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用java解析在OpenStreetMap上下载的地图数据(SAX版,适合比较大的xml文件)

2016-01-14 10:31 429 查看
java程序如下:

package gao.map.preprocess;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.helpers.DefaultHandler;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

/**
* 处理从OpenStreetMap下载的原始数据,将抽取的数据输出为text文件
* @author Administrator
*
*/
public class OpenStreetMap {
static String s = null;
//实现自己的解析方式
static class MySAXHandler extends DefaultHandler {

FileOutputStream fosPoint;
FileOutputStream fosArc;
OutputStreamWriter oswPoint;
OutputStreamWriter oswArc;
BufferedWriter bwPoint;
BufferedWriter bwArc;
//开始解析时调用
public void startDocument() throws SAXException {
// 点信息
File pointFile = new File("D:\\项目\\mongo\\MapPre\\Point.txt");
// 弧信息
File arcFile = new File("D:\\项目\\mongo\\MapPre\\Arc.txt");
try {
fosPoint = new FileOutputStream(pointFile);
fosArc = new FileOutputStream(arcFile);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
oswPoint = new OutputStreamWriter(fosPoint);
oswArc = new OutputStreamWriter(fosArc);
bwPoint = new BufferedWriter(oswPoint);
bwArc = new BufferedWriter(oswArc);
System.out.println("开始解析文档!");
}

//完成解析时调用
public void endDocument() throws SAXException {
try {
bwPoint.close();
oswPoint.close();
fosPoint.close();
bwArc.close();
oswArc.close();
fosArc.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("文档解析完成!");
}

/**
* 开始一个元素的解析
* @param uri
* @param localName
* @param qName 标签名
* @param attributes 属性
* @throws SAXException
*/
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
if ((attributes != null)&&attributes.getLength() > 0) {
if(qName.equals("node")){
StringBuilder sb = new StringBuilder();
sb.append(attributes.getValue("id")+"      ");
sb.append(attributes.getValue("lat")+"      ");
sb.append(attributes.getValue("lon"));
try {
bwPoint.write(sb.toString()+"\r\n");
bwPoint.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(sb.toString());
}else if(qName.equals("way")){
s = attributes.getValue("id")+"      "
+attributes.getValue("version")+"      ";
}else if(qName.equals("nd")){
if(s==null)
return;
try {
bwArc.write(s+attributes.getValue("ref")+"      \r\n");
bwArc.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(s+attributes.getValue("ref")+"      ");
}else if(qName.equals("tag")){
if(s==null)
return;
try {
bwArc.write(s+"      "+attributes.getValue("k")+"\r\n");
bwArc.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(s+"      "+attributes.getValue("k"));
}else if(qName.equals("relation")){
if(s!=null)
s = null;
}
}
}

/**
* 结束一个元素的解析,遇到结束标签时调用此方法 通常在此方法对标签取值并处理
* @param uri
* @param localName
* @param qName
* @throws SAXException
*/
public void endElement(String uri, String localName, String qName)
throws SAXException {

}

//该方法是获得元素间的text文本内容,可以通过new String(ch, start, length)来获得
public void characters(char[] ch, int start, int length)
throws SAXException {
//            System.out.print(new String(ch, start, length));
}
}

public static void main(String[] args) {
SAXParserFactory saxfac = SAXParserFactory.newInstance();
try {
SAXParser saxparser = saxfac.newSAXParser();
InputStream is = new FileInputStream("D:\\项目\\map");
MySAXHandler handler = new MySAXHandler();
saxparser.parse(is, handler);;
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
}


参考链接:

四种生成和解析XML文档的方法详解(介绍+优缺点比较+示例)

快速有效的解析大型XML文件

详解Java解析XML的四种方法—DOM/SAX/jdom/dom4j

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