Question

我正在尝试流解析一个大约4GB的XML文件，并将其中的一部分写入PHP中的新XML文件。

~4GB XML文档的结构是这样的，我试图保留<doc>元素及其<title></title> <url></url>和<abstract></abstract>子元素。

但当我运行此脚本时，我得到的是每行<doc />一个文件。所以基本上它是复制<doc>元素并让它们自我 - 关闭，但不要复制其子女。

<?php

    $interestingNodes = array('title','url','abstract');
    $xmlObject = new XMLReader();
    $xmlObject->open('file.xml');

    $xmlOutput = new XMLWriter();
    $xmlOutput->openURI('destfile.xml');
    $xmlOutput->setIndent(true);
    $xmlOutput->setIndentString("   ");
    $xmlOutput->startDocument('1.0', 'UTF-8');

    while($xmlObject->read()){
        if($xmlObject->name == 'doc'){
             $xmlOutput->startElement('doc');
             $xmlObject->readInnerXML();
             if(array_search($xmlObject->name, $interestingNodes)){
                 $xmlOutput->startElement($xmlObject->name);
                 $xmlOutput->text($xmlObject->value);
                 $xmlOutput->endElement(); //close the current node
             }
             $xmlOutput->endElement(); //close the doc node
        }
    }

    $xmlObject->close();
    $xmlOutput->endDocument();
    $xmlOutput->flush();

?>

这是file.xml的样子：

<feed>
    <doc>
        <title>Title of first doc is here</title>
        <url>URL is here</url>
        <abstract>Abstract is here...</abstract>
        <links>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
       </link>
    </doc>
    <doc>
        <title>Title of second doc is here</title>
        <url>URL is here</url>
        <abstract>Abstract is here...</abstract>
        <links>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
            <sublink>Link is here</sublink>
        </link>
    </doc>
 </feed>

这就是我想要的destfile.xml：

    <doc>
        <title>Title of first doc is here</title>
        <url>URL is here</url>
        <abstract>Abstract is here...</abstract>
    </doc>
    <doc>
        <title>Title of second doc is here</title>
        <url>URL is here</url>
        <abstract>Abstract is here...</abstract>
    </doc>

但是，当我在上面运行该脚本时，我得到的只是：

<doc />
<doc />
<doc />
<doc />
<doc />
<doc />
/* And many, many more <doc />s */

Answer 1

我相信以下内容会做你想要做的事情：

<?php

    $interestingNodes = array('title','url','abstract');
    $xmlObject = new XMLReader();
    $xmlObject->open('file.xml');

    $xmlOutput = new XMLWriter();
    $xmlOutput->openURI('destfile.xml');
    $xmlOutput->setIndent(true);
    $xmlOutput->setIndentString("   ");
    $xmlOutput->startDocument('1.0', 'UTF-8');

    while($xmlObject->read()){
        if($xmlObject->name == 'doc'){
            if($xmlObject->nodeType==XMLReader::END_ELEMENT) $xmlOutput->endElement();
            else $xmlOutput->startElement('doc');
        }
        if(in_array($xmlObject->name, $interestingNodes)){
            $xmlOutput->startElement($xmlObject->name);
            $xmlOutput->text($xmlObject->readString());
            $xmlOutput->endElement(); //close the current node
        }
    }

    $xmlObject->close();
    $xmlOutput->endDocument();
    $xmlOutput->flush();

?>

流解析4GB XML文件，并将部分文件写入PHP中的新XML文件

1 个答案: