Java中的提供程序get()方法

可以使用类java.security.Provider中的get()方法获取键所映射到的值。此方法需要一个参数，即需要其值的键。它返回键所映射的值；如果不存在键所映射的值，则返回null。

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) {
      try {
         SecureRandom sRandom = SecureRandom.getInstance("SHA1PRNG");
         Provider p = sRandom.getProvider();
         Set<Object> set = p.keySet();
         Iterator i = set.iterator();
         int x = 30;
         while (x > 0) {
            Object val = p.get(i.next());
            System.out.println(val);
            x--;
         }
      } catch (NoSuchAlgorithmException e) {
         System.out.println("Error!!! NoSuchAlgorithmException");
      }
   }
}

上面程序的输出如下-

输出结果

SHA1withDSA
SHA1withDSA
SHA1withDSA
Software
sun.security.provider.JavaKeyStore$DualFormatJKS
SHA
sun.security.provider.SHA
sun.security.provider.JavaKeyStore$CaseExactJKS
Software
sun.security.provider.DSA$SHA256withDSA
SHA
SHA1withDSA
Software
Software
Software
sun.security.provider.DSA$RawDSA
X.509
java.security.interfaces.DSAPublicKey|java.security.interfaces.DSAPrivateKey
sun.security.provider.certpath.IndexedCollectionCertStore
sun.security.provider.Sun
SHA
SHA1withDSA
sun.security.provider.DomainKeyStore$DKS
Software
SHA256withDSA
SHA224withDSA
1024
1024
Software
sun.security.provider.DSAKeyFactory