getCanonicalName getSimpleName getName 区别与应用

接口:

package com.test;

public interface Fruit {

}

 

 

一个实现类:

package com.test;

public class Apple implements Fruit {

}

 

基本测试类:

package com.test;

import java.util.ArrayList;
import java.util.List;

public class TestName {
	public static void main(String[] args) {
		Fruit apple=new Apple();
		System.out.println(apple.getClass().getCanonicalName());//返回com.test.Apple
		System.out.println(apple.getClass().getSimpleName());//Apple
		System.out.println(apple.getClass().getName());//返回com.test.Apple
		
		Apple[] arrApple=new Apple[]{};
		System.out.println(arrApple.getClass().getCanonicalName());//返回com.test.Apple[]
		System.out.println(arrApple.getClass().getSimpleName());//返回Apple[]
		System.out.println(arrApple.getClass().getName());//返回[Lcom.test.Apple;
		
		System.out.println(String.class.getCanonicalName());//返回java.lang.String
		System.out.println(String.class.getSimpleName());//返回String
		System.out.println(String.class.getName());//返回java.lang.String
		
		System.out.println(int.class.getCanonicalName());//返回int
		System.out.println(int.class.getSimpleName());//返回int
		System.out.println(int.class.getName());//返回int
		
		Apple a1=new Apple();
		Apple a2=new Apple();
		List<Apple> appleList=new ArrayList<Apple>();
		appleList.add(a1);
		appleList.add(a2);
		System.out.println(appleList.getClass().getCanonicalName());//返回java.util.ArrayList
		System.out.println(appleList.getClass().getSimpleName());//返回ArrayList
		System.out.println(appleList.getClass().getName());//返回java.util.ArrayList
		
	}
}

 

 

实际应用: hql的泛型查询

 

public <T> List<T> getRecords(Class<T> c,Date startDate,Date endDate){
	    StringBuilder hql = new StringBuilder("select t from ");
	    hql.append(c.getCanonicalName());
	    hql.append(" t where t.statTime>=:startTime and t.statTime<:endTime ");

	    Query query = sessionFactory.getCurrentSession().createQuery(hql.toString());
	    query.setParameter("startTime", startDate);
	    query.setParameter("endTime", endDate);
        
	    return query.list();
	}
}