使用Java生成jpg与压缩图片为jpg文件的代码示例

package other.pic;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.RandomAccessFile;
import java.awt.image.BufferedImage;
import java.awt.*;
import java.util.Random;
/**
 * Created by IntelliJ IDEA.
 * User: Administrator
 * Date: 2005-6-10
 * Time: 11:19:49
 * This class can create jpg picture.
 * To change this template use File | Settings | File Templates.
 */
public class ChartGraphics {
  BufferedImage image;
  void createImage(String fileLocation) {
    try {
      FileOutputStream fos = new FileOutputStream(fileLocation);
      BufferedOutputStream bos = new BufferedOutputStream(fos);
      JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
      encoder.encode(image);
      bos.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public void graphicsGeneration(int h1, int h2, int h3, int h4, int h5) {
    final int X = 10;
    int imageWidth = 300;//图片的宽度
    int imageHeight = 300;//图片的高度
    int columnWidth = 30;//柱的宽度
    int columnHeight = 200;//柱的最大高度
    // ChartGraphics chartGraphics = new ChartGraphics();
    image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_RGB);
    Graphics graphics = image.getGraphics();
    graphics.setColor(Color.white);
    graphics.fillRect(0, 0, imageWidth, imageHeight);
    graphics.setColor(Color.red);
    graphics.drawRect(X + 1 * columnWidth, columnHeight - h1, columnWidth, h1);
    graphics.drawRect(X + 2 * columnWidth, columnHeight - h2, columnWidth, h2);
    graphics.drawRect(X + 3 * columnWidth, columnHeight - h3, columnWidth, h3);
    graphics.drawRect(X + 4 * columnWidth, columnHeight - h4, columnWidth, h4);
    graphics.drawRect(X + 5 * columnWidth, columnHeight - h5, columnWidth, h5);
    createImage("D://Temp//chart.jpg");
  }
  public static void main(String[] args) {
    int[] height = {40,50,16,22,85};
     ChartGraphics cg=new ChartGraphics();
    try {
      for (int i = 0; i < 5; i++) {
        cg.graphicsGeneration(height[0],height[1],height[2],height[3],height[4]);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

　　import java.io.File;
　　import java.io.FileOutputStream;
　　import java.awt.Graphics;
　　import java.awt.Image;
　　import java.awt.image.BufferedImage;
　　import com.sun.image.codec.jpeg.JPEGCodec;
　　import com.sun.image.codec.jpeg.JPEGImageEncoder;
　　public class JpgTest {
　　public void JpgTset() throws Exception{
　　File _file = new File("/Order005-0001.jpg"); //读入文件
　　Image src = javax.imageio.ImageIO.read(_file); //构造Image对象
　　int wideth=src.getWidth(null); //得到源图宽
　　int height=src.getHeight(null); //得到源图长
　　BufferedImage tag = new BufferedImage(wideth/2,height/2,BufferedImage.TYPE_INT_RGB);
　　tag.getGraphics()。drawImage(src,0,0,wideth/2,height/2,null); //绘制缩小后的图
　　FileOutputStream out=new FileOutputStream("newfile.jpg"); //输出到文件流
　　JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
　　encoder.encode(tag); //近JPEG编码
　　System.out.print(width+"*"+height);
　　out.close();
　　}
　　}

   JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

    FileOutputStream out = new FileOutputStream(dstName);
     JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
     encoder.encode(dstImage);

    String formatName = dstName.substring(dstName.lastIndexOf(".") + 1);
     //FileOutputStream out = new FileOutputStream(dstName);
     //JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
     //encoder.encode(dstImage);
     ImageIO.write(dstImage, /*"GIF"*/ formatName /* format desired */ , new File(dstName) /* target */ );