jsp 產生縮圖代碼程式

jsp教程 產生縮圖代碼程式

java.io.File file = new java.io.File(saveurl);        //讀入剛才上傳的檔案
    String newurl=request.getRealPath("/")+url+"min_"+filename+"."+ext;  //新的縮圖儲存地址
    Image src = javax.imageio.ImageIO.read(file);                     //構造Image對象
    float tagsize=200;
    int old_w=src.getWidth(null);                                     //得到源圖寬
    int old_h=src.getHeight(null);  
    int new_w=0;
    int new_h=0;                            //得到源圖長
    int temps教程ize;
    float tempdouble;
    if(old_w>old_h){
     tempdouble=old_w/tagsize;
    }else{
     tempdouble=old_h/tagsize;
    }
    new_w=Math.round(old_w/tempdouble);
    new_h=Math.round(old_h/tempdouble);//計算新圖長寬
    BufferedImage tag = new BufferedImage(new_w,new_h,BufferedImage.TYPE_INT_RGB);
    tag.getGraphics().drawImage(src,0,0,new_w,new_h,null);       //繪製縮小後的圖
    FileOutputStream newimage=new FileOutputStream(newurl);          //輸出到檔案流
    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(newimage);      
    encoder.encode(tag);                                               //近JPEG編碼
   
  newimage.close();