java 图片转换工具

package com.sicdt.sicsign.web.utils;

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

import javax.imageio.ImageIO;

import org.apache.commons.io.FileUtils;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.pdf.PdfWriter;

public class MyImgUtil {

    /**
     * <br>描 述: 将图片BASE64字符串转为二进制数组
     * <br>作 者: 七脉
     * @param base64 new Image();img.src或canvas.toDataURL("image/png")
     * @return
     * @throws IOException
     */
    public static byte[] imgBase64ToBytes(String base64) {
        sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
        //因为参数base64来源不一样，需要将附件数据替换清空掉。如果此入参来自canvas.toDataURL("image/png");
        base64 = base64.replaceAll("data:image/png;base64,", "");
        //base64解码并转为二进制数组
        byte[] bytes = null;
        try {
            bytes = decoder.decodeBuffer(base64);
            for (int i = 0; i < bytes.length; ++i) {
                if (bytes[i] < 0) {// 调整异常数据
                    bytes[i] += 256;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return bytes;
    }

    /**
     *
     * <br>描 述:    图片/文件转二进制数组，这个方法有很多，只写一个
     * <br>作 者: 七脉
     * @param imgPath 图片路径
     * @return
     * @throws FileNotFoundException
     */
    public static byte[] imgToBytes(String imgPath) {
        File file = new File(imgPath);
        BufferedImage bi = null;
        ByteArrayOutputStream baos = null;
        try {
            //文件使用其他工具
            bi = ImageIO.read(file);
            baos = new ByteArrayOutputStream();
            int index = imgPath.lastIndexOf(".");
            String format = imgPath.substring(index+1);
            ImageIO.write(bi, format, baos);
            byte[] bytes = baos.toByteArray();
            baos.close();
            return bytes;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     *
     * <br>描 述:    将二进制转换为图片
     * <br>作 者: 七脉
     * @param outPath 将图片输出到哪里
     * @param savePath 保存位置
     */
    public static void bytesToImg(byte[] bytes,String savePath){
        ByteArrayInputStream baos = new ByteArrayInputStream(bytes);
        try {
            BufferedImage bi = ImageIO.read(baos);
            File file = new File(savePath);
            ImageIO.write(bi, "png", file);
            baos.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    /**
     * <br>描 述:    图片二进制数组转PDF二进制数组
     * <br>作 者: 七脉
     * @param imgBytes 图片二进制数组
     * @return
     */
    public static byte[] imgBytesToPdfBytes(byte[] imgBytes){
            byte[] bytes = null;
            Document document = new Document();
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            try {
                PdfWriter.getInstance(document, baos);
                // 设置文档的大小
                document.setPageSize(PageSize.A4);
                // 打开文档
                document.open();
                // 读取一个图片
                Image image = Image.getInstance(imgBytes);
                float imageWidth = image.getScaledWidth();
                int i = 0;
                while (imageWidth > 600) {
                    image.scalePercent(100 - i);
                    i++;
                    imageWidth = image.getScaledWidth();
                }
                image.setAlignment(Image.ALIGN_CENTER);
                // 插入一个图片
                document.add(image);
                //转二进制数组
                bytes = baos.toByteArray();
                return bytes;
            } catch (DocumentException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if(null!=baos){
                    try {
                        baos.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if(null!=document){
                    document.close();
                }
            }
            return bytes;
    }

    /**
     *
     * <br>描 述:    二进制转文件，什么样的二进制转什么样的文件
     * <br>作 者: 七脉
     * @param bytes 二进制数组
     * @param savePath 文件保存路径
     */
    public static void byteArrayToFile(byte[] bytes,String savePath){
        try {
            FileUtils.writeByteArrayToFile(new File(savePath), bytes);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws IOException {
        //bytesToImg(imgToByte("C://Users//Administrator//Desktop//test.png"),"C://Users//Administrator//Desktop//bytes2img.png");
        byteArrayToFile(imgToByte("C://Users//Administrator//Desktop//test.png"),"C://Users//Administrator//Desktop//test2.png");
    }
}