spring注解开发AnnotationConfigApplicationContext的使用

说明

使用AnnotationConfigApplicationContext可以实现基于Java的配置类加载Spring的应用上下文。避免使用application.xml进行配置。相比XML配置，更加便捷。

示例

AppConfig.java

package com.myapp.config;

import com.myapp.Entitlement;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AppConfig {
    @Bean(name="entitlement")
    public Entitlement entitlement() {
        Entitlement ent= new Entitlement();
        ent.setName("Entitlement");
        ent.setTime(1);
        return ent;
    }

    @Bean(name="entitlement2")
    public Entitlement entitlement2() {
        Entitlement ent= new Entitlement();
        ent.setName("Entitlement2");
        ent.setTime(2);
        return ent;
    }
}

注：

@Configuration可理解为用spring的时候xml里面的<beans>标签

@Bean可理解为用spring的时候xml里面的<bean>标签

Entitlement.java

package com.myapp;
public class Entitlement {
    private String name;
    private int time;

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getTime() {
        return time;
    }
    public void setTime(int time) {
        this.time = time;
    }
}

测试

JavaConfigTest.java

package com.myapp;

import com.myapp.config.AppConfig;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class JavaConfigTest {
    public static void main(String[] arg) {
        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
        ctx.register(AppConfig.class);
        ctx.refresh();

        Entitlement ent = (Entitlement)ctx.getBean("entitlement");
        System.out.println(ent.getName());
        System.out.println(ent.getTime());

        Entitlement ent2 = (Entitlement)ctx.getBean("entitlement2");
        System.out.println(ent2.getName());
        System.out.println(ent2.getTime());

        ctx.close();
    }
}

结果

Entitlement
1
Entitlement2
2