使用MyBatisMyBatis Plus实现SQL日志打印与执行监控

使用MyBatis/MyBatis Plus实现SQL日志打印与执行监控

一、背景与价值

在开发过程中，SQL日志的完整输出对于调试和性能优化至关重要。MyBatis默认的日志输出仅显示带占位符的SQL语句，无法直接看到实际参数值，且缺乏执行时间统计。本文将介绍两种实现方案：

原生配置方案：通过日志框架直接输出基础SQL日志
增强方案：使用MyBatis拦截器实现完整SQL打印和执行监控

二、原生配置方案（快速上手）

1. 日志框架配置（以Logback为例）

<!-- logback-spring.xml -->
<configuration><logger name="com.zaxxer.hikari" level="INFO"/><logger name="java.sql.Connection" level="INFO"/><logger name="java.sql.Statement" level="DEBUG"/><logger name="java.sql.PreparedStatement" level="DEBUG"/>
</configuration>

2. 输出示例

java">DEBUG [main] - ==>  Preparing: SELECT * FROM user WHERE name = ?
DEBUG [main] - ==> Parameters: John(String)

3. 局限性

参数值单独显示，无法直接拼接完整SQL
缺乏执行耗时统计
动态SQL处理不够直观

三、增强方案：自定义拦截器实现

1. SQL美化与参数替换

java">public class MybatisPlusAllSqlLog implements InnerInterceptor {public static final Logger log = LoggerFactory.getLogger("sys-sql");@Overridepublic void beforeQuery(Executor executor, MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) throws SQLException {logInfo(boundSql, ms, parameter);}@Overridepublic void beforeUpdate(Executor executor, MappedStatement ms, Object parameter) throws SQLException {BoundSql boundSql = ms.getBoundSql(parameter);logInfo(boundSql, ms, parameter);}private static void logInfo(BoundSql boundSql, MappedStatement ms, Object parameter) {try {log.info("parameter = " + parameter);// 获取到节点的id,即sql语句的idString sqlId = ms.getId();log.info("sqlId = " + sqlId);// 获取节点的配置Configuration configuration = ms.getConfiguration();// 获取到最终的sql语句String sql = getSql(configuration, boundSql, sqlId);log.info("完整的sql:{}", sql);} catch (Exception e) {log.error("异常:{}", e.getLocalizedMessage(), e);}}// 封装了一下sql语句，使得结果返回完整xml路径下的sql语句节点id + sql语句public static String getSql(Configuration configuration, BoundSql boundSql, String sqlId) {return sqlId + ":" + showSql(configuration, boundSql);}// 进行？的替换public static String showSql(Configuration configuration, BoundSql boundSql) {// 获取参数Object parameterObject = boundSql.getParameterObject();List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();// sql语句中多个空格都用一个空格代替String sql = boundSql.getSql().replaceAll("[\\s]+", " ");if (!CollectionUtils.isEmpty(parameterMappings) && parameterObject != null) {// 获取类型处理器注册器，类型处理器的功能是进行java类型和数据库类型的转换TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();// 如果根据parameterObject.getClass(）可以找到对应的类型，则替换if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {sql = sql.replaceFirst("\\?",Matcher.quoteReplacement(getParameterValue(parameterObject)));} else {// MetaObject主要是封装了originalObject对象，提供了get和set的方法用于获取和设置originalObject的属性值,主要支持对JavaBean、Collection、Map三种类型对象的操作MetaObject metaObject = configuration.newMetaObject(parameterObject);for (ParameterMapping parameterMapping : parameterMappings) {String propertyName = parameterMapping.getProperty();if (metaObject.hasGetter(propertyName)) {Object obj = metaObject.getValue(propertyName);sql = sql.replaceFirst("\\?",Matcher.quoteReplacement(getParameterValue(obj)));} else if (boundSql.hasAdditionalParameter(propertyName)) {// 该分支是动态sqlObject obj = boundSql.getAdditionalParameter(propertyName);sql = sql.replaceFirst("\\?",Matcher.quoteReplacement(getParameterValue(obj)));} else {// 打印出缺失，提醒该参数缺失并防止错位sql = sql.replaceFirst("\\?", "缺失");}}}}return sql;}// 如果参数是String，则添加单引号， 如果是日期，则转换为时间格式器并加单引号； 对参数是null和不是null的情况作了处理private static String getParameterValue(Object obj) {String value;if (obj instanceof String) {value = "'" + obj.toString() + "'";} else if (obj instanceof Date) {DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.DEFAULT,DateFormat.DEFAULT, Locale.CHINA);value = "'" + formatter.format(new Date()) + "'";} else {if (obj != null) {value = obj.toString();} else {value = "";}}return value;}}

2. 执行耗时监控

java">@Intercepts({@Signature(type = Executor.class, method = "update", args = {MappedStatement.class,Object.class}),@Signature(type = Executor.class, method = "query", args = {MappedStatement.class,Object.class, RowBounds.class, ResultHandler.class, CacheKey.class, BoundSql.class})})
public class SqlStatementInterceptor implements Interceptor {public static final Logger log = LoggerFactory.getLogger("sys-sql");@Overridepublic Object intercept(Invocation invocation) throws Throwable {long startTime = System.currentTimeMillis();try {return invocation.proceed();} finally {long timeConsuming = System.currentTimeMillis() - startTime;log.info("执行SQL:{}ms", timeConsuming);if (timeConsuming > 999 && timeConsuming < 5000) {log.info("执行SQL大于1s:{}ms", timeConsuming);} else if (timeConsuming >= 5000 && timeConsuming < 10000) {log.info("执行SQL大于5s:{}ms", timeConsuming);} else if (timeConsuming >= 10000) {log.info("执行SQL大于10s:{}ms", timeConsuming);}}}@Overridepublic Object plugin(Object target) {return Plugin.wrap(target, this);}@Overridepublic void setProperties(Properties properties) {}
}

自定义拦截器之后，请注意配置该拦截器

3.输出示例

java">INFO  [http-nio-8080-exec-1] - SQLID: com.example.mapper.UserMapper.selectById
INFO  [http-nio-8080-exec-1] - 完整SQL: SELECT id,name,age FROM user WHERE id=1
INFO  [http-nio-8080-exec-1] - 执行耗时: 48ms
WARN  [http-nio-8080-exec-1] - 慢SQL警告: 执行耗时1204ms