public class ATest {
  public static final String FOO = "foo";
  public static final String FOO1 = "foo1";

    String m_interval = "";
    void foo() {
      if (FOO.equals(<caret>m_interval.substring(1))) {
          System.out.println(FOO);
      } else if (FOO1.equals(m_interval.substring(1))) {
          System.out.println();
      }
    }
}