Spring浅探

时间:2022-05-17 10:42:47

  热度最大的框架,它也称为业务层框架。Spring这个框架的诞生,给程序员揭示了两个主要的思想:Ioc,Aop;

  最近的网页架构可以分为这样。

  Spring浅探

  传统结构中,每个层都得new出依赖层的类进行一些本层操作,而Spring的出现使得这些层与层的依赖关系变得不那么紧致。所有的需要新建的类都由Spring的bean工厂提供。控制权限被反转了,所以称为控制反转(Inversion of Control)。

  而在业务层有很多模块,为了使每个模块更专注于自己的工作,并且不用考虑模块间的耦合,Spring提出了Aop的思想。类与类间的关系除了继承多态,没有定义平行的关系,而Aop弥补了类间关系,使得切面实现业务又丰富又简单。

Spring浅探

  Ioc范例

package IoC_AOP;

public interface Person {
public void speak();
}
package IoC_AOP;

public class Chinese implements Person{
private String name;
private String age;
public Chinese(){ }
public Chinese(String name, String age) {
super();
this.name = name;
this.age = age;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getAge() {
return age;
} public void setAge(String age) {
this.age = age;
} @Override
public void speak() {
// TODO Auto-generated method stub
System.out.println("I'm Chinese,my name is "+this.name+" ,my age is "+this.age); } }
package IoC_AOP;

public class American implements Person{
private String name;
private String age;
public American(){ }
public American(String name, String age) {
super();
this.name = name;
this.age = age;
} public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
@Override
public void speak() {
// TODO Auto-generated method stub
System.out.println("I'm American,my name is "+this.name+" ,my age is "+this.age);
} }
    public void IocTest(){
Injection in = new Injection();
Person p1 = in.proxy1("zhangsan", "18");
Person p2 = in.proxy2("tom", "19");
p1.speak();
p2.speak();
}

   Aop思想原理,通过使用动态代理来实现。

package IoC_AOP;

public interface interface1 {
public void doSomething();
}
package IoC_AOP;

public class subject implements interface1{
public void doSomething(){
System.out.println("hello i'm doing my jobs");
}
}
package IoC_AOP;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method; public class proxySubject implements InvocationHandler{ private Object proxied;
public proxySubject(Object proxied){
this.proxied = proxied;
}
public void setProxied(Object proxied) {
this.proxied = proxied;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// TODO Auto-generated method stub
//执行方法之前可以做一些操作 //执行目标方法
method.invoke(proxied, args);
//之后可以执行一些操作
return null;
} }
        subject real = new subject();
interface1 proxySubject = (interface1)Proxy.newProxyInstance(interface1.class.getClassLoader(),
new Class[]{interface1.class},
new proxySubject(real));
proxySubject.doSomething();
proxy:  指代我们所代理的那个真实对象
method:  指代的是我们所要调用真实对象的某个方法的Method对象
args:  指代的是调用真实对象某个方法时接受的参数

  Spring的配置

    下载spring-framework-3.2.0.RELEASE,在官网下载,然后再下载commons-logging-1.2。

    添加到buildpath。下载下来的包的lib下,同一个jar包有三份。

    Spring浅探

    只要导入jar就行。

    Spring浅探

    然后导入commons-loggin的jar包。

    src下新建applicationContext.xml配置文件。配置文件的bean代表加载一个类,通过Spring的工厂生产出来并注入到应用的类。    

<?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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"
default-autowire="byName" default-lazy-init="true">
<bean id="chinese" class="Beans.Chinese">
<property name="name">
<value>sss</value>
</property>
<property name="age">
<value>18</value>
</property>
</bean>
<bean id="america" class="Beans.American">
<property name="name">
<value>xxx</value>
</property>
<property name="age">
<value>19</value>
</property>
</bean> </beans>

  书写范例 

package Beans;

public interface Person {
public void speak();
}
package Beans;

public class Chinese  implements Person{
private String name;
private int age; 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;
} @Override
public void speak() {
// TODO Auto-generated method stub
System.out.println("I'm Chinese,my name "+this.name+",my age "+this.age); } }
package Beans;

public class American implements Person{
private String name;
private String age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
@Override
public void speak() {
// TODO Auto-generated method stub
System.out.println("I'm American,my name "+this.name+",my age "+this.age);
} }

  使用Junit包进行测试。  

package JunitTest;

import org.junit.Test;
import org.springframework.context.*;
import org.springframework.context.support.ClassPathXmlApplicationContext; import Beans.Person; public class Test1 {
@Test
public void TestSpringMethod(){
ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
Person p1=(Person)context.getBean("chinese");
p1.speak();
p1=(Person)context.getBean("america");
p1.speak(); }
}

Spring浅探

  时日尚浅,没有经验,日后加倍努力。