PHPXML怎么解析_PHPXML数据解析与操作方法教程

<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
    <book category="cooking">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
    </book>
    <book category="children">
        <title lang="en">Harry Potter</title>
        <author>J.K. Rowling</author>
        <year>2005</year>
        <price>29.99</price>
    </book>
</bookstore>

<?php
$xmlString = <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
    <book category="cooking">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
    </book>
    <book category="children">
        <title lang="en">Harry Potter</title>
        <author>J.K. Rowling</author>
        <year>2005</year>
        <price>29.99</price>
    </book>
</bookstore>
XML;

// 从字符串加载XML
$xml = simplexml_load_string($xmlString);

if ($xml === false) {
    echo "Failed to load XML\n";
    foreach(libxml_get_errors() as $error) {
        echo "\t", $error->message;
    }
    exit;
}

echo "--- SimpleXML 解析示例 ---\n";
// 遍历所有书籍
foreach ($xml->book as $book) {
    echo "书名: " . $book->title . " (语言: " . $book->title['lang'] . ")\n";
    echo "作者: " . $book->author . "\n";
    echo "价格: " . $book->price . "\n";
    echo "分类: " . $book['category'] . "\n\n"; // 访问属性
}

// 修改一个节点的值
$xml->book[0]->price = "35.00";
echo "修改后的第一本书价格: " . $xml->book[0]->price . "\n\n";

// 添加一个新节点
$newBook = $xml->addChild('book');
$newBook->addAttribute('category', 'fiction');
$newBook->addChild('title', 'The Hitchhiker\'s Guide to the Galaxy');
$newBook->addChild('author', 'Douglas Adams');
$newBook->addChild('year', '1979');
$newBook->addChild('price', '15.99');

echo "--- 添加新书后的XML ---\n";
echo $xml->asXML(); // 输出修改后的XML
?>

<?php
$xmlString = <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
    <book category="cooking">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
    </book>
</bookstore>
XML;

$dom = new DOMDocument();
$dom->loadXML($xmlString);

echo "\n--- DOMDocument 解析示例 ---\n";
// 获取所有<book>节点
$books = $dom->getElementsByTagName('book');

foreach ($books as $book) {
    $title = $book->getElementsByTagName('title')->item(0)->nodeValue;
    $author = $book->getElementsByTagName('author')->item(0)->nodeValue;
    $category = $book->getAttribute('category');
    echo "书名: $title, 作者: $author, 分类: $category\n";
}

// 修改第一个<book>的<price>
$firstBook = $books->item(0);
$priceNode = $firstBook->getElementsByTagName('price')->item(0);
if ($priceNode) {
    $priceNode->nodeValue = "40.00";
}

// 添加一个新<book>节点
$newBook = $dom->createElement('book');
$newBook->setAttribute('category', 'science');

$newTitle = $dom->createElement('title', 'Cosmos');
$newBook->appendChild($newTitle);
$newAuthor = $dom->createElement('author', 'Carl Sagan');
$newBook->appendChild($newAuthor);
$newYear = $dom->createElement('year', '1980');
$newBook->appendChild($newYear);
$newPrice = $dom->createElement('price', '25.50');
$newBook->appendChild($newPrice);

$dom->getElementsByTagName('bookstore')->item(0)->appendChild($newBook);

echo "\n--- 修改并添加新书后的XML (DOMDocument) ---\n";
echo $dom->saveXML();
?>

<?php
// 假设有一个非常大的XML文件 'large_data.xml'
// 为了演示，我们先创建一个模拟的大文件
$largeXmlContent = '<?xml version="1.0" encoding="UTF-8"?>';
$largeXmlContent .= '<products>';
for ($i = 0; $i < 10000; $i++) { // 模拟1万个产品
    $largeXmlContent .= '<product id="' . $i . '">';
    $largeXmlContent .= '<name>Product ' . $i . '</name>';
    $largeXmlContent .= '<price>' . (rand(10, 1000) / 100) . '</price>';
    $largeXmlContent .= '<description>Description for product ' . $i . '</description>';
    $largeXmlContent .= '</product>';
}
$largeXmlContent .= '</products>';
file_put_contents('large_data.xml', $largeXmlContent);


echo "\n--- 使用XMLReader 解析大型文件 ---\n";
$reader = new XMLReader();
if (!$reader->open('large_data.xml')) {
    die("Failed to open XML file");
}

$productCount = 0;
while ($reader->read()) {
    // 找到<product>元素的开始标签
    if ($reader->nodeType == XMLReader::ELEMENT && $reader->name == 'product') {
        // 可以选择将当前节点及其子节点作为SimpleXML对象加载，方便操作
        // 注意：这里只是加载当前<product>节点及其内部，而不是整个文件
        $node = simplexml_load_string($reader->readOuterXML());
        if ($node) {
            $productCount++;
            // 假设我们只关心前5个产品，或者做一些统计
            if ($productCount <= 5) {
                echo "产品ID: " . $node['id'] . ", 名称: " . $node->name . ", 价格: " . $node->price . "\n";
            }
        }
        // 如果不需要SimpleXML，可以直接通过XMLReader获取属性和子节点
        // $productId = $reader->getAttribute('id');
        // $reader->read(); // 移动到下一个节点
        // if ($reader->name == 'name') {
        //     $reader->read(); // 移动到文本节点
        //     $productName = $reader->value;
        // }
        // ... 继续手动遍历子节点
    }
}
$reader->close();
echo "总共处理了 " . $productCount . " 个产品。\n";

// 清理模拟文件
unlink('large_data.xml');
?>