做下笔记

今天写的代码,做下笔记:

//dom生成xml文件
package test;
import javax.xml.parsers.DocumentBuilder;

public class DOMTest2 {
private String infile = "c://people.xml";
public static void main(String args[]) {
  new DOMTest2();
}
public DOMTest2() {
  try {
   DocumentBuilder Builder = javax.xml.parsers.DocumentBuilderFactory
     .newInstance().newDocumentBuilder();
       org.w3c.dom.Document doc=Builder.newDocument();
       org.w3c.dom.Element root=doc.createElement("root");
       org.w3c.dom.Element left=doc.createElement("left");
       org.w3c.dom.Element right=doc.createElement("right");
       left.appendChild(doc.createTextNode("wo shi left"));
       root.appendChild(left);
       root.appendChild(right);
       doc.appendChild(root);
       javax.xml.transform.Transformer transform = javax.xml.transform.TransformerFactory
   .newInstance().newTransformer();
   transform.setOutputProperty(javax.xml.transform.OutputKeys.ENCODING,"gb2312");
   transform.setOutputProperty(javax.xml.transform.OutputKeys.INDENT,"yes");
transform
   .transform(
     new javax.xml.transform.dom.DOMSource(
       doc),
     new javax.xml.transform.stream.StreamResult(
       infile));
  } catch (Exception e) {
   System.out.print(e);
  }
}
}
==================================================================================
//修改xml
package test;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class DOMTest {
private String outfile = "c://people.xml";
int i = 0;
public static void main(String args[]) {
  new DOMTest();
}
public DOMTest() {
  try {
   DocumentBuilder Builder = javax.xml.parsers.DocumentBuilderFactory
     .newInstance().newDocumentBuilder();
   org.w3c.dom.Document doc = Builder.parse(outfile);
   Node child;
   Node next = doc.getFirstChild();
   NodeList nodelist;
   org.w3c.dom.Element last = doc.createElement("last");
   while ((child = next) != null) {
    System.out.println(next.getNodeName());
    if ((nodelist = next.getChildNodes()) != null) {
     while (i < nodelist.getLength()
       && (child = nodelist.item(i++)) != null) {
    
      if (child.getNodeName().equals("left")) {
       org.w3c.dom.Element newleft = doc
         .createElement("newleft");
       System.out.println(child.getTextContent());
       newleft.appendChild(doc.createTextNode(child
         .getTextContent()));
       doc.getDocumentElement().replaceChild(newleft,
         child);
      }
     }
     next = next.getPreviousSibling();
    }
   }
   //从内存中的dom保存到指定路径的文件中
   javax.xml.transform.Transformer transform = javax.xml.transform.TransformerFactory
     .newInstance().newTransformer();
   transform.transform(new javax.xml.transform.dom.DOMSource(doc),
     new javax.xml.transform.stream.StreamResult(outfile));
  } catch (Exception e) {
   System.out.print(e.getMessage());
  }
}
}