maven实例

1.simple weather项目介绍

maven权威指南中的例子，simple weather是一个基本的命令行驱动的应用程序，它接收邮政编码输入，然后从yahoo！weather RSS源取得数据，然后解析数据并把结果打印到标准输出

 

2.创建项目的基本框架

mvn archetype:create -DgroupId=org.sonatype.mavenbook.ch04 -
DartifactId=simple-weather -DpackageName=org.sonatype.mavenbook -Dversion=1.0

 

成功界面如下：

 

3.在pom.xml中添加组织，法律和开发人员信息

 

<licenses>
  	<license>
  		<name>Apache 2</name>
  		<url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
  		<distribution>repo</distribution>
  		<comments>a business-friendly OSS license</comments>
  	</license>
  </licenses>
  
  <organization>
  	<name>Sonatype</name>
  	<url>http://www.sonatype.com</url>	
  </organization>
  
  <developers>
  	<developer>
  		<id>liang</id>
  		<name>li liang</name>
  		<roles>
  			<role>developer</role>
  		</roles>
  	</developer>
  	</developers>

 

4.在pom.xml中添加新的依赖

 

<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
 
    <dependency>
    	<groupId>log4j</groupId>
    	<artifactId>log4j</artifactId>
    	<version>1.2.14</version>
    </dependency>
    
    <dependency>
    	<groupId>dom4j</groupId>
    	<artifactId>dom4j</artifactId>
    	<version>1.6.1</version>
    </dependency>
    
    <dependency>
    	<groupId>jaxen</groupId>
    	<artifactId>jaxen</artifactId>
    	<version>1.1.1</version>
    </dependency>
    
    <dependency>
    	<groupId>velocity</groupId>
    	<artifactId>velocity</artifactId>
    	<version>1.5</version>
    </dependency>
  </dependencies>

 5.项目源码

Main.java：系统入口

 

package org.sonatype.mavenbook.weather;

import java.io.InputStream;
import org.apache.log4j.PropertyConfigurator;

public class Main{
	public static void main(String[] args) throws Exception{
		PropertyConfigurator.configure(Main.class.getClassLoader()
				.getResource("log4j.properties"));
		int zipcode = 60202;
		try{
			zipcode = Integer.parseInt(args[0]);
		}catch(Exception e){}
		
		new Main(zipcode).start();
	}
	
	private int zip;
	
	public Main(int zip){
		this.zip = zip;
	}
	
	public void start() throws Exception{
		
		InputStream dataIn = new YahooRetriever().retrieve(zip);
		
		Weather weather = new YahooParser().parser(dataIn);
		
		System.out.println(new WeatherFormatter().format(weather));
	}
}

 

Weather.java：java bean

 

package org.sonatype.mavenbook.weather;

public class Weather{
	
	private String city;
	private String region;
	private String country;
	private String condition;
	private String temp;
	private String chill;
	private String humidity;
	public String getCity() {
		return city;
	}
	public void setCity(String city) {
		this.city = city;
	}
	public String getRegion() {
		return region;
	}
	public void setRegion(String region) {
		this.region = region;
	}
	public String getCountry() {
		return country;
	}
	public void setCountry(String country) {
		this.country = country;
	}
	public String getCondition() {
		return condition;
	}
	public void setCondition(String condition) {
		this.condition = condition;
	}
	public String getTemp() {
		return temp;
	}
	public void setTemp(String temp) {
		this.temp = temp;
	}
	public String getChill() {
		return chill;
	}
	public void setChill(String chill) {
		this.chill = chill;
	}
	public String getHumidity() {
		return humidity;
	}
	public void setHumidity(String humidity) {
		this.humidity = humidity;
	}
	
	
	
}

 YahooRetriever.java： 连接到Yahll！weather并返回来自数据源的InputStream

 

package org.sonatype.mavenbook.weather;

import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import org.apache.log4j.Logger;

public class YahooRetriever{
	private static Logger log = Logger.getLogger(YahooRetriever.class);
	
	public InputStream retrieve(int zipcode) throws Exception{
		log.info("retrieving weather data");
		String url="http://weather.yahooapis.com/forecastrss?p=" + zipcode;
		URLConnection conn = new URL(url).openConnection();
		return conn.getInputStream();
	}
}

 YahooParser.java：解析来自Yahoo！weather的XML，返回weather对象

 

package org.sonatype.mavenbook.weather;

import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import org.apache.log4j.Logger;
import org.dom4j.Document;
import org.dom4j.DocumentFactory;
import org.dom4j.io.SAXReader;

public class YahooParser{
	private static Logger log = Logger.getLogger(YahooParser.class);
	
	public Weather parser(InputStream inputStream) throws Exception{
		Weather weather = new Weather();
		
		log.info("creating XML Reader");
		SAXReader xmlReader = createXmlReader();
		Document doc = xmlReader.read(inputStream);
		
		log.info("Parsing XML Response");
		weather.setCity(doc.valueOf("/rss/channel/y:location/@city"));
		weather.setRegion(doc.valueOf("/rss/channel/y:location/@region"));
		weather.setCountry(doc.valueOf("/rss/channel/y:location/@country"));
		weather.setCondition(doc.valueOf("/rss/channel/item/y:condition/@text"));
		weather.setTemp(doc.valueOf("/rss/channel/item/y:condition/@temp"));
		weather.setChill(doc.valueOf("/rss/channel/y:wind/@chill"));
		weather.setHumidity(doc.valueOf("/rss/channel/y:atmosphere/@humidity"));

		return weather;
	}
	
	private SAXReader createXmlReader(){
		Map<String,String> uris = new HashMap<String,String>();
		uris.put("y", "http://xml.weather.yahoo.com/ns/rss/1.0");
		
		DocumentFactory factory = new DocumentFactory();
		factory.setXPathNamespaceURIs(uris);
		
		SAXReader xmlReader = new SAXReader();
		xmlReader.setDocumentFactory(factory);
		return xmlReader;
	}
}

 WeatherFormatter.java：接收weather对象，根据Velocity模板生成结果

 

package org.sonatype.mavenbook.weather;

import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;

import org.apache.log4j.Logger;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;


public class WeatherFormatter{
	private static Logger log = Logger.getLogger(WeatherFormatter.class);
	
	public String format(Weather weather) throws Exception{
		log.info("formatting weather data");
		
		Reader reader = new InputStreamReader(
				getClass().getClassLoader().getResourceAsStream("output.vm"));
		VelocityContext context = new VelocityContext();
		context.put("weather", weather);
		StringWriter writer = new StringWriter();
		Velocity.evaluate(context, writer, "", reader);
		return writer.toString();
	}
}

 6.添加配置信息

在src/main下建立resources目录，在里面建立log4j.properties和output.vm两个文件

log4j.properties

 

log4j.rootCategory=INFO,CONSOLE

log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold=INFO
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-4r %-5p %c{1} %x - %m%n

 output.vm

 

***********************************
Current Weather Conditions for:
${weather.city},${weather.region},${weather.country}

Temperature:${weather.temp}
Condition:${weather.condition}
Humidity:${weather.humidity}
Wind Chill:${weather.chill}
***********************************

 

7.运行

 

mvn exec:java -Dexec.mainClass=org.sonatype.mavenbook.weather.Main

 运行结果