base64使用

 1 public static void main(String args[]) throws Exception {
 2         InputStream in = null;
 3         byte[] data = null;
 4         in = new FileInputStream("C:\\Users\\HP\\Pictures\\unicom.jpg");
 5         data = new byte[in.available()];
 6         in.read(data);
 7         in.close();
 8         BASE64Encoder encoder = new BASE64Encoder();
 9         // 对字节数组Base64第一次编码
10         String base64Encode1 = encoder.encode(data);
11         // 对字节数组Base64再次编码
12         String base64Encode2 = encoder.encode(base64Encode1.getBytes());
13         System.out.println(base64Encode2);
14 
15         BASE64Decoder decoder = new BASE64Decoder();
16         //base64第一次解码
17         byte[] base64Decode1 = decoder.decodeBuffer(base64Encode2);
18         //Base64再次解码
19         byte[] base64Decode2 = decoder.decodeBuffer(new String(base64Decode1));
20         //  System.out.println("解码完成");
21         for(int i=0;i<base64Decode2.length;++i)
22         {
23             if(base64Decode2[i]<0)
24             {//调整异常数据
25                 base64Decode2[i]+=256;
26             }
27         }
28         //生成jpg图片
29         OutputStream out = new FileOutputStream("C:\\Users\\HP\\Pictures\\unicom2.jpg");
30         out.write(base64Decode2);
31         out.flush();
32         out.close();
33     }