使用htmlparser获取sohu的天气预报

首先，我们新建一个类，存放天气信息

/*
* Created on 2005-3-8
*
* To change the template for this generated file go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
package org.exoplatform.portlets.chinaweather.component;

/**
* @author Administrator
*
* To change the template for this generated type comment go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
public class Weather {
private String city;
private String state;
private String temperature;
private String time;
private String wind;
private String windpower;
private long UpdateTime;

/**
* @return
*/
public String getTemperature() {
return temperature;
}

/**
* @return
*/
public String getTime() {
return time;
}

/**
* @return
*/
public String getWind() {
return wind;
}

/**
* @return
*/
public String getWindpower() {
return windpower;
}

/**
* @param string
*/
public void setTemperature(String string) {
temperature = string;
}

/**
* @param string
*/
public void setTime(String string) {
time = string;
}

/**
* @param string
*/
public void setWind(String string) {
wind = string;
}

/**
* @param string
*/
public void setWindpower(String string) {
windpower = string;
}

/**
* @return
*/
public long getUpdateTime() {
return UpdateTime;
}

/**
* @param l
*/
public void setUpdateTime(long l) {
UpdateTime = l;
}

/**
* @return
*/
public String getState() {
return state;
}

/**
* @param string
*/
public void setState(String string) {
state = string;
}

/**
* @return
*/
public String getCity() {
return city;
}

/**
* @param string
*/
public void setCity(String string) {
city = string;
}

}

具体的解析代码为:

private Weather parserWeather() throws Exception {
Weather w = new Weather();
try {

//Parser parser =
//new Parser("file://localhost/I:/projects/query.html");
Parser parser =
new Parser("http://weather.news.sohu.com/query.php?city=镇江");

parser.setEncoding("GBK");
Node nodes[] = parser.extractAllNodesThatAre(TableTag.class);

TableTag table = (TableTag) nodes[3];
//temperature
StringNode[] stringNodes = table.digupStringNode("镇江");
StringNode name = stringNodes[0];
w.setCity(name.toPlainTextString());
CompositeTag td = (CompositeTag) name.getParent();
CompositeTag tr = (CompositeTag) td.getParent();
int columnNo = tr.findPositionOf(td);
TableColumn nextColumn = (TableColumn) tr.childAt(5);
Node expectedName = nextColumn.childAt(0);
Node expectedName2 = nextColumn.childAt(2);
//System.out.println(expectedName.getText());
//System.out.println(expectedName2.getText());
w.setState(expectedName.getText());
w.setTemperature(expectedName2.getText());
//time
stringNodes = table.digupStringNode("时间");
name = stringNodes[0];
//System.out.println(name.toPlainTextString());

String time =
name
.toPlainTextString()
.substring(4, name.toPlainTextString().length())
.trim();
//System.out.println(time);
w.setTime(time);
//wind
stringNodes = table.digupStringNode("风向");
name = stringNodes[0];
//System.out.println(name.toPlainTextString());

String wind =
name
.toPlainTextString()
.substring(4, name.toPlainTextString().length())
.trim();
//System.out.println(wind);
w.setWind(wind);
//wind power
stringNodes = table.digupStringNode("风力");
name = stringNodes[0];
//System.out.println(name.toPlainTextString());

String windpower =
name
.toPlainTextString()
.substring(4, name.toPlainTextString().length())
.trim();
//System.out.println(windpower);
w.setWindpower(windpower);

w.setUpdateTime(System.currentTimeMillis());

} catch (ParserException e) {

e.printStackTrace();
}
return w;
}

解析出来的代码必须做缓存处理，

private static long TIME_TO_LIVE = 1000 * 60 * 60 * 12;

private Weather loadWeather() throws Exception {
Weather weather = weather = (Weather) cache_.get("chinaweather");
long currentTime = System.currentTimeMillis();
if (weather != null
&& currentTime < (weather.getUpdateTime() + TIME_TO_LIVE)) {
cache_.remove("chinaweather");
weather = null;
}

if (weather == null) {
synchronized (cache_) {
weather = parserWeather();
cache_.put("chinaweather", weather);
}
}

return weather;
}