SPRINGMYBATIS01 Unit02： 参数值注入 、 基于注解的组件扫描

1. IOC/DI

(1)什么是IOC(Inversion Of Controll 控制反转)

对象之间的依赖关系由容器来建立。

(2)什么是DI(Dependency Injection 依赖注入

容器可以通过调用set方法或者构造器来建立对象之间的依赖关系。注：    IOC是目标，DI是手段。

(3)依赖注入的两种方式

1)方式一  set方法注入step1. 添加set方法step2. 在配置文件中，使用<property>元素来配置。

2)方式二 构造器注入step1. 添加构造器step2. 在配置文件当中，使用<constructor-arg>元素来配置。

(4)自动装配 (了解)

注：自动装配，指的是容器依据某些规则，自动建立对象之间的依赖关系。1)默认情况下，容器不会自动装配。2)设置autowire属性

(5) 注入基本类型的值

使用value属性来注入，spring容器会帮我们做一些类型的转换工作，比如将字符串转换成数字。

(6) 注入集合类型的值 (List,Set,Map,Properties)

方式一 直接注入

方式二 引用的方式注入step1. 将集合类型的值先配置成一个bean。step2. 再将这个bean注入到对应的bean里面。

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代码演示：

/spring02/pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  <modelVersion>4.0.0</modelVersion>  <groupId>welkin</groupId>  <artifactId>spring02</artifactId>  <version>0.0.1-SNAPSHOT</version>  <packaging>war</packaging>      <dependencies>        <dependency>          <groupId>org.springframework</groupId>          <artifactId>spring-webmvc</artifactId>          <version>3.2.8.RELEASE</version>      </dependency>      <dependency>          <groupId>junit</groupId>          <artifactId>junit</artifactId>          <version>4.12</version>      </dependency>  </dependencies></project>

/spring02/src/main/java/ioc

A.java

package ioc;    public class A {        private IB b;        public void setB(IB b) {            System.out.println("A's setB()");            this.b = b;        }        public A() {            System.out.println("A()");        }        public void service(){            System.out.println("A's service()");            //调用B的f1()方法            b.f1();        }    }

B.java

package ioc;public class B implements IB{        public B(){            System.out.println("B()");        }        public void f1(){            System.out.println("B's f1()");        }}

C.java

package ioc;public class C implements IB {    public void f1() {        System.out.println("C's F1()");    }    public C() {        System.out.println("C()");    }}

IB.java

package ioc;public interface IB {    public void f1();}

Computer .java

package ioc;public class Computer {    public Computer() {        System.out.println("Computer()");    }}

Maneger.java

package ioc;public class Maneger {    private Computer cp;    public Maneger() {        System.out.println("Maneger()");    }    public Maneger(Computer cp) {        System.out.println("Manager(cp)");        this.cp = cp;    }    @Override    public String toString() {        return "Maneger [cp=" + cp + "]";    }}

/spring02/src/main/java/AutoWire

Bar.java

package AutoWire;public class Bar {    private Foo foo;    public Bar() {        System.out.println("Bar()");    }    public void setFoo(Foo foo) {        System.out.println("setFoo()");        this.foo = foo;    }    @Override    public String toString() {        return "Bar [foo=" + foo + "]";    }}

Foo.java

package AutoWire;public class Foo {    public Foo() {        System.out.println("Foo()");    }}

/spring02/src/main/java/value

ExampleBean.java

package value;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.Set;public class ExampleBean {    private List<String> interest;    private Set<String> city;    private Map<String,Double> score;    private Properties db;    @Override    public String toString() {        return "ExampleBean [interest=" + interest + ", city=" + city + ", score=" + score + ", db=" + db + "]";    }    public List<String> getInterest() {        return interest;    }    public void setInterest(List<String> interest) {        this.interest = interest;    }    public Set<String> getCity() {        return city;    }    public void setCity(Set<String> city) {        this.city = city;    }    public Map<String, Double> getScore() {        return score;    }    public void setScore(Map<String, Double> score) {        this.score = score;    }    public Properties getDb() {        return db;    }    public void setDb(Properties db) {        this.db = db;    }}

InfoBean.java

package value;public class InfoBean {    private String name;    private String interest;    private double score;    private int pageSize;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getInterest() {        return interest;    }    public void setInterest(String interest) {        this.interest = interest;    }    public double getScore() {        return score;    }    public void setScore(double score) {        this.score = score;    }    public int getPageSize() {        return pageSize;    }    public void setPageSize(int pageSize) {        this.pageSize = pageSize;    }    @Override    public String toString() {        return "InfoBean [name=" + name + ", interest=" + interest + ", score=" + score + ", pageSize=" + pageSize                + "]";    }}

ValueBean.java

package value;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.Set;public class ValueBean {    private String name;    private int age;    private List<String> interest;    private Set<String> city;    private Map<String,Double> score;    private Properties db;    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 List<String> getInterest() {        return interest;    }    public void setInterest(List<String> interest) {        this.interest = interest;    }    public Set<String> getCity() {        return city;    }    public void setCity(Set<String> city) {        this.city = city;    }    public Map<String, Double> getScore() {        return score;    }    public void setScore(Map<String, Double> score) {        this.score = score;    }    public Properties getDb() {        return db;    }    public void setDb(Properties db) {        this.db = db;    }    @Override    public String toString() {        return "ValueBean [name=" + name + ", age=" + age + ", interest=" + interest + ", city=" + city + ", score="                + score + ", db=" + db + "]";    }}

/spring02/src/main/resources

autowire.xml

<?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:jdbc="http://www.springframework.org/schema/jdbc"      xmlns:jee="http://www.springframework.org/schema/jee"     xmlns:tx="http://www.springframework.org/schema/tx"    xmlns:aop="http://www.springframework.org/schema/aop"     xmlns:mvc="http://www.springframework.org/schema/mvc"    xmlns:util="http://www.springframework.org/schema/util"    xmlns:jpa="http://www.springframework.org/schema/data/jpa"    xsi:schemaLocation="        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">    <bean id="foo" class="AutoWire.Foo"/>    <!--         autowire:表示让容器自动建立对象之间的依赖关系。        byName:依据属性名查找对应的bean(就是以属性名作为bean的id来查找)，找到之后，调用set方法来建立依赖关系。        注：如果找不到，则不注入。        byType:依据属性类型来查找对应的bean,找到之后，调用set方法来建立依赖关系。        注：如果找到多个，则会出错。        constructor:与byType类似，只不过，调用构造器来注入。     -->    <bean id="bar" class="AutoWire.Bar" autowire="byType" /></beans>

config.properties

pageSize=10

ioc.xml

<?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:jdbc="http://www.springframework.org/schema/jdbc"      xmlns:jee="http://www.springframework.org/schema/jee"     xmlns:tx="http://www.springframework.org/schema/tx"    xmlns:aop="http://www.springframework.org/schema/aop"     xmlns:mvc="http://www.springframework.org/schema/mvc"    xmlns:util="http://www.springframework.org/schema/util"    xmlns:jpa="http://www.springframework.org/schema/data/jpa"    xsi:schemaLocation="        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"><!-- set方式注入 -->        <bean id="b1" class="ioc.B" />    <!--         property:让容器调用set方法来注入依赖关系。        其中name属性指定了属性名，ref指定被注入的bean的id。     -->    <bean id="a1" class="ioc.A" >       <!-- 会将属性名首字母大写，前面添加set，比如下面就是setB方法 -->        <property name="b"  ref="c1"/>    </bean>    <bean id="c1" class="ioc.C"/>    <!-- 构造器方式注入 -->    <bean id="cp1" class="ioc.Computer"/>    <bean id="mg1" class="ioc.Maneger">    <!--         constructor-arg：容器会采用构造器来建立依赖关系。        index：指定了参数的下标        ref：被注入的bean的ID     -->        <constructor-arg index="0" ref="cp1"/>    </bean></beans>

value.xml

<?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:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee"    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util"    xmlns:jpa="http://www.springframework.org/schema/data/jpa"    xsi:schemaLocation="        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">    <!-- 使用spring表达式读取其他的Bean的属性  -->    <bean id ="ib1" class="value.InfoBean">        <property name="name" value="#{vb1.name}"/>        <property name="interest" value="#{vb1.interest[1]}"/>        <property name="score" value="#{vb1.score['english']}"/>        <property name="pageSize" value="#{config.pageSize}"/>    </bean>    <!-- 注入基本类型的值 -->    <bean id="vb1" class="value.ValueBean">        <property name="name" value="关关" />        <property name="age" value="22" />        <property name="interest">            <list>                <value>台球</value>                <value>钓鱼</value>                <value>看电视</value>                <value>看电视</value>            </list>        </property>        <property name="city">            <set>                <value>北京</value>                <value>上海</value>                <value>武汉</value>                <value>武汉</value>            </set>        </property>        <property name="score">            <map>                <entry key="english" value="70" />                <entry key="math" value="90" />            </map>        </property>        <property name="db">            <props>                <prop key="username">Sally</prop>                <prop key="password">1234</prop>            </props>        </property>    </bean>    <!-- 将集合类型的值配置成一个bean -->    <!-- util:list 表示使用的是util命名空间下的 list元素。 命名空间:为了区分同名的元素而添加的前缀。 -->    <util:list id="interestBean">        <value>喝酒</value>        <value>烫头</value>        <value>抽烟</value>    </util:list>    <util:set id="cityBean">        <value>长沙</value>        <value>岳阳</value>        <value>华容</value>    </util:set>    <util:map id="scoreBean">        <entry key="math" value="80" />        <entry key="english" value="59.5" />    </util:map>    <util:properties id="dbBean">        <prop key="username">Giving</prop>        <prop key="password">test</prop>    </util:properties>    <!-- 采用引用的方式注入集合类型的值 -->    <bean id="eb1" class="value.ExampleBean">        <property name="interest" ref="interestBean" />        <property name="city" ref="cityBean" />        <property name="score" ref="scoreBean" />        <property name="db" ref="dbBean" />    </bean>    <!-- 读取.properties文件的内容 -->    <!-- location:指定属性文件的位置。 注：classpath,表示让容器依据类路径 去查找属性文件。 容器会读取指定位置的文件的内容，并且         将这些内容存放到Properties对象里面 -->    <util:properties id="config" location="classpath:config.properties" /></beans>

/spring02/src/test/java/test/TestCase.java

package test;import java.util.Properties;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import AutoWire.Bar;import ioc.A;import ioc.Maneger;import value.ExampleBean;import value.InfoBean;import value.ValueBean;public class TestCase {    @Test    // 测试 set方法注入    public void test1() {        String config = "ioc.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        A a = ac.getBean("a1", A.class);        a.service();    }    @Test    // 测试 构造器注入    public void test2() {        String config = "ioc.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        Maneger mg1 = ac.getBean("mg1", Maneger.class);        System.out.println(mg1);    }    @Test    // 测试 自动装配    public void test3() {        String config = "autowire.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        Bar bar = ac.getBean("bar", Bar.class);        System.out.println(bar);    }    @Test    // 测试 注入基本类型的值    public void test4() {        String config = "value.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        ValueBean vb1 = ac.getBean("vb1", ValueBean.class);        System.out.println(vb1);    }    @Test    // 测试 集合类型的值的注入    public void test5() {        String config = "value.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        ExampleBean eb = ac.getBean("eb1", ExampleBean.class);        System.out.println(eb);    }    @Test    // 测试 读取属性文件的内容    public void test6() {        String config = "value.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        Properties props = ac.getBean("config", Properties.class);        System.out.println(props);    }    @Test    //测试 spring表达式    public void test7(){        String config = "value.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(config);        InfoBean ib1 = ac.getBean("ib1",InfoBean.class);        System.out.println(ib1);    }}