BridgeLi's Blog

XML和JSON字符串的解析，是Java程序猿的必备技能，关于XML和JSON如何解析，网上的例子可以说是一拉一大把，解析JSON的有什么GSON、json-lib等一大批做得非常好的第三方工具，解析XML的也有什么DOM4J、JDOM、SAX、DOM等等，今天大桥就给大家展示一下如何有JDK自己解析XML，废话不多说，代码如下：

package cn.bridgeli.parsexmldemo.parsexml;

import java.io.FileNotFoundException;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class ParseXml {

public void parserXml(String fileName) {
    try {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        Document document = db.parse(fileName);
        NodeList rootNode = document.getChildNodes();

        parseNode(rootNode.item(0));

    } catch (FileNotFoundException e) {
        System.out.println(e.getMessage());
    } catch (ParserConfigurationException e) {
        System.out.println(e.getMessage());
    } catch (SAXException e) {
        System.out.println(e.getMessage());
    } catch (IOException e) {
        System.out.println(e.getMessage());
    }
}

public void parseNode(Node node) {
    if (node == null) {
        return;
    }

    // if not have child
    if (!node.hasChildNodes()) {

        NamedNodeMap attrs = node.getAttributes();
        if (attrs != null) {
            for (int i = 0; i < attrs.getLength(); i++) {
                Attr attribute = (Attr) attrs.item(i);
                System.out.print("AttributeName===" + attribute.getName() + " AttributeValue===" + attribute.getValue());
            }
        }
        String str = node.getTextContent().toString().replaceAll("n", "").replaceAll(" ", "");
        if (!str.equals("")) {
            System.out.println("TextContent ===" + str);
        }
    }else {
        // get attributes
        NamedNodeMap attrs = node.getAttributes();
            if (attrs != null) {
                for (int i = 0; i < attrs.getLength(); i++) {
                    Attr attribute = (Attr) attrs.item(i);
                    System.out.println("AttributeName===" + attribute.getName() + " AttributeValue===" + attribute.getValue());
                }
            }

            // get child node
            NodeList nodes = node.getChildNodes();
            for (int j = 0; j < nodes.getLength(); j++) {
                parseNode(nodes.item(j));
            }
        }

    }
}

具体可以参考：

https://www.ibm.com/developerworks/cn/xml/x-jdom/

http://developer.51cto.com/art/200903/117512.htm

后记：

看完这篇文章，再加上之间的<a href=”https://www.bridgeli.cn/archives/54″ title=”动态代理模拟Spring的AOP”></a>，大家是不是自己就可以模拟出Spring的IOC了？其实也很简单，有机会我会自己写一篇出来