Groovy中用JsonBuilder修改JSON整数元素遇值转字符串问题

问题背景 #

现有JSON结构：

def jsonString = '{"studyDTO":{"studyId":191,"studyCode":"test_ispptest2"},"sites":[{"studyId":191,"siteRecid":16521,"siteId":"11001"}],"allSubjects":true,"states":null,"visits":[{"studyId":191,"visitSubmitName":"baseline","visitDisplayName":"Baseline","orderOfDisplay":10}],"modalities":null,"examDates":null,"series":null,"transferType":null,"sftpLocations":[],"dicomLocations":[],"fileSystemLocations":[],"rawFileSystemLocations":[],"customFolder":null,"folderStructure":null,"customFile":null,"fileStructure":null,"includePS":null}'

需要动态使用数据源中的整数更新orderOfDisplay字段，编写了如下Groovy代码（示例值为23，实际需循环10次动态变更）：

def jsonConvert = new JsonSlurper();
def object = jsonConvert.parseText(jsonString);
def builder = new JsonBuilder(object)

builder.content.visits[0].orderOfDisplay = 23

log.info(builder.toPrettyString());

运行后发现更新后的整数被转为字符串（如23变为"23"），需解决该类型异常。

解决方法 #

1. 显式匹配原始字段类型 #

JsonSlurper默认会将JSON数值解析为BigDecimal类型，直接赋值普通整数会导致类型不匹配，序列化时转为字符串。可将赋值的整数转为BigDecimal：

builder.content.visits[0].orderOfDisplay = new BigDecimal(23)

2. 指定JsonSlurper的整数解析模式 #

解析JSON时设置类型模式，让数值直接解析为Integer，后续赋值普通整数就不会出现类型转换问题：

def jsonConvert = new JsonSlurper().setType(JsonParserType.INTEGER_MODE);
def object = jsonConvert.parseText(jsonString);
def builder = new JsonBuilder(object)

builder.content.visits[0].orderOfDisplay = 23

3. 直接修改原始解析对象 #

跳过builder.content的中间修改，直接修改JsonSlurper解析后的原始对象，再用JsonBuilder重新构建：

def jsonConvert = new JsonSlurper();
def object = jsonConvert.parseText(jsonString);
object.visits[0].orderOfDisplay = 23
def builder = new JsonBuilder(object)

log.info(builder.toPrettyString());

内容的提问来源于stack exchange，提问作者MAX GRIMM