Java实现BASE64编码和解码的方法

/*** 
   * 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; 
  } 

/** 
   * @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)); 
  } 

/** 
  * 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;  
  }