SpringIOC之加载属性

一.注解方式加载属性properties

1.数据库的配置文件

driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
url=jdbc:sqlserver://127.0.0.1:1433;DatabaseName=MidnightSun
user=sa
password=abc123456*
#定义初始连接数
initialSize=0
#定义最大连接数
maxActive=20
#定义最大空闲
maxIdle=20
#定义最小空闲
minIdle=1
#定义最长等待时间
maxWait=60000

2.扫描包

@PropertySource(value = {"classpath:jdbc.properties"},ignoreResourceNotFound = false)
public class ApplicationConfig {
}

3.测试类

 public static void main(String []y){
        BeanTest beanTest = new BeanTest();
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfig.class);
        String url = context.getEnvironment().getProperty("url");
        System.out.print(url);

4.下面是项目结构

二.注解方式加载属性文件，解析${}表达式

1.属性文件配置

现在maven中添加jar

 <dependency>
      <groupId>commons-dbcp</groupId>
      <artifactId>commons-dbcp</artifactId>
      <version>1.4</version>
    </dependency>

package com.hly.spring.pojo.springBean;

import org.apache.commons.dbcp.BasicDataSourceFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;

import javax.sql.DataSource;
import java.util.Properties;

/**
 * @author :hly
 * @date :2018/5/11
 */
@ComponentScan
public class DataSourceBean {

    @Value("${driver}")
    private String driver = null;
    @Value("${url}")
    private String url = null;
    @Value("${user}")
    private String user = null;
    @Value("${password}")
    private String password = null;

    @Bean(name = "dataSource")
    public DataSource getDataSource() {
        Properties props = new Properties();
        props.setProperty("driver", driver);
        props.setProperty("url", url);
        props.setProperty("user", user);
        props.setProperty("password", password);
        DataSource dataSource = null;
        try {
            dataSource = BasicDataSourceFactory.createDataSource(props);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("url:"+url);
        return dataSource;

    }
}

2.解析占位符的配置

package com.hly.spring.pojo.springBean;

import com.hly.spring.ServiceImpl.RoleServiceImpl;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;

/**
 * @author :hly
 * @date :2018/5/10
 */

@ComponentScan(basePackages = {"com.hly.spring.pojo.springBean"})
@PropertySource(value = {"classpath:jdbc.properties"},ignoreResourceNotFound =  true)
public class ApplicationConfig {
    //spring能够解析属性占位符，没有这一句将不会解析${url}
    @Bean
    public PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer(){
        return new PropertySourcesPlaceholderConfigurer();
    }
}

3.测试类

import com.hly.spring.pojo.springBean.ApplicationConfig;
//import com.hly.spring.pojo.springBean.PojoConfig;
import com.hly.spring.pojo.springBean.DataSourceBean;
import com.hly.spring.pojo.springBean.Role;
import com.hly.spring.pojo.springIOC.JuiceMaker;
import com.hly.spring.service.RoleService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.stereotype.Component;

import javax.sql.DataSource;

/**
 * @author :hly
 * @date :2018/5/10
 */
@Component
public class BeanTest { 
    public static void main(String[] y) {
        
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfig.class,DataSourceBean.class);
        //String url = context.getEnvironment().getProperty("url");
        DataSource dataSource = (DataSource) context.getBean("dataSource");
        System.out.println(dataSource);        
    }
}