spring注解配置方式（一）环境以代码准备

先准备代码相关
1.先准备相关代码。下面贴工程的pom文件

<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.gee</groupId>
  <artifactId>springframework-demo</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <spring.version>5.0.2.RELEASE</spring.version>
    </properties>

      <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
    
        <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-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
    </dependencies>
    
    <build>
        <plugins>
            <!-- 指定maven编译的jdk的版本 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

2.源码自行准备,工程使用的spring版本为5.0.2
3.项目准备
3.1分别建立controller,service,entity几个包，工程结构，如下图所示。

image.png

controller的代码

@Controller
@RequestMapping(value = "/hello")
public class HelloController {
    @Autowired
    private HelloService helloService;
}

service的代码

public interface HelloService {
    public String sayHello();
}

serviceImpl的代码

@Service
public class HelloServiceImp implements HelloService{
    @Override
    public String sayHello() {
        return "say hello";
    }
}

最后测试该方法，代码如下

@Configuration
@ComponentScan(basePackages = "com.gee")
public class Config {
    
    public static void main(String args[]) {
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(Config.class);
        System.out.println(applicationContext.getBean(HelloService.class).sayHello());
    }
}

执行main方法，最后输出一个"say hello "