复用代码系列：mybatis插件——打印SQL语句并记录执行时间

- 日理万妓 2022-05-24 06:07 271阅读 0赞

废话不多说，直接上代码，代码可用：

import org.apache.ibatis.executor.statement.StatementHandler;
    import org.apache.ibatis.mapping.BoundSql;
    import org.apache.ibatis.mapping.ParameterMapping;
    import org.apache.ibatis.plugin.*;
    import org.apache.ibatis.session.ResultHandler;
    import org.apache.ibatis.session.defaults.DefaultSqlSession.StrictMap;
    
    import java.lang.reflect.Field;
    import java.sql.Statement;
    import java.util.Collection;
    import java.util.List;
    import java.util.Map;
    import java.util.Properties;
    
    /**
     * Sql执行时间记录拦截器 
     */
    @Intercepts({@Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class}),
        @Signature(type = StatementHandler.class, method = "update", args = {Statement.class}),
        @Signature(type = StatementHandler.class, method = "batch", args = { Statement.class })})
    public class SqlCostInterceptor implements Interceptor {
    
        @Override
        public Object intercept(Invocation invocation) throws Throwable {
            Object target = invocation.getTarget();
            
            long startTime = System.currentTimeMillis();
            StatementHandler statementHandler = (StatementHandler)target;
            try {
                return invocation.proceed();
            } finally {
                long endTime = System.currentTimeMillis();
                long sqlCost = endTime - startTime;
                
                BoundSql boundSql = statementHandler.getBoundSql();
                String sql = boundSql.getSql();
                Object parameterObject = boundSql.getParameterObject();
                List<ParameterMapping> parameterMappingList = boundSql.getParameterMappings();
                
                // 格式化Sql语句，去除换行符，替换参数
                sql = formatSql(sql, parameterObject, parameterMappingList);
    
                String logStr = String.format("\n执行以下SQL耗时[%dms]===> \n%s\n", sqlCost, sql);
                System.out.println(logStr);
            }
        }
    
        @Override
        public Object plugin(Object target) {
            return Plugin.wrap(target, this);
        }
    
        @Override
        public void setProperties(Properties properties) {
            
        }
        
        @SuppressWarnings("unchecked")
        private String formatSql(String sql, Object parameterObject, List<ParameterMapping> parameterMappingList) {
            // 输入sql字符串空判断
            if (sql == null || sql.length() == 0) {
                return "";
            }
            
            // 美化sql
            sql = beautifySql(sql);
            
            // 不传参数的场景，直接把Sql美化一下返回出去
            if (parameterObject == null || parameterMappingList == null || parameterMappingList.size() == 0) {
                return sql;
            }
            
            // 定义一个没有替换过占位符的sql，用于出异常时返回
            String sqlWithoutReplacePlaceholder = sql;
            
            try {
                if (parameterMappingList != null) {
                    Class<?> parameterObjectClass = parameterObject.getClass();
    
                    // 如果参数是StrictMap且Value类型为Collection，获取key="list"的属性，这里主要是为了处理<foreach>循环时传入List这种参数的占位符替换
                    // 例如select * from xxx where id in <foreach collection="list">...</foreach>
                    if (isStrictMap(parameterObjectClass)) {
                        StrictMap<Collection<?>> strictMap = (StrictMap<Collection<?>>)parameterObject;
                        
                        if (isList(strictMap.get("list").getClass())) {
                            sql = handleListParameter(sql, strictMap.get("list"));
                        }
                    } else if (isMap(parameterObjectClass)) {
                        // 如果参数是Map则直接强转，通过map.get(key)方法获取真正的属性值
                        // 这里主要是为了处理<insert>、<delete>、<update>、<select>时传入parameterType为map的场景
                        Map<?, ?> paramMap = (Map<?, ?>) parameterObject;
                        sql = handleMapParameter(sql, paramMap, parameterMappingList);
                    } else {
                        // 通用场景，比如传的是一个自定义的对象或者八种基本数据类型之一或者String
                        sql = handleCommonParameter(sql, parameterMappingList, parameterObjectClass, parameterObject);
                    }
                }
            } catch (Exception e) {
                // 占位符替换过程中出现异常，则返回没有替换过占位符但是格式美化过的sql，这样至少保证sql语句比BoundSql中的sql更好看
                return sqlWithoutReplacePlaceholder;
            }
            
            return sql;
        }
        
        /**
         * 美化Sql
         */
        private String beautifySql(String sql) {
            // sql = sql.replace("\n", "").replace("\t", "").replace("  ", " ").replace("( ", "(").replace(" )", ")").replace(" ,", ",");
            sql = sql.replaceAll("[\\s\n ]+"," ");
            return sql;
        }
        
        /**
         * 处理参数为List的场景
         */
        private String handleListParameter(String sql, Collection<?> col) {
            if (col != null && col.size() != 0) {
                for (Object obj : col) {
                    String value = null;
                    Class<?> objClass = obj.getClass();
                    
                    // 只处理基本数据类型、基本数据类型的包装类、String这三种
                    // 如果是复合类型也是可以的，不过复杂点且这种场景较少，写代码的时候要判断一下要拿到的是复合类型中的哪个属性
                    if (isPrimitiveOrPrimitiveWrapper(objClass)) {
                        value = obj.toString();
                    } else if (objClass.isAssignableFrom(String.class)) {
                        value = "\"" + obj.toString() + "\""; 
                    }
                    
                    sql = sql.replaceFirst("\\?", value);
                }
            }
            
            return sql;
        }
        
        /**
         * 处理参数为Map的场景
         */
        private String handleMapParameter(String sql, Map<?, ?> paramMap, List<ParameterMapping> parameterMappingList) {
            for (ParameterMapping parameterMapping : parameterMappingList) {
                Object propertyName = parameterMapping.getProperty();
                Object propertyValue = paramMap.get(propertyName);
                if (propertyValue != null) {
                    if (propertyValue.getClass().isAssignableFrom(String.class)) {
                        propertyValue = "\"" + propertyValue + "\"";
                    }
    
                    sql = sql.replaceFirst("\\?", propertyValue.toString());
                }
            }
            
            return sql;
        }
        
        /**
         * 处理通用的场景
         */
        private String handleCommonParameter(String sql, List<ParameterMapping> parameterMappingList, Class<?> parameterObjectClass, 
                Object parameterObject) throws Exception {
            for (ParameterMapping parameterMapping : parameterMappingList) {
                String propertyValue = null;
                // 基本数据类型或者基本数据类型的包装类，直接toString即可获取其真正的参数值，其余直接取paramterMapping中的property属性即可
                if (isPrimitiveOrPrimitiveWrapper(parameterObjectClass)) {
                    propertyValue = parameterObject.toString();
                } else {
                    String propertyName = parameterMapping.getProperty();
                    
                    Field field = parameterObjectClass.getDeclaredField(propertyName);
                    // 要获取Field中的属性值，这里必须将私有属性的accessible设置为true
                    field.setAccessible(true);
                    propertyValue = String.valueOf(field.get(parameterObject));
                    if (parameterMapping.getJavaType().isAssignableFrom(String.class)) {
                        propertyValue = "\'" + propertyValue + "\'";
                    }
                }
    
                sql = sql.replaceFirst("\\?", propertyValue);
            }
            
            return sql;
        }
        
        /**
         * 是否基本数据类型或者基本数据类型的包装类
         */
        private boolean isPrimitiveOrPrimitiveWrapper(Class<?> parameterObjectClass) {
            return parameterObjectClass.isPrimitive() || 
                    (parameterObjectClass.isAssignableFrom(Byte.class) || parameterObjectClass.isAssignableFrom(Short.class) ||
                            parameterObjectClass.isAssignableFrom(Integer.class) || parameterObjectClass.isAssignableFrom(Long.class) ||
                            parameterObjectClass.isAssignableFrom(Double.class) || parameterObjectClass.isAssignableFrom(Float.class) ||
                            parameterObjectClass.isAssignableFrom(Character.class) || parameterObjectClass.isAssignableFrom(Boolean.class));
        }
        
        /**
         * 是否DefaultSqlSession的内部类StrictMap
         */
        private boolean isStrictMap(Class<?> parameterObjectClass) {
            return parameterObjectClass.isAssignableFrom(StrictMap.class);
        }
        
        /**
         * 是否List的实现类
         */
        private boolean isList(Class<?> clazz) {
            Class<?>[] interfaceClasses = clazz.getInterfaces();
            for (Class<?> interfaceClass : interfaceClasses) {
                if (interfaceClass.isAssignableFrom(List.class)) {
                    return true;
                }
            }
            
            return false;
        }
        
        /**
         * 是否Map的实现类
         */
        private boolean isMap(Class<?> parameterObjectClass) {
            Class<?>[] interfaceClasses = parameterObjectClass.getInterfaces();
            for (Class<?> interfaceClass : interfaceClasses) {
                if (interfaceClass.isAssignableFrom(Map.class)) {
                    return true;
                }
            }
            
            return false;
        }
        
    }

在mybatis-config.xml中将上述插件配置到：