import com.sun.security.auth.UnixNumericUserPrincipal; //导入依赖的package包/类
/**
 * Authenticate the user (first phase).
 *
 * <p> The implementation of this method attempts to retrieve the user's
 * Unix <code>Subject</code> information by making a native Unix
 * system call.
 *
 * <p>
 *
 * @exception FailedLoginException if attempts to retrieve the underlying
 *          system information fail.
 *
 * @return true in all cases (this <code>LoginModule</code>
 *          should not be ignored).
 */
public boolean login() throws LoginException {

    long[] unixGroups = null;

    ss = new UnixSystem();

    if (ss == null) {
        succeeded = false;
        throw new FailedLoginException
                            ("Failed in attempt to import " +
                            "the underlying system identity information");
    } else {
        userPrincipal = new UnixPrincipal(ss.getUsername());
        UIDPrincipal = new UnixNumericUserPrincipal(ss.getUid());
        GIDPrincipal = new UnixNumericGroupPrincipal(ss.getGid(), true);
        if (ss.getGroups() != null && ss.getGroups().length > 0) {
            unixGroups = ss.getGroups();
            for (int i = 0; i < unixGroups.length; i++) {
                UnixNumericGroupPrincipal ngp =
                    new UnixNumericGroupPrincipal
                    (unixGroups[i], false);
                if (!ngp.getName().equals(GIDPrincipal.getName()))
                    supplementaryGroups.add(ngp);
            }
        }
        if (debug) {
            System.out.println("\t\t[UnixLoginModule]: " +
                    "succeeded importing info: ");
            System.out.println("\t\t\tuid = " + ss.getUid());
            System.out.println("\t\t\tgid = " + ss.getGid());
            unixGroups = ss.getGroups();
            for (int i = 0; i < unixGroups.length; i++) {
                System.out.println("\t\t\tsupp gid = " + unixGroups[i]);
            }
        }
        succeeded = true;
        return true;
    }
}
 

import com.sun.security.auth.UnixNumericUserPrincipal; //导入依赖的package包/类
/**
 * Authenticate the user (first phase).
 *
 * <p> The implementation of this method attempts to retrieve the user's
 * Unix {@code Subject} information by making a native Unix
 * system call.
 *
 * @exception FailedLoginException if attempts to retrieve the underlying
 *          system information fail.
 *
 * @return true in all cases (this {@code LoginModule}
 *          should not be ignored).
 */
public boolean login() throws LoginException {

    long[] unixGroups = null;

    try {
        ss = new UnixSystem();
    } catch (UnsatisfiedLinkError ule) {
        succeeded = false;
        throw new FailedLoginException
                            ("Failed in attempt to import " +
                            "the underlying system identity information" +
                            " on " + System.getProperty("os.name"));
    }
    userPrincipal = new UnixPrincipal(ss.getUsername());
    UIDPrincipal = new UnixNumericUserPrincipal(ss.getUid());
    GIDPrincipal = new UnixNumericGroupPrincipal(ss.getGid(), true);
    if (ss.getGroups() != null && ss.getGroups().length > 0) {
        unixGroups = ss.getGroups();
        for (int i = 0; i < unixGroups.length; i++) {
            UnixNumericGroupPrincipal ngp =
                new UnixNumericGroupPrincipal
                (unixGroups[i], false);
            if (!ngp.getName().equals(GIDPrincipal.getName()))
                supplementaryGroups.add(ngp);
        }
    }
    if (debug) {
        System.out.println("\t\t[UnixLoginModule]: " +
                "succeeded importing info: ");
        System.out.println("\t\t\tuid = " + ss.getUid());
        System.out.println("\t\t\tgid = " + ss.getGid());
        unixGroups = ss.getGroups();
        for (int i = 0; i < unixGroups.length; i++) {
            System.out.println("\t\t\tsupp gid = " + unixGroups[i]);
        }
    }
    succeeded = true;
    return true;
}