《一头扎进Spring4》学习笔记（二）Spring 之 ioc 详解

第一节 Spring ioc 简介

IOC（控制反转：Inverse of Control），又称作依赖注入，是一种重要的面向对象编程的法则来削减计算机程序的耦合问题，也是轻量级的Spring框架的核心。

第二节 Spring ico 实例

1、接口类

1 public interface Tester {
2   public void test();
3 }

2、实体类继承接口类

 1 public class Lisi implements Tester{
 2     public void test(){
 3         System.out.println("李四-测试程序");
 4     }
 5 }
 6 
 7 public class ZhangSan implements Tester{
 8     public void test(){
 9         System.out.println("张三-测试程序");
10     }
11 }

3、控制类

public class JavaWork {
    
    private Tester tester;
    
    public void setTester(Tester tester) {
        this.tester = tester;
    }

    public void doTest(){        
        tester.test();
    }
}

4、beans.xml，Spring管理bean

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans
 5         http://www.springframework.org/schema/beans/spring-beans.xsd">
 6 
 7     <bean id="zhangsan" class="com.java1234.service.ZhangSan"></bean>
 8     
 9     <bean id="lisi" class="com.java1234.service.Lisi"></bean>
10     
11     <bean id="javaWork" class="com.java1234.service.JavaWork">
12         <property name="tester" ref="lisi"></property>
13     </bean>
14   
15 </beans>

property标签设置参数，ref 设置会自动调用JavaWork的set方法给tester赋值

5、测试类

1 public class Test2 {
2 　　
3     public static void main(String[] args) {
4         ApplicationContext ac=new ClassPathXmlApplicationContext("beans.xml");
5         JavaWork javaWork=(JavaWork)ac.getBean("javaWork");
6         javaWork.doTest();
7     }
8 }

第三节装配一个bean

第四节依赖注入

1、属性注入

2、构造函数注入（通过类型，通过索引，联合使用）

3、工厂方法注入（非静态工厂，静态工厂）

4、泛型依赖注入

5、实例：

实体类People

 1 package com.java1234.entity;
 2 
 3 public class People {
 4 
 5     private int id;
 6     private String name;
 7     private int age;
 8     
 9     public People() {
10         super();
11         // TODO Auto-generated constructor stub
12     }
13         
14     public People(int id, String name, int age) {
15         super();
16         this.id = id;
17         this.name = name;
18         this.age = age;
19     }
20 
21     public int getId() {
22         return id;
23     }
24     public void setId(int id) {
25         this.id = id;
26     }
27     public String getName() {
28         return name;
29     }
30     public void setName(String name) {
31         this.name = name;
32     }
33     public int getAge() {
34         return age;
35     }
36     public void setAge(int age) {
37         this.age = age;
38     }
39 
40     @Override
41     public String toString() {
42         return "People [id=" + id + ", name=" + name + ", age=" + age + "]";
43     }
44     
45 }

非静态工厂类

 1 package com.java1234.factory;
 2 import com.java1234.entity.People;
 3 
 4 public class PeopleFactory {
 5 
 6     public People createPeople(){
 7         People p=new People();
 8         p.setId(5);
 9         p.setName("小七");
10         p.setAge(77);
11         return p;
12     }
13 }

静态工厂类

 1 package com.java1234.factory;
 2 import com.java1234.entity.People;
 3 
 4 public class PeopleFactory2 {
 5 
 6     public static People createPeople(){
 7         People p=new People();
 8         p.setId(8);
 9         p.setName("小八");
10         p.setAge(88);
11         return p;
12     }
13 }

beans.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans
 5         http://www.springframework.org/schema/beans/spring-beans.xsd">
 6 
 7     <bean id="people" class="com.java1234.entity.People"></bean>
 8     
 9     <bean id="people2" class="com.java1234.entity.People">
10         <property name="id" value="1"></property>
11         <property name="name" value="张三"></property>
12         <property name="age" value="11"></property>
13     </bean>
14     
15     <bean id="people3" class="com.java1234.entity.People">
16         <constructor-arg type="int" value="2"></constructor-arg>
17         <constructor-arg type="String" value="李四"></constructor-arg>
18         <constructor-arg type="int" value="22"></constructor-arg>
19     </bean>
20     
21     <bean id="people4" class="com.java1234.entity.People">
22         <constructor-arg index="0" value="3"></constructor-arg>
23         <constructor-arg index="1" value="王五"></constructor-arg>
24         <constructor-arg index="2" value="55"></constructor-arg>
25     </bean>
26     
27     <bean id="people5" class="com.java1234.entity.People">
28         <constructor-arg index="0" type="int" value="4"></constructor-arg>
29         <constructor-arg index="1" type="String" value="招六"></constructor-arg>
30         <constructor-arg index="2" type="int" value="66"></constructor-arg>
31     </bean>
32     
33     <bean id="peopleFactory" class="com.java1234.factory.PeopleFactory"></bean>
34     
35     <bean id="people7" factory-bean="peopleFactory" factory-method="createPeople"></bean>
36   
37       <bean id="people8" class="com.java1234.factory.PeopleFactory2" factory-method="createPeople"></bean>
38 </beans>

　　注：

　　　　1) 属性注入 property[name,value]

　　　　2) 构造函数注入 constructor-arg[type|index,value]

　　　　3) 工厂注入非静态工厂先声明工厂bean,再通过 factory-bean、factory-method 引用

　　　　　　　　　　静态工厂直接指定工厂类class，再 factory-method

测试类

 1 package com.java1234.test;
 2 import org.springframework.context.ApplicationContext;
 3 import org.springframework.context.support.ClassPathXmlApplicationContext;
 4 import com.java1234.entity.People;
 5 
 6 public class Test2 {
 7 
 8     public static void main(String[] args) {
 9         ApplicationContext ac=new ClassPathXmlApplicationContext("beans.xml");
10         People people=(People)ac.getBean("people");
11         System.out.println(people);
12         
13         // 属性注入
14         People people2=(People)ac.getBean("people2");
15         System.out.println(people2);
16         
17         // 构造方法注入
18         People people3=(People)ac.getBean("people3");
19         System.out.println(people3);
20         
21         People people4=(People)ac.getBean("people4");
22         System.out.println(people4);
23         
24         People people5=(People)ac.getBean("people5");
25         System.out.println(people5);
26         
27         // 工厂方法注入
28         People people7=(People)ac.getBean("people7");
29         System.out.println(people7);
30         
31         People people8=(People)ac.getBean("people8");
32         System.out.println(people8);
33     }
34 }

第五节注入参数

1、基本类型值

2、注入 bean

3、内部 bean

4、null 值

5、级联属性

6、集合类型属性

7、实例

实体类People.java

 1 package com.java1234.entity;
 2 
 3 import java.util.ArrayList;
 4 import java.util.HashMap;
 5 import java.util.HashSet;
 6 import java.util.List;
 7 import java.util.Map;
 8 import java.util.Properties;
 9 import java.util.Set;
10 
11 public class People {
12 
13     private int id;
14     private String name;
15     private int age;
16     private Dog dog;
17     private List<String> hobbies=new ArrayList<String>();
18     private Set<String> loves=new HashSet<String>();
19     private Map<String,String> works=new HashMap<String,String>();
20     private Properties addresses=new Properties();
21     
22     public People() {
23         super();
24         // TODO Auto-generated constructor stub
25     }
26     
27     public People(int id, String name, int age) {
28         super();
29         this.id = id;
30         this.name = name;
31         this.age = age;
32     }
33 
34     public Set<String> getLoves() {
35         return loves;
36     }
37 
38     public void setLoves(Set<String> loves) {
39         this.loves = loves;
40     }
41 
42     public List<String> getHobbies() {
43         return hobbies;
44     }
45     public void setHobbies(List<String> hobbies) {
46         this.hobbies = hobbies;
47     }
48     public Map<String, String> getWorks() {
49         return works;
50     }
51     public void setWorks(Map<String, String> works) {
52         this.works = works;
53     }
54 
55     public Properties getAddresses() {
56         return addresses;
57     }
58     public void setAddresses(Properties addresses) {
59         this.addresses = addresses;
60     }
61 
62     public Dog getDog() {
63         return dog;
64     }
65     public void setDog(Dog dog) {
66         this.dog = dog;
67     }
68 
69     public int getId() {
70         return id;
71     }
72     public void setId(int id) {
73         this.id = id;
74     }
75     public String getName() {
76         return name;
77     }
78     public void setName(String name) {
79         this.name = name;
80     }
81     public int getAge() {
82         return age;
83     }
84     public void setAge(int age) {
85         this.age = age;
86     }
87 
88     @Override
89     public String toString() {
90         return "People [id=" + id + ", name=" + name + ", age=" + age
91                 + ", dog=" + dog + ", hobbies=" + hobbies + ", loves=" + loves
92                 + ", works=" + works + ", addresses=" + addresses + "]";
93     }
94 
95 
96     
97 }

实体类Dog.java

 1 package com.java1234.entity;
 2 
 3 public class Dog {
 4 
 5     private String name;
 6 
 7     public String getName() {
 8         return name;
 9     }
10 
11     public void setName(String name) {
12         this.name = name;
13     }    
14     
15 }

beans.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans
 5         http://www.springframework.org/schema/beans/spring-beans.xsd">
 6 
 7     
 8     <bean id="people1" class="com.java1234.entity.People">
 9         <property name="id" value="1"></property>
10         <property name="name" value="张三"></property>
11         <property name="age" value="11"></property>
12     </bean>
13     
14     <bean id="dog1" class="com.java1234.entity.Dog">
15         <property name="name" value="Jack"></property>
16     </bean>
17     
18     <bean id="people2" class="com.java1234.entity.People">
19         <property name="id" value="1"></property>
20         <property name="name" value="张三"></property>
21         <property name="age" value="11"></property>
22         <property name="dog" ref="dog1"></property>
23     </bean>
24     
25     <bean id="people3" class="com.java1234.entity.People">
26         <property name="id" value="1"></property>
27         <property name="name" value="张三"></property>
28         <property name="age" value="11"></property>
29         <property name="dog">
30             <bean class="com.java1234.entity.Dog">
31                 <property name="name" value="Tom"></property>
32             </bean>
33         </property>
34     </bean>
35     
36     <bean id="people4" class="com.java1234.entity.People">
37         <property name="id" value="1"></property>
38         <property name="name" value="张三"></property>
39         <property name="age" value="11"></property>
40         <property name="dog">
41             <null></null>
42         </property>
43     </bean>
44     
45     <!-- <bean id="people5" class="com.java1234.entity.People">
46         <property name="id" value="1"></property>
47         <property name="name" value="张三"></property>
48         <property name="age" value="11"></property>
49         <property name="dog.name" value="Jack2"></property>
50     </bean> -->
51     
52     <bean id="people6" class="com.java1234.entity.People">
53         <property name="id" value="1"></property>
54         <property name="name" value="张三"></property>
55         <property name="age" value="11"></property>
56         <property name="dog" ref="dog1"></property>
57         <property name="hobbies">
58             <list>
59                 <value>唱歌</value>
60                 <value>跳舞</value>
61             </list>
62         </property>
63         <property name="loves">
64             <set>
65                 <value>唱歌2</value>
66                 <value>跳舞2</value>
67             </set>
68         </property>
69         <property name="works">
70             <map>
71                 <entry>
72                     <key><value>上午</value></key>
73                     <value>写代码</value>
74                 </entry>
75                 <entry>
76                     <key><value>下午</value></key>
77                     <value>测试代码</value>
78                 </entry>
79             </map>
80         </property>
81         <property name="addresses">
82             <props>
83                 <prop key="address1">aaaaa</prop>
84                 <prop key="address2">bbbbb</prop>
85             </props>
86         </property>
87     </bean>
88     
89 </beans>

测试类Junit test case

 1 package com.java1234.test;
 2 
 3 import org.junit.Before;
 4 import org.junit.Test;
 5 import org.springframework.context.ApplicationContext;
 6 import org.springframework.context.support.ClassPathXmlApplicationContext;
 7 
 8 import com.java1234.entity.People;
 9 
10 public class T {
11 
12     private ApplicationContext ac;
13 
14     @Before
15     public void setUp() throws Exception {
16         ac=new ClassPathXmlApplicationContext("beans.xml");
17     }
18 
19     // 基本类型值
20     @Test
21     public void test1() {
22         People people=(People)ac.getBean("people1");
23         System.out.println(people);
24     }
25     
26     // 注入bean
27     @Test
28     public void test2() {
29         People people=(People)ac.getBean("people2");
30         System.out.println(people);
31     }
32     
33     
34     // 内部bean
35     @Test
36     public void test3() {
37         People people=(People)ac.getBean("people3");
38         System.out.println(people);
39     }
40     
41     // 注入null
42     @Test
43     public void test4() {
44         People people=(People)ac.getBean("people4");
45         System.out.println(people);
46     }
47     
48     // 级联属性
49     @Test
50     public void test5() {
51         People people=(People)ac.getBean("people5");
52         System.out.println(people);
53     }
54     
55     // 注入集合
56     @Test
57     public void test6() {
58         People people=(People)ac.getBean("people6");
59         System.out.println(people);
60     }
61 }

第六节 Spring 自动装配

通过配置 default-autowire 属性，Spring IOC容器可以自动为程序注入bean；默认是no，不启动自动装配；default-autowire 的类型有 byName,byType,constructor;

byName:通过名称进行自动匹配；

byType:根据类型进行自动匹配；

constructor:和byType类似，只不过它是根据构造方法注入而言的，根据类型，自动注入。

建议：自动装配机制慎用，它屏蔽了装配细节，容易产生潜在的错误。

第七节方法注入

Spring bean 作用域默认是单例 singleton；可以通过配置 prototype 实现多例。

方法注入 lookup-method

第八节方法替换

第九节 bean之间的关系

1、继承(abstract="true"、parent="beanid")

2、依赖(depends-on="beanid")

3、引用

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans
 5         http://www.springframework.org/schema/beans/spring-beans.xsd">
 6     
 7     <bean id="dog" class="com.java1234.entity.Dog">
 8         <property name="name" value="jack"></property>
 9     </bean>
10     
11     <bean id="abstractPeople" class="com.java1234.entity.People" abstract="true">
12         <property name="className" value="高三5班"></property>
13         <property name="age" value="19"></property>
14     </bean>
15     
16     <bean id="zhangsan" parent="abstractPeople" depends-on="autority">
17         <property name="id" value="1"></property>
18         <property name="name" value="张三"></property>
19     </bean>
20     
21     <bean id="lisi" parent="abstractPeople">
22         <property name="id" value="2"></property>
23         <property name="name" value="李四"></property>
24         <property name="age" value="20"></property>
25         <property name="dog" ref="dog"></property>
26     </bean>
27     
28     
29     <bean id="autority" class="com.java1234.service.Authority"></bean>
30 </beans>

第十节 bean 作用范围

1、singleton Spring IOC 容器中仅有一个 bean 实例，bean 已单例的方式存在；

2、prototype 每次从容器中调用 bean 时，都返回一个新的实例；

3、request 每次http 请求都会创建一个新的bean;

4、session 同一个 http session 共享一个 bean；

5、global session 同一个全局 session 共享一个 bean，一般用于portlet应用环境；

6、application 同一个 application 共享一个 bean;