springboot-cache3自定义缓存加载数据库属性配置

需求：

由于项目中配置项太多，配置文件维护很不方便，将配置项放在数据库中维护，通过项目启动时将数据库配置加载到环境变量中，其他需要使用的业务直接使用引用的方式是@Value("${字段}")

项目结构：

pom.xml引入依赖包

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example.springboot</groupId>
    <artifactId>springboot-cache3</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot-cache3</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.12.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 引入mybatis 数据库操作包 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- 引入mybatis 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>4.1.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

配置日志记录

log4j.rootLogger=INFO, stdout , R

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L %m%n

log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=${catalina.home}/logs/platform.log
log4j.appender.R.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L %m%n
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.MaxFileSize=51200KB
log4j.appender.R.MaxBackupIndex=10000

log4j.logger.org.springframework=ERROR
log4j.logger.org.quartz=INFO

#输出打印SQL语句，其中需要填写dao所在的包路径，不能使用模糊匹配
log4j.logger.com.example.spring=DEBUG

配置数据库连接

#server.port=8090

#标示使用的是mysql/oracle/sqlserver
datasource.type=mysql
#mysql数据连接
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=root
#spring.datasource.max-active=20
#spring.datasource.max-idle=8
#spring.datasource.min-idle=8
#spring.datasource.initial-size=20

#mybatis 配置
# 配置映射文件加载
mybatis.mapper-locations=classpath*:mapper/*.xml
# 实体类通过别名使用
#mybatis.type-aliases-package=

表结构：

-- ----------------------------
-- Table structure for `test_tb_propertiesconf`
-- ----------------------------
DROP TABLE IF EXISTS `test_tb_propertiesconf`;
CREATE TABLE `test_tb_propertiesconf` (
  `ConfKey` varchar(50) NOT NULL,
  `Remark` varchar(200) DEFAULT NULL,
  `ConfValue` varchar(50) NOT NULL,
  PRIMARY KEY (`ConfKey`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of test_tb_propertiesconf
-- ----------------------------

创建初始化数据库配置类

package com.example.springboot.cache3.config;

import com.example.springboot.cache3.dao.PropertiesMapper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.core.env.PropertySource;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.regex.Pattern;

/**
 * @Description: 动态加载数据库中的配置
 * 然后根据数据库中的配置字段信息同步到上下文中让其它xml或者类引用，
 * 引用方式是xml通过${字段}，类引用的方式是@Value("${字段}")
 */
@Configuration
//order 控制初始化加载配置顺序，值越小加载越优先
@Order(value = 2)
public class PropertiesConfig {

   private static final Log log = LogFactory.getLog(PropertiesConfig.class);

   // 声明一个对象用于存储数据库中的配置字段信息
   private Properties properties = new Properties();
   // 上下文环境信息
   @Autowired
   private ConfigurableEnvironment env;
   // 调用查询数据库的dao
   @Autowired
   private PropertiesMapper propertiesMapper;

   // 查询配置文件表的SQL语句
   private String query = "select ConfKey,ConfValue,Remark from WFBDCMain.dbo.ISIP_tb_PropertiesConf WITH (NOLOCK) where CurFlag > 0";

   /**
    * 调用并初始化数据库中的配置字段到全局对象中
    */
   @PostConstruct
   private void initProperties() {
      log.info("数据库表配置-->读取数据表配置服务:开始!");
      long startTime = System.nanoTime();
      MutablePropertySources propertySources = env.getPropertySources();
      try {
         List<Map<String, Object>> propertyMap = propertiesMapper.queryPropertiesConfg();
         // 打印读取的数据表配置数据
         log.debug(propertyMap.toString());
         // 遍历所有数据表中的数据，然后把数据添加到properties配置字段中
         for (Map<String, Object> tmp : propertyMap) {
            // 把数据表中的key和value添加到环境中
            properties.put(tmp.get("ConfKey").toString(), tmp.get("ConfValue"));
         }
         PropertiesPropertySource dbPropertySource = new PropertiesPropertySource("dbPropertySource", properties);
         // 定义一个正则判断环境变量中是否存在相关的配置
         Pattern p = Pattern.compile("^applicationConfig.*");
         String name = null;
         boolean flag = false;
         for (PropertySource<?> source : propertySources) {
            if (p.matcher(source.getName()).matches()) {
               name = source.getName();
               // 表示环境中存在该环境的配置，可以退出
               flag = true;
               break;
            }
         }
         if (flag) {
            propertySources.addBefore(name, dbPropertySource);
         } else {
            propertySources.addFirst(dbPropertySource);
         }
         long endTime = System.nanoTime();
         // 计算加载配置文件的耗时
         double useTime = (endTime - startTime) / 1E9;
         log.info("数据库表配置-->读取数据表配置服务:结束,加载耗时:" + useTime + "秒!");
         String key = env.getProperty("init_delay").toString();
         log.info("数据库表配置-->" + key);
      } catch (Exception e) {
         // 错误信息打印
         log.error("数据库表配置-->读取数据表配置服务异常： " + e);
      }
   }
}

创建mapper接口

package com.example.springboot.cache3.dao;

import org.apache.ibatis.annotations.Mapper;

import java.util.List;
import java.util.Map;

/**
 * @desc 加载数据库属性配置
 * @Author wangsh
 * @date 2018/5/7 21:34
 * @return
 */
@Mapper
public interface PropertiesMapper {

   public List<Map<String, Object>> queryPropertiesConfg();
}

创建mapper配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.example.springboot.cache3.dao.PropertiesMapper">
    <!-- 查询数据配置 -->
    <select id="queryPropertiesConfg" resultType="java.util.Map">
       select ConfKey,ConfValue,Remark from test.test_tb_PropertiesConf  where CurFlag > 0
    </select>

</mapper>

创建controller类

package com.example.springboot.cache3.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

/**
 * @desc 测试读取数据库缓存配置
 * @Author wangsh
 * @date 2018/5/7 20:57
 */
@RestController
@RequestMapping("/cache")
public class CacheController {

   @Value("${init_delay}")
   private String init_delay;

   @ResponseBody
   @RequestMapping("/hello")
   public String hello() {

      System.out.println(">>>>>测试读取数据库缓存配置........" + init_delay);
      return init_delay;
   }
}

创建启动服务类

package com.example.springboot.cache3;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.example.springboot.cache3")
@SpringBootApplication
public class SpringbootCache3Application {

   public static void main(String[] args) {
      SpringApplication.run(SpringbootCache3Application.class, args);
   }
}

启动服务测试如下

浏览器访问： http://localhost:8080/cache/hello

日志记录：