关于mybatis-plus:聊聊mybatisplus的SafetyEncryptProcessor

序

本文次要钻研一下 mybatis-plus 的 SafetyEncryptProcessor

SafetyEncryptProcessor

mybatis-plus-boot-starter/src/main/java/com/baomidou/mybatisplus/autoconfigure/SafetyEncryptProcessor.java

public class SafetyEncryptProcessor implements EnvironmentPostProcessor {

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        /**
         * 命令行中获取密钥
         */
        String mpwKey = null;
        for (PropertySource<?> ps : environment.getPropertySources()) {if (ps instanceof SimpleCommandLinePropertySource) {SimpleCommandLinePropertySource source = (SimpleCommandLinePropertySource) ps;
                mpwKey = source.getProperty("mpw.key");
                break;
            }
        }
        /**
         * 解决加密内容
         */
        if (StringUtils.isNotBlank(mpwKey)) {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
            if (CollectionUtils.isNotEmpty(map)) {environment.getPropertySources().addFirst(new MapPropertySource("custom-encrypt", map));
            }
        }
    }
}

SafetyEncryptProcessor 实现了 EnvironmentPostProcessor 接口，在 postProcessEnvironment 办法中先是找到 mpw.key，而后遍历所有 PropertySource 的所有属性，找到 mpw: 结尾的，而后进行解密并替换到密文，最初放在 environment 的第一个 PropertySource

spring.factories

mybatis-plus-boot-starter/src/main/resources/META-INF/spring.factories

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

小结

之前的文章聊聊 springboot 的 EnvironmentPostProcessor 提到 springboot 提供了 EnvironmentPostProcessor 接口，该接口有 postProcessEnvironment 办法，其中 envrionment 参数类型为 ConfigurableEnvironment，即利用能够通过实现这个接口进行 env 环境变量的操作。而 mybatis-plus 的 SafetyEncryptProcessor 正是一个实战的好例子。