java dom getelementbyid_java,_java xml 操作 getElementById 获取到的总是 null，java - phpStudy...

java xml 操作 getElementById 获取到的总是 null

用的是 org.w3c.dom 中的类

我确定 id 存在的，但是获取到的总是 null。

测试代码如下：

import org.w3c.dom.Document;

import org.w3c.dom.NodeList;

import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import java.io.ByteArrayInputStream;

import java.io.IOException;

import java.io.InputStream;

public class XmlTest {

private static final String originXml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +

"\n" +

" \n" +

" com.sunyard.dragon.organ.Terminal.start#.\n" +

" SequenceFlow_0dx3fgt\n" +

" \n" +

" com.sunyard.dragon.organ.Switch.branch#S.\n" +

" \n" +

" SequenceFlow_0dx3fgt\n" +

" \n" +

"\n";

public static void main(String[] args) throws IOException, SAXException, ParserConfigurationException {

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

factory.setValidating(true);

factory.setNamespaceAware(true); // never forget this!

DocumentBuilder builder = factory.newDocumentBuilder();

InputStream is = new ByteArrayInputStream(originXml.getBytes("UTF-8"));

Document doc = builder.parse(is);

NodeList list = doc.getElementsByTagName("bpmn2:task");

for (int i = 0; i < list.getLength() ; i++){

System.out.println(list.item(i));

}

System.out.println(doc.getElementById("Task_0mhraek"));

}

经过搜索认为问题是没有在 DTD 中定义 ID 是 ID。但是还是不会修改。