Java中的提供程序keys()方法

可以使用keys()类java.security.Provider中的方法获得所需哈希表的键的枚举。此方法不需要任何参数，它返回哈希表的键的枚举。

演示此的程序如下所示-

示例

import java.security.*;
import java.util.*;
public class Demo {
   public static void main(String[] argv) throws Exception {
      try {
         Signature sign = Signature.getInstance("DSA");
         Provider p = sign.getProvider();
         Enumeration<Object> enumeration = p.keys();
         System.out.println("The enumeration of the keys is as follows: \n");
         int x = 30;
         while (x > 0) {
            System.out.println(enumeration.nextElement());
            x--;
         }
      } catch (NoSuchAlgorithmException e) {
            System.out.println("Error!!! NoSuchAlgorithmException");
      }
   }
}

输出结果

The enumeration of the keys is as follows:
Alg.Alias.Signature.SHA1/DSA
Alg.Alias.Signature.1.2.840.10040.4.3
Alg.Alias.Signature.DSS
SecureRandom.SHA1PRNG ImplementedIn
KeyStore.JKS
Alg.Alias.MessageDigest.SHA-1
MessageDigest.SHA
KeyStore.CaseExactJKS
CertStore.com.sun.security.IndexedCollection ImplementedIn
Signature.SHA256withDSA
Alg.Alias.MessageDigest.OID.1.3.14.3.2.26
Alg.Alias.Signature.DSA
KeyFactory.DSA ImplementedIn
KeyStore.JKS ImplementedIn
AlgorithmParameters.DSA ImplementedIn
Signature.NONEwithDSA
Alg.Alias.CertificateFactory.X509
Signature.SHA256withDSA SupportedKeyClasses
CertStore.com.sun.security.IndexedCollection
Provider.id className
Alg.Alias.MessageDigest.1.3.14.3.2.26
Alg.Alias.Signature.SHA-1/DSA
KeyStore.DKS
CertificateFactory.X.509 ImplementedIn
Alg.Alias.Signature.OID.2.16.840.1.101.3.4.3.2
Alg.Alias.Signature.OID.2.16.840.1.101.3.4.3.1
Signature.SHA1withDSA KeySize
Signature.NONEwithDSA KeySize
CertPathValidator.PKIX ImplementedIn
KeyFactory.DSA