MicroCommunity/Api/src/main/java/com/java110/api/rest/PicTest.java

package com.java110.api.rest;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;

import javax.imageio.ImageIO;
import javax.imageio.stream.FileImageOutputStream;

public class PicTest {

    static int a = 0;
    public static void main(String[] args) throws IOException {
        /*long timeStart = System.currentTimeMillis();
        String imgLocalUrl = "D:\\白静雪.jpg";

        byte[] imgBytes = getByteByPic(imgLocalUrl);
        byte[] resultImg = compressUnderSize(imgBytes,800 * 1024);
        byte2image(resultImg,"E:\\tp\\timga.jpg");
        long timeEnd = System.currentTimeMillis();
        System.out.println("耗时："+ (timeEnd - timeStart));*/
        char i= 8;
        int j = 0;
        for (;i >0;j-=3){
            ++j;
        }
        System.out.printf("%d\n",j);

       // System.out.printf("a= "+ fib(5));
    }

    public static int fib(int i) {
        a++;
        if(i == 0){
            return 1;
        }else{
            if(i== 1){
                return 2;
            }else{
                return  fib(i-1)+fib(i-2);
            }

        }

    }

    public static byte[] getByteByPic(String imageUrl) throws IOException{
        File imageFile = new File(imageUrl);
        InputStream inStream = new FileInputStream(imageFile);
        BufferedInputStream bis = new BufferedInputStream(inStream);
        BufferedImage bm = ImageIO.read(bis);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        String type = imageUrl.substring(imageUrl.length() - 3);
        ImageIO.write(bm, type, bos);
        bos.flush();
        byte[] data = bos.toByteArray();
        return data;
    }
    /**
     * 将图片压缩到指定大小以内
     *
     * @param srcImgData 源图片数据
     * @param maxSize 目的图片大小
     * @return 压缩后的图片数据
     */
    public static byte[] compressUnderSize(byte[] srcImgData, long maxSize) {
        double scale = 0.9;
        byte[] imgData = Arrays.copyOf(srcImgData, srcImgData.length);

        if (imgData.length > maxSize) {
            do {
                try {
                    imgData = compress(imgData, scale);

                } catch (IOException e) {
                    throw new IllegalStateException("压缩图片过程中出错，请及时联系管理员！", e);
                }

            } while (imgData.length > maxSize);
        }

        return imgData;
    }

    /**
     * 按照 宽高 比例压缩
     *
     * @param scale 压缩刻度
     * @return 压缩后图片数据
     * @throws IOException 压缩图片过程中出错
     */
    public static byte[] compress(byte[] srcImgData, double scale) throws IOException {
        BufferedImage bi = ImageIO.read(new ByteArrayInputStream(srcImgData));
        int width = (int) (bi.getWidth() * scale); // 源图宽度
        int height = (int) (bi.getHeight() * scale); // 源图高度

        Image image = bi.getScaledInstance(width, height, Image.SCALE_SMOOTH);
        BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        Graphics g = tag.getGraphics();
        g.setColor(Color.RED);
        g.drawImage(image, 0, 0, null); // 绘制处理后的图
        g.dispose();

        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
        ImageIO.write(tag, "JPEG", bOut);

        return bOut.toByteArray();
    }

    //byte数组到图片
    public static void byte2image(byte[] data,String path){
        if(data.length<3||path.equals("")) return;
        try{
            FileImageOutputStream imageOutput = new FileImageOutputStream(new File(path));
            imageOutput.write(data, 0, data.length);
            imageOutput.close();
            System.out.println("Make Picture success,Please find image in " + path);
        } catch(Exception ex) {
            System.out.println("Exception: " + ex);
            ex.printStackTrace();
        }
    }

}