Dom創建與修改xml文件詳解

一、基本概念

SAX（Simple API for XML）

• 只能讀，不能修改，只能順序訪問，適合解析大型XML，解析速度快
• 常應用於處理大量數據的XML，實現異構系統的數據訪問，實現跨平臺
• 從文檔的開始通過每一節點移動，定位一個特定的節點

DOM（Document Object Model）

• 不僅能讀，還能修改，而且能夠實現隨機訪問，缺點是解析速度慢，適合解析小型文檔
• 一般應用與小型的配置XML，方便操作
• 爲載入到內存的文檔節點建立類型描述，呈現可橫向移動、潛在巨大的樹型結構
• 在內存中生成節點樹操作代價昂貴

JDOM

•      僅使用具體類而不使用接口
•      API大量使用了Collections類

DOM4J：

•      是JDOM的一種智能分支，它合併了許多超出基本xml文檔表示的功能
•      使用接口和抽象基本類方法，是一個優秀的java xml API
•      具有性能優異、靈活性好、功能強大和極端易用的特點
•      是一個開放源代碼的軟件

二、關於性能

性能測試：（少量數據時）SAX>DOM>DOM4J>JDOM

三、功能詳解

解析xml格式的 sdl文件sld:ColorMapEntry 並且修改color屬性顏色#F7FCB9更改成#000000，文件內容如下↓。

四、測試代碼

package com.kero99.utils;
import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
/**
 * dom解析sdl文件
 * @author ygc
 *
 */
public class DomTest {
		public static void main(String[] args) throws SAXException, IOException, TransformerException {
			//創建解析工廠
			DocumentBuilderFactory sdl=DocumentBuilderFactory.newInstance();		
			try {
				//創建文件解析
				DocumentBuilder file= sdl.newDocumentBuilder();
				//解析文件路徑及名稱
				Document  document= file.parse("D:\\cottonproduct.sld");
				NodeList list=document.getElementsByTagName("sld:ColorMapEntry");
				   for(int i=0;i<list.getLength();i++) {
					   Element node=(Element) list.item(i);
					   if(node.getAttribute("color").equals("#F7FCB9")) {
                                                    //修改屬性
						   node.setAttribute("color", "#000000");
					   }
					   //輸出color屬性值
		               String color=node.getAttributes().getNamedItem("color").getNodeValue();
		               System.out.println(color);
		               TransformerFactory tff = TransformerFactory.newInstance();
			            try {
			            	//保存修改
							Transformer tf= tff.newTransformer();
							tf.transform(new DOMSource(document),new StreamResult(new File("D:\\cottonproduct.sld")));
						} catch (TransformerConfigurationException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
				   }
			
			} catch (ParserConfigurationException e) {
				e.printStackTrace();
			}
		}
}

五、測試結果

成功如下圖所示，參數可以在接口改爲動態的。

六、創建XML

package com.kero99.utils;

import java.io.File;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
/**
 * 生成產量sld文件xml
 * @author ygc
 *
 */
public class CreateSld {
	public DocumentBuilder getDocumentBuilder(){
		// 創建一個DocumentBuilderFactory的對象
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		// 創建DocumentBuilder對象
		DocumentBuilder db =null;
		try {
			db = dbf.newDocumentBuilder();
		} catch (ParserConfigurationException e) {
			e.printStackTrace();
		}
		return db;
	}
	/**
	 * 生成xml
	 */
	public void CreateSldFile(){
		DocumentBuilder db = getDocumentBuilder();
		Document document = db.newDocument();
		document.setXmlStandalone(true);
		Element StyledLayerDescriptor = document.createElement("sld:StyledLayerDescriptor");
		StyledLayerDescriptor.setAttribute("xmlns","http://www.opengis.net/sld");
		StyledLayerDescriptor.setAttribute("xmlns:sld","http://www.opengis.net/sld");
		StyledLayerDescriptor.setAttribute("xmlns:gml", "http://www.opengis.net/gml");
		StyledLayerDescriptor.setAttribute("xmlns:ogc", "http://www.opengis.net/ogc");
		StyledLayerDescriptor.setAttribute("version", "1.0.0");
		//向bookstore根節點中添加子節點book
		Element UserLayer = document.createElement("sld:UserLayer");
		StyledLayerDescriptor.appendChild(UserLayer);
		Element LayerFeatureConstraints = document.createElement("sld:LayerFeatureConstraints");
		UserLayer.appendChild(LayerFeatureConstraints);
		
		Element FeatureTypeConstraint = document.createElement("sld:FeatureTypeConstraint");
		LayerFeatureConstraints.appendChild(FeatureTypeConstraint);

		Element UserStyle = document.createElement("sld:UserStyle");
		UserLayer.appendChild(UserStyle);
		Element Name = document.createElement("sld:Name");
		UserStyle.appendChild(Name);
		Name.setTextContent("yumi");
		Element FeatureTypeStyle = document.createElement("sld:FeatureTypeStyle");
		UserStyle.appendChild(FeatureTypeStyle);
		Element Name2 = document.createElement("sld:Name");
		Name2.setTextContent("name");
		FeatureTypeStyle.appendChild(Name2);
		Element FeatureTypeName = document.createElement("sld:FeatureTypeName");
		FeatureTypeName.setTextContent("Feature");
		FeatureTypeStyle.appendChild(FeatureTypeName);
		Element Rule = document.createElement("sld:Rule");
		FeatureTypeStyle.appendChild(Rule);
		Element RasterSymbolizer = document.createElement("sld:RasterSymbolizer");
		Rule.appendChild(RasterSymbolizer);
		document.appendChild(StyledLayerDescriptor);
		Element ColorMap = document.createElement("sld:ColorMap");
		RasterSymbolizer.appendChild(ColorMap);
		Element ColorMapEntry = document.createElement("sld:ColorMapEntry");
		ColorMapEntry.setAttribute("color","#FFFFE5");
		ColorMapEntry.setAttribute("opacity","0.0");
		Element ColorMapEntry1 = document.createElement("sld:ColorMapEntry");
		ColorMapEntry1.setAttribute("color","#F7FCB9");
		ColorMapEntry1.setAttribute("opacity","1.0");
		Element ColorMapEntry2 = document.createElement("sld:ColorMapEntry");
		ColorMapEntry2.setAttribute("color","#ADDD8E");
		ColorMapEntry2.setAttribute("opacity","1.0");
		Element ColorMapEntry3 = document.createElement("sld:ColorMapEntry");
		ColorMapEntry3.setAttribute("color","#87e670");
		ColorMapEntry3.setAttribute("opacity","1.0");
		Element ColorMapEntry4 = document.createElement("sld:ColorMapEntry");
		ColorMapEntry4.setAttribute("color","#00d65c");
		ColorMapEntry4.setAttribute("opacity","1.0");
		Element ColorMapEntry5 = document.createElement("sld:ColorMapEntry");
		ColorMapEntry5.setAttribute("color","#00ac6e");
		ColorMapEntry5.setAttribute("opacity","1.0");
		ColorMap.appendChild(ColorMapEntry);
		ColorMap.appendChild(ColorMapEntry1);
		ColorMap.appendChild(ColorMapEntry2);
		ColorMap.appendChild(ColorMapEntry3);
		ColorMap.appendChild(ColorMapEntry4);
		ColorMap.appendChild(ColorMapEntry5);
		
		//創建TransformerFactory對象
		TransformerFactory tff = TransformerFactory.newInstance();
		try {
			//創建Transformer對象
			Transformer tf = tff.newTransformer();
			tf.setOutputProperty(OutputKeys.INDENT, "yes");
			String uuid=UuidUtil.getUUID32();
			tf.transform(new DOMSource(document),new StreamResult(new File("D://"+uuid+".sld")));
		} catch (TransformerConfigurationException e) {
			e.printStackTrace();
		} catch (TransformerException e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args) {
		CreateSld createSld = new CreateSld();
		createSld.CreateSldFile();
	}
}

七、創建結果