Java实现图片的压缩（包括文件上传的图片压缩）

2016/10/11
package com.xj.console.util;
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;
//此包是针对文件的上传时引用的包(springMVC)
import org.springframework.web.multipart.MultipartFile;
//下面这两个包已经被JDK1.7移除，在引用的时候要是报错的话
//在Eclipse中将编译器针对过时的类报错的地方改成警告即可
//（Preferences/Java/compiler/errors/warning/forbidden-->waring）
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
 *本类的作用就是将图片文件压缩成指定的宽度和长度
 */
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;//输出图片宽度
	private int outputHeight = 100;//输出图片高度
	private boolean proportion = true;//输出图片是否等比缩放(默认为true)
	private MultipartFile myFile;//文件上传MultipartFile对象

	//初始化变量
	public CompressPicDemo(){
		inputDir = "";
		outputDir = "";
		inputFileName = "";
		outputFileName = "";
		outputWidth = 100;
		outputHeight = 100;
	}

	//属性set方法为对象赋值
	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;
	}

	public void setMyFile(MultipartFile myFile) {
		this.myFile = myFile;
	}

	//-----------------下面就是调用的方法

	/**
	 *获得图片大小 
	 *String path:图片路径
	 */
	 public long getPicSize(String path){
		file = new File(path);
		if(!file.exists){
			return 0;
		}else{
			return file.length();
		}
	 }

	 /*
	  *图片处理:不涉及文件上传,简单根据传过来的图片路径和图片名称进行压缩处理
	  */
	  public String compressPic(){
		try{
			//获得文件源
			file = new File(inputDir+inputFileName);
			if(!file.exists()){
				return "";
			}
			//imageIO.read(arg);图片解析,可传入文件,文件输入流等
			Image img = ImageIO.read(file);
			if(img.getWidth(null) == -1){
				return "no";
			}else{
				int newWidth;
				int newHeight;
				//判断是否等比缩放
				if(this.proportion == true ){
					double rate = (double)img.getWidth(null)/(double)outputWidth;
					newWidth = outputWidth;
					newHeight = ((double)img.getHeight(null)/rate).intValue();
				}else{
					newWidth = outputWidth;
					newHeight = outputHeght;
				}
				/**
				 *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,生成的图片质量好但是速度慢
				 *根据具体要求取舍时间或是质量
				 */
				BufferedImage tag = new BufferedImage((int)newWidth,(int)newHeight,BufferedImage.TYPE_INT_RGB);
				/* @param    img    the specified image to be drawn. 
				 * @param    x      x坐标.
				 * @param    y      y坐标.
				 * @param    width  the width of the rectangle.
				 * @param    height the height of the rectangle.
				 * @param    observer   像素是否被改变			
				 */
				tag.getGraphics().drawImage(img,0,0,newWidth,newHeight,null);
				FileOutputStream out = new FileoutputStream(outputDir+outputFileName);
				//JPEGImageEncoder可适用于其他图片的类型的转换
				JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
				encoder.encode(tag);
				out.close;
			}
			
		}
	  
	  }
	  /*
	  *图片处理:涉及文件上传,上传文件获取的是MultipartFile对象,而不是文件路径或是文件名
	  */
	  public String compressPicVersion2(){
		try{
			if(myFile.empty()){
				return "";
			}
			Image img = ImageIO.read(myFile.getInputStream());
			if(img.getWidth(null) == -1){
				return "no";
			}else{
				int newWidth;
				int newHeight;
				if(this.proportion == true ){
					double rate = (double)img.getWidth(null)/(double)outputWidth;
					newWidth = outputWidth;
					newHeight = ((double)img.getHeight(null)/rate).intValue();
				}else{
					newWidth = outputWidth;
					newHeight = outputHeght;
				}				
				BufferedImage tag = new BufferedImage((int)newWidth,(int)newHeight,BufferedImage.TYPE_INT_RGB);				
				tag.getGraphics().drawImage(img,0,0,newWidth,newHeight,null);
				FileOutputStream out = new FileoutputStream(outputDir+outputFileName);
				JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
				encoder.encode(tag);
				out.close;
			}
			
		}
	  
	  }

	  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();
	}
	
	public String compressPicVersion2( MultipartFile myFile , String outputDir, String outputFileName,
			int width, int height, boolean gp) {
		this.myFile = myFile;
		// 输出图路径
		this.outputDir = outputDir;
		// 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 compressPicVersion2();
	}

	// 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();
		int count = 0; // 记录全部图片压缩所用时间
		for (int i = 0; i < 10; i++) {//压缩十张图片
			System.out.println("输入的图片大小：" + mypic.getPicSize("e:/temp/"+i+".jpg") / 1024 + "KB");
			int start = (int) System.currentTimeMillis(); // 开始时间
			mypic.compressPic("e:/temp/", "e:/tempCopy/", i+".jpg", "r1" + i + ".jpg", 600, 600, true);
			int end = (int) System.currentTimeMillis(); // 结束时间
			int re = end - start; // 但图片生成处理时间
			count += re;
			System.out.println("第" + (i + 1) + "张图片压缩处理使用了: " + re + "毫秒");
			System.out.println("输出的图片大小：" + mypic.getPicSize("e:/tempCopy/r1" + i + ".jpg") / 1024 + "KB");
		}
		System.out.println("总共用了：" + count + "毫秒");
	}

	
}