图片缩放加水印

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigDecimal;
import java.math.MathContext;
import java.util.ArrayList;

import javax.imageio.ImageIO;

/**

• Thumbnails用法：
• 指定长宽 Thumbnails.of(inputStream).size(width,height).keepAspectRatio(false不安原比例true按原比例).asBufferedImage
• 按照比例缩放 Thumbnails.of(inputStream).scale(0.25f).asBufferedImage
• 图片旋转 Thumbnails.of(inputStream).size(width,height).rotate(90).asBufferedImage
• 水印并降质 Thumbnails.of(inputStream).size(width,height).watermark(Positions.CENTER, ImageIO.read(水印图), 0.5f).outputQuality(0.8f).asBufferedImage
• 因：Thumbnails的scale在压缩时会导致PNG变大、某些图png转jpg底色发红等BUG
• 故：编写此工具类，用来处理图片缩放，水印
• @author LiChuntao

*/
public class ImgUtil {

/**
* 判断图片类型
* 
* @param ins
* @return
* @throws IOException
*/
public static String getImgTypeByStream(InputStream ins) throws IOException {
    byte[] b = new byte[4];
    ins.read(b, 0, b.length);
    String type = IOUtil.byteToHex(b).toUpperCase();
    if (type.contains("FFD8FF")) {
        return "jpg";
    } else if (type.contains("89504E47")) {
        return "png";
    } else if (type.contains("47494638")) {
        return "gif";
    } else if (type.contains("424D")) {
        return "bmp";
    } else {
        return "unknown";
    }
}

/**
* 等比例缩放图片
* 
* @param stream
* @param scale
*            大于1放大、小于1缩小、等于1降质
* @return
* @throws IOException
*/
public static InputStream scaleImg(InputStream stream, float scale, String type) throws IOException {
    
    BufferedImage inputImg = ImageIO.read(stream);
    int width = (int) (inputImg.getWidth() * scale);
    int height = (int) (inputImg.getHeight() * scale);
    
    //如不设置PNG转JPG背景发红
    BufferedImage outputImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics graphics = outputImage.getGraphics();
    
    Image image = inputImg.getScaledInstance(width, height, Image.SCALE_SMOOTH);
    graphics.drawImage(image, 0, 0, null);
    graphics.dispose();

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ImageIO.write(outputImage, type, out);
    ByteArrayInputStream result = new ByteArrayInputStream(out.toByteArray());
    out.close();

    return result;
}

/**
* 生成指定宽高的图片
* 
* @param stream
* @param width
* @param height
* @param auto
*            保持原图片长宽比例
* @param type
* @return
* @throws IOException
*/
public static InputStream generatorImgByWidthHeight(InputStream stream, int setWidth, int setHeight, boolean auto,
        String type) throws IOException {
    
    BufferedImage inputImg = ImageIO.read(stream);
    if (auto) {
        ArrayList paramsArrayList = getAutoWidthAndHeight(inputImg, setWidth, setHeight);
        setWidth = paramsArrayList.get(0);
        setHeight = paramsArrayList.get(1);
    }
    
    BufferedImage outputImage = new BufferedImage(setWidth, setHeight, BufferedImage.TYPE_INT_RGB);
    Graphics graphics = outputImage.getGraphics();
    
    Image image = inputImg.getScaledInstance(setWidth, setHeight, Image.SCALE_DEFAULT);
    graphics.drawImage(image, 0, 0, null);
    graphics.dispose();

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ImageIO.write(outputImage, type, out);
    ByteArrayInputStream result = new ByteArrayInputStream(out.toByteArray());
    out.close();

    return result;
}

/**
* 添加全局水印
* @param stream 
* @param content 水印内容
* @param font 水印字体--> 幼圆
* @param color 字体颜色  -->255,255,240
* @param degree 旋转 --> -40
* @return
* @throws IOException 
*/
public static InputStream imgWatermark(InputStream stream,String content,Font font,Color color,Integer degree,String type) throws IOException{
    
    
    BufferedImage inputImg = ImageIO.read(stream);
    Image image = inputImg.getScaledInstance(inputImg.getWidth(), inputImg.getHeight(), Image.SCALE_DEFAULT);
    int srcImgWidth = image.getWidth(null);
    int srcImgHeight = image.getHeight(null);
    
    BufferedImage outputImage = new BufferedImage(srcImgWidth, srcImgHeight, BufferedImage.TYPE_INT_RGB);
    Graphics2D g = outputImage.createGraphics();
    g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BILINEAR);
    g.drawImage(image.getScaledInstance(image.getWidth(null),image.getHeight(null), Image.SCALE_SMOOTH),0,0,null);
    
    if(degree!=null){
        g.rotate(Math.toRadians(degree),(double)inputImg.getWidth() / 2,(double)inputImg.getHeight() / 2);
    }
    g.setColor(color);
    g.setFont(font);
    g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.5f));
    
    int x = -srcImgWidth / 2;
    int y = -srcImgHeight / 2;
    int markWidth = font.getSize() * getTextLength(content);
    int markHeight = font.getSize();
    
    while (x < srcImgWidth * 1.5) {
        y = -srcImgHeight / 2;
        while (y < srcImgHeight * 1.5) {
            g.drawString(content, x, y);
            y += markHeight + 100;
        }
        x += markWidth + 100;
    }
    g.dispose();
    
    
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ImageIO.write(outputImage, type, out);
    ByteArrayInputStream result = new ByteArrayInputStream(out.toByteArray());
    out.close();
    return result;
}

private static int getTextLength(String text) {
    int length = text.length();
    for (int i = 0; i < text.length(); i++) {
        String s = String.valueOf(text.charAt(i));
        if (s.getBytes().length > 1) {
            length++;
        }
    }
    length = length % 2 == 0 ? length / 2 : length / 2 + 1;
    return length;
}


private static ArrayList getAutoWidthAndHeight(BufferedImage inputImg, int setWidth, int setHeight) {
    ArrayList arrayList = new ArrayList();
    int width = inputImg.getWidth();
    int height = inputImg.getHeight();
    double w = getDot2Decimal(setWidth, width);
    double h = getDot2Decimal(setHeight, height);
    if (w < h) {
        arrayList.add((int) (w * width));
        arrayList.add((int) (w * height));
    } else {
        arrayList.add((int) (h * width));
        arrayList.add((int) (h * height));
    }
    return arrayList;
}

private static double getDot2Decimal(int a, int b) {
    BigDecimal bigDecimal_1 = new BigDecimal(a);
    BigDecimal bigDecimal_2 = new BigDecimal(b);
    BigDecimal bigDecimal_result = bigDecimal_1.divide(bigDecimal_2, new MathContext(4));
    Double double1 = new Double(bigDecimal_result.toString());
    return double1;
}

public static void main(String[] args) throws Exception {

    File file = new File("D:\\ddd\\微信图片_20191029173946.jpg");

    InputStream input = new FileInputStream(file);

    // 大于1.5M在进行压缩
    InputStream result = null;
    if (input.available() > 1500000) {
        result = scaleImg(input, 1f, "jpg");
    } else {
        result = input;
    }

// Font font = new Font(“幼圆”, Font.PLAIN, 40);
// Color color = new Color(255,255,240);
// result = imgWatermark(input,“干就完了”,font,color,-40,“jpg”);

    FileOutputStream out = new FileOutputStream(new File("D:\\ddd\\4c.jpg"));
    out.write(IOUtil.toByteArray(result));
    out.close();
    result.close();
    input.close();

}

}