eclipse2020-R-12、Spring-5.3.2-dist.zip、Tomcat9.0、commons-logging-1.2.jar
src文件夹中创建包、类和配置文件:
Spring配置文件:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- 将指定类TestDaoImpl配置给Spring,让Spring创建其实例 -->
<bean id="test" class="dao.TestDaoImpl" />
</beans>
dao包下的ITestDao接口:
package dao;
public interface ITestDao {
void sayHello();
}
ITestDao接口的实现子类TestDaoImpl类:
package dao;
public class TestDaoImpl implements ITestDao{
@Override
public void sayHello() {
System.out.println("Hello! Spring!");
}
}
test包下的Test测试类:
package test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import dao.ITestDao;
public class Test {
public static void main(String[] args) {
// 初始化Spring容器ApplicationContext,加载配置文件
// @SuppressWarnings抑制警告的关键字,有泛型未指定类型
@SuppressWarnings("resource")
ApplicationContext appCon = new ClassPathXmlApplicationContext("config/applicationContext.xml");
// 通过容器获取test实例
ITestDao tt = (ITestDao) appCon.getBean("test"); // test为配置文件中的id
tt.sayHello();
}
}
输出结果:
这样就完成了Spring程序的初始应用。