Java automatically generates thumbnail images __java

First, automatically generate thumbnails method:

Package writeimg;
Import Java.awt.geom.AffineTransform;
Import java.awt.image.AffineTransformOp;
Import Java.awt.image.BufferedImage;
Import Java.io.File;
Import java.io.IOException;

Import Javax.imageio.ImageIO; public class Jpegtool {private Boolean isinitflag = false;//Whether the object has already been initialized private String Pic_big_ Pathfilename = null; Defines the filename with the path directory that contains the source picture private String pic_small_pathfilename = null; Create a small picture of the file name with the path directory private int smallpicwidth = 0; 
        Define the width and height of the generated small picture, give it one can be private int smallpicheight = 0;
        private int pic_big_width=0;
        private int pic_big_height=0; Private double Picscale = 0;
                Defines the proportions of a small picture compared to the original picture/** * constructor * @param no parameters/public Jpegtool () { 
        This.isinitflag = false; /** * Private Function, reset all parameters * @param no parameters * @return no return parameters/private void Resetjpegtoolparams () {This.piCscale = 0; 
                this.smallpicwidth = 0; 
                this.smallpicheight = 0; 
        This.isinitflag = false; /** * @param scale set miniature image relative to the source image size ratio such as 0.5 * @throws jpegtoolexception * * PU 
                                Blic void Setscale (double scale) throws Jpegtoolexception {if (scale<=0) { throw new Jpegtoolexception ("Scaling cannot be 0 and negative.") 
                "); 
                } this.resetjpegtoolparams (); 
                This.picscale = scale; 
        This.isinitflag = true; /** * @param smallpicwidth Set the width of the miniature image * @throws jpegtoolexception * * Public
                void setsmallwidth (int smallpicwidth) throws Jpegtoolexception {if (smallpicwidth<=0) {throw new Jpegtoolexception ("Miniature pictures cannot be 0 and negative.") 
                "); } this.resetjpegtoolparams (); 
                This.smallpicwidth = Smallpicwidth; 
        This.isinitflag = true; /** * @param smallpicheight Sets the height of the miniature image * @throws jpegtoolexception * * Publ
                IC void setsmallheight (int smallpicheight) throws Jpegtoolexception {if (smallpicheight<=0) {throw new Jpegtoolexception ("miniature pictures cannot have a height of 0 and a negative number.") 
                "); 
                } this.resetjpegtoolparams (); 
                This.smallpicheight = Smallpicheight; 
        This.isinitflag = true;
                /** * Returns the large picture path/public String Getpic_big_pathfilename () {
        return this.pic_big_pathfilename; /** * Returns the small picture path/public String Getpic_small_pathfilename () {R
        Eturn This.pic_small_pathfilename;
                public int GETSRCW () {return this.pic_big_width;
        public int Getsrch () {return this.pic_big_height; /** * Generates a miniature image of the source image * @param pic_big_pathfilename source image file name containing the path (such as Windows c:\\pic.jpg under Linux/ home/abner/pic/pic.jpg) * @param pic_small_pathfilename generated miniature image file name containing the path (such as Windows c:\\pic_small.jpg under Linux /home/abner/pic/pic_small.jpg) * @throws jpegtoolexception */public void dofinal (String pic_b 
                    Ig_pathfilename,string pic_small_pathfilename) throws Jpegtoolexception {if (!this.isinitflag) { throw new Jpegtoolexception ("Object parameter not initialized.") 
                "); } if (Pic_big_pathfilename==null | | pic_small_pathfilename==null) {throw new Jpegtool Exception ("The path containing the filename is empty.) 
                "); The If ((!pic_big_pathfilename.tolowercase (). EndsWith ("JPG")) && (!pic_big_pathfilename.tolowercase ( ). EndsWith ("JPEG")) { 
                    throw new Jpegtoolexception ("Only jpg/jpeg files can be processed.") 
                "); if (!pic_small_pathfilename.tolowercase (). EndsWith ("JPG")) &&!pic_small_pathfilename.tolowerca Se (). EndsWith ("JPEG")) {throw new Jpegtoolexception ("Only jpg/jpeg files can be processed.") 
                ");
                } this.pic_big_pathfilename=pic_big_pathfilename;
                This.pic_small_pathfilename=pic_small_pathfilename; 
                int SMALLW = 0; 
                int SMALLH = 0; 
                A new source picture and a generated small picture of the file object files fi = new file (pic_big_pathfilename); 
                File fo = new file (pic_small_pathfilename); 
                Generate image Transform object AffineTransform transform = new AffineTransform (); 
                Read into the source image file by buffering bufferedimage bsrc = null; 
                try {bsrc = Imageio.read (FI); }catch (IOException ex) {throw new JpegtOolexception ("Error reading source image file. 
                "); This.pic_big_width= bsrc.getwidth ()//The length of the original image this.pic_big_height = Bsrc.getheight (); /The width of the original image double scale = (double) pic_big_width/pic_big_height;//the long width ratio of the image if (this.smallpic 
                        width!=0) {//Length SMALLW = this.smallpicwidth;//The length of the newly generated thumbnail image based on the set width SMALLH = (smallw*pic_big_height)/pic_big_width//The width of the newly generated thumbnail image} else if (thi 
                        s.smallpicheight!=0) {//Width SMALLH = this.smallpicheight;//The length of the newly generated thumbnail image according to the set length
                SMALLW = (smallh*pic_big_width)/pic_big_height;//the width of the newly generated thumbnail image} else if (this.picscale!=0) {//sets the length and width smallw = (int) (float) of the image according to the set reduction scale Pic_big_wid 
                        Th*this.picscale); 
 SMALLH = (int) ((float) pic_big_height*this.picscale);               else {throw new Jpegtoolexception ("Object parameter initialization is not correct.") 
                "); Double SX = (double) smallw/pic_big_width;//width ratio of small/large images double sy = (double) Smallh/pic_bi 
                g_height;//the height ratio of small/large images transform.settoscale (sx,sy);//Set the scale of the image conversion//Generate image conversion manipulation objects 
                Affinetransformop ato = new Affinetransformop (transform,null); 
                The buffer object that produces the shrinking image bufferedimage Bsmall = new BufferedImage (SMALLW,SMALLH,BUFFEREDIMAGE.TYPE_3BYTE_BGR); 
                Generate small Image ato.filter (Bsrc,bsmall); 
                Output small image try{Imageio.write (bsmall, "jpeg", FO);  The catch (IOException Ex1) {throw new Jpegtoolexception ("error writing to the thumbnail image file. 
                "); } 
        }
}

Second, the exception processing class:

    Package jpegtool;

    public class Jpegtoolexception extends Exception {
            private String errmsg = ""; 
            Public jpegtoolexception (String errmsg) 
            { 
                    this.errmsg = errmsg; 
            } 

            Public String getmsg () {return 
                "jpegtoolexception:" +THIS.ERRMSG; 
            } 
    }

Third, the invocation of the example:

Package writeimg;

public class T {public


	static void Main (string[] args) {

		Jpegtool j = new Jpegtool ();
		try {
			J.setscale (0.7);
			J.setsmallheight (m);
			J.dofinal ("D:\\305\\c\\javatest\\src\\11.jpg", "d:\\305\\c\\javatest\\src\\22.jpg");
		} catch (Jpegtoolexception e) {
			//TODO auto-generated catch block
			e.printstacktrace ();
		}
	}

}