Spring框架的基本入门知识笔记（1）

Spring的概念

Spring是开源的轻量级框架
1.核心：
AOP：面向切面编程，扩展功能不需要修改源代码实现
IOC：控制反转
2.一站式框架
在JavaWeb三层框架中每一层都有相对应的解决技术
Web层：SpringMVC
Service：IOC
Dao层：MyBatis
版本：4.1.3

package pojo;

import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

/**
*
*这个注解相当于<bean id ="person" class = "pojo.Person"/>
*通过注解配置IOC
*/
//@Component(value="person")
//@Scope(value="prototype")
public class Person {
/**
* @Value赋值
*
*/
@Value(value="John")
private String name;
@Value(value="20")
private int age;
private String[] hobby;
private List<String> hobby1;

public Person(String name, int age, String[] hobby, List<String> hobby1) {
super();
this.name = name;
this.age = age;
this.hobby = hobby;
this.hobby1 = hobby1;
}

public List<String> getHobby1() {
return hobby1;
}

public void setHobby1(List<String> hobby1) {
this.hobby1 = hobby1;
}

public Person(String name, int age, String[] hobby) {
super();
this.name = name;
this.age = age;
this.hobby = hobby;
}

public String[] getHobby() {
return hobby;
}

public void setHobby(String[] hobby) {
this.hobby = hobby;
}

public Person() {

}

public Person(String name, int age) {
super();
this.name = name;
this.age = age;
}

@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + ", hobby=" + Arrays.toString(hobby) + ", hobby1=" + hobby1
+ "]";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}

public void run(){
System.out.println("run......");
}
}

3.创建Spring配置文件，配置要创建对象相应的类
(1).Spring核心配置文件名称和文职是不固定的，建议放在src下，名称官方建议applicationContext。xml
(2).引入schema约束

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> 
</beans>

（3）.需要配置创建对象相应的类
在<beans></beans>标签内配置

<!--
id 为Bean 起名字，唯一，必须以字母开始
name 没有ID用name
单例的.........单例设计模式 懒汉式 饿汉式 两种方式的区别
scope：
prototype :多例
默认是单例    singleton
使用类的无参数构造方法创建：要求类当中要有无参的构造方法
-->
<bean id="person" class="pojo.Person" scope="prototype"></bean>

4.测试（代码仅用于测试）
创建一个JUnit测试
代码：

package test;

import static org.junit.Assert.*;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import pojo.Car;
import pojo.Person;

public class IOCTest {

@Test
public void test() {
//加载配置文件
ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
//创建对象
Person p = (Person) context.getBean("person");
p.run();

}

}