Question

我通过Web服务收到XML，并且我使用遗留代码（使用dom4j）来执行某些xml转换。将原始XML加载/解析为VTD-XML（VTDGen）工作正常，不会抛出任何异常。但是，在将xml加载到dom4j之后，我注意到一些元素名称空间声明和属性被重新排列。显然，这种重新安排会导致VTD-XML抛出以下异常：

例外：名称空间限定例外：前缀属性不合格

行号：101偏移量：1827

以下是原始XML中此行号的元素：

＆lt; RR_PerformanceSite：PerformanceSite_1_4 RR_PerformanceSite：FormVersion =＆＃34; 1.4＆＃34;的xmlns：NSF_ApplicationChecklist =＆＃34; HTTP：//apply.grants.gov/forms/NSF_ApplicationChecklist-V1.1"的xmlns：NSF_CoverPage =＆＃34; HTTP：//apply.grants.gov/forms/NSF_CoverPage-V1.1"的xmlns：NSF_DeviationAuthorization =＆＃34; HTTP：//apply.grants.gov/forms/NSF_DeviationAuthorization-V1.1"的xmlns：NSF_Registration =＆＃34; HTTP：//apply.grants.gov/forms/NSF_Registration-V1.1"的xmlns：NSF_SuggestedReviewers =＆＃34; HTTP：//apply.grants.gov/forms/NSF_SuggestedReviewers-V1.1"的xmlns：PHS398_CareerDevelopmentAwardSup =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_CareerDevelopmentAwardSup_1_1-V1.1"的xmlns：PHS398_Checklist =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_Checklist_1_3-V1.3"的xmlns：PHS398_CoverPageSupplement =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_CoverPageSupplement_1_4-V1.4"的xmlns：PHS398_ModularBudget =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_ModularBudget-V1.1"的xmlns：PHS398_ResearchPlan =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_ResearchPlan_1_3-V1.3"的xmlns：PHS_CoverLetter =＆＃34; HTTP：//apply.grants.gov/forms/PHS_CoverLetter_1_2-V1.2"的xmlns：RR_Budget =＆＃34; HTTP：//apply.grants.gov/forms/RR_Budget-V1.1"的xmlns：RR_KeyPersonExpanded =＆＃34; HTTP：//apply.grants.gov/forms/RR_KeyPersonExpanded_1_2-V1.2"的xmlns：RR_OtherProjectInfo =＆＃34; HTTP：//apply.grants.gov/forms/RR_OtherProjectInfo_1_2-V1.2"的xmlns：RR_PerformanceSite =＆＃34; HTTP：//apply.grants.gov/forms/PerformanceSite_1_4-V1.4"的xmlns：RR_PersonalData =＆＃34; HTTP：//apply.grants.gov/forms/RR_PersonalData-V1.1"的xmlns：RR_SF424 =＆＃34; HTTP：//apply.grants.gov/forms/RR_SF424_1_2-V1.2"的xmlns：RR_SubawardBudget =＆＃34; HTTP：//apply.grants.gov/forms/RR_SubawardBudget-V1.2"的xmlns：SF424C =＆＃34; HTTP：//apply.grants.gov/forms/SF424C-V1.0"的xmlns：ATT =＆＃34; HTTP：//apply.grants.gov/system/Attachments-V1.0"的xmlns：码=＆＃34; HTTP：//apply.grants.gov/system/UniversalCodes-V2.0"的xmlns：globlib =＆＃34; HTTP：//apply.grants.gov/system/GlobalLibrary-V2.0"＆GT;

加载到dom4j后，这是相同的元素：

＆lt; RR_PerformanceSite：PerformanceSite_1_4 xmlns：RR_PerformanceSite =＆＃34; http：//apply.grants.gov/forms/PerformanceSite_1_4-V1.4"的xmlns：NSF_ApplicationChecklist =＆＃34; HTTP：//apply.grants.gov/forms/NSF_ApplicationChecklist-V1.1"的xmlns：NSF_CoverPage =＆＃34; HTTP：//apply.grants.gov/forms/NSF_CoverPage-V1.1"的xmlns：NSF_DeviationAuthorization =＆＃34; HTTP：//apply.grants.gov/forms/NSF_DeviationAuthorization-V1.1"的xmlns：NSF_Registration =＆＃34; HTTP：//apply.grants.gov/forms/NSF_Registration-V1.1"的xmlns：NSF_SuggestedReviewers =＆＃34; HTTP：//apply.grants.gov/forms/NSF_SuggestedReviewers-V1.1"的xmlns：PHS398_CareerDevelopmentAwardSup =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_CareerDevelopmentAwardSup_1_1-V1.1"的xmlns：PHS398_Checklist =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_Checklist_1_3-V1.3"的xmlns：PHS398_CoverPageSupplement =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_CoverPageSupplement_1_4-V1.4"的xmlns：PHS398_ModularBudget =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_ModularBudget-V1.1"的xmlns：PHS398_ResearchPlan =＆＃34; HTTP：//apply.grants.gov/forms/PHS398_ResearchPlan_1_3-V1.3"的xmlns：PHS_CoverLetter =＆＃34; HTTP：//apply.grants.gov/forms/PHS_CoverLetter_1_2-V1.2"的xmlns：RR_Budget =＆＃34; HTTP：//apply.grants.gov/forms/RR_Budget-V1.1"的xmlns：RR_KeyPersonExpanded =＆＃34; HTTP：//apply.grants.gov/forms/RR_KeyPersonExpanded_1_2-V1.2"的xmlns：RR_OtherProjectInfo =＆＃34; HTTP：//apply.grants.gov/forms/RR_OtherProjectInfo_1_2-V1.2"的xmlns：RR_PersonalData =＆＃34; HTTP：//apply.grants.gov/forms/RR_PersonalData-V1.1"的xmlns：RR_SF424 =＆＃34; HTTP：//apply.grants.gov/forms/RR_SF424_1_2-V1.2"的xmlns：RR_SubawardBudget =＆＃34; HTTP：//apply.grants.gov/forms/RR_SubawardBudget-V1.2"的xmlns：SF424C =＆＃34; HTTP：//apply.grants.gov/forms/SF424C-V1.0"的xmlns：ATT =＆＃34; HTTP：//apply.grants.gov/system/Attachments-V1.0"的xmlns：码=＆＃34; HTTP：//apply.grants.gov/system/UniversalCodes-V2.0"的xmlns：globlib =＆＃34; HTTP：//apply.grants.gov/system/GlobalLibrary-V2.0" RR_PerformanceSite：FormVersion =＆＃34; 1.4＆＃34;＆GT;

问题在于新XML元素中的属性（在元素末尾的偏移1827处）：RR_PerformanceSite：FormVersion =＆＃34; 1.4＆＃34;

以下是删除异常的原因： 1.将此元素的RR_PerformanceSite xmlns声明添加到XML文档的根元素。 2.用原始元素替换新元素。这个SEEMS让我相信在解析时属性/ ns声明的顺序会影响VTD。

注意：我将xml doc设置解析为＆＃39; true＆＃39;使用两个xml文档（原始和后dom4j xml）。此外，还为每个xml，原始和后dom4j创建了新的VTD对象。

我试图将＆＃39; RR_PerformanceSite：FormVersion =＆＃34; 1.4＆＃34;＆＃39;在元素的开头像原始但不会删除异常。由于属性位置的改变，错误消息中的偏移量是不同的。 xmlns声明的顺序是否会影响VTD？

我查看了VTDGen源代码，但无法弄清楚为什么会抛出此异常。

为什么dom4j会解析新的doc并且vtd无法解析？任何人都可以对此有所了解吗？

Answer 1

它似乎是VTD-XML的一个错误，与命名空间声明顺序有关。

始终可以使用以下Java代码重现

public class SchemaTester {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {

        String bad = "C:/Temp/VTD_bad.xml"; // XML files to test
        String good = "C:/Temp/VTD_good.xml";

        StringBuilder sb = new StringBuilder();

        char[] buf = new char[4*1024];
        FileReader fr = new FileReader(bad);
        int readed = 0;

        while ((readed = fr.read(buf, 0, buf.length)) != -1) {
            sb.append(buf, 0, readed);
        }

        fr.close();

        String x = sb.toString();

        //instantiate VTDGen
        //and call parse 
        VTDGen vg = new VTDGen();
        vg.setDoc(x.getBytes("UTF-8"));
        vg.parse(true);  // set namespace awareness to true
        VTDNav vn = vg.getNav();



        AutoPilot ap = new AutoPilot (vn);
        ap.selectXPath("//*/@*");

        int i= -1;
        while((i=ap.evalXPath()) != -1) {
            // i will be attr name, i+1 will be attribute value
            System.out.println("\t\tAttribute ==> " + vn.toNormalizedString(i));
            System.out.println("\t\tValue ==> " + vn.toNormalizedString(i+1));
        } 

    }
}

OP已将XML上传到https://gist.github.com/2696220

VTD-XML异常：名称空间限定异常：前缀属性未限定

1 个答案: