如何将节点附加到java中的现有XML文件

时间:2011-06-22 20:03:44

标签: java xml

public static void addALLToXML(Collection<Server> svr) throws IOException,
      ParserConfigurationException, TransformerException
{
    DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
        .newInstance();
    DocumentBuilder documentBuilder = documentBuilderFactory
        .newDocumentBuilder();
    Document document = documentBuilder.newDocument();

    // Root Element
    Element rootElement = document.createElement("Servers");
    document.appendChild(rootElement);

    for (Server i : svr)
    {
        // server elements
        Element server = document.createElement("server");
        rootElement.appendChild(server);

        Element name = document.createElement("name");
        name.appendChild(document.createTextNode(i.getName()));
        server.appendChild(name);

        Element port = document.createElement("port");
        port.appendChild(document.createTextNode(Integer.toString(i.getPort())));
        server.appendChild(port);
    }

    TransformerFactory transformerFactory = TransformerFactory.newInstance();
    Transformer transformer = transformerFactory.newTransformer();
    DOMSource source = new DOMSource(document);

    StreamResult result = new StreamResult("/home/user/server.xml");
    transformer.transform(source, result);
}

这是我需要帮助的功能:

public static void addNodeToXML(String nameIn, String portIn)
      throws ParserConfigurationException, SAXException, IOException
{
    DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
            .newInstance();
    DocumentBuilder documentBuilder = documentBuilderFactory
            .newDocumentBuilder();

    /* parse existing file to DOM */
    Document document = documentBuilder
            .parse(new File("/home/user/server.xml"));

    // Root Element
    Element rootElement = document.createElement("Servers");
    document.appendChild(rootElement);

    // server elements
    Element server = document.createElement("server");
    rootElement.appendChild(server);

    Element name = document.createElement("name");
    name.appendChild(document.createTextNode(nameIn));
    server.appendChild(name);

    Element port = document.createElement("port");
    port.appendChild(document.createTextNode(portIn));
    server.appendChild(port);
}

原件:

<Servers>
 <server>
  <name>something</name>
  <port>port</port>
 </server>
 </Servers>

通缉:

<Servers> 
  <server>
   <name>something</name>
   <port>port</port>
  </server>
  <server>
   <name>something</name>
   <port>port</port>
  </server>
<Servers>

5 个答案:

答案 0 :(得分:34)

以下完整示例将从当前目录中读取现有 server.xml文件,附加新服务器并将文件重新写入server.xml。如果没有现有的.xml文件,它就无法运行,因此您需要修改代码来处理这种情况。

import java.util.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
import javax.xml.transform.dom.*;
import org.w3c.dom.*;
import javax.xml.parsers.*;

public class AddXmlNode {
    public static void main(String[] args) throws Exception {

        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
        Document document = documentBuilder.parse("server.xml");
        Element root = document.getDocumentElement();

        Collection<Server> servers = new ArrayList<Server>();
        servers.add(new Server());

        for (Server server : servers) {
            // server elements
            Element newServer = document.createElement("server");

            Element name = document.createElement("name");
            name.appendChild(document.createTextNode(server.getName()));
            newServer.appendChild(name);

            Element port = document.createElement("port");
            port.appendChild(document.createTextNode(Integer.toString(server.getPort())));
            newServer.appendChild(port);

            root.appendChild(newServer);
        }

        DOMSource source = new DOMSource(document);

        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        StreamResult result = new StreamResult("server.xml");
        transformer.transform(source, result);
    }

    public static class Server {
        public String getName() { return "foo"; }
        public Integer getPort() { return 12345; }
    }
}

示例 server.xml 文件:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Servers>
  <server>
    <name>something</name>
    <port>port</port>
  </server>
</Servers>

代码的主要更改是而不是创建新的“root”元素。上面的示例只使用现有server.xml中的当前根节点,然后只需附加一个新的 Server 元素并重写该文件。

答案 1 :(得分:6)

要附加新数据元素,只需执行此操作...

Document doc = docBuilder.parse(is);        
Node root=doc.getFirstChild();
Element newserver=doc.createElement("new_server");
root.appendChild(newserver);

easy ....'is'是一个InputStream对象。休息类似于你的代码....刚刚尝试过......

答案 2 :(得分:1)

您可以将现有XML文件解析为DOM,并将新元素附加到DOM。与您在创建全新XML时所做的非常相似。我假设您不必担心重复的服务器。如果你不必担心这一点,你将不得不浏览DOM中的元素来检查重复项。

DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();

/* parse existing file to DOM */
Document document = documentBuilder.parse(new File("exisgint/xml/file"));

Element root = document.getDocumentElement();

for (Server newServer : Collection<Server> bunchOfNewServers){
  Element server = Document.createElement("server");
  /* create and setup the server node...*/

 root.appendChild(server);
}

/* use whatever method to output DOM to XML (for example, using transformer like you did).*/

答案 3 :(得分:0)

如果需要在某个特定位置插入节点/元素,可以执行后续步骤

  1. 将原始xml分为两部分
  2. 首先将您的新节点/元素作为子元素添加到第一个(第一部分应该在您想要添加元素之后以元素结束)
  3. 将第二部分附加到新文档。
  4. 这是一个简单的算法,但应该有效...

答案 4 :(得分:-1)

你可以使用DOM4j来做这件事。