Bean标签
Spring中Bean标签在Spring Boot中的使用:
图片介绍:
javaConfig:
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
*
*
*
*
*/
@Configuration
public class Config {
@Bean(name={"sb"},initMethod = "init",destroyMethod = "destroy")
public SomeBean someBean(){
return new SomeBean();
}
}
测试代码:
@Test
public void testDemo() throws IOException {
AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);
SomeBean sb = ctx.getBean("sb",SomeBean.class);
System.out.println(sb);
ctx.close();
}
一月 10, 2018 7:57:26 下午 org.springframework.context.annotation.AnnotationConfigApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@7cef4e59: startup date [Wed Jan 10 19:57:26 CST 2018]; root of context hierarchy
===init===
一月 10, 2018 7:57:26 下午 org.springframework.context.annotation.AnnotationConfigApplicationContext doClose
信息: Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@7cef4e59: startup date [Wed Jan 10 19:57:26 CST 2018]; root of context hierarchy
com.fan.springboot.SomeBean@400cff1a
===destroy===
以上介绍了id,name,init-method,destroy-method在Spring Boot中的配置,其中init-method和destroy-method另外两种配置方式如下:
public class SomeBean {
@PostConstruct
public void init(){
System.out.println("===init===");
}
@PreDestroy
public void destroy(){
System.out.println("===destroy===");
}
}
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
public class SomeBean implements InitializingBean,DisposableBean {
public void destroy(){
System.out.println("===destroy===");
}
@Override
public void afterPropertiesSet() throws Exception {
System.out.println("===init===");
}
}
bean标签的scope属性不在bean标签的参数上而在类上(未测试):
/**
* 作用域:
* 基本作用域(singleton、prototype)
* singleton(单例,默认)
* prototype原型,多例
* Web 作用域(reqeust、session、globalsession)
* 自定义作用域
*/
@Scope("prototype")
public class SomeBean {
public void init(){
System.out.println("===init===");
}
public void destroy(){
System.out.println("===destroy===");
}
}
spring中的FactoryBean在Spring Boot中的应用代码示例:
public class SomeBeanFactory implements FactoryBean {
@Override
public SomeBean getObject() throws Exception {
return new SomeBean();
}
@Override
public Class getObjectType() {
return SomeBean.class;
}
@Override
public boolean isSingleton() {
return true;
}
}
@Configuration
public class Config {
@Bean
public SomeBeanFactory someBean(){
return new SomeBeanFactory();
}
}
测试代码:
@Test
public void testDemo() throws IOException {
AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);
SomeBean sb = ctx.getBean("someBean",SomeBean.class);
System.out.println(sb);
SomeBeanFactory someBeanFactory = ctx.getBean("&someBean",SomeBeanFactory.class);
System.out.println(someBeanFactory);
}
测试结果: