Java MessageDigest isEqual()用法及代码示例

java.security.MessageDigest类的isEqual()方法用于测试两个消息摘要是否相等。

用法:

public static boolean
  isEqual(byte[] digesta, byte[] digestb)

参数：此方法需要2个字节的数组进行比较。

返回值：此方法提供布尔值，如果两个摘要相等，则为true，否则为false。

下面是说明isEqual()方法的示例：

示例1:对于相等的摘要值

// Java program to demonstrate 
// isEqual() method 
  
import java.security.*; 
import java.util.*; 
  
public class GFG1 { 
    public static void main(String[] argv) 
    { 
        try { 
  
            // creating object of MessageDigest 
            MessageDigest msd1 
                = MessageDigest.getInstance("SHA-256"); 
  
            // creating object of MessageDigest 
            MessageDigest msd2 
                = MessageDigest.getInstance("SHA-256"); 
  
            // getting provider used in object msd 
            // using getAlgorithm() method 
            boolean status 
                = MessageDigest 
                      .isEqual(msd1.digest(), 
                               msd2.digest()); 
  
            // check the condition 
            if (status) 
                System.out.println("msd1 is equals to msd2"); 
            else
                System.out.println("msd1 is not equals to msd2"); 
        } 
  
        catch (NoSuchAlgorithmException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
        catch (ProviderException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

输出：

msd1 is equals to msd2

示例2:对于不相等的摘要值

// Java program to demonstrate 
// isEqual() method 
  
import java.security.*; 
import java.util.*; 
  
public class GFG1 { 
    public static void main(String[] argv) 
    { 
        try { 
  
            // creating object of MessageDigest 
            MessageDigest msd1 
                = MessageDigest.getInstance("MD5"); 
  
            // creating object of MessageDigest 
            MessageDigest msd2 
                = MessageDigest.getInstance("SHA-256"); 
  
            // getting provider used in object msd 
            // using getAlgorithm() method 
            boolean status 
                = MessageDigest.isEqual(msd1.digest(), 
                                        msd2.digest()); 
  
            // check the condition 
            if (status) 
                System.out.println("msd1 is equals to msd2"); 
            else
                System.out.println("msd1 is not equals to msd2"); 
        } 
  
        catch (NoSuchAlgorithmException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
        catch (ProviderException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

输出：

msd1 is not equals to msd2

参考： https://docs.oracle.com/javase/9/docs/api/java/security/MessageDigest.html#isEqual-byte:A-byte:A-

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注：本文由纯净天空筛选整理自RohitPrasad3大神的英文原创作品 MessageDigest isEqual() method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。