳转url(包含参数等信息)
     */
    public static void createQrcodePicByPath(String createPath, String exurl){
        MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
        Map<EncodeHintType, String> hints = new HashMap<EncodeHintType, String>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        BitMatrix bitMatrix;
        try {
            //这里指定大小
            bitMatrix = multiFormatWriter.encode(exurl, BarcodeFormat.QR_CODE, 220, 220, hints);
            /*bitMatrix = deleteWhite(bitMatrix);*/
            BufferedImage bimage = toBufferedImage(bitMatrix);
            OutputStream os = new FileOutputStream(createPath);
            //创键编码器，用于编码内存中的图象数据。
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            en.encode(bimage);
            os.close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

　　

httpclent请求地址生成特殊二维码(小程序):

　　// 获取小程序二维码,需要的参数,这里主要是httpclient发送get请求,解析返回结果(图片地址)
    public static String createQrcodePicByMiniProgramma(String wxcid, String token,String path){
        CloseableHttpResponse response = null;
        CloseableHttpClient httpClient = HttpClients.createDefault();
        try {
            URIBuilder builder = new URIBuilder("http://......");
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("cid",wxcid));
            params.add(new BasicNameValuePair("token",token));
            params.add(new BasicNameValuePair("path",path));
            builder.setParameters(params);
            HttpGet get = new HttpGet(builder.build());
            response = httpClient.execute(get);
            if(response != null && response.getStatusLine().getStatusCode() == 200){
                HttpEntity entity = response.getEntity();
                String string = entityToString(entity);
                log.info("pms消息转发成功,返回结果"+string);
                return string;
            }
        } catch (Exception e) {
            e.printStackTrace();log.error("pms消息转发失败"+response.getEntity());
        } finally {
            try {
                httpClient.close();if(response != null)response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

　　

//解析httpclient返回结果,转换成String
    private static String entityToString(HttpEntity entity) throws IOException {
        String result = null;
        if(entity != null)
        {
            long lenth = entity.getContentLength();
            if(lenth != -1 && lenth < 2048){
                result = EntityUtils.toString(entity,"UTF-8");
            }else {
                InputStreamReader reader1 = new InputStreamReader(entity.getContent(), "UTF-8");
                CharArrayBuffer buffer = new CharArrayBuffer(2048);
                char[] tmp = new char[1024];
                int l;
                while((l = reader1.read(tmp)) != -1) {
                    buffer.append(tmp, 0, l);
                }
                result = buffer.toString();
            }
        }
        return result;
    }