Spring Cloud 基于Consul 实现配置服务

Spring Cloud体系中提供了Config组件来进行配置服务管理。而Consul除了提供服务注册与发现功能外，同时也提供配置管理功能。本位将介绍如何结合Spring Cloud + Consul实现配置管理。

本文中使用的工程及环境参考上篇文章《Spring Cloud 基于Consul 实现服务注册与发现》

添加配置依赖

在leon-consumer项目中添加配置依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>

添加项目配置

新建bootstrap.yml文件，在文件中添加配置服务相关参数配置：

spring:
  application:
    name: leon-consumer
  cloud:
    consul:
      host: localhost
      port: 8500
      config:
        enabled: true
        format: yaml
        prefix: config
        default-context: leon-consumer
        data-key: data

添加配置文件及数据

新建application-dev.yml、application-test.yml配置文件，分别代表开发、测试环境配置文件，其中分别指定开发和测试环境的端口为8081、8082

server:
  port: 8081

server:
  port: 8082

然后在application.yml中指定想要启用的环境配置

spring:
  profiles:
    active: test

此时代表项目启动使用测试环境，服务应该运行在8082端口，整个配置文件体系结构如下：

然后在web管理界面选择key/value，点击create，新增配置信息

分别填入想要保存的配置信息，以key-value的形式保存

这里key值需要和项目工程中的配置保持一致。

仔细对比，相信都能明白字段对应的位置。建议先按照默认的配置，能够正常访问得到数据后在进行自由更改。

spring:
  cloud:
    consul:
      host: localhost
      port: 8500
      config:
        enabled: true # 开启配置管理服务
        format: yaml  # 配置的格式，有四种选择
        prefix: config # 配置所在的应用目录名称
        default-context: leon-consumer # 服务名称，也就是spring.application.name的值
        data-key: data # 默认为data，可以更改，需要和consul创建时保持一致

填入value值后点击save保存即可。注意如果是YAML格式，那么数据间的冒号后要有空格。

在项目中获取配置

在leon-consumer项目中，新建ConfigController类，读取线上配置信息

@RestController
public class ConfigController {
<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${dbName}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String dbName<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${dbPassword}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String dbPassword<span class="token punctuation">;</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/getdbinfo"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">getDBInfo</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> <span class="token string">"数据库用户名："</span> <span class="token operator">+</span> dbName <span class="token operator">+</span> <span class="token string">" | 数据库密码: "</span> <span class="token operator">+</span> dbPassword<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

运行服务，然后访问接口getdbinfo,查看结果。注意此时我们运行是test环境，所以需要访问8082端口。

自动刷新配置信息

能够获取到配置信息后，此时更改线上配置数据：

此时我们刷新浏览器，访问getdbinfo接口是无法刷新数据的。想要能够实时刷新配置数据，需要在类上添加注解 @RefreshScope

@RestController
@RefreshScope
public class ConfigController {
<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${dbName}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String dbName<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${dbPassword}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String dbPassword<span class="token punctuation">;</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/getdbinfo"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">getDBInfo</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> <span class="token string">"数据库用户名："</span> <span class="token operator">+</span> dbName <span class="token operator">+</span> <span class="token string">" | 数据库密码: "</span> <span class="token operator">+</span> dbPassword<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

添加注解后，重新启动服务，然后测试下就线上配置数据更改后就可以自动更新了，不用在重启服务。

复杂配置

上文中我们配置了简单的键值对信息，除此之外我们还可以配置复杂数据,更新配置数据：

dbName: leon
dbPassword: 666666
user:
  name: leon
  age: 18
  desc: 帅哥

在项目中添加引用

@RestController
@RefreshScope
public class ConfigController {
<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${dbName}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String dbName<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${dbPassword}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String dbPassword<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${user.name}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String name<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${user.age}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> <span class="token keyword">int</span> age<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${user.desc}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String desc<span class="token punctuation">;</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/getuserinfo"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">getUserInfo</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> name <span class="token operator">+</span> <span class="token string">" | "</span> <span class="token operator">+</span> age <span class="token operator">+</span> <span class="token string">" | "</span> <span class="token operator">+</span> desc<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/getdbinfo"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">getDBInfo</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> <span class="token string">"数据库用户名："</span> <span class="token operator">+</span> dbName <span class="token operator">+</span> <span class="token string">" | 数据库密码: "</span> <span class="token operator">+</span> dbPassword<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

重新启动后，访问 getuserinfo 接口，可以看到能够正常访问

如果觉得这种方式比较繁琐（Java可是要面向对象的啊），可以通过一个对象类获取整个配置信息。
添加两个Bean类:

public class User {
    private String name;
    private int age;
    private String desc;
    //...get/set方法
}

@ConfigurationProperties()
public class ConfigBean {
    private String dbName;
    private String dbPassword;
    private User user;
    //...get/set方法
}

注意此时已经给ConfigBean添加了注解：@ConfigurationProperties()
然后给启动类添加注解：@EnableConfigurationProperties(ConfigBean.class)

@SpringBootApplication
@EnableFeignClients
@EnableConfigurationProperties(ConfigBean.class)
public class LeonConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(LeonConsumerApplication.class, args);
    }
}

然后就可以直接调用获取信息，在之前的Controller类中添加引用：

@Autowired
private ConfigBean configBean;
@GetMapping("/getallinfo")

public String getAllInfo() {

StringBuilder allInfo = new StringBuilder();

allInfo.append(configBean.getDbName() + " | ");

allInfo.append(configBean.getDbPassword() + " | ");

allInfo.append(configBean.getUser().getName() + " | ");

allInfo.append(configBean.getUser().getAge() + " | ");

allInfo.append(configBean.getUser().getDesc() + " | ");

return allInfo.toString();

}

重新运行服务，然后访问接口查看信息 http://localhost:8082/getallinfo

小问题

在配置类中添加@ConfigurationProperties注解后会出现提示信息。

此提示信息不影响项目运行。
查询过后了解到是因为在注解中没有配置（prefix=""），没有指定 classpath 时，IDEA 提示没有找到 classpath，在spring boot1.5以上版本@ConfigurationProperties取消location注解，我们使用1.5.21版本所以会由此问题，可以在IDEA中配置取消提醒，具体方式可以参考文章：https://blog.csdn.net/expect521/article/details/77151094

配置文件使用线上配置

除去前面说的可以在项目代码中引用线上配置，同时还可以在配置文件中直接引用线上配置。
在项目中添加MySQL和Mybatis的依赖

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.2.0</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

为了方便，复用之前的User类。在User类中添加id字段

privata long id;

在项目中添加Mapper类：

@Mapper
public interface UserMapper {
    public User getDmUserById(@Param(value = "id") String id) throws Exception;
}

在resource目录下添加配置文件：

<mapper namespace="cn.leon.leonconsumer.mapper.UserMapper">
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getDmUserById<span class="token punctuation">"</span></span> <span class="token attr-name">resultType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cn.leon.leonconsumer.config.User<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    select
            id as id,
            name as name,
            age as age，
            description as description
    from user
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>trim</span> <span class="token attr-name">prefix</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>where<span class="token punctuation">"</span></span> <span class="token attr-name">prefixOverrides</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>and | or<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>if</span> <span class="token attr-name">test</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id != null<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            and id=#{id}
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>if</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>trim</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>select</span><span class="token punctuation">&gt;</span></span>

修改application-test.yml文件，添加mybatis和mysql的相关配置：

server:
  port: 8082
mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/temp?useUnicode=true&characterEncoding=gbk&zeroDateTimeBehavior=convertToNull
    username: ${dbName}
    password: ${dbPassword}
    driver-class-name: com.mysql.jdbc.Driver

修改线上配置参数，配置正确的账号和密码

添加获取用户方法

@Autowired
private UserMapper userMapper;
@RequestMapping("/getUser")

public String getUser() throws Exception {

User user =  userMapper.getDmUserById(1);

return user.toString();

}

User定义的字段desc可能会和数据库关键字冲突，改成description.xml文件上文已改

然后访问此方法，可以看到能够正常连接数据库获取信息：

同时我们还可以将整个配置信息都放到线上，这样每个项目都不需要在自己的项目中再单独配置。
将application-test.dev.yml中的数据库配置信息都删掉

然后将数据库配置都放到线上：

然后重新启动服务，发现正常运行，接口可以调用。

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