无参构造

xml中

<bean id="userDao" class="com.wjb.dao.impl.UserDaoImpl" scope="singleton" init-method="init" destroy-method="destory"></bean>

test

package com.wjb.test;

import com.wjb.dao.UserDao;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTest {
    @Test
    //测试scope属性
    public void test1(){
        ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserDao userDao1 = (UserDao) app.getBean("userDao");
        System.out.println(userDao1);


    }

}