What is the java configuration method in springboot
1. Create User entity class.
@Data public class User { private String username; private String password; private Integer age; }
2. Create UserDao to simulate database interaction.
public class UserDao{ public List<user> queryUserList() { List<user> result = new ArrayList<user>(); //模拟数据库查询 for(int i = 1;i <p><strong>3. Write UserService to implement User data operation business logic. </strong></p> <pre class="brush:php;toolbar:false">@service public class UserService{ @Autowired//注入Spring容器中的bean对象 private UserDao userDao; public List<user> queryUserList() { //调用userDao中的方法进行查询。 return this.userDao.queryUserList(); } }</user>
4. Write SpringConfig to instantiate the Spring container.
@Configuration//通过该注解来表明该类是一个spring的配置,相当于一个xml文件。 //配置扫描包。 @ComponentScan(basePackages = "cn.my.springboot.javaconfig") public class SpringConfig { @Bean//通过该注解来表明是一个Bean对象,相当于xml中的<bean> public UserDao getUserDao() { return new UserDao();//直接new对象作演示。 } }</bean>
5. Write a test method to start the Spring container.
public class Test { public static void main(String[] args) { //通过java配置来实例化Spring容器。 AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class); //在Spring容器中获取bean对象 UserService userService = context.getBean(UserService.class); //调用对象中的方法 List<user> list = userService.queryUserList(); for(User user : list) { System.out.println(user.getUsername() + "|" user.getPassword() + "|" user.getAge()); //销毁该容器 context.destroy; } } }</user>
Test results:
You can use java code to perfectly replace the XML configuration file.
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