Java的提供程序 entrySet() 方法和示例

Java.security.Provider类的entrySet()方法用于返回此 Provider 中包含的属性条目的不可修改的 Set 视图。

句法：

public Set entrySet()

返回值：此方法返回此映射中包含的映射的集合视图

下面是说明elements()方法的示例：

示例 1：

// Java program to demonstrate
// entrySet() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
    {
        // Declaring int value i
        int i = 10;
  
        try {
            // creating the object of SecureRandom
            SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
  
            // getting the Provider of the SecureRandom sr
            // by using method getProvider()
            Provider provider = sr.getProvider();
  
            // Declaring the variable of set type
            Set > set;
  
            // getting unmodifiable Set view of the property entries
            set = provider.entrySet();
  
            // Creating the object of iterator to iterate set
            Iterator iter = set.iterator();
  
            // printing the set elements
            System.out.println("unmodifiable Set view : \n ");
            while (i > 0) {
                System.out.println("Value is : " + iter.next());
                i--;
            }
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

unmodifiable Set view : 
 
Value is : Alg.Alias.Signature.SHA1/DSA=SHA1withDSA
Value is : Alg.Alias.Signature.1.2.840.10040.4.3=SHA1withDSA
Value is : Alg.Alias.Signature.DSS=SHA1withDSA
Value is : SecureRandom.SHA1PRNG ImplementedIn=Software
Value is : KeyStore.JKS=sun.security.provider.JavaKeyStore$DualFormatJKS
Value is : Alg.Alias.MessageDigest.SHA-1=SHA
Value is : MessageDigest.SHA=sun.security.provider.SHA
Value is : KeyStore.CaseExactJKS=sun.security.provider.JavaKeyStore$CaseExactJKS
Value is : CertStore.com.sun.security.IndexedCollection ImplementedIn=Software
Value is : Signature.SHA256withDSA=sun.security.provider.DSA$SHA256withDSA

示例 2：

// Java program to demonstrate
// entrySet() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        // Declaring int value i
        int i = 10;
  
        try {
            // creating the object of  KeyPairGenerator
            KeyPairGenerator sr = KeyPairGenerator.getInstance("DSA", "SUN");
  
            // getting the Provider of the KeyPairGenerator sr
            // by using method getProvider()
            Provider provider = sr.getProvider();
  
            // Declaring the variable of set type
            Set > set;
  
            // getting unmodifiable Set view of the property entries
            set = provider.entrySet();
  
            // Creating the object of iterator to iterate set
            Iterator iter = set.iterator();
  
            // printing the set elements
            System.out.println("unmodifiable Set view : \n ");
            while (i > 0) {
                System.out.println("Value is : " + iter.next());
                i--;
            }
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

unmodifiable Set view : 
 
Value is : Alg.Alias.Signature.SHA1/DSA=SHA1withDSA
Value is : Alg.Alias.Signature.1.2.840.10040.4.3=SHA1withDSA
Value is : Alg.Alias.Signature.DSS=SHA1withDSA
Value is : SecureRandom.SHA1PRNG ImplementedIn=Software
Value is : KeyStore.JKS=sun.security.provider.JavaKeyStore$DualFormatJKS
Value is : Alg.Alias.MessageDigest.SHA-1=SHA
Value is : MessageDigest.SHA=sun.security.provider.SHA
Value is : KeyStore.CaseExactJKS=sun.security.provider.JavaKeyStore$CaseExactJKS
Value is : CertStore.com.sun.security.IndexedCollection ImplementedIn=Software
Value is : Signature.SHA256withDSA=sun.security.provider.DSA$SHA256withDSA