Examples of java.util.Comparator.compare()

java.util.Comparator.compare()
Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.
In the foregoing description, the notation sgn(expression) designates the mathematical signum function, which is defined to return one of -1, 0, or 1 according to whether the value of expression is negative, zero or positive.
The implementor must ensure that sgn(compare(x, y)) == -sgn(compare(y, x)) for all x and y. (This implies that compare(x, y) must throw an exception if and only if compare(y, x) throws an exception.)
The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.
Finally, the implementor must ensure that compare(x, y)==0 implies that sgn(compare(x, z))==sgn(compare(y, z)) for all z.
It is generally the case, but not strictly required that (compare(x, y)==0) == (x.equals(y)). Generally speaking, any comparator that violates this condition should clearly indicate this fact. The recommended language is "Note: this comparator imposes orderings that are inconsistent with equals." @param o1 the first object to be compared. @param o2 the second object to be compared. @return a negative integer, zero, or a positive integer as thefirst argument is less than, equal to, or greater than the second. @throws ClassCastException if the arguments' types prevent them frombeing compared by this comparator.


    public void testCompare() {
        Comparator comparator = new ToStringComparator();


        assertTrue(comparator.compare(new TestBean("a"), new TestBean("b")) < 0);
        assertTrue(comparator.compare(new TestBean("b"), new TestBean("a")) > 0);
        assertTrue(comparator.compare(new TestBean("a"), new TestBean("a")) == 0);
    }


}

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    public void testCompare() {
        Comparator comparator = new ToStringComparator();


        assertTrue(comparator.compare(new TestBean("a"), new TestBean("b")) < 0);
        assertTrue(comparator.compare(new TestBean("b"), new TestBean("a")) > 0);
        assertTrue(comparator.compare(new TestBean("a"), new TestBean("a")) == 0);
    }


}

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  public void testComparableComparator() {
    Comparator c = new ComparableComparator();
    String s1 = "abc";
    String s2 = "cde";
    assertTrue(c.compare(s1, s2) < 0);
  }


  public void testComparableComparatorIllegalArgs() {
    Comparator c = new ComparableComparator();
    Object o1 = new Object();

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  public void testComparableComparatorIllegalArgs() {
    Comparator c = new ComparableComparator();
    Object o1 = new Object();
    Object o2 = new Object();
    try {
      c.compare(o1, o2);
    }
    catch (IllegalArgumentException e) {
      return;
    }
    fail("Comparator should have thrown a cce");

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    fail("Comparator should have thrown a cce");
  }


  public void testBooleanComparatorTrueLow() {
    Comparator c = BooleanComparator.TRUE_LOW;
    assertTrue(c.compare(new Boolean(true), new Boolean(false)) < 0);
  }


  public void testBooleanComparatorTrueHigh() {
    Comparator c = BooleanComparator.TRUE_HIGH;
    assertTrue(c.compare(new Boolean(true), new Boolean(false)) > 0);

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    assertTrue(c.compare(new Boolean(true), new Boolean(false)) < 0);
  }


  public void testBooleanComparatorTrueHigh() {
    Comparator c = BooleanComparator.TRUE_HIGH;
    assertTrue(c.compare(new Boolean(true), new Boolean(false)) > 0);
    assertTrue(c.compare(Boolean.TRUE, Boolean.TRUE) == 0);
  }


  public void testPropertyComparator() {
    Dog dog = new Dog();

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  }


  public void testBooleanComparatorTrueHigh() {
    Comparator c = BooleanComparator.TRUE_HIGH;
    assertTrue(c.compare(new Boolean(true), new Boolean(false)) > 0);
    assertTrue(c.compare(Boolean.TRUE, Boolean.TRUE) == 0);
  }


  public void testPropertyComparator() {
    Dog dog = new Dog();
    dog.setNickName("mace");

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    assertTrue(c.compare(dog, dog2) == 0);
  }


  public void testNullSafeComparatorNullsLow() {
    Comparator c = NullSafeComparator.NULLS_LOW;
    assertTrue(c.compare(null, "boo") < 0);
  }


  public void testNullSafeComparatorNullsHigh() {
    Comparator c = NullSafeComparator.NULLS_HIGH;
    assertTrue(c.compare(null, "boo") > 0);

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    assertTrue(c.compare(null, "boo") < 0);
  }


  public void testNullSafeComparatorNullsHigh() {
    Comparator c = NullSafeComparator.NULLS_HIGH;
    assertTrue(c.compare(null, "boo") > 0);
    assertTrue(c.compare(null, null) == 0);
  }


  public void testCompoundComparatorEmpty() {
    Comparator c = new CompoundComparator();

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  }


  public void testNullSafeComparatorNullsHigh() {
    Comparator c = NullSafeComparator.NULLS_HIGH;
    assertTrue(c.compare(null, "boo") > 0);
    assertTrue(c.compare(null, null) == 0);
  }


  public void testCompoundComparatorEmpty() {
    Comparator c = new CompoundComparator();
    try {

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