在搭建项目环境时出现了以下编译错误:
Access restriction: The constructor SunJCE() is not accessible due to restriction on required library J:\jdk\jre\lib\ext\sunjce_provider.jar
访问限制:由于J:\jdk\jre\lib\ext\sunjce_provider.jar库的限制,SunJCE() 构造函数不可访问。
在网上搜了一下,解决办法是修改编译选项,方法如下:Window -> Preferences -> Java -> Compiler -> Errors/Warnings -> Deprecated and restricted API -> Forbidden reference (access rules) -> Warnings或者Ignore即可。
样例程序
package des;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
public class ThreeDes {
/**
* 在java中调用sun公司提供的3DES加密解密算法时,需要使用到$JAVA_HOME/jre/lib/目录下如下的4个jar包:
* jce.jar security/US_export_policy.jar security/local_policy.jar
* ext/sunjce_provider.jar
*/
private static final String Algorithm = "DESede"; // 定义加密算法,可用
// DES,DESede,Blowfish
// keybyte为加密密钥,长度为24字节
// src为被加密的数据缓冲区(源)
public static byte[] encryptMode(byte[] keybyte, byte[] src) {
try {
// 生成密钥
SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);
// 加密
Cipher c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.ENCRYPT_MODE, deskey);
return c1.doFinal(src);// 在单一方面的加密或解密
} catch (java.security.NoSuchAlgorithmException e1) {
// TODO: handle exception
e1.printStackTrace();
} catch (javax.crypto.NoSuchPaddingException e2) {
e2.printStackTrace();
} catch (java.lang.Exception e3) {
e3.printStackTrace();
}
return null;
}
// keybyte为加密密钥,长度为24字节
// src为加密后的缓冲区
public static byte[] decryptMode(byte[] keybyte, byte[] src) {
try {
// 生成密钥
SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);
// 解密
Cipher c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.DECRYPT_MODE, deskey);
return c1.doFinal(src);
} catch (java.security.NoSuchAlgorithmException e1) {
// TODO: handle exception
e1.printStackTrace();
} catch (javax.crypto.NoSuchPaddingException e2) {
e2.printStackTrace();
} catch (java.lang.Exception e3) {
e3.printStackTrace();
}
return null;
}
// 转换成十六进制字符串
public static String byte2Hex(byte[] b) {
String hs = "";
String stmp = "";
for (int n = 0; n < b.length; n++) {
stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
if (stmp.length() == 1) {
hs = hs + "0" + stmp;
} else {
hs = hs + stmp;
}
if (n < b.length - 1)
hs = hs + ":";
}
return hs.toUpperCase();
}
public static void main(String[] args) {
// TODO Auto-generated method stub
// 添加新安全算法,如果用JCE就要把它添加进去
Security.addProvider(new com.sun.crypto.provider.SunJCE());
final byte[] keyBytes = { 0x11, 0x22, 0x4F, 0x58, (byte) 0x88, 0x10, 0x40, 0x38, 0x28, 0x25, 0x79, 0x51, (byte) 0xCB,
(byte) 0xDD, 0x55, 0x66, 0x77, 0x29, 0x74, (byte) 0x98, 0x30, 0x40, 0x36, (byte) 0xE2 }; // 24字节的密钥
String szSrc = "This is a 3DES test. 测试";
System.out.println("加密前的字符串:" + szSrc);
byte[] encoded = encryptMode(keyBytes, szSrc.getBytes());
System.out.println("加密后的字符串:" + new String(encoded));
byte[] srcBytes = decryptMode(keyBytes, encoded);
System.out.println("解密后的字符串:" + (new String(srcBytes)));
}
}