图片缩略图 简单应用

package com.utils.file;

import java.awt.Container;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.sql.Timestamp;
import java.util.Date;
import java.util.UUID;
import javax.imageio.ImageIO;import wfc.service.database.BlobHelper;
import...Condition;
import...Conditions;
import...SQL;

public class imageThumbnail {

private static void createThumbnail(String filename, int thumbWidth, int thumbHeight, String outFilename)throws Exception{
          //根据地址载入图片
          Image image = Toolkit.getDefaultToolkit().getImage(filename);
          MediaTracker mediaTracker = new MediaTracker(new Container());
          mediaTracker.addImage(image, 0);
          mediaTracker.waitForID(0);
          
          double thumbRatio = (double)thumbWidth / (double)thumbHeight;
          int imageWidth = image.getWidth(null);
          int imageHeight = image.getHeight(null);
          double imageRatio = (double)imageWidth / (double)imageHeight;
          if (thumbRatio < imageRatio) {
          thumbHeight = (int)(thumbWidth / imageRatio);
          } else {
          thumbWidth = (int)(thumbHeight * imageRatio);
          }
          
          BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
          Graphics2D graphics2D = thumbImage.createGraphics();
          graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
          graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);
          File fileThumbnail = new File(outFilename);  
          ImageIO.write(thumbImage, "jpg", fileThumbnail);

          
          //获取缩略图做其他业务用--放在别处
          BufferedInputStream in = new BufferedInputStream(new FileInputStream(outFilename));  
            File file = new File("C:\\Users\\Desktop\\jjjj.jpg");  
            if (file != null) {  
                file.createNewFile();  
            }  
            // 指定要写入文件的缓冲输出字节流  
            BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(file));  
            byte[] bb = new byte[1024];// 用来存储每次读取到的字节数组  
            int n;// 每次读取到的字节数组的长度  
            while ((n = in.read(bb)) != -1) {  
                out.write(bb, 0, n);// 写入到输出流  
            }  
            out.close();// 关闭流  
            in.close();  
            fileThumbnail.delete();//删除缩略图
          
            
              //或把缩略图入库
            byte [] filebyte = FileLoadUtil.File2byte(fileThumbnail);
            Timestamp  saveTime=new Timestamp(new Date().getTime());
              String uuid = UUID.randomUUID().toString();
            String fjId = "202004"+UUID.randomUUID().toString();
            String sql = "insert into DAN_FJ(FJ_ID,ST_APP_ID,TIME) values (?,?,?)";
            Object[] objects = new Object[] {uuid,fjId,saveTime};
            SQL.execute(sql,objects);
            Conditions conds = Conditions.newOrConditions();
            conds.add(new Condition("FJ_ID", Condition.OT_EQUAL, uuid));
            BlobHelper.setBlob("DAN_FJ", "APPLY_FJ", conds.toString(),filebyte, conds.getObjectArray());
            fileThumbnail.delete();//删除缩略图
  }
    
    public static void main(String[] args) throws Exception {
        //原地址，缩略图高，宽，输出地址和缩略图名
        createThumbnail("C:\\Users\\Desktop\\jj.jpg",100,75,"C:\\Users\\Desktop\\jjj.jpg");
    }
    
}

/**
         * 将文件转换成byte数组
         * @param filePath
         * @return
         */
        public static byte[] File2byte(File tradeFile){
            byte[] buffer = null;
            try
            {
                FileInputStream fis = new FileInputStream(tradeFile);
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                byte[] b = new byte[10240];
                int n;
                while ((n = fis.read(b)) != -1)
                {
                    bos.write(b, 0, n);
                }
                fis.close();
                bos.close();
                buffer = bos.toByteArray();
            }catch (FileNotFoundException e){
                e.printStackTrace();
            }catch (IOException e){
                e.printStackTrace();
            }
            return buffer;
        }