在Go中解析xml

Question

我想解析示例中结构化的XML片段。我一直遇到值是空的。这是我正在使用的简化版本，仅用于显示问题。

package main

import (

        "encoding/xml"

        "fmt"

)

type Entry struct {

        VulnCveId   string  `xml:"entry>vuln:cve-id"`

}

func main() {

        v := Entry{}

        err := xml.Unmarshal([]byte(data), &v)

        if err != nil {

                fmt.Printf("error: %v", err)

                return

        }

        fmt.Println(v.VulnCveId)

}

const data = `

  <entry id="CVE-2005-4895">

    <vuln:vulnerable-configuration id="http://nvd.nist.gov/">

      <cpe-lang:logical-test negate="false" operator="OR">

        <cpe-lang:fact-ref name="cpe:/a:csilvers:gperftools:0.3" />

        <cpe-lang:fact-ref name="cpe:/a:csilvers:gperftools:0.2" />

        <cpe-lang:fact-ref name="cpe:/a:csilvers:gperftools:0.1" />

      </cpe-lang:logical-test>

    </vuln:vulnerable-configuration>

    <vuln:vulnerable-software-list>

      <vuln:product>cpe:/a:csilvers:gperftools:0.3</vuln:product>

      <vuln:product>cpe:/a:csilvers:gperftools:0.1</vuln:product>

      <vuln:product>cpe:/a:csilvers:gperftools:0.2</vuln:product>

    </vuln:vulnerable-software-list>

    <vuln:cve-id>CVE-2005-4895</vuln:cve-id>

    <vuln:published-datetime>2012-07-25T15:55:01.273-04:00</vuln:published-datetime>

    <vuln:last-modified-datetime>2012-08-09T00:00:00.000-04:00</vuln:last-modified-datetime>

    <vuln:cvss>

      <cvss:base_metrics>

        <cvss:score>5.0</cvss:score>

        <cvss:access-vector>NETWORK</cvss:access-vector>

        <cvss:access-complexity>LOW</cvss:access-complexity>

        <cvss:authentication>NONE</cvss:authentication>

        <cvss:confidentiality-impact>NONE</cvss:confidentiality-impact>

        <cvss:integrity-impact>NONE</cvss:integrity-impact>

        <cvss:availability-impact>PARTIAL</cvss:availability-impact>

        <cvss:source>http://nvd.nist.gov</cvss:source>

v.VulnCveId在此实例中为空。我究竟做错了什么？