7.高级装配(一)

1. 环境与Profile

1.解决不同环境不同配置

maven构建时，使用profiles来确定将哪一个配置编译到可部署的应用
1. 缺点：不同环境重新构建，可能引入bug
使用Spring profile

2.配置方式

Java

可以放在类上和方法上，类上的级别会覆盖方法上的，放在类级别上，表示该类型所有的bean都受此影响

package com.desmond.springlearning.profiles;

import com.desmond.springlearning.profiles.vo.Person;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;

/**
 * Created by presleyli on 2018/4/6.
 */
@Configuration
@Profile("dev")
public class ConfigurationConfig {

    @Bean
    @Profile("prod")
    public Person getProdPerson() {
        Person person = new Person();
        person.setName("prod");

        return person;
    }

    @Bean
    public String name() {
        return "prod";
    }

    @Bean
    @Profile("test")
    public Person getTestPerson() {
        Person person = new Person();
        person.setName("test");

        return person;
    }

    @Bean
    @Profile("dev")
    public Person getDevPerson() {
        Person person = new Person();
        person.setName("dev");

        return person;
    }
}

JVM配置参数 -Dspring.profiles.default=dev

XML

xml中只能放在上

代码

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
    http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd">

    <beans profile="prod">
        <bean id="person" class="com.desmond.springlearning.profiles.vo.Person">
            <constructor-arg value="prod" />
        </bean>
    </beans>

    <beans profile="test">
        <bean id="testPerson" class="com.desmond.springlearning.profiles.vo.Person">
            <constructor-arg value="test"/>
        </bean>
    </beans>

    <beans profile="dev">
        <bean id="devPerson" class="com.desmond.springlearning.profiles.vo.Person">
            <constructor-arg value="dev"/>
        </bean>
    </beans>
</beans>

JVM配置参数 -Dspring.profiles.default=dev

测试类

package com.desmond.springlearning.profiles;

import com.desmond.springlearning.profiles.vo.Person;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author presleyli
 * @date 2018/10/9 下午10:15
 */
public class XmlTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("profiles/config.xml");

        Person person = context.getBean(Person.class);

        System.out.println(person.getName());
    }
}

激活 profile
1. 须依赖两个属性 spring.profiles.active和 spring.profiles.default, 如果设置了active, 先用active；否使用default. 如果两者均未设置，则无激活的profile, 也就只加载哪些没有定义在profile里的bean.
2. 多种方式设置这两个属性
  1. DispatcherServlet 初始化参数
  2. Web应用上下文
  3. JNDI
  4. 环境变量
  5. JVM 变量 eg. -Dspring.profiles.default=dev
  6. 在集成测试类上，使用注解 @ActiveProfiles

2. 条件化bean

1. 概念

当一个或者多个bean需要遇到特定条件才创建

2. 举例

假设当Person类，当环境中设置人名为Tom时，才认为此人标签为牛掰

首先，定义一个条件类，实现Condition接口

package com.desmond.springlearning.conditional;

import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.type.AnnotatedTypeMetadata;

/**
 * @author presleyli
 * @date 2018/10/9 下午10:55
 */
public class PersonCondition implements Condition{
    public boolean matches(ConditionContext conditionContext, AnnotatedTypeMetadata annotatedTypeMetadata) {
        String name = conditionContext.getEnvironment().getProperty("name");

        return "Tom".equalsIgnoreCase(name);
    }
}

定义configuration

package com.desmond.springlearning.conditional;

/**
 * @author presleyli
 * @date 2018/10/9 下午10:53
 */

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Conditional;
import org.springframework.context.annotation.Configuration;

@Configuration
public class ConConfiguration {
    @Bean
    @Conditional(PersonCondition.class)
    public Person person() {
        Person person = new Person();

        person.setNotes("此人牛掰.");

        return person;
    }
}

Person

package com.desmond.springlearning.conditional;

import lombok.Data;

/**
 * @author presleyli
 * @date 2018/10/9 下午10:52
 */
@Data
public class Person {
    public String notes;
}

测试

package com.desmond.springlearning.conditional;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

/**
 * @author presleyli
 * @date 2018/10/9 下午10:15
 */
public class AnnoCondTest {
    public static void main(String[] args) {
        ApplicationContext context = new AnnotationConfigApplicationContext(ConConfiguration.class);

        Person person = context.getBean(Person.class);

        System.out.println(person.getNotes());
    }
}

添加环境变量 name=Tom

结果
此人牛掰. 否则找不到bean:

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.desmond.springlearning.conditional.Person' available

从4.0 @Profile也使用此法：

注解

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.springframework.context.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented

@Conditional({ProfileCondition.class}) // 条件

public @interface Profile {
    String[] value();
}

condition

/*
 * Copyright 2002-2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.context.annotation;

import org.springframework.core.type.AnnotatedTypeMetadata;
import org.springframework.util.MultiValueMap;

/**
 * {@link Condition} that matches based on the value of a {@link Profile @Profile}
 * annotation.
 *
 * @author Chris Beams
 * @author Phillip Webb
 * @author Juergen Hoeller
 * @since 4.0
 */
class ProfileCondition implements Condition {

	@Override
	public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
		if (context.getEnvironment() != null) {
			MultiValueMap<String, Object> attrs = metadata.getAllAnnotationAttributes(Profile.class.getName());
			if (attrs != null) {
				for (Object value : attrs.get("value")) {
					if (context.getEnvironment().acceptsProfiles(((String[]) value))) {
						return true;
					}
				}
				return false;
			}
		}
		return true;
	}

}

7.高级装配(一)

文章目录

7.高级装配(一)

1. 环境与Profile

1.解决不同环境不同配置

2.配置方式

2. 条件化bean

1. 概念

2. 举例

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