去掉mybatis plus插件生成的mapper.xml文件

小鱼儿 2022-03-16 10:36 743阅读 0赞

前言：使用mybatis自动生成mapper.xml文件，同时自己写的sql放在mapperExt.xml中，随着表的增加，启动越来越慢，为减少加载xml的时间，去掉生成的mapper.xml文件，步骤如下

1.重写AutoSqlInjector的inject(...)方法

/**
    	 * 自定义方法，注入点（子类需重写该方法）
    	 */
    	public void inject(Configuration configuration, MapperBuilderAssistant builderAssistant, Class<?> mapperClass,
    			Class<?> modelClass, TableInfo table) {
    		// to do nothing
    	}

重写后如下：

public class CustomAutoSqlInjector {
    
        /**
         * 自定义方法，注入点（子类需重写该方法）
         */
        @Override
        public void inject(Configuration configuration, MapperBuilderAssistant builderAssistant, Class<?> mapperClass, Class<?> modelClass, TableInfo table) {
            injectSelectRecordsSql(configuration, builderAssistant, mapperClass, modelClass, table);
            injectSelectRecordsByConditionSql(configuration, builderAssistant, mapperClass, modelClass, table);
            injectSelectIdPageSql(configuration, builderAssistant, mapperClass, modelClass, table);
        }
    
        protected void injectSelectRecordsSql(Configuration configuration, MapperBuilderAssistant builderAssistant, Class<?> mapperClass, Class<?> modelClass, TableInfo table) {
            String method = "selectRecords";
            String sql = selectRecordsSql(table);
            SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
            this.addSelectMappedStatement(mapperClass, method, sqlSource, modelClass, table);
        }
    
        protected void injectSelectRecordsByConditionSql(Configuration configuration, MapperBuilderAssistant builderAssistant, Class<?> mapperClass, Class<?> modelClass, TableInfo table) {
            String method = "selectRecordsByCondition";
            String sql = selectRecordsByCondition(table);
            SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
            this.addSelectMappedStatement(mapperClass, method, sqlSource, modelClass, table);
        }
    
        protected void injectSelectIdPageSql(Configuration configuration, MapperBuilderAssistant builderAssistant, Class<?> mapperClass, Class<?> modelClass, TableInfo table) {
            String method = "selectIdPage";
            String sql = selectIdPageSql(table);
            SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
            this.addSelectMappedStatement(mapperClass, method, sqlSource, modelClass, table);
        }
    
        protected String selectRecordsSql(TableInfo tableInfo) {
            StringBuilder sql = new StringBuilder();
            sql.append("<script>");
            sql.append("select ").append(sqlSelectColumns(tableInfo, false)).append(" from ").append(tableInfo.getTableName());
            sql.append("\n<where>del_flg = 1");
            tableInfo.getFieldList().forEach(t -> {
                sql.append("\n<if test=\"").append(t.getProperty()).append(" != null\">");
                sql.append("\nand ").append(t.getColumn()).append(" = #{").append(t.getProperty()).append("}");
                sql.append("\n</if>");
            });
            sql.append("\n<if test=\"keyword != null and keyword != '' and fields.size() > 0 \">");
            sql.append("\nand <foreach collection=\"fields\" close=\")\" open=\"(\" index=\"index\" item=\"item\" separator=\"or\">");
            sql.append("\n${item} like concat('%',#{keyword},'%')");
            sql.append("\n</foreach>");
            sql.append("\n</if>");
            sql.append("\n</where>");
            sql.append("\n<if test=\"orderBy != null and orderBy != ''\">");
            sql.append("\norder by ${orderBy}");
            sql.append("\n</if>");
            sql.append("</script>");
            return sql.toString();
        }
    
        protected String selectRecordsByCondition(TableInfo tableInfo) {
            StringBuilder sql = new StringBuilder();
            sql.append("<script>");
            sql.append("select ").append(sqlSelectColumns(tableInfo, false)).append(" from ").append(tableInfo.getTableName());
            sql.append("\n${cw.sqlSegment}");
            sql.append("\nand del_flg = 1");
            tableInfo.getFieldList().forEach(t -> {
                sql.append("\n<if test=\"em.").append(t.getProperty()).append(" != null\">");
                sql.append("\nand ").append(t.getColumn()).append(" = #{em.").append(t.getProperty()).append("}");
                sql.append("\n</if>");
            });
            sql.append("\n<if test=\"em.keyword != null and em.keyword != '' and em.fields.size() > 0 \">");
            sql.append("\nand <foreach collection=\"em.fields\" close=\")\" open=\"(\" index=\"index\" item=\"item\" separator=\"or\">");
            sql.append("\n${item} like concat('%',#{em.keyword},'%')");
            sql.append("\n</foreach>");
            sql.append("\n</if>");
            sql.append("\n<if test=\"em.orderBy != null and em.orderBy != ''\">");
            sql.append("\norder by ${em.orderBy}");
            sql.append("\n</if>");
            sql.append("</script>");
            return sql.toString();
        }
    
        protected String selectIdPageSql(TableInfo tableInfo){
            StringBuilder sql = new StringBuilder();
            sql.append("<script>");
            sql.append("select id from ").append(tableInfo.getTableName());
            sql.append("\n<where>del_flg = 1");
            tableInfo.getFieldList().forEach(t -> {
                sql.append("\n<if test=\"cm.").append(t.getProperty()).append(" != null\">");
                sql.append("\nand ").append(t.getColumn()).append(" = #{cm.").append(t.getProperty()).append("}");
                sql.append("\n</if>");
            });
            sql.append("\n<if test=\"cm.keyword != null and cm.keyword != ''\">");
            sql.append("\nand (");
            tableInfo.getFieldList().forEach(t -> {
                sql.append("\nor ").append(t.getColumn()).append(" like concat('%',#{cm.keyword},'%')");
            });
            sql.append("\n)</if>");
            sql.append("\n</where>");
            sql.append("</script>");
            return sql.toString();
        }
    }

2.修改mybatis-plus配置文件（application.yml）指定刚刚自定义的注入器位置

mybatis-plus:
        type-aliases-package: com.xxx.dal.model
        mapper-locations: classpath*:com/xxx/dal/mapper/**/*.xml
        configuration:
            map-underscore-to-camel-case: true
            default-fetch-size: 100
            default-statement-timeout: 30
        global-config:
          sql-injector: com.xxx.dal.config.CustomAutoSqlInjector

可以删除自动生产mapper.xml文件，只保留maperExt.xml即可

另：也可以重写update语句中的set部分,支持update空字符串

/**
         * SQL 更新 set 语句
         *
         * @param table  表
         * @param prefix 前缀
         */
        @Override
        protected String sqlSet(TableInfo table, String prefix) {
            StringBuilder set = new StringBuilder();
            set.append("<trim prefix=\"SET\" suffixOverrides=\",\">");
            List<TableFieldInfo> fieldList = table.getFieldList();
            for (TableFieldInfo fieldInfo : fieldList) {
                set.append(convertIfTagForUpdate(true, fieldInfo, prefix, false));
                set.append(fieldInfo.getColumn()).append("=#{");
                if (null != prefix) {
                    set.append(prefix);
                }
                set.append(fieldInfo.getEl()).append("},");
                set.append(convertIfTagForUpdate(true, fieldInfo, null, true));
            }
            set.append("\n</trim>");
            return set.toString();
        }
    
        /**
         * IF 条件转换方法
         *
         * @param ignored   允许忽略
         * @param fieldInfo 字段信息
         * @param prefix    条件前缀
         * @param colse     是否闭合标签
         */
        protected String convertIfTagForUpdate(boolean ignored, TableFieldInfo fieldInfo, String prefix, boolean colse) {
            /* 忽略策略 */
            FieldStrategy fieldStrategy = fieldInfo.getFieldStrategy();
            if (fieldStrategy == FieldStrategy.IGNORED) {
                if (ignored) {
                    return "";
                }
                // 查询策略，使用全局策略
                GlobalConfiguration.getGlobalConfig(configuration).getFieldStrategy();
            }
            // 关闭标签
            if (colse) {
                return "</if>";
            }
            // 前缀处理
            String property = fieldInfo.getProperty();
            if (null != prefix) {
                property = prefix + property;
            }
            return String.format("\n\t<if test=\"%s!=null\">", property);
        }