Lazy Loading In SpringBoot With JDBC

Question

I am using spring boot 2.5.2 and java 11 with JDBC to connect with MSSQL But I want to lazy load the JDBCTemplate bean with @Lazy annotation

It is not loading lazily Can someone help?

import lombok.extern.slf4j.Slf4j;
import net.media.strategyconfig.models.SemArbConfigDetails;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Lazy;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;

import javax.sql.DataSource;

@EnableConfigurationProperties(SerbConfigDetails.class)
@Configuration
@Slf4j
public class DBConfig {

    @Lazy
    @RefreshScope
    @Bean
    public DataSource semArbDataSource(SerbConfigDetails serbDetails) {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        log.info("Hii");
        dataSource.setDriverClassName(semArbDetails.getDriverClassName());
        dataSource.setUrl(semArbDetails.getJdbcUrl());
        dataSource.setUsername(semArbDetails.getUsername());
        dataSource.setPassword(semArbDetails.getPassword());
        return dataSource;
    }

    @Lazy
    @RefreshScope
    @Bean
    public JdbcTemplate serbMsSqlJdbcTemplate(SerbConfigDetails serbDetails) {
        log.info("Hii 2");
        return new JdbcTemplate(semArbDataSource(serbDetails));
    }
}

This is my config file and bean serbMsSqlJdbcTemplate is included in a constructor where I have also used @Lazy annotation

public StranDao(@Qualifier("serbMsSqlJdbcTemplate") @Lazy JdbcTemplate serbTemplate) {
    this.serbTemplate = serbTemplate;
}

but it is not working

Answer 1

https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/context/annotation/Lazy.html

May be used on any class directly or indirectly annotated with @Component or on methods annotated with @Bean.

Did you try to put it on the class and not on the beans?

Did you also try to use it through the bean? like this:

public class StranDao {

    @Lazy
    @Autowired
    private JdbcTemplate template;

    public StranDao() {
        System.out.println("ReStranDaon bean initialized");
    }

    
}