package com.oumyye.圖片;import java.awt.image.BufferedImage;    import java.io.ByteArrayInputStream;    import java.io.ByteArrayOutputStream;    import java.io.File;    import java.io.IOException;       import javax.imageio.ImageIO;       import sun.misc.BASE64Decoder;    import sun.misc.BASE64Encoder;       public class TestImageBinary {        static BASE64Encoder encoder = new sun.misc.BASE64Encoder();        static BASE64Decoder decoder = new sun.misc.BASE64Decoder();                public static void main(String[] args) {            System.out.PRintln(getImageBinary());                        base64StringToImage(getImageBinary());        }            /**         * 將圖片轉換成二進制         * @return         */    static String getImageBinary(){            File f = new File("e:/1.jpg");                   BufferedImage bi;            try {                bi = ImageIO.read(f);                ByteArrayOutputStream baos = new ByteArrayOutputStream();                ImageIO.write(bi, "jpg", baos);                byte[] bytes = baos.toByteArray();                                return encoder.encodeBuffer(bytes).trim();            } catch (IOException e) {                e.printStackTrace();            }            return null;        }                /**     * 將二進制轉換為圖片     * @param base64String     */    static void base64StringToImage(String base64String){            try {                byte[] bytes1 = decoder.decodeBuffer(base64String);                                ByteArrayInputStream bais = new ByteArrayInputStream(bytes1);                BufferedImage bi1 =ImageIO.read(bais);                File w2 = new File("e://QQ.jpg");//可以是jpg,png,gif格式                ImageIO.write(bi1, "jpg", w2);//不管輸出什么格式圖片，此處不需改動            } catch (IOException e) {                e.printStackTrace();            }        }       } 

需要導入sun.misc.BASE64Decoder.jar包

導入以后在代碼中有錯誤提示可以忽略