是否可以在不解析其子元素的情况下流式解析 XML 父元素？

Question

给定以下 XML：

<Report name="scan_against_stuff">

    <ReportHost>

        ....

    </ReportHost>

    <ReportHost>

        ....

    </ReportHost>

    <ReportHost>

        ....

    </ReportHost>

    <ReportHost>

        ....

    </ReportHost>

    <ReportHost>

        ....

    </ReportHost>

</Report>

我想在 Go 中流式解析这个 XML。特别是，我想流式解析<ReportHost>元素，而不是一次将它们全部加载到内存中。问题是我还想检索元素的name属性。<Report>为什么这是个问题？那么我熟悉的流解析方法需要我解析整个<Report>元素，这将包括所有<ReportHost>元素，因为它们是元素的子<Report>元素。有什么方法可以让我在<Report>不解析子元素的情况下解析父<ReportHost>元素？

编辑

根据 Volker 的评论，我正在编辑此内容以进行澄清。使用下面的代码，块永远不会else if ty.Local.Name == "ReportHost"触发，而如果块被删除（并更改为），它会触发。我认为这是因为一旦元素被丢弃，作为其子元素的元素就不再可用于处理。"ty.Local.Name == "Report"else ififReportReportHost

parsexml.go

type ReportName struct {

    Name string `xml:"name,attr"`

}

type ReportHost struct{

   ....

}

d := xml.NewDecoder(f)

    for {

        tok, err := d.Token()

        if tok == nil || err == io.EOF {

            // EOF means we're done.

            break

        } else if err != nil {

            log.Fatalf("Error decoding token: %s", err)

        }

        //

        switch element := tok.(type) {

        case xml.StartElement:

            if element.Name.Local == "Report" {

                if err = d.DecodeElement(&reportName, &element); err != nil {

                    log.Fatalf("Error decoding item: %s", err)

                }

            else if element.Name.Local == "ReportHost" {

                if err = d.DecodeElement(&reportHost, &element); err != nil {

                    log.Fatalf("Error decoding item: %s", err)

                }

            }

Answer 1

decode 方法会吞噬元素的所有子元素。要通过元素的子元素进行流式传输，请直接访问元素的属性，而不是使用 decode。&nbsp; &nbsp; switch element := tok.(type) {&nbsp; &nbsp; case xml.StartElement:&nbsp; &nbsp; &nbsp; &nbsp; if element.Name.Local == "Report" {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Look for report name in attributes.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for _, attr := range element.Attr {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if attr.Name.Local == "name" {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("name =", attr.Value)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; } else if element.Name.Local == "ReportHost" {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var reportHost ReportHost&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if err = d.DecodeElement(&reportHost, &element); err != nil {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; log.Fatalf("Error decoding item: %s", err)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("host =", reportHost.Data)&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }