一、说明
环境：idea 2019.2 + druid-1.1.6
springboot集成Druid 请参考博文：springboot项目配置Druid

二、执行命令加密数据库密码
java -cp druid的jar包路径 com.alibaba.druid.filter.config.ConfigTools you_password

2-1、项目中定位到druid的jar包

2-2、右键 -> Open Library Settings -> ctrl +c 复制jar路径

得到druid的jar包路径：
D:\apache-maven-3.3.9\mydata\Repository\com\alibaba\druid\1.1.6\druid-1.1.6.jar

2-3、打开cmd命令行窗口
假如你的密码是 1234
winds键 + r -> 输入cmd -> 按回车键

命令行执行（注意每次执行结果不一样，执行完请将结果复制保存下）

java -cp D:\apache-maven-3.3.9\mydata\Repository\com\alibaba\druid\1.1.6\druid-1.1.6.jar com.alibaba.druid.filter.config.ConfigTools 1234 >aaa.txt

输出:

cprivateKey:MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEA04tkqzedSRvSl4EDTVg183gKxSDlc1imRbLjBvAl+7w58rvmNP9lOT30uSPBVbN2i7u81PsW44aW/PE19mCU2wIDAQABAkBTvY9ZM8fAhBIGRVzgRjX9LhzdUhtiYMpZNuol+fSfRHfCKUWC3QkcizPP8KwazePslqVvpMJAX/AEg/sCN3Z5AiEA+5hmCo0bsly1Y7gwD45PVEjutoSXRnA9YGbMNfDU5IcCIQDXP36lE2TCfH8/alrXjE2KDjMvhN/urI6H0tJSlV+2DQIgD5/pRmJ5A9yqDyVTJsQpvQxCdudJFcDGrwPzTq5EKmUCIQC2YnPCFiO7c9gyeMDOgXC2OQAAFLvWNdpzlhxmo3E9BQIhAKu5ooDRq2b64sIc9UfS1h0rm4qfsGDBNjKOosM6Y7pc
publicKey:MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBANOLZKs3nUkb0peBA01YNfN4CsUg5XNYpkWy4wbwJfu8OfK75jT/ZTk99LkjwVWzdou7vNT7FuOGlvzxNfZglNsCAwEAAQ==
password:tkn8Joi6uWC1ZRX/l3HQGUwfIN0RbNPOZNDaeaHLNrzxRDaBASxZ63CNSXk/aTRSGLvr0ZbpsVGzxozMFV9Baw==

命令行截图：

三、修改配置文件application.properties
3-1、password 修改为 上面命令行执行得到的password

spring.datasource.password=tkn8Joi6uWC1ZRX/l3HQGUwfIN0RbNPOZNDaeaHLNrzxRDaBASxZ63CNSXk/aTRSGLvr0ZbpsVGzxozMFV9Baw==

3-2、filter属性追加config

spring.datasource.filters=stat,wall,slf4j,config

3-3、connectionProperties属性

connectionProperties属性追加 ;config.decrypt=true;config.decrypt.key=${publickey}

${publickey}为上面命令行执行得到的publicKey

spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000;config.decrypt=true;config.decrypt.key=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBANOLZKs3nUkb0peBA01YNfN4CsUg5XNYpkWy4wbwJfu8OfK75jT/ZTk99LkjwVWzdou7vNT7FuOGlvzxNfZglNsCAwEAAQ==

3-4、application.properties相关druid完整配置

spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=tkn8Joi6uWC1ZRX/l3HQGUwfIN0RbNPOZNDaeaHLNrzxRDaBASxZ63CNSXk/aTRSGLvr0ZbpsVGzxozMFV9Baw==
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

#连接池的配置信息
## 初始化大小，最小，最大
spring.datasource.initialSize=5
spring.datasource.minIdle=5
spring.datasource.maxActive=20
## 配置获取连接等待超时的时间
spring.datasource.maxWait=60000
# 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
spring.datasource.timeBetweenEvictionRunsMillis=60000
# 配置一个连接在池中最小生存的时间，单位是毫秒
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=SELECT 1 FROM DUAL
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
# 打开PSCache，并且指定每个连接上PSCache的大小（防火墙这一块一定不能开，sqlite不支持，会导致奇怪的异常）
spring.datasource.poolPreparedStatements=false
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
# 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
spring.datasource.filters=stat,wall,slf4j,config
# 通过connectProperties属性来打开mergeSql功能；慢SQL记录
spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000;config.decrypt=true;config.decrypt.key=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBANOLZKs3nUkb0peBA01YNfN4CsUg5XNYpkWy4wbwJfu8OfK75jT/ZTk99LkjwVWzdou7vNT7FuOGlvzxNfZglNsCAwEAAQ==
# 合并多个DruidDataSource的监控数据
spring.datasource.useGlobalDataSourceStat=true

四、启动springboot项目验证

五、官网参考
https://github.com/alibaba/druid/wiki/%E4%BD%BF%E7%94%A8ConfigFilter

六、解密

public static void main(String[] args) {
         String pwd = "Z8w7Q6hQ87k7hfcREdK5oIAMPBMjBX4YzazHfz0SR42sOFyOW5DTRwV18blXkFJ8EftvKkQMuRw5YxFF8al+Qw==";
         String pub = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAKmzTBHpY+2ovMM4XK4KVRtt+uMYSgddjE4whx0vL3orgSwCM6x0JjQov1SD26eQrZVMXJuaP42VNKup5sn20UcCAwEAAQ==";
      try {
          String depwd = ConfigTools.decrypt(pub, pwd);
          System.out.println(depwd);
      } catch (Exception e) {
          e.printStackTrace();
      }
  }