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