java-如何改变图片大小。

import java.awt.Image;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import javax.imageio.ImageIO;

import com.sun.image.codec.jpeg.JPEGCodec;

import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class JpgChange {

// path 路径 ,旧文件名称 ,新文件名称,n 改变倍数

public void changeImage(String path, String oldimg, String newimg, int n) {

try {

File file = new File(path + oldimg);

Image img = ImageIO.read(file);

// 构造Image对象

int wideth = img.getWidth(null); // 得到源图宽

int height = img.getHeight(null); // 得到源图长

BufferedImage tag = new BufferedImage(n * wideth, n * height,

BufferedImage.TYPE_INT_RGB);

tag.getGraphics()

.drawImage(img, 0, 0, n * wideth, n * height, null); // 绘制后的图

FileOutputStream out = new FileOutputStream(path + newimg);

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

encoder.encode(tag); // 近JPEG编码

out.close();

} catch (IOException e) {

System.out.println("处理文件出现异常");

e.printStackTrace();

}

public static void main(String[] args) {

JpgChange jc = new JpgChange();

jc.changeImage("E:\\", "1.jpg", "2.jpg", 3);

}