java实现图像缩略
import java.io.*; import java.util.*; import com.sun.image.codec.jpeg.*; import java.awt.image.*; import java.awt.*; import java.net.*; import java.applet.*; import java.sql.*; //缩略图类， //本java类能将jpg图片文件，进行等比或非等比的大小转换。 //具体使用方法 //s_pic(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 class DwindlePic{ String InputDir; //输入图路径 String OutputDir; //输出图路径 String InputFileName; //输入图文件名 String OutputFileName; //输出图文件名 int OutputWidth = 80; //默认输出图片宽 int OutputHeight = 80; //默认输出图片高 int rate = 0; boolean proportion = true; //是否等比缩放标记(默认为等比缩放) public DwindlePic() { //初始化变量 InputDir = ""; OutputDir = ""; InputFileName = ""; OutputFileName = ""; OutputWidth = 80; OutputHeight = 80; rate = 0; } 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 setW_H(int width, int height) { this.OutputWidth = width; this.OutputHeight = height; } public String s_pic() { BufferedImage image; String NewFileName; //建立输出文件对象 File file = new File(OutputDir + OutputFileName); FileOutputStream tempout = null; try { tempout = new FileOutputStream(file); } catch (Exception ex) { System.out.println(ex.toString()); } Image img = null; Toolkit tk = Toolkit.getDefaultToolkit(); Applet app = new Applet(); MediaTracker mt = new MediaTracker(app); try { img = tk.getImage(InputDir + InputFileName); mt.addImage(img, 0); mt.waitForID(0); } catch (Exception e) { e.printStackTrace(); } if (img.getWidth(null) == -1) { System.out.println(" can't read,retry!" + "<BR>"); return "no"; } else { int new_w; int new_h; 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; double rate = rate1 > rate2 ? rate1 : rate2; new_w = (int) ( ( (double) img.getWidth(null)) / rate); new_h = (int) ( ( (double) img.getHeight(null)) / rate); } else { new_w = OutputWidth; //输出的图片宽度 new_h = OutputHeight; //输出的图片高度 } BufferedImage buffImg = new BufferedImage(new_w, new_h, BufferedImage.TYPE_INT_RGB); Graphics g = buffImg.createGraphics(); g.setColor(Color.white); g.fillRect(0, 0, new_w, new_h); g.drawImage(img, 0, 0, new_w, new_h, null); g.dispose(); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(tempout); try { encoder.encode(buffImg); tempout.close(); } catch (IOException ex) { System.out.println(ex.toString()); } } return "ok"; } public String s_pic(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 s_pic(); } public String s_pic(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 setW_H(width, height); //是否是等比缩放 标记 this.proportion = gp; return s_pic(); } /** public static void main(String[] a) { //s_pic(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) DwindlePic mypic = new DwindlePic(); System.out.println( mypic.s_pic("e:\\Tomcat\\webapps\\pms\\image\", "e:\\Tomcat\\webapps\\pms\\image\", "test.jpg", "new.jpg", 120, 80, true) ); } */ } ?