*本事例主要讲了如下几点: 

 * 1:将图片转换为BASE64加密字符串. 

 * 2:将图片流转换为BASE64加密字符串. 

 * 3:将BASE64加密字符串转换为图片. 

 * 4:在jsp文件中以引用的方式和BASE64加密字符串方式展示图片.

首先看工具类:

1 import java.awt.image.BufferedImage;    2 import java.io.ByteArrayInputStream;    3 import java.io.ByteArrayOutputStream;    4 import java.io.File;    5 import java.io.IOException;    6 import java.io.InputStream;    7      8 import javax.imageio.ImageIO;    9     10 import sun.misc.BASE64Decoder;   11 import sun.misc.BASE64Encoder;   12     13 /**  14  * @author IluckySi  15  * @since 20150122  16  */  17 public class ImageUtil {   18     19     private static BASE64Encoder encoder = new sun.misc.BASE64Encoder();   20     private static BASE64Decoder decoder = new sun.misc.BASE64Decoder();   21     22     /**  23      * 将图片转换为BASE64加密字符串.  24      * @param imagePath 图片路径.  25      * @param format 图片格式.  26      * @return  27      */  28     public String convertImageToByte(String imagePath, String format) {   29         File file = new File(imagePath);   30         BufferedImage bi = null;   31         ByteArrayOutputStream baos = null;   32         String result = null;   33         try {   34             bi = ImageIO.read(file);   35             baos = new ByteArrayOutputStream();   36             ImageIO.write(bi, format == null ? "jpg" : format, baos);   37             byte[] bytes = baos.toByteArray();   38             result = encoder.encodeBuffer(bytes).trim();   39             System.out.println("将图片转换为BASE64加密字符串成功！");   40         } catch (IOException e) {   41             System.out.println("将图片转换为 BASE64加密字符串失败: " + e);   42         } finally {   43             try {   44                 if(baos != null) {   45                     baos.close();   46                     baos = null;   47                 }   48             } catch (Exception e) {   49                 System.out.println("关闭文件流发生异常: " + e);   50             }   51         }   52         return result;   53     }   54         55     /**  56      * 将图片流转换为BASE64加密字符串.  57      * @param imageInputStream  58      * @param format 图片格式.  59      * @return  60      */  61     public String convertImageStreamToByte(InputStream imageInputStream, String format) {   62         BufferedImage bi = null;   63         ByteArrayOutputStream baos = null;   64         String result = null;   65         try {   66             bi = ImageIO.read(imageInputStream);   67             baos = new ByteArrayOutputStream();   68             ImageIO.write(bi, format == null ? "jpg" : format, baos);   69             byte[] bytes = baos.toByteArray();   70             result = encoder.encodeBuffer(bytes).trim();   71             System.out.println("将图片流转换为BASE64加密字符串成功！");   72         } catch (IOException e) {   73             System.out.println("将图片流转换为 BASE64加密字符串失败: " + e);   74         } finally {   75             try {   76                 if(baos != null) {   77                     baos.close();   78                     baos = null;   79                 }   80             } catch (Exception e) {   81                 System.out.println("关闭文件流发生异常: " + e);   82             }   83         }   84         return result;   85     }   86         87     /**  88      * 将BASE64加密字符串转换为图片.  89      * @param base64String  90      * @param imagePath 图片生成路径.  91      * @param format 图片格式.  92      */  93     public void convertByteToImage(String base64String, String imagePath, String format) {   94         byte[] bytes = null;   95         ByteArrayInputStream bais = null;   96         BufferedImage bi = null;   97         File file = null;   98         try {   99             bytes = decoder.decodeBuffer(base64String);  100             bais = new ByteArrayInputStream(bytes);  101             bi = ImageIO.read(bais);  102             file = new File(imagePath);  103             ImageIO.write(bi, format == null ? "jpg" : format, file);  104             System.out.println("将BASE64加密字符串转换为图片成功！");  105         } catch (IOException e) {  106             System.out.println("将BASE64加密字符串转换为图片失败: " + e);  107         } finally {  108             try {  109                 if(bais != null) {  110                     bais.close();  111                     bais = null;  112                 }  113             } catch (Exception e) {  114                 System.out.println("关闭文件流发生异常: " + e);  115             }  116         }  117     }  118 }

然后看测试类：

1 import java.io.InputStream;   2     3 import com.ilucky.util.image.ImageUtil;   4     5 /**  6  * 本事例主要讲了如下几点:  7  * 1:将图片转换为BASE64加密字符串.  8  * 2:将图片流转换为BASE64加密字符串.  9  * 3:将BASE64加密字符串转换为图片. 10  * 4:在jsp文件中以引用的方式和BASE64加密字符串方式展示图片. 11  * @author IluckySi 12  * @since 20150122 13  */ 14 public class MainTest {  15    16     public static void main(String[] args) {  17         ImageUtil imageUtil = new ImageUtil();  18            19         String base64String = imageUtil.convertImageToByte("D:\\test.png", "png");  20         System.out.println(base64String);  21         imageUtil.convertByteToImage(base64String, "D:\\test2.png", "png");  22                    23         InputStream is = MainTest.class.getResourceAsStream("test.png");  24         String base64String2 = imageUtil.convertImageStreamToByte(is, "png");  25         System.out.println(base64String2);  26         imageUtil.convertByteToImage(base64String2, "D:\\test3.png", "png");  27     }  28 }

最后看jsp文件:

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