转载的出处:https://www.cnblogs.com/wsygdb/p/7890237.html
最近研究项目,JDK是9.0.4,在IDEA上配置好JDK为9后,发现项目有错,查看发现sun.misc.BASE64Decoder和sun.misc.BASE64Encoder不可用。
错误提示:
Error:(29, 16) java: 找不到符号
符号: 类 BASE64Decoder
位置: 程序包 sun.misc
解决方法:
在和报错同目录下创建一个Base64.class,将以下代码粘贴过去
package com.img.base64;
public class Base64
{
/**
* Base64编码表。
*/
private static final char[] BASE64CODE =
{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',
'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/',};
/**
* Base64解码表。
*/
private static final byte[] BASE64DECODE =
{-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1,
-1,
-1, // 注意两个63,为兼容SMP,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 63,
-1,
63, // “/”和“-”都翻译成63。
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, 0, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13,
14, // 注意两个0:
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1,
-1, // “A”和“=”都翻译成0。
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
-1, -1, -1, -1, -1,};
private static final int HEX_255 = 0x0000ff;
private static final int HEX_16515072 = 0xfc0000;
private static final int HEX_258048 = 0x3f000;
private static final int HEX_4032 = 0xfc0;
private static final int HEX_63 = 0x3f;
private static final int HEX_16711680 = 0xff0000;
private static final int HEX_65280 = 0x00ff00;
private static final int NUMBER_TWO = 2;
private static final int NUMBER_THREE = 3;
private static final int NUMBER_FOUR = 4;
private static final int NUMBER_SIX = 6;
private static final int NUMBER_EIGHT = 8;
private static final int NUMBER_TWELVE = 12;
private static final int NUMBER_SIXTEEN = 16;
private static final int NUMBER_EIGHTEEN = 18;
/**
* 构造方法私有化,防止实例化。
*/
public Base64()
{
}
/**
* Base64编码。将字节数组中字节3个一组编码成4个可见字符。
*
* @param b
* 需要被编码的字节数据。
* @return 编码后的Base64字符串。
*/
public static String encode(byte[] b)
{
int code = 0;
// 按实际编码后长度开辟内存,加快速度
StringBuffer sb = new StringBuffer(((b.length - 1) / NUMBER_THREE) << NUMBER_TWO + NUMBER_FOUR);
// 进行编码
for (int i = 0; i < b.length; i++)
{
code |=
(b[i] << (NUMBER_SIXTEEN - i % NUMBER_THREE * NUMBER_EIGHT))
& (HEX_255 << (NUMBER_SIXTEEN - i % NUMBER_THREE * NUMBER_EIGHT));
if (i % NUMBER_THREE == NUMBER_TWO || i == b.length - 1)
{
sb.append(BASE64CODE[(code & HEX_16515072) >>> NUMBER_EIGHTEEN]);
sb.append(BASE64CODE[(code & HEX_258048) >>> NUMBER_TWELVE]);
sb.append(BASE64CODE[(code & HEX_4032) >>> NUMBER_SIX]);
sb.append(BASE64CODE[code & HEX_63]);
code = 0;
}
}
// 对于长度非3的整数倍的字节数组,编码前先补0,编码后结尾处编码用=代替,
// =的个数和短缺的长度一致,以此来标识出数据实际长度
if (b.length % NUMBER_THREE > 0)
{
sb.setCharAt(sb.length() - 1, '=');
}
if (b.length % NUMBER_THREE == 1)
{
sb.setCharAt(sb.length() - NUMBER_TWO, '=');
}
return sb.toString();
}
/**
* Base64解码。
*
* @param code
* 用Base64编码的ASCII字符串
* @return 解码后的字节数据
*/
public static byte[] decode(String code)
{
// 检查参数合法性
if (code == null)
{
return null;
}
int len = code.length();
if (len % NUMBER_FOUR != 0)
{
throw new IllegalArgumentException("Base64 string length must be 4*n");
}
if (code.length() == 0)
{
return new byte[0];
}
// 统计填充的等号个数
int pad = 0;
if (code.charAt(len - 1) == '=')
{
pad++;
}
if (code.charAt(len - NUMBER_TWO) == '=')
{
pad++;
}
// 根据填充等号的个数来计算实际数据长度
int retLen = len / NUMBER_FOUR * NUMBER_THREE - pad;
// 分配字节数组空间
byte[] ret = new byte[retLen];
// 查表解码
char ch1, ch2, ch3, ch4;
int i;
for (i = 0; i < len; i += NUMBER_FOUR)
{
int j = i / NUMBER_FOUR * NUMBER_THREE;
ch1 = code.charAt(i);
ch2 = code.charAt(i + 1);
ch3 = code.charAt(i + NUMBER_TWO);
ch4 = code.charAt(i + NUMBER_THREE);
int tmp =
(BASE64DECODE[ch1] << NUMBER_EIGHTEEN) | (BASE64DECODE[ch2] << NUMBER_TWELVE)
| (BASE64DECODE[ch3] << NUMBER_SIX) | (BASE64DECODE[ch4]);
ret[j] = (byte)((tmp & HEX_16711680) >> NUMBER_SIXTEEN);
if (i < len - NUMBER_FOUR)
{
ret[j + 1] = (byte)((tmp & HEX_65280) >> NUMBER_EIGHT);
ret[j + NUMBER_TWO] = (byte)((tmp & HEX_255));
}
else
{
if (j + 1 < retLen)
{
ret[j + 1] = (byte)((tmp & HEX_65280) >> NUMBER_EIGHT);
}
if (j + NUMBER_TWO < retLen)
{
ret[j + NUMBER_TWO] = (byte)((tmp & HEX_255));
}
}
}
return ret;
}
}
我的是项目下的这个class报错
然后在报错的class里面,把报错的部分进行类似以下的修改,创建Base64的一个对象,调用它里面的encode和decode方法就行。