spring boot in @ConfigurationProperties use

　　Project development, we sometimes want the profile information, and automatically reading package entity classes, like this, we use the code in which more convenient. We can use @ConfigurationProperties, the configuration information of entity class used to automatic packaging. Wherein the configuration information in a configuration file or the configuration center, for example Nacos.

Profile (center) of the following information:

liaowenhui.datasource：
　　validationQuery: SELECT 1
　　jdbcUrl:jdbc:mysql://192.168.xx.xx:3306/xxx?useUnicode=true&characterEncoding=UTF-8
　　jdbcUserName: liaowenhui
　　jdbcUserPassword: liaowenhui

Entity class defines a load profile information to DataSourceProperties.java

// configuration information from the information search prefix liaowenhui.datasource reads and automatically encapsulated entity class 
@ConfigurationProperties (prefix = "liaowenhui.datasource")
 public  class DataSourceProperties { 

    Private String validationQuery;
     Private String the jdbcUrl;
     Private String jdbcUserName;
     Private String jdbcUserPassword; 

    public String getValidationQuery () {
         return validationQuery; 
    } 

    public  void setValidationQuery (String validationQuery) {
         the this .validationQuery = validationQuery; 
    } 

    public String getJdbcUrl () {
        return jdbcUrl;
    }

    public void setJdbcUrl(String jdbcUrl) {
        this.jdbcUrl = jdbcUrl;
    }

    public String getJdbcUserName() {
        return jdbcUserName;
    }

    public void setJdbcUserName(String jdbcUserName) {
        this.jdbcUserName = jdbcUserName;
    }

    public String getJdbcUserPassword() {
        return jdbcUserPassword;
    }

    public void setJdbcUserPassword(String jdbcUserPassword) {
        this.jdbcUserPassword = jdbcUserPassword;
    }
}

Use @EnableConfigurationProperties (xxx.class) need to explicitly specify which entity class used to load configuration information

@Configuration
@EnableConfigurationProperties({DataSourceProperties.class })
public class DataSourceConfig {
    private static final Logger logger = LoggerFactory.getLogger(DataSourceConfig.class);

    @Bean(destroyMethod = "close")
    @RefreshScope
    public DataSource dataSourcePgProduct(DataSourceProperties dataSourceProperties) throws SQLException {

        logger.debug("数据库连接信息：{}　", dataSourceProperties.getJdbcUrl());
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUrl(dataSourceProperties.getJdbcUrl());
        dataSource.setUsername(dataSourceProperties.getJdbcUserName());
        dataSource.setPassword(dataSourceProperties.getJdbcUserPassword());
        dataSource.setValidationQuery(dataSourceProperties.getValidationQuery());
　　　　　......
        dataSource.init();
        return dataSource;
    }

Description: @EnableConfigurationProperties equivalent to the use @ConfigurationProperties classes conducted an injection, but not necessarily @EnableConfigurationProperties notes to use, can be used directly @Autowired DataSourceProperties dataSourceProperties be injected, if not @EnableConfigurationProperties, then, in addition to the entity classes to add @ ConfigurationProperties plus @Component configuration information to the IOC injected into the container.

May refer to: About @EnableConfigurationProperties comment