如何从网页上获取城市天气信息？

编写一段Java代码，从如下网站http://www.weather.com.cn/ 获得西安的天气信息：
package com.url;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Weather {

	public static void main(String[] args) {

		String weatherReturn = getWeatherInfo();

		//获得层div
		Pattern pattern = Pattern
				.compile("<div class=\"weatherYubaoBox\">.*?</div>");

		Matcher matcher = pattern.matcher(weatherReturn);

		String weatherTable = "";

		if (matcher.find()) {
			weatherTable = matcher.group();
		}

		//找表
		String weatherToday = "";
		
		if (!weatherTable.equals("") && weatherTable.length() > 0) {
			
			pattern = Pattern
					.compile("<table class=\"yuBaoTable\".*?>.*?</table>");
			matcher = pattern.matcher(weatherTable);
			
			if (matcher.find()) {
				weatherToday = matcher.group();
			}
		}

		pattern = Pattern.compile("<a.*?</a>");
		
		matcher = pattern.matcher(weatherToday);
		
		List<String> weatherList = new ArrayList<String>();
		while (matcher.find()) {
			
			weatherList.add(matcher.group());
			System.out.println(replaceTagA(matcher.group()));
			
		}
	}

	// 获取网页上的内容
	public static String getWeatherInfo() {

		URL url = null;
		InputStreamReader inReader = null;
		BufferedReader reader = null;
		
		try {

			// 建立一个url
			url = new URL("http://www.weather.com.cn/weather/101110101.shtml");

			// 打开一个流,并设置编码格式
			inReader = new InputStreamReader(url.openStream(), "utf-8");
			reader = new BufferedReader(inReader);

			StringBuffer sb = new StringBuffer();

			String inputLine;

			while ((inputLine = reader.readLine()) != null) {
				sb.append(inputLine);
			}
			
			return sb.toString();
		} catch (Exception e) {

			e.printStackTrace();
			
		} finally {
			// 关闭流
			if (reader != null) {
				try {
					reader.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (inReader != null) {
				try {
					inReader.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return null;
	}

	//从超连接中取数据
	public static String replaceTagA(String orginal) {
		
		List<String> resultList = new ArrayList<String>();
		
		if (orginal != null && !"".equals(orginal)) {

			Pattern pattern = Pattern.compile(">.*?<");
			Matcher matcher = pattern.matcher(orginal);
			while (matcher.find()) {
				String temp = matcher.group();
				temp = temp.replace('>', ' ');
				temp = temp.replace('<', ' ');
				resultList.add(temp.trim());
			}
		}
		StringBuffer result = new StringBuffer();
		for (String temp : resultList) {
			result.append(temp);
		}
		return result.toString().trim();
	}
}