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SAX解析器用于解析xml文件,更好地用于内存管理,而不是xml解析器和DOM。它不会在内存中保留任何数据,因此可用于非常大的文件。以下示例将显示如何使用SAX API从xml获取数据。

SAX.xml

XML应如下 -

<?xml version = "1.0" encoding = "utf-8"?>
<tutors>
   <course>
      <name>Android</name>
      <country>India</country>
      <email>contact@vue5.com</email>
      <phone>123456789</phone>
   </course>
   
   <course>
      <name>Java</name>
      <country>India</country>
      <email>contact@tutorialspoint.com</email>
      <phone>123456789</phone>
   </course>
   
   <course>
      <name>HTML</name>
      <country>India</country>
      <email>contact@tutorialspoint.com</email>
      <phone>123456789</phone>
   </course>
</tutors>

SAX.php

Php文件应如下 -

<?php
   //Reading XML using the SAX(Simple API for XML) parser 
   
   $tutors   = array();
   $elements   = null;
   
   // Called to this function when tags are opened 
   function startElements($parser, $name, $attrs) {
      global $tutors, $elements;
      
      if(!empty($name)) {
         if ($name == "COURSE") {
            // creating an array to store information
            $tutors []= array();
         }
         $elements = $name;
      }
   }
   
   // Called to this function when tags are closed 
   function endElements($parser, $name) {
      global $elements;
      
      if(!empty($name)) {
         $elements = null;
      }
   }
   
   // Called on the text between the start and end of the tags
   function characterData($parser, $data) {
      global $tutors, $elements;
      
      if(!empty($data)) {
         if ($elements == "NAME" || $elements == "COUNTRY" ||  $elements == "EMAIL" ||  $elements == "PHONE") {
            $tutors[count($tutors)-1][$elements] = trim($data);
         }
      }
   }
   
   // Creates a new XML parser and returns a resource handle referencing it to be used by the other XML functions. 
   $parser = xml_parser_create(); 
   
   xml_set_element_handler($parser, "startElements", "endElements");
   xml_set_character_data_handler($parser, "characterData");
   
   // open xml file
   if (!($handle = fopen("sax.xml", "r"))) {
      die("could not open XML input");
   }
   
   while($data = fread($handle, 4096)) // read xml file {
      xml_parse($parser, $data);  // start parsing an xml document 
   }
   
   xml_parser_free($parser); // deletes the parser
   $i = 1;
   
   foreach($tutors as $course) {
      echo "course No - ".$i."<br/>";
      echo "course Name - ".$course["NAME"]."<br/>";
      echo "Country - ".$course["COUNTRY"]."<br/>";
      echo "Email - ".$course["EMAIL"]."<br/>";
      echo "Phone - ".$course["PHONE"]."<hr/>"; 
      $i++; 
   }
?>

输出结果如下 -

SAX