【JavaSpring】注解开发

注解开发定义bean

不指定名称

package org.example.service.impl;import org.example.dao.BookDao;
import org.example.service.BookService;
import org.springframework.stereotype.Component;@Component
public class BookServiceimpl implements BookService {private BookDao bookDao;public void setBookDao(BookDao bookDao) {this.bookDao = bookDao;}public void save() {System.out.println("book service save");bookDao.save();}
}

指定名称

package org.example.dao.impl;import org.example.dao.BookDao;
import org.springframework.stereotype.Component;@Component("bookDao")
public class BookDaoimpl implements BookDao {@Overridepublic void save() {System.out.println("book dao save");}
}

xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!--        开启context命名空间-->
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsd"><context:component-scan base-package="org.example.dao.impl"/><context:component-scan base-package="org.example.service.impl"/>
</beans>

package org.example;import org.example.dao.BookDao;
import org.example.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;public class AppForDIAtuoware {public static void main(String[] args) {ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");BookDao bookDao = (BookDao) ctx.getBean("bookDao");bookDao.save();BookService bookService=ctx.getBean(BookService.class);System.out.println(bookService);}
}