Spring Boot 实现配置文件加解密原理

spring:
 datasource:
  url: mpw:qRhvCwF4GOqjessEB3G+a5okP+uXXr96wcucn2Pev6BfaoEMZ1gVpPPhdDmjQqoM
  password: mpw:Hzy5iliJbwDHhjLs1L0j6w==
  username: mpw:Xb+EgsyuYRXw7U7sBJjBpA==

spring:
 redis:
  password: mpw:Hzy5iliJbwDHhjLs1L0j6w==

public class SafetyEncryptProcessor implements EnvironmentPostProcessor {

 @Override
 public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
 //命令行中获取密钥
 String mpwKey = null;

 // 返回全部形式的配置源（环境变量、命令行参数、配置文件 ...）
 for (PropertySource<?> ps : environment.getPropertySources()) {
  // 判断是否需要含有加密密码，没有就直接跳过
  if (ps instanceof SimpleCommandLinePropertySource) {
  SimpleCommandLinePropertySource source = (SimpleCommandLinePropertySource) ps;
  mpwKey = source.getProperty("mpw.key");
  break;
  }
 }

 //处理加密内容（获取到原有配置，然后解密放到新的map 里面（key是原有key））
 HashMap<String, Object> map = new HashMap<>();
 for (PropertySource<?> ps : environment.getPropertySources()) {
  if (ps instanceof OriginTrackedMapPropertySource) {
  OriginTrackedMapPropertySource source = (OriginTrackedMapPropertySource) ps;
  for (String name : source.getPropertyNames()) {
   Object value = source.getProperty(name);
   if (value instanceof String) {
   String str = (String) value;
   if (str.startsWith("mpw:")) {
    map.put(name, AES.decrypt(str.substring(4), mpwKey));
   }
   }
  }
  }
 }
 // 将解密的数据放入环境变量，并处于第一优先级上 (这里一定要注意，覆盖其他配置)
 if (!map.isEmpty()) {
  environment.getPropertySources().addFirst(new MapPropertySource("custom-encrypt", map));
 }
 }
}

org.springframework.boot.env.EnvironmentPostProcessor=\
 com.baomidou.mybatisplus.autoconfigure.SafetyEncryptProcessor

System.getProperty("mpw.key")

// 此处思路，参考 druid ConfigFilter
public Properties loadConfig(String filePath) {
   Properties properties = new Properties();

   InputStream inStream = null;
   try {
     boolean xml = false;
     if (filePath.startsWith("file://")) {
       filePath = filePath.substring("file://".length());
       inStream = getFileAsStream(filePath);
       xml = filePath.endsWith(".xml");
     } else if (filePath.startsWith("http://") || filePath.startsWith("https://")) {
       URL url = new URL(filePath);
       inStream = url.openStream();
       xml = url.getPath().endsWith(".xml");
     } else if (filePath.startsWith("classpath:")) {
       String resourcePath = filePath.substring("classpath:".length());
       inStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(resourcePath);
       // 在classpath下应该也可以配置xml文件吧？
       xml = resourcePath.endsWith(".xml");
     } else {
       inStream = getFileAsStream(filePath);
       xml = filePath.endsWith(".xml");
     }

     if (inStream == null) {
       LOG.error("load config file error, file : " + filePath);
       return null;
     }

     if (xml) {
       properties.loadFromXML(inStream);
     } else {
       properties.load(inStream);
     }

     return properties;
   } catch (Exception ex) {
     LOG.error("load config file error, file : " + filePath, ex);
     return null;
   } finally {
     JdbcUtils.close(inStream);
   }
 }