htmlparser的简单使用说明

一、DOM过滤 

    1. 根据attribute过滤 
        Parser parser = new Parser(htmlString);// or new Parser(url) 
        NodeFilter filter = new HasAttributeFilter("class", "sidebar");//　本例为根据class过滤，当然可以标签中的任意attribute 
        NodeList nodelist = parser.extractAllNodesThatMatch(filter); 

    2. 根据tag过滤 
        NodeList nodelist = parser.parse(new TagNameFilter("table"));// 根据table标签过滤 
        or 
        NodeList  nodelist = parser.parse(new NodeClassFilter(TableTag.class)); 

    3. 层级and过滤 
        // 如查找示例1中class="sidebar"下面的tr标签 
        NodeFilter filter = new HasAttributeFilter("class", "sidebar"); 
        NodeFilter f = new AndFilter(new TagNameFilter("tr"), new HasParentFilter(filter)); 
        NodeList nodelist = parser.parse(f); 
        or 
        // 查找所有table下面的tr 
        NodeFilter f = new AndFilter(new TagNameFilter("tr"), new HasParentFilter(new TagNameFilter("table"))); 
        NodeList nl = parser.parse(f); 

    4. or满足 
        Parser parser = new Parser(url); 
        // parser.setEncoding("UTF-8"); 
        // 过滤得到class为toptext，或者id为sample的内容 
        HasAttributeFilter[] f = new HasAttributeFilter[] { 
    new HasAttributeFilter("class", "toptext"), 
    new HasAttributeFilter("id", "sample") 
        }; 
        NodeFilter nodeFilter = new OrFilter(f); 

       // and过滤类似 



二、NodeList遍历及子节点 
    1. for循环 
       for (int i = 0; i < nodeList.size(); i++) { 
            Node node = nodeList.elementAt(i); 
       } 

    2. SimpleNodeIterator 
       SimpleNodeIterator iterator = nodeList.elements(); 
       while(iterator.hasMoreNodes()) { 
            Node node = iterator.nextNode(); 
       } 

    3. 子节点 
       NodeList pList = node.getChildren();// 获取子节点 
     


三、节点判断 
    // 判断node是否为head标签 
    if (node instanceof org.htmlparser.tags.HeadingTag) {...} 

    // 判断node是否为div标签 
    if (node instanceof org.htmlparser.tags.Div) {...} 

    // 判断node是否为p标签 
    if (node instanceof org.htmlparser.tags.ParagraphTag) {...} 

    // MORE ... 

    // etc：判断当前div是否class为section 
    if ("section".equals(((org.htmlparser.tags.Div) node).getAttribute("class"))) {...} 


四、内容获取 

    // 获取节点源html内容 
    node.toHtml() 
    
    // 获取节点文本内容，如输入“<td>abc</td>”，输出“abc” 
    node.toPlainTextString