src/main/java/com/itfsw/mybatis/generator/plugins/utils/XmlElementGeneratorTools.java
private static XmlElement generateCommColumnsSelective(List<IntrospectedColumn> columns, String prefix, boolean bracket, int type) {
        XmlElement trimEle = generateTrim(bracket);
        for (IntrospectedColumn introspectedColumn : columns) {
            generateSelectiveToTrimEleTo(trimEle, introspectedColumn, prefix, type);
        }
        return trimEle;
    }
private static XmlElement generateCommColumnsSelective(List<IntrospectedColumn> columns, String prefix, boolean bracket, int type) {
        XmlElement trimEle = generateTrim(bracket);
        for (IntrospectedColumn introspectedColumn : columns) {
            generateSelectiveToTrimEleTo(trimEle, introspectedColumn, prefix, type);
        }
        return trimEle;
    }
通用遍历columns
@param columns
@param prefix
@param bracket
@param type    1:key,2:value,3:set
@return