mybatis自定义拦截器

自定义注解

/**
 * 获取sql注解
 *
 * @author ruoyi
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SqlLogs
{
    /**
     * 是否打印sql
     */
    public boolean hasSqlLog() default false;



}

自定义拦截器

@Slf4j
@AllArgsConstructor
//@Aspect
@Intercepts({
        @Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}),
        @Signature(type = StatementHandler.class, method = "prepare", args = {Connection.class, Integer.class})
})
@Component
public class SqlLogsInterceptor extends AbstractSqlParserHandler implements Interceptor {
 
    private DataSource dataSource;
 
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        Map sqlMap = new HashMap<>();
        Boolean hasSqlLogs = false;
        StatementHandler statementHandler = PluginUtils.realTarget(invocation.getTarget());
        MetaObject metaObject = SystemMetaObject.forObject(statementHandler);
        this.sqlParser(metaObject);
        // 先判断是不是SELECT操作 不是直接过滤
        MappedStatement mappedStatement =
                (MappedStatement) metaObject.getValue("delegate.mappedStatement");
        if (!SqlCommandType.SELECT.equals(mappedStatement.getSqlCommandType())) {
            return invocation.proceed();
        }
 
        final Object[] args = invocation.getArgs();
        //获取执行方法的位置
        String namespace = mappedStatement.getId();
        //获取mapper名称
        String className = namespace.substring(0,namespace.lastIndexOf("."));
        //获取方法名
        String methedName= namespace.substring(namespace.lastIndexOf(".") + 1,namespace.length());
        //获取当前mapper 的方法
        Method[] ms = Class.forName(className).getMethods();
        for(Method m : ms){
            if(m.getName().equals(methedName)){
　　　　　　　　　　//获取注解  来判断是不是要储存sql
                SqlLogs annotation = m.getAnnotation(SqlLogs.class);
                if(annotation != null){
                    hasSqlLogs = annotation.hasSqlLog();
                }
            }
        }
        //如果是有注解值为true，便获取sql处理参数
        if(hasSqlLogs){
            BoundSql boundSql = (BoundSql) metaObject.getValue("delegate.boundSql");
            // 执行的SQL语句
            String originalSql = boundSql.getSql();
            // SQL语句的参数
            Object parameterObject = boundSql.getParameterObject();
            if(parameterObject != null){
                originalSql = showSql(configuration, boundSql);
            }
            System.err.println("sql :"+originalSql);
        }
        return invocation.proceed();
 
    }
 
    /**
     * 生成拦截对象的代理
     *
     * @param target 目标对象
     * @return 代理对象
     */
    @Override
    public Object plugin(Object target) {
        if (target instanceof StatementHandler) {
            return Plugin.wrap(target, this);
        }
        return target;
    }
 
    /**
     * 获取参数值
     * @param obj
     * @return
     */
    private static String getParameterValue(Object obj) {
        String value = null;
        if (obj instanceof String) {
            value = "'" + obj.toString() + "'";
        } else if (obj instanceof Date) {
            DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.CHINA);
            value = "to_date('" + formatter.format(obj) + "','yyyy-MM-dd hh24:mi:ss')";
        } else {
            if (obj != null) {
                value = obj.toString();
            } else {
                value = "";
            }
 
        }
        System.err.println("获取值: "+value);
        return value;
    }
 
    /***
     * sql 参数替换
     * @param configuration
     * @param boundSql
     * @return
     */
    public static String showSql(Configuration configuration, BoundSql boundSql) {
        //获取参数对象
        Object parameterObject = boundSql.getParameterObject();
        //获取当前的sql语句有绑定的所有parameterMapping属性
        List parameterMappings = boundSql.getParameterMappings();
        //去除空格
        String sql = boundSql.getSql().replaceAll("[\\s]+", " ");
        if (parameterMappings.size() > 0 && parameterObject != null) {
            TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
            /* 如果参数满足：org.apache.ibatis.type.TypeHandlerRegistry#hasTypeHandler(java.lang.Class)
            org.apache.ibatis.type.TypeHandlerRegistry#TYPE_HANDLER_MAP
            * 即是不是属于注册类型(TYPE_HANDLER_MAP...等/有没有相应的类型处理器)
             * */
            if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
                sql = sql.replaceFirst("\\?", getParameterValue(parameterObject));
            } else {
                //装饰器，可直接操作属性值 ---》 以parameterObject创建装饰器
                //MetaObject 是 Mybatis 反射工具类，通过 MetaObject 获取和设置对象的属性值
                MetaObject metaObject = configuration.newMetaObject(parameterObject);
                //循环 parameterMappings 所有属性
                for (ParameterMapping parameterMapping : parameterMappings) {
                    //获取property属性
                    String propertyName = parameterMapping.getProperty();
                    System.err.println("propertyName: "+propertyName);
                    //是否声明了propertyName的属性和get方法
                    if (metaObject.hasGetter(propertyName)) {
                        Object obj = metaObject.getValue(propertyName);
                        sql = sql.replaceFirst("\\?", getParameterValue(obj));
                    } else if (boundSql.hasAdditionalParameter(propertyName)) {
                        //判断是不是sql的附加参数
                        Object obj = boundSql.getAdditionalParameter(propertyName);
                        sql = sql.replaceFirst("\\?", getParameterValue(obj));
                    }
                }
            }
        }
        return sql;
    }
 
}

在MybatisPlusConfig中注册bean

@Bean
    @ConditionalOnMissingBean //有此实例便不进行注册
    public SqlLogsInterceptor dataScopeInterceptor(DataSource dataSource) {
        return new SqlLogsInterceptor(dataSource);
    }

使用注解

 @SqlLogs(hasSqlLog = true)
    List selectByLqw(@Param(Constants.WRAPPER) Wrapper queryWrapper);

2.详细关于mybatis拦截器：

https://www.cnblogs.com/top-sky-hua/p/11306376.html