Grails - 将地图从服务迭代到 csv 文件 - Groovy

Question

如何将结果映射迭代到 CSV 文件中？ 当我在控制器块中有我的方法时，我可以很好地迭代它们，但是如果我把它放在服务中并调用，它就无法识别键并返回空行。 （无法识别 it.column_1。）

class someController {
    def someService

    def export(Person personInstance) {
        def resultRows = someService.result(personInstance)

        response.setHeader("Content-disposition", "attachment; filename=sample.csv")
        response.contentType = "application/vnd.ms-excel"

        def outs = response.outputStream

        outs << "${personInstance}\n"
        outs << "Column1,Column2,Column3,Column4\n"

        resultRows.each() { 
            outs << it.column_1 + "," + it.column_2 + "," + it.column_3 + "," + it.column_4
            outs << "\n"
        }
        outs.flush()
        outs.close()
    }       
}

提前谢谢你。

编辑 我已经包含了有效的代码。

当我在 someService.result 之后 println resultRows 到控制台时，我得到了

[[column_1:John,column_2:Doe,column_3:123 Main Street,column_4:(123)456-7890][column_1:John,column_2:Doe,column_3:123 Main Street,column_4:(123)456- 7890]]

通过以下代码，我得到了一个 excel 格式的可下载 CSV 文件。

class someController {

    def export(Person personInstance) {
        def sql = new Sql(dataSource)
        def resultRows = sql.rows('select * from table where person_id = ?', [personInstance.id])

        [resultRows:resultRows]

        response.setHeader("Content-disposition", "attachment; filename=sample.csv")
        response.contentType = "application/vnd.ms-excel"

        def outs = response.outputStream

        outs << "${personInstance}\n"
        outs << "Column1,Column2,Column3,Column4\n"

        resultRows.each() { 
            outs << it.column_1 + "," + it.column_2 + "," + it.column_3 + "," + it.column_4
            outs << "\n"
        }
        outs.flush()
        outs.close()
    }       
}

编辑 - 找到答案

啊，我发现了问题所在。我在服务中有 [resultRows:resultRows]。我删除了该行并将其放在控制器中 def resultRows 行的正下方。

def export(Person personInstance) {
    def resultRows = someService.result(personInstance)
    [resultRows:resultRows]
....
}

谢谢你们！

Answer 1

啊，我发现了问题所在。我在服务中有 [resultRows:resultRows]。我删除了该行并将其放在控制器中 def resultRows 行的正下方。

def export(Person personInstance) {
    def resultRows = someService.result(personInstance)
    [resultRows:resultRows]
....
}

谢谢你们！