1、新建一个maven工程：
mvn archetype:create -DgroupId=org.sonatype.mavenbook.ch04 -DartifactId=simple-weather -DpackageName=org.sonatype.mavenbook
2、创建java文件：
Main.java：关键代码
// Configure Log4J 取log4j的属性文件的时候，可以直接这么取
PropertyConfigurator.configure(Main.class.getClassLoader().getResource("log4j.properties");
Weather.java
WeatherFormatter.java
YahooParser.java
YahooRetriever.java
3、创建资源文件：
log4j.properties
output.vm
4、构建项目：mvn install
5、运行程序:
mvn exec:java -Dexec.mainClass=org.sonatype.mavenbook.weather.Main
显示结果：
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building simple-weather 1.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- exec-maven-plugin:1.3.1:java (default-cli) @ simple-weather ---
[WARNING] Warning: killAfter is now deprecated. Do you need it ? Please comment on MEXEC-6.
0 INFO YahooRetriever - Retrieving Weather Data
411 INFO YahooParser - Creating XML Reader
518 INFO YahooParser - Parsing XML Response
559 INFO WeatherFormatter - Formatting Weather Data
642 INFO mavenbook - *********************************
Current Weather Conditions for:
Evanston, IL, US
Temperature: 72
Condition: Partly Cloudy
Humidity: 87
Wind Chill: 72
*********************************
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.831s
[INFO] Finished at: Wed Jun 25 10:21:45 CST 2014
[INFO] Final Memory: 9M/23M
[INFO] ------------------------------------------------------------------------