XML文件xpath获取数据

一、用xpath不能获取xml数据，是由于xml文件本身的约束限制。如：xmlns等

<?xml version="1.0" encoding="UTF-8"?>
<ClinicalDocument xmlns="urn:hl7-org:v3" xmlns:mif="urn:hl7-org:v3/mif" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:hl7-org:v3 ..\sdschemas\SDA.xsd">

解决方法：

替换掉了相关约束，只留下了xmlns:xsi属性，xpath提取数据成功。

二、常用XPATH解析

<?xml version="1.0" encoding="UTF-8"?>

<class> 
  <student> 
    <name>张三</name>  
    <sid>111111</sid> 
  </student>  
  <student id="stu1"> 
    <name>李四</name>  
    <sid>222222</sid> 
  </student> 
</class>

import java.util.List;
import org.dom4j.Document;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
public class Dom4jXpath {

    public static void main(String[] args) throws Exception {
        select();//查询所有name的值
        //select2();//查询id=stu1的学生的name的值
    }
    //查询所有name的值
    private static void select() throws Exception {
        SAXReader saxReader=new SAXReader();
        Document document=saxReader.read("src/1.xml");
        List<Node>list=document.selectNodes("//name");
        for(int i=0;i<list.size();i++)
            System.out.println(list.get(i).getText());
    }
    //查询id=stu1的学生的name的值
    private static void select2() throws Exception {
        SAXReader saxReader=new SAXReader();
        Document document=saxReader.read("src/1.xml");
        Node node=document.selectSingleNode("//student[@id='stu1']/name");
        System.out.println(node.getText());
    }
}

已用示例

Map<String, String> result = new HashMap<>();

List<Node> nodes = document.selectNodes(
    "//ClinicalDocument/component/structuredBody/component/section/entry/observation");

for (Node node : nodes) {
    List<Node> nodeList = node.selectNodes("code[@displayName='主诉']");
    if (nodeList.size() != 0) {
        String value = node.selectSingleNode("value").getText();
        result.put("主诉", value);
    }

    List<Node> nodeList2 = node.selectNodes("code[@displayName='现病史']");
    if (nodeList2.size() != 0) {
        String value = node.selectSingleNode("value").getText();
        result.put("现病史", value);
    }

    List<Node> nodeList3 = node.selectNodes("code[@displayName='确定诊断-西医诊断名称']");
    if (nodeList3.size() != 0) {
        String value = node.selectSingleNode("value").getText();
        result.put("诊断", value);
    }

}