code: public final static String getDefaultType() {
          String kstype;
          kstype = AccessController.doPrivileged(new PrivilegedAction<String>() {
              public String run() {
                  return Security.getProperty(KEYSTORE_TYPE);
              }
          });
          if (kstype == null) {
              kstype = "jks";
          }
          return kstype;
      }
docs: Returns the default keystore type as specified in the Java security
  properties file, or the string
  &quot;jks&quot; (acronym for &quot;Java keystore&quot;)
  if no such property exists.
  The Java security properties file is located in the file named
  &lt;JAVA_HOME&gt;/lib/security/java.security.
  &lt;JAVA_HOME&gt; refers to the value of the java.home system property,
  and specifies the directory where the JRE is installed.
  
  <p>The default keystore type can be used by applications that do not
  want to use a hard-coded keystore type when calling one of the
  <code>getInstance</code> methods, and want to provide a default keystore
  type in case a user does not specify its own.
  
  <p>The default keystore type can be changed by setting the value of the
  "keystore.type" security property (in the Java security properties
  file) to the desired keystore type.
  
  @return the default keystore type as specified in the
  Java security properties file, or the string &quot;jks&quot;
  if no such property exists.