In Java: What is the difference between: Object o1= .... o1.getClass().getSimpleName(); o1.getClass().getName(); o1.getClass().getCanonicalName();

DifferenceClassNamesTest.java

    /**
    In Java: What is the difference between:
    Object o1= ....
    o1.getClass().getSimpleName();
    o1.getClass().getName();
    o1.getClass().getCanonicalName();
    **/
    @Test
    public void testNames() throws Exception {
        //primative
        System.out.println(int.class.getName());   // int
        System.out.println(int.class.getCanonicalName());  // int
        System.out.println(int.class.getSimpleName()); // int

        System.out.println();

        //class
        System.out.println(String.class.getName());   // java.lang.String
        System.out.println(String.class.getCanonicalName()); // java.lang.String
        System.out.println(String.class.getSimpleName()); // String

        System.out.println();

        //inner class
        System.out.println(HashMap.SimpleEntry.class.getName()); // java.util.AbstractMap$SimpleEntry
        System.out.println(HashMap.SimpleEntry.class.getCanonicalName());  // java.util.AbstractMap.SimpleEntry
        System.out.println(HashMap.SimpleEntry.class.getSimpleName());  // SimpleEntry

        System.out.println();

        //anonymous inner class
        System.out.println(new Serializable(){}.getClass().getName());  // com.ailk.ecs.esf.base.cache.ConcurrCacheITest$1
        System.out.println(new Serializable(){}.getClass().getCanonicalName()); // null
        System.out.println(new Serializable(){}.getClass().getSimpleName());  // (blank string)
    }