Spring的javaconfig

@configuration:表示当前类是一个配置类
@Bean:容器中创建出一个对象
@PropertySource:寻找属性配置文件
@ImportResource:寻找xml配置文件
@import注解:引入另位外一个配置文件
@ComponentScan:扫描组件

代码：
pom.xml：

<?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>text</groupId>
    <artifactId>Spring02</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>


    <properties>
        <!--
            定义全局变量:变量名为project.spring.version
        -->
        <project.spring.version>5.0.0.RELEASE</project.spring.version>

    </properties>


    <dependencies>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>


        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${project.spring.version}</version>
        </dependency>


        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <!--德鲁伊连接池-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>
        <!--mysql连接驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>




    </dependencies>



    <build>

        <!--加载资源文件-->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>

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


    </build>

</project>

db.properties：

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring
jdbc.username=root
jdbc.password=admin

App.java：

package text.spring._07_javaconfig;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.sql.DataSource;

/**
 * Created by thinkpad on 2019/9/3.
 */



@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = Config.class)
public class App {



    @Autowired
    private DataSource dataSource;


    @Test
    public void tetHelloWorld() throws Exception{

        //获取容器
        AnnotationConfigApplicationContext context
                = new AnnotationConfigApplicationContext(Config.class);

        DataSource dataSource = context.getBean(DataSource.class);


        System.out.println(dataSource.getConnection());


    }


    @Test
    public void testDatasoure() throws Exception {
        System.out.println(dataSource.getConnection());
    }
}

Config.java：

package text.spring._07_javaconfig;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.*;

import javax.sql.DataSource;

/**
 * Created by thinkpad on 2019/9/3.
 */
@Configuration
@PropertySource("classpath:db.properties")
//@ImportResource()

//@Import(Config2.class)
//@ComponentScan("com.ujiuye")
public class Config {

    @Value("${jdbc.driverClassName}")
    private String driverClassname;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;


    @Bean
    public DataSource dataSource(){
        DruidDataSource data = new DruidDataSource();
        data.setDriverClassName(driverClassname);
        data.setUrl(url);
        data.setUsername(username);
        data.setPassword(password);
        return data;
    }


}

Config2.java：

package text.spring._07_javaconfig;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportResource;
import org.springframework.context.annotation.PropertySource;

import javax.sql.DataSource;

/**
 * Created by thinkpad on 2019/9/3.
 */
@Configuration
@PropertySource("classpath:db.properties")
@ImportResource()
public class Config2 {

    @Value("${jdbc.driverClassName}")
    private String driverClassname;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;


    @Bean
    public DataSource dataSource(){
        DruidDataSource data = new DruidDataSource();
        data.setDriverClassName(driverClassname);
        data.setUrl(url);
        data.setUsername(username);
        data.setPassword(password);
        return data;
    }


}