spring .properties文件的读取 mybatis连接池的配置

配置文件db.properties

url=jdbc:mysql://localhost:3306/seller_admin?useUnicode=true&characterEncoding=utf8
driver=com.mysql.jdbc.Driver
username=root
password=root
maxActive=100
maxIdle=25
maxWait=28000
defaultAutoCommit=false

继承PropertyPlaceholderConfigurer类，读取.properties文件中的参数  

public class AthenaPropertyConfigurer extends PropertyPlaceholderConfigurer {

    public void init(Properties props) throws IOException {
        String confPath = System.getProperties().getProperty("conf.path");
        if (confPath == null) {
            confPath = "/data/admin/conf";//文件路径
        }
        File file = new File(confPath);
        String[] urls = file.list((dir, name) -> name.endsWith(".properties"));
        for (int i = 0; i < urls.length; i++) {
            PropertiesLoaderUtils.fillProperties(props, new FileSystemResource(confPath + File.separator + urls[i]));
        }
    }

    @Override
    protected void loadProperties(Properties props) throws IOException {
        init(props);
        super.loadProperties(props);
    }
}

在配置文件spring-config-file.xml和servlet.xml中添加配置：

<bean id="propertyConfigurer" class="AthenaPropertyConfigurer"><!--AthenaPropertyConfigurer的路径-->
  <property name="ignoreResourceNotFound" value="true"/>
</bean>

做好上面两步之后就可以通过注解获取到.properties中的值了，例如数据库的配置。
第一种：通java类配置

@Configuration
public class DaoConfig {

    @Bean
    public BasicDataSource dataSource(
            @Value("${driver}") String driver,
            @Value("${url}") String url,
            @Value("${username}") String username,
            @Value("${password}") String password,
            @Value("${defaultAutoCommit}") Boolean defaultAutoCommit,
            @Value("${maxActive}") Integer maxActive,
            @Value("${maxIdle}") Integer maxIdle,
            @Value("${maxWait}") Long maxWait
    ) throws IOException {
　　　　　//获取配置文件中的参数
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName(driver);//数据库驱动
        dataSource.setUrl(url);//数据库地址
        dataSource.setUsername(username);//用户名称
        dataSource.setPassword(password);//密码
        dataSource.setDefaultAutoCommit(defaultAutoCommit);//是否默认自动提交回滚
        dataSource.setMaxActive(maxActive);//最大连接数，0表示没有限制
        dataSource.setMaxIdle(maxIdle);//最大等待链接数，0没有限制
        dataSource.setMaxWait(maxWait);//最大等待时间，单位：ms
        dataSource.setValidationQuery("select 1");//设置常用，MySQL默认select 1
        dataSource.setConnectionInitSqls(Collections.singletonList("set names utf8mb4"));//设置编码
        dataSource.setTestWhileIdle(true);//申请连接时检测
        dataSource.setTestOnBorrow(true);
        dataSource.setTimeBetweenEvictionRunsMillis(3600000L);//检测空闲连接
        dataSource.setMinEvictableIdleTimeMillis(18000000L);//断开空闲连接，知道最小连接数
        return dataSource;
    }

    @Bean(name = "sqlSessionFactoryBeanName")
    @Autowired
    public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource) {
        SqlSessionFactoryBean sqlFactory = new SqlSessionFactoryBean();
        sqlFactory.setDataSource(dataSource);
        sqlFactory.setTypeAliasesPackage("com.admin.server.dao.dataobject");
        sqlFactory.setConfigLocation(new ClassPathResource("com/admin/server/dao/sqlmap/sqlmap.xml"));
        ResourceArrayPropertyEditor editor = new ResourceArrayPropertyEditor();
        editor.setValue(null);
        editor.setAsText("classpath:com/admin/server/dao/sqlmap/mapping/*-mapping.xml");
        sqlFactory.setMapperLocations((Resource[]) editor.getValue());
        return sqlFactory;
    }

    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactoryBeanName");
        mapperScannerConfigurer.setBasePackage("com.admin.server.dao");
        return mapperScannerConfigurer;
    }

    @Bean
    @Autowired
    public DataSourceTransactionManager txManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    @Autowired
    public TransactionTemplate transactionTemplate(DataSourceTransactionManager txManager) {
        return new TransactionTemplate(txManager);
    }
}

第二种，直接在配置文件spring-config-file.xml中添加配置

<bean id="dataSource"class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName"value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${username}"/>
<property name="password" value="${password}" />
<property name="defaultAutoCommit" value="${defaultAutoCommit}" />
<property name="maxActive" value="${maxActive}" />
<property name="maxIdle" value="${maxIdle}" />
<property name="maxWait" value="${maxWait}" />
<property name="validationQuery" value="select 1" />
</bean>

自己在学习，说得不对的地方希望大家指出来，相互学习。