/**
 * mainメソッド実装クラスをテストする基底クラス。
 */
public abstract class AbstractMainTester {
  private static final String ARGS_DELIMITER = " ";
  protected static final String LINE_SEPARATOR = System.getProperty("line.separator");
  private static final PrintStream stdOut = System.out;
  private static final PrintStream stdErr = System.err;
  private static final SecurityManager securityManager = System.getSecurityManager();

  /**
   * 正常終了確認
   *
   * @return 標準出力
   */
  protected String invorkeMainNomal(Class<?> cl, String arg, int exitCode) {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    System.setOut(new PrintStream(out));

    invorkeMain(cl, arg, exitCode);

    System.setOut(stdOut);
    return out.toString();
  }

  /**
   * 異常終了確認
   *
   * @return 標準エラー出力
   */
  protected String invorkeMainError(Class<?> cl, String arg, int exitCode) {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    System.setErr(new PrintStream(out));

    invorkeMain(cl, arg, exitCode);

    System.setErr(stdOut);
    return out.toString();
  }

  /**
   * mainメソッド実行
   */
  private void invorkeMain(Class<?> cl, String arg, int exitCode) {
    System.setSecurityManager(new TestSecurityManager());
    try {
      Method m = cl.getMethod("main", String[].class);
      m.invorke(null, new Object[] { arg.split(ARGS_DELIMITER) });
    } catch (InvocationTargetException ite) {
      assertThat(((ExitException)ite.getTargetException()).getStatus(), is(exitCode));
    } catch (Exception e) {
      throw RuntimeException(e);
    }
  System.setSecurityManager(securityManager);
  }
}