Spring cloud配置客户端（三）

覆盖远程配置属性

默认情况，Spring Cloud是允许覆盖的，spring.cloud.config.allowOverride=true
通过程序启动参数，调整这个值为"false"

--spring.cloud.config.allowOverride=true

启动后，重新Postman发送POST请求，调整spring.application.name值为"spring-cloud-new"

重点：如果spring.application.name不写的话，默认的话是项目名

自定义Bootstrap配置

1. 创建META-INF/spring.factories文件{类似于Spring boot 自定义Starter｝
2. 自定义Bootstrap配置Configurtion

package com.segmentfault.springcloudlesson1.bootstrap;

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;

import java.util.HashMap;
import java.util.Map;

/**
 * bootstrap 配置bean
 */
@Configuration
public class MyConfiguration implements ApplicationContextInitializer {
    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        //从ConfigurableApplicationContext获取ConfigurableEnvironment实例
        ConfigurableEnvironment environment = applicationContext.getEnvironment();
        //获取PropertySources
        MutablePropertySources propertySources = environment.getPropertySources();
        //定义一个新的 propertySource，并放置在首位
        propertySources.addFirst(createPropertySource());
    }

    private PropertySource createPropertySource() {
        Map<String, Object> source = new HashMap<>();
        source.put("name", "shuai");
        PropertySource propertySource = new MapPropertySource("my-property-source", source);
        return propertySource;
    }
}

三. 配置MEAT-INF/spring.factories文件，关联Key

org.springframework.cloud.bootstrapConfiguration= \
com.segmentfault.springcloudlesson2.bootstrap.Myconfiguration

自定义Bootstrap配置属性源

1. 实现PropertySourceLocator

package com.segmentfault.springcloudlesson1.bootstrap;

import org.springframework.cloud.bootstrap.config.PropertySourceLocator;
import org.springframework.core.env.*;

import java.util.HashMap;
import java.util.Map;

/**
 * 自定义{@link PropertySourceLocator}实现
 */
public class MyPropertySourceLocator implements PropertySourceLocator {
    @Override
    public PropertySource<?> locate(Environment environment) {
        if (environment instanceof ConfigurableEnvironment) {
            ConfigurableEnvironment configurableEnvironment = ConfigurableEnvironment.class.cast(environment);
            //获取PropertySources
            MutablePropertySources propertySources = configurableEnvironment.getPropertySources();
            //定义一个新的 propertySource，并放置在首位
            propertySources.addFirst(createPropertySource());
        }
        return null;
    }

    private PropertySource createPropertySource() {
        Map<String, Object> source = new HashMap<>();
        source.put("spring.application.name", "shuaishuai");
        //设置名称和来源
        PropertySource propertySource = new MapPropertySource("over-bootstrap", source);
        return propertySource;
    }
}

1. 配置META-INF/spring.factories

org.springframework.cloud.bootstrapConfiguration= \
com.segmentfault.springcloudlesson1.bootstrap.MyConfiguration,\
com.segmentfault.springcloudlesson1.bootstrap.MyPropertySourceLocator