xml解析最常用的方法

String xpath = String format("/root/shools/shool[@id=\"%d\"]",xx);
String xpath = "/root/shools";
String xpath  = "/root/shools/shool[@id=1]";
String xpath = "//root/shools/shool/class/student[@name=\"alice\"]";

1.获得文档
a.新的
Document document = DocumentHelper.createDocument();
b.旧的
InputStreamReader read=new InputStreamReader(new FileInputStream(filePath), “UTF8”);
SAXReader reader = new SAXReader();
Document document = reader.read(read);

2.查找document单个节点
Node node = document.selectSingleNode(xpath);

3.查找document子节点列表
List<Node> list = document.selectNodes(xpath);

4.写文档
        OutputFormat format = null;
        format = OutputFormat.createCompactFormat();  紧凑格式
        format = OutputFormat.createPrettyPrint();    非紧凑格式  
        format.setTrimText(false); ??
        format.setPadText(false);  ??
        format.setEncoding("GB2312");//用于支持中文
        XMLWriter writer = new XMLWriter(new FileWriter(savePath), format);
        writer.write( document );
        writer.close();

        <也能支持中文>
        OutputFormat format = OutputFormat.createPrettyPrint();    非紧凑格式
        FileOutputStream fos = new FileOutputStream(savePath);
        XMLWriter writer = new XMLWriter(fos, format);
        writer.write(document);
        writer.close();
        
       
        5. 增加根节点
        Element root = document.addElement(“root”);
       
        6.新增加元素
        Element shoolElement = root.addElement("school");
       
        7.增加属性
        shoolElement.addAttribute("shoolName", "xxxx学校");
       
        7.设置元素文本???
        element.setText("sdfsdfs");
       
        9.查找node下的单个节点
        xpath = String.format("/root/shools/shool/class[@classid=\"%d\"]",1);
        Node selNode = node.selectSingleNode(xpath);
       
        10.查找node下的多个节点
        List<Node> list = node.selectNodes(xpath);
       
        11. 取得节点属性值
        String attribute = node.valueOf("@属性名");  必加@
       
        12.取得Element属性值
        element.attributeValue(attribute_name);
       
        13. 修改属性值
                Attribute attribute = element.attribute(attribute_name);
if (attribute != null)
attribute.setValue(attribute_value);

14.删除节点
if (node.getParent() == null) 
       document.remove(node);
else    node.getParent().remove(node);

15.判断字符串是否是合法的XML
DocumentHelper.parseText(content);