Thinking in MyLife

     Compass是一流的开放源码JAVA搜索引擎框架，对于你的应用修饰，搜索引擎语义更具有能力。依靠顶级的Lucene搜索引擎，Compass 结合了，像 Hibernate和 Sprin的流行的框架，为你的应用提供了从数据模型和数据源同步改变的搜索力.并且添加了2方面的特征,事物管理和快速更新优化. Compass的目标是：把java应用简单集成到搜索引擎中.编码更少，查找数据更便捷。
    下面以一个应用场景分步骤讲解如何利用compass实现搜索引擎：
1. 这里我们有一个Article表，希望利用compass实现对它的搜索。
  Article的结构如下：
  CREATE TABLE `article` (
    `ArticleID` bigint(20) NOT NULL,
    `PersonInfoID` bigint(20) default NULL,
    `ArticleTitle` varchar(200) default NULL,
    `PublishDate` datetime default NULL,
    `Summary` text,
    `Content` longtext,
    `KeyList` text,
    PRIMARY KEY  (`ArticleID`),
    KEY `PersonInfoArticle_FK` (`PersonInfoID`)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
  我们希望利用compass对它的ArticleTitle、Summary、Content和KeyList进行全文检索。下面开始行动吧。
  
2. 首先到http://www.opensymphony.com/compass/download.action 上下载一个compass的发布版，我们下载的是Version 1.0.0的With Dependencies 。这样就可能省去寻找相关信赖库的麻烦了。

3. 将compass1.0解压到一个合适的目录，我们的工作目录是d:\develop\compass1.0

4. 我们是在eclipse环境下实现当前要求的，所以建议你也安装一个eclipse 3.2。

5. 首先我们在eclipse中建立了一个java工程，名为mycompass。

6. 然后我们在工程目录中建立了一个lib目录，用来存放本次工程所需要的所有compass和其它相关的库文件，并将他们设置为当前工程构建路径中需要的库文件。所有这些文件可以在compass的安装目录的lib目录找到。

  下面是我们的库文件列表：
 
7. 建立了Article表的pojo类。
  package com.darkhe.sample.mycompass;
  
  // Generated 2006-8-2 10:57:06 by Hibernate Tools 3.2.0.beta6a
  
  import java.util.Date;
  
  /**
   * Article generated by hbm2java
   */
  public class Article implements java.io.Serializable {
  
   // Fields   
  
   private long articleId;
  
   private Long personInfoId;
  
   private String articleTitle;
  
   private Date publishDate;
  
   private String summary;
  
   private String content;
  
   private String keyList;
  
   // Constructors
  
   /** default constructor */
   public Article() {
   }
  
   /** minimal constructor */
   public Article(long articleId) {
    this.articleId = articleId;
   }
  
   /** full constructor */
   public Article(long articleId, Long personInfoId, String articleTitle,
     Date publishDate, String summary, String content, String keyList) {
    this.articleId = articleId;
    this.personInfoId = personInfoId;
    this.articleTitle = articleTitle;
    this.publishDate = publishDate;
    this.summary = summary;
    this.content = content;
    this.keyList = keyList;
   }
  
   // Property accessors
   public long getArticleId() {
    return this.articleId;
   }
  
   public void setArticleId(long articleId) {
    this.articleId = articleId;
   }
  
   public Long getPersonInfoId() {
    return this.personInfoId;
   }
  
   public void setPersonInfoId(Long personInfoId) {
    this.personInfoId = personInfoId;
   }
  
   public String getArticleTitle() {
    return this.articleTitle;
   }
  
   public void setArticleTitle(String articleTitle) {
    this.articleTitle = articleTitle;
   }
  
   public Date getPublishDate() {
    return this.publishDate;
   }
  
   public void setPublishDate(Date publishDate) {
    this.publishDate = publishDate;
   }
  
   public String getSummary() {
    return this.summary;
   }
  
   public void setSummary(String summary) {
    this.summary = summary;
   }
  
   public String getContent() {
    return this.content;
   }
  
   public void setContent(String content) {
    this.content = content;
   }
  
   public String getKeyList() {
    return this.keyList;
   }
  
   public void setKeyList(String keyList) {
    this.keyList = keyList;
   }
  
  }

8. 建立hibernate的pojo到数据表映射文件
 <?xml version="1.0"?>
 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 <!-- Generated 2006-8-2 10:57:07 by Hibernate Tools 3.2.0.beta6a -->
 <hibernate-mapping>
    <class name="com.darkhe.sample.mycompass.Article" table="article" catalog="freedom">
        <comment></comment>
        <id name="articleId" type="long">
            <column name="ArticleID" />
            <generator class="assigned" />
        </id>
        <property name="personInfoId" type="java.lang.Long">
            <column name="PersonInfoID">
                <comment></comment>
            </column>
        </property>
        <property name="articleTitle" type="string">
            <column name="ArticleTitle" length="200">
                <comment></comment>
            </column>
        </property>
        <property name="publishDate" type="timestamp">
            <column name="PublishDate" length="19">
                <comment></comment>
            </column>
        </property>
        <property name="summary" type="string">
            <column name="Summary" length="65535">
                <comment></comment>
            </column>
        </property>
        <property name="content" type="string">
            <column name="Content">
                <comment></comment>
            </column>
        </property>
        <property name="keyList" type="string">
            <column name="KeyList" length="65535">
                <comment></comment>
            </column>
        </property>
    </class>
 </hibernate-mapping>

9. 开始配置compass，首先是compass的系统配置文件 mycompass.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<compass-core-config
 xmlns="http://www.opensymphony.com/compass/schema/core-config"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://www.opensymphony.com/compass/schema/core-config
           http://www.opensymphony.com/compass/schema/compass-core-config.xsd">

 <compass name="default"> <!—这个名字随你取了，但它是必须的-->

  <connection>
   <file path="target" /> <!—这里是索引文件的存放路径，我们设置的是当前工程的相对路径target-?
  </connection>

  <searchEngine>
    <!-- 因是使用自己的分词算法，所以这里的类型必须是CustomAnalyzer -->
          <analyzer name="MMAnalyer" type="CustomAnalyzer" analyzerClass="jeasy.analysis.MMAnalyzer">
              <stopWords>
                  <stopWord value="test" />
              </stopWords>
          </analyzer>
      </searchEngine>

 </compass>
</compass-core-config>
 在上面的配置中，我们使用的我们选用的一个中文分词算法库，你可以用compass自带的。具体compass提供了哪些分词算法，请查阅compass的手册。

10. 然后是mycompass.cmd.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE compass-core-meta-data PUBLIC
    "-//Compass/Compass Core Meta Data DTD 1.0//EN"
    "http://www.opensymphony.com/compass/dtd/compass-core-meta-data.dtd">

<compass-core-meta-data>

<!-- 定义一个实体和字段组-->
    <meta-data-group id="mycompass" displayName="My Compass">
   
        <descrīption>Mycompass Meta Data</descrīption>      
        <uri>http://com/darkhe/sample/mycompass</uri>
   
       
<!-- 申明所有需要检索的实体-->       
        <alias id="Article" displayName="Article">
            <descrīption>Article alias</descrīption>
            <uri>http://com/darkhe/sample/mycompass/alias/Article</uri>
            <name>Article</name>
        </alias>
       
 <!-- 申明所有需要检索的属性或者字段，而不管这些属性或者字段是哪个实体的 -->       
        <meta-data id="ArticleTitle" displayName="ArticleTitle">
            <descrīption>ArticleTitle</descrīption>
            <uri>http://com/darkhe/sample/mycompass/alias/ArticleTitle</uri>
            <name>ArticleTitle</name>
        </meta-data>
       
        <meta-data id="PublishDate" displayName="PublishDate">
            <descrīption>PublishDate</descrīption>
            <uri>http://com/darkhe/sample/mycompass/alias/PublishDate</uri>
            <name format="yyyy-MM-dd hh:mm:ss">date</name>
        </meta-data>
       
        <meta-data id="Summary" displayName="Summary">
            <descrīption>Summary</descrīption>
            <uri>http://com/darkhe/sample/mycompass/alias/Summary</uri>
            <name>Summary</name>
        </meta-data>
       
        <meta-data id="Content" displayName="Content">
            <descrīption>Content</descrīption>
            <uri>http://com/darkhe/sample/mycompass/alias/Content</uri>
            <name>Content</name>
        </meta-data>

        <meta-data id="KeyList" displayName="KeyList">
            <descrīption>KeyList</descrīption>
            <uri>http://com/darkhe/sample/mycompass/alias/KeyList</uri>
            <name>KeyList</name>
        </meta-data>       
                       
    </meta-data-group>
   
</compass-core-meta-data>

11. 再是mycompass.cpm.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE compass-core-mapping PUBLIC
    "-//Compass/Compass Core Mapping DTD 1.0//EN"
    "http://www.opensymphony.com/compass/dtd/compass-core-mapping.dtd">

<!-- 这里的包名必须和pojo的包名一致 -->
<compass-core-mapping package="com.darkhe.sample.mycompass">

<!-- 定义实体及其字段的对应关系 -->

<!-- 注意实体及其字段的名称的大小写应当与pojo对象一致，而不是与数据库一致
  关于pojo与数据库的对应表的一致性关系由hibernate的映谢文件定义，而不是这个文件
  当前映射文件只定义compass与hibernate的关系 -->

 <class name="Article" alias="${mycompass.Article}">
  <id name="ArticleId" />
  
  <property name="ArticleTitle">
   <meta-data>${mycompass.ArticleTitle}</meta-data>
  </property>

  <property name="PublishDate">
   <meta-data>${mycompass.PublishDate}</meta-data>
  </property>

  <property name="Summary">
   <meta-data>${mycompass.Summary}</meta-data>
  </property>

  <property name="Content">
   <meta-data>${mycompass.Content}</meta-data>
  </property>

  <property name="KeyList">
   <meta-data>${mycompass.KeyList}</meta-data>
  </property>
 </class>
 </compass-core-mapping>

12. log4j.properties
log4j.rootLogger=WARN, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p %c - %m%n
log4j.logger.org.compass=INFO

13. jdbc.properties
# Properties file with JDBC-related settings.
# Applied by PropertyPlaceholderConfigurer from "applicationContext-*.xml".
# Targeted at system administrators, to avoid touching the context XML files.
jdbc.driverClassName=com.mysql.jdbc.Driver
#jdbc.driverClassName=org.hsqldb.jdbcDriver
#jdbc.url=jdbc:hsqldb:hsql://localhost:9001
jdbc.url=jdbc:mysql://localhost:3306/testdb
jdbc.username=test
jdbc.password=test
# Property that determines the Hibernate dialect
# (only applied with "applicationContext-hibernate.xml")
#hibernate.dialect=org.hibernate.dialect.HSQLDialect
hibernate.dialect=org.hibernate.dialect.MySQLDialect

14. 最后是applicationContext-hibernate.xml，这里集中配置了compass如何与spring与hibernate结合的。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<!--
 - Application context definition for Petclinic on Hibernate.
-->
<beans>
 <!-- ========================= RESOURCE DEFINITIONS ========================= -->
 <!-- Configurer that replaces ${...} placeholders with values from a properties file -->
 <!-- (in this case, JDBC-related settings for the dataSource definition below) -->
 <bean id="propertyConfigurer"
  class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
  <property name="location">
   <value>classpath:jdbc.properties</value>
  </property>
 </bean>
 <!-- Local DataSource that works in any environment -->
 <!-- Note that DriverManagerDataSource does not pool; it is not intended for production -->
 <!-- See JPetStore for an example of using Commons DBCP BasicDataSource as alternative -->
 <!-- See Image Database for an example of using C3P0 ComboPooledDataSource as alternative -->
 <bean id="dataSource"
  class="org.springframework.jdbc.datasource.DriverManagerDataSource">
  <property name="driverClassName">
   <value>${jdbc.driverClassName}</value>
  </property>
  <property name="url">
   <value>${jdbc.url}</value>
  </property>
  <property name="username">
   <value>${jdbc.username}</value>
  </property>
  <property name="password">
   <value>${jdbc.password}</value>
  </property>
 </bean>
 <!-- JNDI DataSource for J2EE environments -->
 <!--
  <bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
  <property name="jndiName"><value>java:comp/env/jdbc/petclinic</value></property>
  </bean>
 -->
 <!-- Hibernate SessionFactory -->
 <bean id="sessionFactory"
  class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
  <property name="dataSource">
   <ref local="dataSource" />
  </property>
  <property name="mappingResources">
   <list>
    <value>
     com/darkhe/sample/mycompass/Article.hbm.xml <!-- 这里是hibernate里需要的数据映射文件 -->
    </value>
   </list>
  </property>
  <property name="hibernateProperties">
   <props>
    <prop key="hibernate.dialect">
     ${hibernate.dialect}
    </prop>
    <prop key="hibernate.show_sql">false</prop>
    <prop key="hibernate.generate_statistics">true</prop>
   </props>
  </property>
  <property name="eventListeners">
   <map>
    <entry key="merge">
     <bean
      class="org.springframework.orm.hibernate3.support.IdTransferringMergeEventListener" />
    </entry>
   </map>
  </property>
 </bean>

 <!-- COMPASS START -->
 <bean id="compass" class="org.compass.spring.LocalCompassBean">
  <property name="resourceLocations">
   <list>
    <value>classpath:mycompass.cmd.xml</value> <!-- 这里是compass所需要的两个关于数据项的配置文件 -->
    <value>classpath:mycompass.cpm.xml</value>
   </list>
  </property>
  <property name="configLocation">
   <value>classpath:mycompass.cfg.xml</value> <!-- 这里是compass的系统配置文件的路径 -->
  </property>
  <!--         <property name="compassSettings">
   <props>
   <prop key="compass.engine.connection">file://d:/target</prop>
   <prop key="compass.transaction.factory">org.compass.spring.transaction.SpringSyncTransactionFactory</prop>
   </props>
   </property>-->

  <property name="transactionManager">
   <ref local="transactionManager" />
  </property>
 </bean>

 <bean id="hibernateGpsDevice"
  class="org.compass.spring.device.hibernate.SpringHibernate3GpsDevice">
  <property name="name">
   <value>hibernateDevice</value>
  </property>
  <property name="sessionFactory">
   <ref local="sessionFactory" />
  </property>
 </bean>
 <bean id="compassGps" class="org.compass.gps.impl.SingleCompassGps"
  init-method="start" destroy-method="stop">
  <property name="compass">
   <ref bean="compass" />
  </property>
  <property name="gpsDevices">
   <list>
    <bean
     class="org.compass.spring.device.SpringSyncTransactionGpsDeviceWrapper">
     <property name="gpsDevice" ref="hibernateGpsDevice" />
    </bean>
   </list>
  </property>
 </bean>
 <!-- COMPASS END -->
</beans>

15. 注意上面的所以配置文件，根据我们上面的配置，都应当放到classpath的根路径。
16. 建立工具类，用来进行spring引擎的初始化工作。
/**
 * <p>@(#) IOC.java 2006-2-1 0:08:23</p>
 * <p>Copyright (c) 2005-2006 ???????????????????</p>
 */
package com.darkhe.sample.mycompass;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 *
 *
 * @version 1.0 2006-2-1
 * @author darkhe
 */
public class IOC {
 private static ApplicationContext context = null;

 private static boolean isInit = false;

 private IOC() {
  super();
 }

 private static void init() {
 
  if (isInit == false) {
   String[] xmlfilenames = { "applicationContext-hibernate.xml" };

   context = new ClassPathXmlApplicationContext(xmlfilenames);

   isInit = true;
  }
 }

 /**
  * 
  * @return
  */
 public static ApplicationContext getContext() {
  if (context == null || isInit == false) {
   init();
  }
  return context;
 }

 /**
  *
  * @param name
  * @return
  */
 public static Object getBean(String name) {
  return getContext().getBean(name);
 }

}

17. 建立索引程序，用来数据库中的建立索引
/*
 * Copyright (c) 2005-2006
 * ChongQing Man-Month Technology Development Co. ,Ltd
 *
 * ---------------------------------------------------------------------------------
 * @(#) Inder.java, 2006-8-1 下午09:01:14
 * ---------------------------------------------------------------------------------
 */
package com.darkhe.sample.mycompass;

import java.io.FileNotFoundException;

import org.compass.gps.CompassGps;
import org.springframework.context.ApplicationContext;

/**
 * @author darkhe
 *
 */
public class Indexer {

 /**
  * @param args
  * @throws FileNotFoundException
  */
 public static void main(String[] args) throws FileNotFoundException {

   // 加裁自定义词典
  DictionaryUtils.loadCustomDictionary();

  ApplicationContext context = IOC.getContext();

  // 得到spring环境中已经配置和初始化好的compassGps对象
  CompassGps compassGps = (CompassGps) context.getBean("compassGps");
  // 调用index方法建立索引
  compassGps.index();

 }

}

18. 建立搜索程序，检证compass的应用。
/*
 * Copyright (c) 2005-2006
 * ChongQing Man-Month Technology Development Co. ,Ltd
 *
 * ---------------------------------------------------------------------------------
 * @(#) Searcher.java, 2006-8-1 下午09:36:29
 * ---------------------------------------------------------------------------------
 */

package com.darkhe.sample.mycompass;

import java.io.FileNotFoundException;

import org.compass.core.Compass;
import org.compass.core.CompassCallbackWithoutResult;
import org.compass.core.CompassException;
import org.compass.core.CompassHits;
import org.compass.core.CompassSession;
import org.compass.core.CompassTemplate;
import org.compass.core.Resource;
import org.springframework.context.ApplicationContext;

/**
 * @author darkhe
 *
 */
public class Searcher {

 /**
  * @param args
  * @throws FileNotFoundException
  */
 public static void main(String[] args) throws FileNotFoundException {

  // 加裁自定义词典
  DictionaryUtils.loadCustomDictionary();

  ApplicationContext context = IOC.getContext();

  Compass compass = (Compass) context.getBean("compass");

  CompassTemplate template = new CompassTemplate(compass);

  template.execute(new CompassCallbackWithoutResult() {
   protected void doInCompassWithoutResult(CompassSession session)
     throws CompassException {
    CompassHits hits = session.find("大头人");

    System.out.println("Found [" + hits.getLength()
      + "] hits for [大头人] query");
    System.out
      .println("======================================================");
    for (int i = 0; i < hits.getLength(); i++) {
     print(hits, i);
    }

    hits.close();
   }
  });

 }

 public static void print(CompassHits hits, int hitNumber) {
  Object value = hits.data(hitNumber);
  Resource resource = hits.resource(hitNumber);
  System.out.println("ALIAS [" + resource.getAlias() + "]  SCORE ["
    + hits.score(hitNumber) + "]");
  System.out.println(":::: " + value);
  System.out.println("");
 }
}

19. 工具类DictionaryUtils是用来管理我们自己采用的中文分词算法的加载自定义词典的。
/**
 * Copyright (c) 2005-2006 重庆人月科技发展有限公司
 *
 * ------------------------------------------------------------------------------
 * @(#) DictionaryUtils.java, 2006-8-2 下午04:55:22
 * ------------------------------------------------------------------------------
 */
package com.darkhe.sample.mycompass;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;

import jeasy.analysis.MMAnalyzer;

/**
 *
 * @author darkhe
 * @version 1.0.0
 */
public class DictionaryUtils {
 // 静态变量
 private static boolean isInit = false;

 // 静态初始化

 // 静态方法
 public static void loadCustomDictionary() throws FileNotFoundException {

  if (isInit == false) {

   // 添加我们自己的词典
   FileReader fr = new FileReader(new File("dict.txt"));
   MMAnalyzer.addDictionary(fr);
   
   //System.out.println("添加我们自己的词典");

   isInit = true;
  }
 }
}
20. 执行Indexer，再执行Seracher后控制台信息如下：

Found [1] hits for [大头人] query
================================================
ALIAS [Article] SCORE [0.3988277]
:::: com.darkhe.sample.mycompass.Article@bla4e2

具体结果和你的数据表中的内容有别。

21. 这样，我们便实现了如何利用compass构建我们自己的搜索引擎的一个简单实现。