Java中的 KeyStore getCertificateChain() 方法及示例

Java.security.KeyStore类的getCertificateChain()方法用于为请求的别名提供证书链。 .

句法：

public final Certificate[]
  getCertificateChain(String alias)
  throws KeyStoreException

参数：此方法接受一个参数别名，该别名是别名的名称。

返回值：此方法返回所请求别名的证书链（如果存在）。

异常：如果您不初始化此密钥库，此方法将引发KeyStoreException 。

注意：本文中的所有程序都不会在在线 IDE 上运行，因为不存在“privatekey”密钥库。您可以在系统上的Java编译器上检查此代码。要检查此代码，请在您的系统上创建一个密钥库“privatekey”并设置您自己的密钥库密码以访问该密钥库。

以下是说明getCertificateChain()方法的示例：

示例 1：

// Java program to demonstrate
// getCertificate() method
  
import java.security.*;
import java.security.cert.*;
import java.util.*;
import java.io.*;
  
public class GFG {
    public static void main(String[] argv)
    {
  
        try {
  
            // creating the object of KeyStore
            // and getting instance
            // By using getInstance() method
            KeyStore sr = KeyStore.getInstance("JKS");
  
            // Keystore password is required
            // to access Keystore
            char[] pass = ("123456").toCharArray();
  
            // creating and initializing
            // object of InputStream
            InputStream is
                = new FileInputStream(
                    "f:/java/private key.store");
  
            // initializing keystore object
            sr.load(is, pass);
  
            // getting the certificate
            // using getCertificate() method
            Certificate[] certchain
                = sr.getCertificateChain("ftpkey");
  
            // display the result
            System.out.println(
                "Type of certificate at index 0 : "
                + certchain[0].getType());
        }
  
        catch (Exception e) {
  
            System.out.println(e);
        }
    }
}

输出：

Type of certificate at index 0 : X.509

示例 2：对于KeyStoreException

// Java program to demonstrate
// getCertificate() method
  
import java.security.*;
import java.security.cert.*;
import java.util.*;
import java.io.*;
  
public class GFG {
    public static void main(String[] argv)
    {
        try {
  
            // creating the object of KeyStore
            // and getting instance
            // By using getInstance() method
            KeyStore sr
                = KeyStore.getInstance("JKS");
  
            // initializing keystore object
            // sr.load(is, pass);
  
            // getting the certificate
            // using getCertificate() method
            Certificate[] certchain
                = sr.getCertificateChain("ftpkey");
  
            // display the result
            System.out.println(
                "Type of certifacte at index 0 : "
                + certchain[0].getType());
        }
        catch (Exception e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

Exception thrown :
 java.security.KeyStoreException:
 Uninitialized keystore

参考： https://docs.oracle.com/javase/9/docs/api/ Java/security/KeyStore.html#getCertificateChain-java.lang.String-