IDEA下——Spring入门程序

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1. 创建一个maven的项目，我的项目结构如下：
   
2. 在pom文件里写下需要导入的依赖：

    <?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.abc</groupid>
       <artifactid>01-first(spring)</artifactid>
       <version>1.0-snapshot</version>
       <build>
           <plugins>
               <plugin>
                   <groupid>org.apache.maven.plugins</groupid>
                   <artifactid>maven-compiler-plugin</artifactid>
                   <configuration>
                       <source>6</source>
                      <target>6</target>
                   </configuration>
               </plugin>
           </plugins>
       </build>
       <properties>
           <project.build.sourceencoding>utf-8</project.build.sourceencoding>
           <maven.compiler.source>10</maven.compiler.source>
           <maven.compiler.target>10</maven.compiler.target>
           <spring.version>5.1.0.release</spring.version>
       </properties>
       <dependencies>
           <dependency>
               <groupid>org.springframework</groupid>
               <artifactid>spring-beans</artifactid>
               <version>${spring.version}</version>
           </dependency>
           <dependency>
               <groupid>org.springframework</groupid>
               <artifactid>spring-core</artifactid>
               <version>${spring.version}</version>
           </dependency>
           <dependency>
               <groupid>org.springframework</groupid>
               <artifactid>spring-context</artifactid>
               <version>${spring.version}</version>
           </dependency>
           <dependency>
               <groupid>org.springframework</groupid>
               <artifactid>spring-expression</artifactid>
               <version>${spring.version}</version>
           </dependency>
           <dependency>
               <groupid>org.springframework</groupid>
               <artifactid>spring-jcl</artifactid>
               <version>${spring.version}</version>
           </dependency>
           <dependency>
               <groupid>junit</groupid>
               <artifactid>junit</artifactid>
               <version>4.12</version>
               <scope>test</scope>
           </dependency>
       </dependencies>
       <build>
           <plugins>
               <plugin>
                   <artifactid>maven-compiler-plugin</artifactid>
                   <configuration>
                       <source>1.10</source>
                       <target>1.10</target>
                   </configuration>
               </plugin>
           </plugins>
       </build>
     </project>

1. 在java文件夹下新建package，在package包下新建接口及其实现类
   接口：
   public interface someservice { void dosome(); }
   实现类：

       public class someserviceimpl implements someservice {
       public someserviceimpl() {
           system.out.println("创建someserviceimpl对象");
       }
   
       @override
       public void dosome() {
           system.out.println("执行someserviceimpl里的dosome()方法");
       }
       }

2. 在resources目录下新建applicationcontext.xml文件

• 我们需要在spring容器的配置文件中进行注册该bean

• spring使用的配置文件为xml文件，当然需要引入约束文件，一般将spring的配置文件命名为applicationcontext.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"
              xsi:schemalocation="http://www.springframework.org/schema/beans
             http://www.springframework.org/schema/beans/spring-beans.xsd">    
       <!--注册servcie其造价于如下代码：   someserviceimpl someservice = new someserviceimpl();
                  其底层是通过反射机制创建的someservice对象
          object someservice = class.forname("com.abc.service.someserviceimpl").newinstance();-->
                  <bean id="someservice" class="com.abc.service.someserviceimpl"/>
   </beans>

• spring的根元素是benas显然是注册bean，子标签是bean
• 注册:<bean id="someservice" class="com.abc.service.someserviceimpl"/>
• id属性为了唯一确定一个对象，class属性里边应写类全名

1. 注册完毕后我们要在测试类中获取spring容器,而获取spring容器有两种方式。

    package com.abc.service;
    import org.junit.test;
    import org.springframework.context.applicationcontext;
    import org.springframework.context.support.classpathxmlapplicationcontext;
    import org.springframework.context.support.filesystemxmlapplicationcontext;

    public class someserviceimplttest {
         // spring容器获取的两种方式
         @test
         public void test01(){
             //在类路径下加载spring配置文件
             applicationcontext ac = new classpathxmlapplicationcontext("applicationcontext.xml");
             //在当前目录的根下加载该配置文件,路径应为文件实际存放的目录
                applicationcontext ac2 = new filesystemxmlapplicationcontext
                       ("d:\\idea-workspace\\01-first(spring)\\src\\main\\resources\\applicationcontext.xml");
                system.out.println(ac2);
          }    
        @test
        public void test02() {
             // 加载spring配置文件，创建spring容器对象
             applicationcontext ac = new classpathxmlapplicationcontext("applicationcontext.xml");
             //调用spring容器的getbean方法获取carimpl，方法参数为bean的id
             someservice service = (someservice) ac.getbean("someservice");
             service.dosome();
            }
        }

spring入门程序到此就结束了