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本文主要研究一下mybatis-plus的SafetyEncryptProcessor
SafetyEncryptProcessor
mybatis-plus-boot-starter/src/main/java/com/baomidou/mybatisplus/autoconfigure/SafetyEncryptProcessor.java
public class SafetyEncryptProcessor implements EnvironmentPostProcessor {@Overridepublic 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;}}/*** 处理加密内容*/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方法中先是找到mpw.key，然后遍历所有PropertySource的所有属性，找到mpw:开头的，然后进行解密并替换到密文，最后放在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方法，其中envrionment参数类型为ConfigurableEnvironment，即应用可以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。
