Spring IOC容器の HelloWorld

1.新建对象的项目和模块，maven项目

新建一个项目，移除原有的模块，新建一个空白的java模块!

2.通过maven导入spring对应的jar包

右键，add framework support 添加Maven支持，通过Maven导入spring对应的jar包：

<?xml version="1.0" encoding="UTF-8"?>
<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>com.crud</groupId>
    <artifactId>ssm-crud</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <junit.version>4.12</junit.version>
        <spring.version>4.3.10.RELEASE</spring.version>
        <mybatis.version>3.4.5</mybatis.version>
        <mybatis.spring.version>1.3.1</mybatis.spring.version>
        <druid.version>1.1.6</druid.version>
        <commons-dbcp.version>1.4</commons-dbcp.version>
        <jstl.version>1.2</jstl.version>
        <log4j.version>1.2.17</log4j.version>
        <fastjson.version>1.2.45</fastjson.version>
        <slf4j.version>1.7.25</slf4j.version>
        <jackson.version>2.8.9</jackson.version>
        <commons-fileupload.version>1.3.3</commons-fileupload.version>
        <commons-io.version>2.5</commons-io.version>
        <commons-codec.version>1.10</commons-codec.version>
        <aspectjweaver.version>1.8.10</aspectjweaver.version>
    </properties>


    <dependencies>
        <!-- Junit测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>

        <!-- spring包 core、web、oxm、tx、jdbc、webmvc、aop、context、test -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- mybatis核心包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <!-- mybatis  代码生成器 -->
        <dependency>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-core</artifactId>
            <version>1.3.6</version>
        </dependency>
        <!-- mybatis/spring包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>${mybatis.spring.version}</version>
        </dependency>

        <!-- 导入Mysql数据库链接jar包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.45</version>
        </dependency>
        <!--  阿里巴巴   -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>

        <!-- 导入dbcp的jar包，用来在applicationContext.xml中配置数据库 -->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>${commons-dbcp.version}</version>
        </dependency>
        <!-- JSTL标签类 -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>${jstl.version}</version>
        </dependency>
        <!-- 日志文件管理包 -->

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>

        <!--  <dependency>
              <groupId>org.apache.logging.log4j</groupId>
              <artifactId>log4j-core</artifactId>
              <version>2.3</version>
          </dependency>

          <dependency>
              <groupId>org.apache.logging.log4j</groupId>
              <artifactId>log4j-api</artifactId>
              <version>2.3</version>
          </dependency>-->
        <!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jsp-api -->
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jsp-api</artifactId>
            <version>7.0.86</version>
        </dependency>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1</version>
        </dependency>

        <!-- 格式化对象，方便输出日志 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>${fastjson.version}</version>
        </dependency>

        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <!-- json和bean之间相互转换 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>


        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson.version}</version>
        </dependency>


        <!-- 上传组件包 -->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>${commons-fileupload.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>${commons-io.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>${commons-codec.version}</version>
        </dependency>


        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>${aspectjweaver.version}</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>




    </dependencies>


    <build>
        <!--能加载 java 文件夹中的资源文件 -->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>

            <resource>
                <directory>src/main/resources</directory>
            </resource>
        </resources>

        <plugins>
            <!-- Jetty 插件  -->
            <plugin>
                <groupId>org.eclipse.jetty</groupId>
                <artifactId>jetty-maven-plugin</artifactId>
                <version>9.4.8.v20171121</version>
                <configuration>
                    <scanIntervalSeconds>1</scanIntervalSeconds>
                    <reload>automatic</reload>
                    <httpConnector>
                        <port>8080</port>
                    </httpConnector>
                    <stopKey>jettyStopKey1</stopKey>
                    <stopPort>8520</stopPort>
                    <webAppSourceDirectory>${basedir}/web</webAppSourceDirectory>
                </configuration>
            </plugin>

            <!-- Tomcat 7 插件-->
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <port>8080</port>
                    <contextReloadable>true</contextReloadable>
                    <warSourceDirectory>${basedir}/web</warSourceDirectory>
                </configuration>
            </plugin>
            <!--  打war 的插件 -->
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <configuration>
                    <warSourceDirectory>${basedir}/web</warSourceDirectory>
                </configuration>
            </plugin>

            <!-- 编译java 文件 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

将以上代码的dependcy部分复制到pom.xml中的相应位置，静静等待包的下载完毕
2.复制java1.8的插件进入pom.xml

配置resource,这样可以让我们的xml文件在指定的路径可以被读取，被粘贴的位置在build和plugins之间（build>resources=plugins)

<resources>
           <resource>
               <directory>src/main/java</directory>
               <includes>
                   <include>**/*.*</include>
               </includes>
           </resource>
           <resource>
               <directory>src/main/resources</directory>
               <includes>
                   <include>**/*.*</include>
               </includes>
           </resource>
       </resources>

3.新建实体对象类和测试类

创建javapackage，新建一个实体对象Student以及测试类
Student.java

public class Student {
    String id;
    String name;
    String stuNo;
}
//无参构造，全参构造，以及全参的get set 省略

HelloWorldTest.java

@Test
    public void test1(){
        System.out.println("hello");
    }
//运行成功，可以进行下一步

4.创建IOC容器

新建spring配置文件（spring-xxx.xml 或 applicationContext-xx.xml)
spring-beans.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"
    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-4.0.xsd">
    <!-- 使用bean元素定义一个由IOC容器创建的对象 -->
    <!-- class属性指定用于创建bean的全类名 -->
    <!-- id属性指定用于引用bean实例的标识 -->
    <bean id="student" class="com.helloworld.bean.Student">
        <!-- 使用property子元素为bean的属性赋值 -->
        <property name="studentId" value="1001"/>
        <property name="stuName" value="Tom2015"/>
        <property name="age" value="20"/>
    </bean>
</beans>

只复制这一些代码进去

Test.java

@Test
    public void test1(){
        BeanFactory beanFactory = new ClassPathXmlApplicationContext("spring-beans.xml");
        System.out.println(beanFactory);
    }

运行结果

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
org.springframework.context.support.ClassPathXmlApplicationContext@66048bfd: startup date [Thu Nov 14 17:08:33 CST 2019]; root of context hierarchy

上面的警告是因为日志我们还没有配置，下方打印出了我们的beanFactory对象

Test.java

@Test
    public void test1(){
//        BeanFactory beanFactory = new ClassPathXmlApplicationContext("spring-beans.xml");
//        System.out.println(beanFactory);
        Student student = new Student();
        student.setId("qwer");
        student.setStuNo("stu001");
        student.setName("hkx");
        System.out.println(student);
    }

运行结果

Student{id='qwer', name='hkx', stuNo='stu001'}

使用BeanFactory

Test.java

public void test1(){
        BeanFactory beanFactory = new ClassPathXmlApplicationContext("spring-beans.xml");
        Student student = (Student) beanFactory.getBean("s1");
        //此时使用BeanFactory对实体类Student进行生产，可是模板是什么呢？
        System.out.println(student);}

此时要将spring-beans.xml进行完善，告诉BeanFactory模板是什么

修改spring-beans.xml文件，在beans标签中添加以下代码

<!--name属性可以容纳诸如"/abc"这样的名称，但是id不可以，当id中的"s1"无法被找到时将寻找name中的值。-->
<!--最好是能用id就不用name-->
<!--id对应的是test类中getBean的参数-->
<!--    <bean id="s1" name="s1"></bean>-->
    <bean id="s1" class="top.leafii.springdemo.demo1helloworld.domain.Student">
</bean>

再次修改xml文件，增加一个Student类的对象student2

spring-beans.xml

<bean id="s2" class="top.leafii.springdemo.demo1helloworld.domain.Student">
        <property name="id" value="AA"></property>
        <property name="name">
            <value>yys</value>
        </property>
<!--以上两种方式无差异-->
<!--什么时候用以上的那种子标签呢？如果value里有很多很多很多文字就可以用这个方式了 增强代码的可读性-->
        <property name="stuNo" value="stu007"/>
        <property name="student" ref="s1"/>
<!--注意在类中引用对象要用ref而不是value-->
    </bean>

Test.java

BeanFactory beanFactory = new ClassPathXmlApplicationContext("spring-beans.xml");
       Student student1 = (Student) beanFactory.getBean("s1");
       Student student2 = (Student) beanFactory.getBean("s2");
       //此时使用BeanFactory对实体类Student进行生产，可是模板是什么呢？
       System.out.println("student1:"+student1);
       System.out.println("student2:"+student2);

运行结果（记得重写Student类的toString方法）

student1:Student{id='qwer', name='hkx', stuNo='stu001', student=null}
student2:Student{id='AA', name='yys', stuNo='stu007', student=Student{id='qwer', name='hkx', stuNo='stu001', student=null}}

5.注入

此时我们要想一下使用spring-beans.xml构造对象时，使用的是哪种方法，是按照参数的顺序直接进行构造方法，还是先new一个无参对象，再使用属性的set方法呢？

两种注入的方法:

Student student1 = new Student("idAAA","hkx","stu001");//构造注入
Student student = new Student();
student.setId("qwer");
student.setStuNo("stu001");
student.setName("hkx");
//setter注入

通过下图这样的测试，我们得知，使用spring-beans默认所使用的注入方法为setter注入
但是可以通过指定的方式设置使用构造注入进行注入

使用constructor-arg标签之后，不关注属性名，只关注该属性值在构造函数中的位置
此时我们放弃过时的BeanFactory,使用新的框架

Test.java

@Test
    public void test1(){
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-beans.xml");
//      BeanFactory beanFactory = new ClassPathXmlApplicationContext("spring-beans.xml");
//      Student student2 = (Student) beanFactory.getBean("s2");
        Student student3 = (Student) context.getBean("s3");
        System.out.println(student3);

    }

总结

新建对象的项目和模块，maven项目
通过maven导入spring对应的jar包
新建实体对象类和测试类

创建IOC容器
4.1 新建spring配置文件（spring-xxx.xml 或 applicationContext-xx.xml）
4.2 写spring-xxx.xml

<bean id="s1" class="top.leafii.springdemo.demo1helloworld.domain.Student">
        <property name="id" value="qwer"/>
        <property name="name">
            <value>hkx</value>
        </property>
<!--以上两种方式无差异-->
<!--什么时候用以上的那种子标签呢？如果value里有很多很多很多文字就可以用这个方式了 增强代码的可读性-->
        <property name="stuNo" value="stu001"/>
    </bean>

4.3 在实体类中添加“引用类型”的属性

<property name="student" ref="s1"/>
4.4 配置构造注入的方式

<bean id="s3" class="top.leafii.springdemo.demo1helloworld.domain.Student">
        <constructor-arg value="idCCC" index="0"/>
        <constructor-arg value="yysssy" index="1"/>
        <constructor-arg value="stu003" index="2"/>
</bean>

需要掌握以下几点：

简单类型和引用类型的配置方式：value和ref
构造注入的方式

IOC容器的创建

ApplicationContext context = new ClassPathXmlApplicationContext("spring-beans.xml");

Spring IOC容器 の HelloWorld

1.新建对象的项目和模块，maven项目

2.通过maven导入spring对应的jar包

3.新建实体对象类和测试类

4.创建IOC容器

5.注入

总结

Spring IOC容器の HelloWorld