依赖pom

    			
     
      net.coobird
     			
     
      thumbnailator
     			
     
      0.4.8
     		
    

地址：

1、指定大小进行缩放

//size(宽度, 高度)            /*        * 若图片横比200小，高比300小，不变        * 若图片横比200小，高比300大，高缩小到300，图片比例不变        * 若图片横比200大，高比300小，横缩小到200，图片比例不变        * 若图片横比200大，高比300大，图片按比例缩小，横为200或高为300        */       Thumbnails.of("images/a380_1280x1024.jpg")               .size(200, 300)              .toFile("c:/a380_200x300.jpg");            Thumbnails.of("images/a380_1280x1024.jpg")               .size(2560, 2048)               .toFile("c:/a380_2560x2048.jpg");

2、按照比例进行缩放

Java代码  收藏代码    //scale(比例)      Thumbnails.of("images/a380_1280x1024.jpg")               .scale(0.25f)              .toFile("c:/a380_25%.jpg");            Thumbnails.of("images/a380_1280x1024.jpg")               .scale(1.10f)              .toFile("c:/a380_110%.jpg");

3、不按照比例，指定大小进行缩放

//keepAspectRatio(false) 默认是按照比例缩放的       Thumbnails.of("images/a380_1280x1024.jpg")           .size(200, 200)           .keepAspectRatio(false)           .toFile("c:/a380_200x200.jpg")

4、旋转

//rotate(角度),正数：顺时针 负数：逆时针  Thumbnails.of("images/a380_1280x1024.jpg")           .size(1280, 1024)          .rotate(90)           .toFile("c:/a380_rotate+90.jpg");     Thumbnails.of("images/a380_1280x1024.jpg")           .size(1280, 1024)          .rotate(-90)           .toFile("c:/a380_rotate-90.jpg");

5、水印

//watermark(位置，水印图，透明度)      Thumbnails.of("images/a380_1280x1024.jpg")               .size(1280, 1024)              .watermark(Positions.BOTTOM_RIGHT, ImageIO.read(new File("images/watermark.png")), 0.5f)               .outputQuality(0.8f)               .toFile("c:/a380_watermark_bottom_right.jpg");            Thumbnails.of("images/a380_1280x1024.jpg")               .size(1280, 1024)              .watermark(Positions.CENTER, ImageIO.read(new File("images/watermark.png")), 0.5f)               .outputQuality(0.8f)               .toFile("c:/a380_watermark_center.jpg");

6、裁剪

//sourceRegion()            //图片中心400*400的区域      Thumbnails.of("images/a380_1280x1024.jpg")              .sourceRegion(Positions.CENTER, 400,400)              .size(200, 200)              .keepAspectRatio(false)               .toFile("c:/a380_region_center.jpg");            //图片右下400*400的区域      Thumbnails.of("images/a380_1280x1024.jpg")              .sourceRegion(Positions.BOTTOM_RIGHT, 400,400)              .size(200, 200)              .keepAspectRatio(false)               .toFile("c:/a380_region_bootom_right.jpg");            //指定坐标      Thumbnails.of("images/a380_1280x1024.jpg")              .sourceRegion(600, 500, 400, 400)              .size(200, 200)              .keepAspectRatio(false)               .toFile("c:/a380_region_coord.jpg");

7、转化图像格式

//outputFormat(图像格式)  Thumbnails.of("images/a380_1280x1024.jpg")           .size(1280, 1024)          .outputFormat("png")           .toFile("c:/a380_1280x1024.png");     Thumbnails.of("images/a380_1280x1024.jpg")           .size(1280, 1024)          .outputFormat("gif")           .toFile("c:/a380_1280x1024.gif");

8、输出到OutputStream

  //toOutputStream(流对象)      OutputStream os = new FileOutputStream("c:/a380_1280x1024_OutputStream.png");      Thumbnails.of("images/a380_1280x1024.jpg")               .size(1280, 1024)              .toOutputStream(os);

9、输出到BufferedImage

//asBufferedImage() 返回BufferedImage  BufferedImage thumbnail = Thumbnails.of("images/a380_1280x1024.jpg")           .size(1280, 1024)          .asBufferedImage();  ImageIO.write(thumbnail, "jpg", new File("c:/a380_1280x1024_BufferedImage.jpg"));