java base64编码和解码的三种方式

方式一:使用commons-codec.jar

    /** 
         * @param bytes 
         * @return 
         */  
        public static byte[] decode(final byte[] bytes) {  
            return Base64.decodeBase64(bytes);  
        }  
      
        /** 
         * 二进制数据编码为BASE64字符串 
         * 
         * @param bytes 
         * @return 
         * @throws Exception 
         */  
        public static String encode(final byte[] bytes) {  
            return new String(Base64.encodeBase64(bytes));  
        }  

测试:

String base64String = "whuang123";  
        byte[] result = Base64.encodeBase64(base64String.getBytes()); 

方式二:通过反射使用java 中不对外公开的类

    /*** 
         * encode by Base64 
         */  
        public static String encodeBase64(byte[]input) throws Exception{  
            Class clazz=Class.forName("com.sun.org.apache.xerces.internal.impl.dv.util.Base64");  
            Method mainMethod= clazz.getMethod("encode", byte[].class);  
            mainMethod.setAccessible(true);  
             Object retObj=mainMethod.invoke(null, new Object[]{input});  
             return (String)retObj;  
        }  
        /*** 
         * decode by Base64 
         */  
        public static byte[] decodeBase64(String input) throws Exception{  
            Class clazz=Class.forName("com.sun.org.apache.xerces.internal.impl.dv.util.Base64");  
            Method mainMethod= clazz.getMethod("decode", String.class);  
            mainMethod.setAccessible(true);  
             Object retObj=mainMethod.invoke(null, input);  
             return (byte[])retObj;  
        }  

方式三:使用sun.misc.BASE64Encoder

    /** 
         * 编码 
         *  
         * @param bstr 
         * @return String 
         */  
         public static String encode(byte[] bstr) {  
         return new sun.misc.BASE64Encoder().encode(bstr);  
         }  
      
        /** 
         * 解码 
         *  
         * @param str 
         * @return string 
         */  
         public static byte[] decode(String str) {  
         byte[] bt = null;  
         try {  
         sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();  
         bt = decoder.decodeBuffer(str);  
         } catch (IOException e) {  
         e.printStackTrace();  
         }  
          
         return bt;  
         }  

测试:

    package com.jn.base64;  
      
    import junit.framework.Assert;  
      
    import org.apache.commons.codec.binary.Base64;  
      
    import com.common.util.SystemUtil;  
      
    public class BaseTest {  
        public static void main(String[] args) throws Exception {  
            String base64String = "whuang123";  
            byte[] result = Base64.encodeBase64(base64String.getBytes());  
            SystemUtil.printBytes(result);  
            byte[] result2 = SystemUtil.encode(base64String.getBytes()).getBytes();  
            System.out.println("result2:"+result2);  
            byte[] result3 = SystemUtil.encodeBase64(base64String.getBytes()).getBytes();  
            boolean isSuccess = SystemUtil.isSame(result, result2);  
            Assert.assertEquals(true, isSuccess);  
            SystemUtil.printBytes(result2);  
            SystemUtil.printBytes(result3);  
            System.out.println(isSuccess);  
        }  
    }  

运行结果:

参考:

http://hw1287789687.iteye.com/blog/1971297

http://hw1287789687.iteye.com/blog/1910853