JAVA图片压缩详解编程语言

package com.lea.test; 
 
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 CompreeImages { 
	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 CompreeImages() {  
		inputDir = ""; 
		outputDir = ""; 
		inputFileName = ""; 
		outputFileName = ""; 
		outputWidth = 100; 
		outputHeight = 100; 
	} 
	 
	public static void main(String[] arg) { 
		CompreeImages mypic = new CompreeImages(); 
		File filePath = new File("F://img_test"); 
		File[] files = filePath.listFiles(); 
		for (File file : files) { 
			String name = file.getName(); 
			int index = name.lastIndexOf("."); 
			StringBuffer sb = new StringBuffer(); 
			sb.append(name); 
			sb.insert(index, "_s"); 
			mypic.compressPic("F://img_test//", "F://img_test//sc//", file.getName(), sb.toString(), 120, 120, true); 
		} 
	} 
 
	public String compressPic() { 
		try { 
			file = new File(inputDir + inputFileName); 
			if (!file.exists()) { 
				return ""; 
			} 
			Image img = ImageIO.read(file); 
			if (img.getWidth(null) == -1) { 
				return "no"; 
			} else { 
				int newWidth; 
				int newHeight; 
				if (this.proportion == true) { // 判断是否是等比缩放 
					// 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 = outputWidth; // 输出的图片宽度 
					newHeight = outputHeight; // 输出的图片高度 
				} 
				BufferedImage tag = new BufferedImage((int) newWidth,(int) newHeight, BufferedImage.TYPE_INT_RGB); 
 
				tag.getGraphics().drawImage(img.getScaledInstance(newWidth, newHeight,Image.SCALE_SMOOTH), 0, 0, null); 
				FileOutputStream out = new FileOutputStream(outputDir + outputFileName); 
				JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);// JPEGImageEncoder可适用于其他图片类型的转换 
				encoder.encode(tag); 
				out.close(); 
			} 
		} catch (IOException ex) { 
			ex.printStackTrace(); 
		} 
		return "ok"; 
	} 
 
	public String compressPic(String inputDir, String outputDir,String inputFileName, String outputFileName) { 
		this.inputDir = inputDir; 
		this.outputDir = outputDir; 
		this.inputFileName = inputFileName; 
		this.outputFileName = outputFileName; 
		return compressPic(); 
	} 
 
	/** 
	 *  
	 * @param inputDir 	输入图路径 
	 * @param outputDir	输出图路径 
	 * @param inputFileName		输入图文件名 
	 * @param outputFileName	输出图文件名 
	 * @param width			设置图片宽 
	 * @param height		设置图片长 
	 * @param gp		是否是等比缩放 标记 
	 * @return 
	 */ 
	public String compressPic(String inputDir, String outputDir, String inputFileName, String outputFileName, int width, int height,boolean gp) { 
		this.inputDir = inputDir; 
		this.outputDir = outputDir; 
		this.inputFileName = inputFileName; 
		this.outputFileName = outputFileName; 
		setWidthAndHeight(width, height); 
		this.proportion = gp; 
		return compressPic(); 
	} 
 
 
	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; 
	} 
}