@ConfigurationProperties如何配置复杂类型

@ConfigurationProperties 注解可以以前缀的形式统一注入某个前缀的参数 如下面的示例
示例

#数据源
spring.datasource.druid.write.url=jdbc:mysql://localhost:3306/jpa
spring.datasource.druid.write.username=root
spring.datasource.druid.write.password=1
spring.datasource.druid.write.driver-class-name=com.mysql.jdbc.Driver

spring.datasource.druid.read.url=jdbc:mysql://localhost:3306/jpa
spring.datasource.druid.read.username=root
spring.datasource.druid.read.password=1
spring.datasource.druid.read.driver-class-name=com.mysql.jdbc.Driver

@Configuration
public class DruidDataSourceConfig {
    /**
     * DataSource 配置
     * @return
     */
    @ConfigurationProperties(prefix = "spring.datasource.druid.read")
    @Bean(name = "readDruidDataSource")
    public DataSource readDruidDataSource() {
        return new DruidDataSource();
    }


    /**
     * DataSource 配置
     * @return
     */
    @ConfigurationProperties(prefix = "spring.datasource.druid.write")
    @Bean(name = "writeDruidDataSource")
    @Primary
    public DataSource writeDruidDataSource() {
        return new DruidDataSource();
    }
}

问题
可以看到示例中的配置其实是有两个前缀 spring.datasource.druid.read、spring.datasource.druid.write 如果需要用一个配置类去接收应该怎么去做？可以参考下面的示例
解决方案
下面的配置实现了将read和write两个不同前缀的配置放在了一个配置类中进行注入 核心思想就是利用了内部类

/**
 * @ConfigurationProperties 注解必须配合@Component、@Bean、@Configuration注解一起使用
 * 也就是说@ConfigurationProperties注解的类 必须被spring托管
 * @date 2021/11/06
 **/
@Component
@ConfigurationProperties(prefix = "spring.datasource.druid")
public class DataSourceProperties {

    //write内部类 用于配置前缀为spring.datasource.druid.write的配置
    private Write write = new Write();

    //read内部类 用于配置前缀为spring.datasource.druid.read的配置
    private Read read = new Read();

    public Write getWrite() {
        return write;
    }

    public void setWrite(Write write) {
        this.write = write;
    }

    public Read getRead() {
        return read;
    }

    public void setRead(Read read) {
        this.read = read;
    }

    public class Write {
        private String url;
        private String username;
        private String password;
        private String driverClassName;

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }

        public String getUsername() {
            return username;
        }

        public void setUsername(String username) {
            this.username = username;
        }

        public String getPassword() {
            return password;
        }

        public void setPassword(String password) {
            this.password = password;
        }

        public String getDriverClassName() {
            return driverClassName;
        }

        public void setDriverClassName(String driverClassName) {
            this.driverClassName = driverClassName;
        }
    }

    public class Read {
        private String url;
        private String username;
        private String password;
        private String driverClassName;

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }

        public String getUsername() {
            return username;
        }

        public void setUsername(String username) {
            this.username = username;
        }

        public String getPassword() {
            return password;
        }

        public void setPassword(String password) {
            this.password = password;
        }

        public String getDriverClassName() {
            return driverClassName;
        }

        public void setDriverClassName(String driverClassName) {
            this.driverClassName = driverClassName;
        }
    }
}