将图片转成base64字符串并在JSP页面显示的Java代码

 *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:

import java.awt.image.BufferedImage;  import java.io.ByteArrayInputStream;  import java.io.ByteArrayOutputStream;  import java.io.File;  import java.io.IOException;  import java.io.InputStream;  import javax.imageio.ImageIO;  import sun.misc.BASE64Decoder;  import sun.misc.BASE64Encoder;  /**  * @author IluckySi  * @since 20150122  */  public class ImageUtil {      private static BASE64Encoder encoder = new sun.misc.BASE64Encoder();      private static BASE64Decoder decoder = new sun.misc.BASE64Decoder();      /**      * 将图片转换为BASE64加密字符串.      * @param imagePath 图片路径.      * @param format 图片格式.      * @return      */      public String convertImageToByte(String imagePath, String format) {          File file = new File(imagePath);          BufferedImage bi = null;          ByteArrayOutputStream baos = null;          String result = null;          try {              bi = ImageIO.read(file);              baos = new ByteArrayOutputStream();              ImageIO.write(bi, format == null ? "jpg" : format, baos);              byte[] bytes = baos.toByteArray();              result = encoder.encodeBuffer(bytes).trim();              System.out.println("将图片转换为BASE64加密字符串成功！");          } catch (IOException e) {              System.out.println("将图片转换为 BASE64加密字符串失败: " + e);          } finally {              try {                  if(baos != null) {                      baos.close();                      baos = null;                  }              } catch (Exception e) {                  System.out.println("关闭文件流发生异常: " + e);              }          }          return result;      }      /**      * 将图片流转换为BASE64加密字符串.      * @param imageInputStream      * @param format 图片格式.      * @return      */      public String convertImageStreamToByte(InputStream imageInputStream, String format) {          BufferedImage bi = null;          ByteArrayOutputStream baos = null;          String result = null;          try {              bi = ImageIO.read(imageInputStream);              baos = new ByteArrayOutputStream();              ImageIO.write(bi, format == null ? "jpg" : format, baos);              byte[] bytes = baos.toByteArray();              result = encoder.encodeBuffer(bytes).trim();              System.out.println("将图片流转换为BASE64加密字符串成功！");          } catch (IOException e) {              System.out.println("将图片流转换为 BASE64加密字符串失败: " + e);          } finally {              try {                  if(baos != null) {                      baos.close();                      baos = null;                  }              } catch (Exception e) {                  System.out.println("关闭文件流发生异常: " + e);              }          }          return result;      }      /**      * 将BASE64加密字符串转换为图片.      * @param base64String      * @param imagePath 图片生成路径.      * @param format 图片格式.      */      public void convertByteToImage(String base64String, String imagePath, String format) {          byte[] bytes = null;          ByteArrayInputStream bais = null;          BufferedImage bi = null;          File file = null;          try {              bytes = decoder.decodeBuffer(base64String);              bais = new ByteArrayInputStream(bytes);              bi = ImageIO.read(bais);              file = new File(imagePath);              ImageIO.write(bi, format == null ? "jpg" : format, file);              System.out.println("将BASE64加密字符串转换为图片成功！");          } catch (IOException e) {              System.out.println("将BASE64加密字符串转换为图片失败: " + e);          } finally {              try {                  if(bais != null) {                      bais.close();                      bais = null;                  }              } catch (Exception e) {                  System.out.println("关闭文件流发生异常: " + e);              }          }      }  }  

然后看测试类：

import java.io.InputStream;  import com.ilucky.util.image.ImageUtil;  /**  * 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.  * @author IluckySi  * @since 20150122  */  public class MainTest {      public static void main(String[] args) {          ImageUtil imageUtil = new ImageUtil();          String base64String = imageUtil.convertImageToByte("D:\\test.png", "png");          System.out.println(base64String);          imageUtil.convertByteToImage(base64String, "D:\\test2.png", "png");          InputStream is = MainTest.class.getResourceAsStream("test.png");          String base64String2 = imageUtil.convertImageStreamToByte(is, "png");          System.out.println(base64String2);          imageUtil.convertByteToImage(base64String2, "D:\\test3.png", "png");      }  }  

最后看jsp文件:

    <!DOCTYPE html>      <html>        <head>          <title>index.html</title>          <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">          <meta http-equiv="description" content="this is my page">          <meta http-equiv="content-type" content="text/html; charset=UTF-8">        </head>        <body>          <!--           data表示取得数据的协定名称,image/png是数据类型名称,base64 是数据的编码方法,          逗号后面是image/png文件base64编码后的数据.           data:text/css;base64,base64编码的CSS代码           data:text/javascript,Javascript代码           data:text/javascript;base64,base64编码的Javascript代码           data:image/gif;base64,base64编码的gif图片数据           data:image/png;base64,base64编码的png图片数据           data:image/jpeg;base64,base64编码的jpeg图片数据           data:image/x-icon;base64,base64编码的icon图片数据            -->          <img src="test.png"/>          <img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAYAAABzenr0AAAFYklEQVR42sVXfUyUdRz/8XKhMZQO                  7nmeuwMFwrBEVJqgDOcUHZvNuTarrdKam0zdKrckAy4goowxbaM5hE1yjVVzLjLRokBFz2qsQPGF                  F8vmamtkL4s4OHDy6ff5EQcXx91hf/jHB777fj8v3+d57p7nOQFA3EuoPxcLhV90SlxziOSeUrHd                  WRz5fv1uc1fl03OGizdGgmBd/5K5mzNyyO0M4EkEXqBAiI58Ed9WEFp1+MXYm1vW68hKM7AwJR5W                  mx3RZqsCa/Y4I4dcaqilx10t0PGqCOssEjuvH7H9vW1zEgzNgK5ZYVh02HUN86w65tvGwJo9zhRH                  cqmhlh70mtEC7a8Ie2ep6dPfW5eM3OnbhMo9S6GbLV6h04Eccqmhlh70omdQC3TsFbbLZaYL/W2Z                  wA+PYbQ9B780rUJu1nxoMZaAC5BDLjXU0oNe9KS33wXkqRKXXguv+as1HejOxYhzNdwS+G4NjlUs                  U0cX7+cscEYOudRQSw960ZPezPC9QIE69dv6Pk4exLX1GDm/Cu5z2Qojzmy4WrOxZUOSPELNz9Fr                  ikMuNR699KInvZkx/sH0WqB9rzCuH5j7Mzrk1uel8HQW3GcmgK+y4axOR0qCVX7gpoazxxk55E7W                  0oue9GYGs7wXKFCnP7+/cdEovs7GUHMm3C0rvHD7jMTZFSjYugAW89RvAXuckUPuf/X0pDczmMVM                  zwJyI8v3lVFX7pzLxMiXGXB/sdwncDoDvfXLkJFqh1WbuBSs2eOMnOn09GYGs5g5eYHcXw/HAWcz                  MfRZOtwSQz7APloexcHdD0GLnVhAlzV7nPnT8j8zmMVMzwKdjtCy/qPJuN0kSY1L/OL250tw61ga                  Nqy0Q7doCqzZ4yygXmYwi5meBa6Wmk4NNaRgpDEVQ8cX+YVbAk2L0VCcrL52BGv23AG0hMqQWcz0                  LNBTHtGFkw9D4UQQkLxR+X/LujiF0RMz0xIqc3yBb4sifmp+80G0lCcFhWYJZ0USDu6ar8C6OUit                  0sssZnoWaNhh+tFqGIg3dM9p9QvJM5t1vP1cvALrmWiZxUzPAidfMLWlJBjqZhKMiRarY+UiAzer                  5ymwZi8Y7dgNywAzPQuc3xNet3Ypv8+Bn3Y0sUqTQ3k24MM4BdZW3f9zYuKeoYNZzPQscNkRsv35                  1WbExhoBDXT5zN+4XMcfNVYMv2dTYM0eZ4H0zGAWMz0L9JaK1P1PRQ7EWa0Bn3aJdh2NL2vAEQ2u                  2jGwZo+zQHq7zJBZrusyc9IZEOEX8sM/yFxokafI8LO9jrx1GgaqY+CujYHr0BhYs5eXoynO9Kff                  ADOc+eEfyUyT19Owp0SsKd0U5eYrlU+xvMaLk3S0OcxAbTRcB73BHmdpSWNcn5dPejNDZq2d8jiW                  G4W07Q39JCctVr3T+br2ZY+bcac6CoPvzoGryhvscUaOr88CPenNDGb5fCPqKha2o3kRF1MTKfA+                  +uxHNNx4IwrDVZFwveMbnJFD7uSzQC960psZft8Je4rFkzXPzh5eME+HTTfUs94mbxx1W+cCVbMw                  uH82XNOAM3LIpUZppQe96EnvoN6K5TXaVfPMbCxO1BAVbeCJzBj89tYsDO+/DwOVEX5BDrmbpYZa                  etCLnkG/ll8qEqK7WOQe32lybs54AKd23I/RA+EYqDAFBXJPSg219KAXPWf8y+iKQxhXHaLyRklI                  363yUAzsC8OghGtfqE9wRg651FBLj7v/aTb+ul4oUi4VipIuh+i+WSKG+spC8Gd5CPr/BWv2OJOc                  Hsl9XWoW/v/fht5LhLUXiARZb71cJOquFIlv5BH2EqzZ40xyEsm9OJMfp/cS/wC6xRqbyM2GFQAA                  AABJRU5ErkJggg=="/>         </body>      </html>  

部署项目，启动服务器,访问jsp页面,会看到浏览器上有两张一样的图片.本文转自：http://www.open-open.com/code/view/1437973465238