J2ME从服务器解析并读取xml文件

J2ME从服务器解析并读取xml文件，其实跟在本地读取xml文件相似，只是我们在下载服务器的xml时，需要注意将xml转码为“UTF-8”,服务器的xml文件跟我上次写的xiaochao.xml文件内容一样，所以这里就不再写了，大家可以去看上一期的博客，代码如下：

package com.mopietek;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.lcdui.Choice;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.List;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordStore;
import javax.microedition.rms.RecordStoreException;
import javax.microedition.rms.RecordStoreNotOpenException;

import org.kxml2.io.KXmlParser;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

public class KXMLliao extends MIDlet implements CommandListener{

	private Display display;
	private Form form;
	private List choose = null;
	
	private Command exitCommand = new Command("退出",Command.EXIT,1);
	private Command viewCommand = new Command("浏览",Command.SCREEN,1);
	private Command delCommand = new Command("删除",Command.SCREEN,2);
	
	RecordStore rs = null;
	
	public KXmlParser parser = new KXmlParser();
	
	public KXMLliao() {
	
		display = Display.getDisplay(this);
		rs = openRS("XMLRS"); //创建记录存储

	}

	//读取网络上的xml文件
	public void loadText() throws XmlPullParserException{
		
		try{
		
			String URL = "http://dev.mopietek.net:8080/waptest03/xiaochao.xml";
			HttpConnection httpConnection = (HttpConnection) Connector.open(URL);
			
			parser.setInput(new InputStreamReader(httpConnection.openInputStream(),"UTF-8"));
			
		}catch(IOException e){
			e.printStackTrace();
		}
		
		
		
	}
	

	protected void startApp() throws MIDletStateChangeException {

		try{
			Interpret();
			
		}catch(XmlPullParserException xpp){
			
		}
		
		
		display.setCurrent(form);
		
		
	}
	
	
	 //解析XML文件
	public void Interpret() throws XmlPullParserException{
		
		form = new Form("解析XML");
		form.addCommand(exitCommand);
		form.addCommand(viewCommand);
		form.setCommandListener(this);
		
		String str3;
		
		this.loadText(); //调用这个方法来加载网络上的XML文件
		int eventType = parser.getEventType();
		
		try{
			
			while(eventType != XmlPullParser.END_DOCUMENT){
				//如果当前标签为开始标签，且标签内容为person的话
				if(eventType == XmlPullParser.START_TAG && parser.getName().equals("person")){
					
					str3 = parser.getAttributeValue(0);
					addNewData(str3);

					
					//转到下一个标签
					eventType = parser.nextTag();
					//如果是ID标签
					if(parser.getName().equals("name")){
						
						//提取name标签的内容
						str3 = parser.nextText();
						addNewData(str3);
						
					}
					
				
					
					//转到下一个标签
					eventType = parser.nextTag();
					
					//如果是Text标签
					if(parser.getName().equals("attack")){
						//提取attack标签的内容
						str3 = parser.nextText();
						addNewData(str3);
					}
					
					
				}
				
				eventType = parser.next();
			}
			
		}catch(IOException ioe){
			ioe.printStackTrace();
		}
		
		form.append("解析XML文件完毕并且以存到RMS中！"+"\n" +"按浏览键可以浏览全部记录");
	}
	
	
	
	//加入记录到记录存储
	//各个记录由字节数组表示，所以加入记录就意味着:把字节数组加入到记录存储
	//synchronized代表同步，即同一时刻，保证只有一个线程对RecordStore进行操作
	public synchronized void addNewData(String record){
		
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		
		DataOutputStream daos = new DataOutputStream(baos);
	
		try{
		
			daos.writeUTF(record);
		}catch(IOException ioe){
			ioe.printStackTrace();
		}
		
		//把接收到的数据放到bytearr数组中
		byte[] bytearr = baos.toByteArray();
		
		try{
			
			//加入记录到记录存储，该方法有三个参数，第一个是要加入的字节数组
			//第二个是字节数组内的offset（位移），第三个指要加入的字节数目
			rs.addRecord(bytearr, 0, bytearr.length);
			System.out.println("加入到RMS中的数据：" + baos.toString());
			
		}catch(RecordStoreException rse){
			System.out.println(rse);
			rse.printStackTrace();
		}
		
	}
	
	

	
	public void commandAction(Command c, Displayable d) {
	
		if(c == exitCommand){
			try {
				destroyApp(false);
			} catch (MIDletStateChangeException e) {
				e.printStackTrace();
			}
			notifyDestroyed();
		}
		else if(c == viewCommand){
			System.out.println("准备调用相关函数浏览全部记录");
			this.listItems();
		}
		else if(c == delCommand){
			System.out.println("准备调用相关函数删除全部记录");
			try {
				this.closeRS();
			} catch (RecordStoreNotOpenException e) {
				e.printStackTrace();
			} catch (RecordStoreException e) {
				e.printStackTrace();
			}
		}
		
	}
	
	
	private RecordStore openRS(String fileName) {

		try{
			//打开fileName记录存储，第二个参数true代表如果记录存储不存在的话就创建新的记录存储
			//如果为false值则引发RecordStoreNotFoundException异常
			
			rs = RecordStore.openRecordStore(fileName, true);
			System.out.println("已创建" + fileName + "记录存储");
			
		}catch(RecordStoreException rse){
			rse.printStackTrace();
		}
		return rs;
		
	}
	
	
	//遍历记录存储中的记录
	public synchronized RecordEnumeration enumerate() throws RecordStoreNotOpenException{
		return rs.enumerateRecords(null, null, false);
	}
	
	
	//列出全部记录信息
	public void listItems(){
		
		choose = new List("全部记录",Choice.IMPLICIT);
		choose.addCommand(delCommand);
		choose.addCommand(exitCommand);
		choose.setCommandListener(this);
		
		try{
		
			RecordEnumeration re = enumerate();
			
			while(re.hasNextElement()){
				String theList = new String(re.nextRecord(),"UTF-8");
				choose.append(theList, null);
				
			}
		}catch(Exception e){
			e.printStackTrace();
		}
		
		display.setCurrent(choose);
		
	}
	
	
	
	protected void destroyApp(boolean unconditional)
	throws MIDletStateChangeException {

		System.out.println("关闭记录存储");
		try{
			closeRS();
		}catch(Exception e){e.printStackTrace();}

	}
	
	
	protected void pauseApp() {
	
		System.out.println("准备关闭记录存储");
		display.setCurrent(null);
		form = null;
		try{
			closeRS();
		}catch(Exception e){
			e.printStackTrace();
		}
	
	}
	
	//关闭记录存储
	public void  closeRS() throws RecordStoreNotOpenException,RecordStoreException{
		
		String fileName = rs.getName();
		//检测记录存储中的记录总数，如果记录存储时空的则删除这个记录存储
		if(rs.getNumRecords() == 0){
			
			rs.closeRecordStore();
			rs.deleteRecordStore(fileName);
			System.out.println("已关闭" + fileName +"记录存储");
			
		}else{
			rs.closeRecordStore();
			System.out.println("已关闭" + fileName +"记录存储");
		}
		
	}
	

}