import java.awt.Image; import java.awt.image.BufferedImage; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import javax.imageio.ImageIO; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; public class CompressPicDemo { private File file = null; // 文件对象 private String inputDir; // 输入图路径 private String outputDir; // 输出图路径 private String inputFileName; // 输入图文件名 private String outputFileName; // 输出图文件名 private int outputWidth = 100; // 默认输出图片宽 private int outputHeight = 100; // 默认输出图片高 private boolean proportion = true; // 是否等比缩放标记(默认为等比缩放) public CompressPicDemo() { // 初始化变量 inputDir = ""; outputDir = ""; inputFileName = ""; outputFileName = ""; outputWidth = 100; outputHeight = 100; } public void setInputDir(String inputDir) { this.inputDir = inputDir; } public void setOutputDir(String outputDir) { this.outputDir = outputDir; } public void setInputFileName(String inputFileName) { this.inputFileName = inputFileName; } public void setOutputFileName(String outputFileName) { this.outputFileName = outputFileName; } public void setOutputWidth(int outputWidth) { this.outputWidth = outputWidth; } public void setOutputHeight(int outputHeight) { this.outputHeight = outputHeight; } public void setWidthAndHeight(int width, int height) { this.outputWidth = width; this.outputHeight = height; } /* * 获得图片大小 * 传入参数 String path :图片路径 */ public long getPicSize(String path) { file = new File(path); return file.length(); } // 图片处理 public String compressPic() { try { //获得源文件 file = new File(inputDir + inputFileName); if (!file.exists()) { return ""; } Image img = ImageIO.read(file); // 判断图片格式是否正确 if (img.getWidth(null) == -1) { System.out.println(" can't read,retry!" + "<BR>"); return "no"; } else { int newWidth; int newHeight; // 判断是否是等比缩放 if (this.proportion == true) { // 为等比缩放计算输出的图片宽度及高度 double rate1 = ((double) img.getWidth(null)) / (double) outputWidth + 0.1; double rate2 = ((double) img.getHeight(null)) / (double) outputHeight + 0.1; // 根据缩放比率大的进行缩放控制 double rate = rate1 > rate2 ? rate1 : rate2; newWidth = (int) (((double) img.getWidth(null)) / rate); newHeight = (int) (((double) img.getHeight(null)) / rate); } else { newWidth = img.getWidth(null); // 输出的图片宽度 newHeight = img.getHeight(null); // 输出的图片高度 } BufferedImage tag = new BufferedImage((int) newWidth, (int) newHeight, BufferedImage.TYPE_INT_RGB); /* * Image.SCALE_SMOOTH 的缩略算法 生成缩略图片的平滑度的 * 优先级比速度高 生成的图片质量比较好 但速度慢 */ tag.getGraphics().drawImage(img.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH), 0, 0, null); FileOutputStream out = new FileOutputStream(outputDir + outputFileName); // JPEGImageEncoder可适用于其他图片类型的转换 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); encoder.encode(tag); out.close(); } } catch (IOException ex) { ex.printStackTrace(); } return "ok"; } public String compressPic (String inputDir, String outputDir, String inputFileName, String outputFileName) { // 输入图路径 this.inputDir = inputDir; // 输出图路径 this.outputDir = outputDir; // 输入图文件名 this.inputFileName = inputFileName; // 输出图文件名 this.outputFileName = outputFileName; return compressPic(); } public String compressPic(String inputDir, String outputDir, String inputFileName, String outputFileName, int width, int height, boolean gp) { // 输入图路径 this.inputDir = inputDir; // 输出图路径 this.outputDir = outputDir; // 输入图文件名 this.inputFileName = inputFileName; // 输出图文件名 this.outputFileName = outputFileName; // 设置图片长宽 setWidthAndHeight(width, height); // 是否是等比缩放 标记 this.proportion = gp; return compressPic(); } // main测试 // compressPic(大图片路径,生成小图片路径,大图片文件名,生成小图片文名,生成小图片宽度,生成小图片高度,是否等比缩放(默认为true)) public static void main(String[] arg) { CompressPicDemo mypic = new CompressPicDemo(); System.out.println("输入的图片大小:" + mypic.getPicSize("e:\\1.jpg")/1024 + "KB"); mypic.compressPic("e:\\", "e:\\test\\", "1.jpg", "r1.jpg", 120, 120, false); } }