Java中的 MessageDigest getProvider() 方法及示例

Java.security.MessageDigest类的getProvider()方法用于获取此消息摘要的提供者。

句法：

public final Provider getProvider()

返回值：此方法返回此 MessageDigest 的提供者。

以下是说明 getProvider() 方法的示例：

示例 1：对于算法MD5

// Java program to demonstrate
// getAlgorithm() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
    {
        try {
            // creating object of MessageDigest
            MessageDigest msd
                = MessageDigest.getInstance("MD5");
  
            // getting provider used in object msd
            // using getAlgorithm() method
            Provider pro = msd.getProvider();
  
            // display the provider
            System.out.println("Provider : " + pro);
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown : " + e);
        }
        catch (ProviderException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

Provider : SUN version 1.8

示例 2：对于算法SHA-256

// Java program to demonstrate
// getAlgorithm() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
    {
        try {
            // creating object of MessageDigest
            MessageDigest msd
                = MessageDigest.getInstance("SHA-256");
  
            // getting provider used in object msd
            // using getAlgorithm() method
            Provider pro = msd.getProvider();
  
            // display the provider
            System.out.println("Provider : " + pro);
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown : " + e);
        }
        catch (ProviderException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

Provider : SUN version 1.8

参考： https://docs.oracle.com/javase/9/docs/api/ Java/security/MessageDigest.html#getAlgorithm–