一个简单的加密/解密示例程序:import java.security.*;
import javax.crypto.*;
public class testdes {
public static void main(String[] args){
testdes my=new testdes();
my.run();
}
public void run() {
//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());
String Algorithm="DES"; //定义 加密算法,可用 DES,DESede,Blowfish
String myinfo="要加密的信息";
try {
//生成密钥
KeyGenerator keygen = KeyGenerator.getInstance(Algorithm);
SecretKey deskey = keygen.generateKey(); //加密
System.out.println("加密前的二进串:"+byte2hex(myinfo.getBytes()));
System.out.println("加密前的信息:"+myinfo);
Cipher c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.ENCRYPT_MODE,deskey);
byte[] cipherByte=c1.doFinal(myinfo.getBytes());
System.out.println("加密后的二进串:"+byte2hex(cipherByte));
//解密
c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.DECRYPT_MODE,deskey);
byte[] clearByte=c1.doFinal(cipherByte);
System.out.println("解密后的二进串:"+byte2hex(clearByte));
System.out.println("解密后的信息:"+(new String(clearByte))); }
catch (java.security.NoSuchAlgorithmException e1) {e1.printStackTrace();}
catch (javax.crypto.NoSuchPaddingException e2) {e2.printStackTrace();}
catch (java.lang.Exception e3) {e3.printStackTrace();}
}
public String byte2hex(byte[] b) //二行制转字符串
{
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();
}}javac编译通过,但执行时出错:c:\java testdes报错:Exception in method "main" java.lang.NoSuchMethodError
at javax.crypto.SunJCE_b.<clinit><DashoA6275>
at javax.crypto.KeyGenerator.getInstance<DashoA6275>
at testdes.run<testdes.java:15>
at testdes.main<testdes.java:6>
classpath都设置好了,.;%JAVA_HOME%\lib\tools.jar;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\bin;%JAVA_HOME%\jre\lib\jce.jar;%JAVA_HOME%\jre\lib\rt.jar;%JAVA_HOME%\jre\lib\ext\sunjce_provider.jar;
谁能告诉我是什么问题啊?
import javax.crypto.*;
public class testdes {
public static void main(String[] args){
testdes my=new testdes();
my.run();
}
public void run() {
//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());
String Algorithm="DES"; //定义 加密算法,可用 DES,DESede,Blowfish
String myinfo="要加密的信息";
try {
//生成密钥
KeyGenerator keygen = KeyGenerator.getInstance(Algorithm);
SecretKey deskey = keygen.generateKey(); //加密
System.out.println("加密前的二进串:"+byte2hex(myinfo.getBytes()));
System.out.println("加密前的信息:"+myinfo);
Cipher c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.ENCRYPT_MODE,deskey);
byte[] cipherByte=c1.doFinal(myinfo.getBytes());
System.out.println("加密后的二进串:"+byte2hex(cipherByte));
//解密
c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.DECRYPT_MODE,deskey);
byte[] clearByte=c1.doFinal(cipherByte);
System.out.println("解密后的二进串:"+byte2hex(clearByte));
System.out.println("解密后的信息:"+(new String(clearByte))); }
catch (java.security.NoSuchAlgorithmException e1) {e1.printStackTrace();}
catch (javax.crypto.NoSuchPaddingException e2) {e2.printStackTrace();}
catch (java.lang.Exception e3) {e3.printStackTrace();}
}
public String byte2hex(byte[] b) //二行制转字符串
{
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();
}}javac编译通过,但执行时出错:c:\java testdes报错:Exception in method "main" java.lang.NoSuchMethodError
at javax.crypto.SunJCE_b.<clinit><DashoA6275>
at javax.crypto.KeyGenerator.getInstance<DashoA6275>
at testdes.run<testdes.java:15>
at testdes.main<testdes.java:6>
classpath都设置好了,.;%JAVA_HOME%\lib\tools.jar;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\bin;%JAVA_HOME%\jre\lib\jce.jar;%JAVA_HOME%\jre\lib\rt.jar;%JAVA_HOME%\jre\lib\ext\sunjce_provider.jar;
谁能告诉我是什么问题啊?
但你的
public class testdes {
却没有:
extends Thread
或
implements Runnable
PATH=.;%JAVA_HOME%\bin