利用Compass實現一個簡單的搜索引擎

Compass是一流的開放源碼JAVA搜索引擎框架，對於你的應用修飾，搜索引擎語義更具有能力。依靠頂級的Lucene搜索引擎，Compass 結合了，像 Hibernate和 Sprin的流行的框架，爲你的應用提供了從數據模型和數據源同步改變的搜索力.並且添加了2方面的特徵,事物管理和快速更新優化. Compass的目標是：把java應用簡單集成到搜索引擎中.編碼更少，查找數據更便捷。

下面以一個應用場景分步驟講解如何利用compass實現搜索引擎：

1. 這裏我們有一個Article表，希望利用compass實現對它的搜索。

Article的結構如下：

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;

我們希望利用compass對它的ArticleTitle、Summary、Content和KeyList進行全文檢索。下面開始行動吧。

2. 首先到http://www.opensymphony.com/compass/download.action 上下載一個compass的發佈版，我們下載的是Version 1.0.0的With Dependencies 。這樣就可能省去尋找相關信賴庫的麻煩了。

3. 將compass1.0解壓到一個合適的目錄，我們的工作目錄是d:\develop\compass1.0

4. 我們是在eclipse環境下實現當前要求的，所以建議你也安裝一個eclipse 3.2。

5. 首先我們在eclipse中建立了一個java工程，名爲mycompass。

6. 然後我們在工程目錄中建立了一個lib目錄，用來存放本次工程所需要的所有compass和其它相關的庫文件，並將他們設置爲當前工程構建路徑中需要的庫文件。所有這些文件可以在compass的安裝目錄的lib目錄找到。

下面是我們的庫文件列表：

7. 建立了Article表的pojo類。

CODE:

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;
}

}


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8. 建立hibernate的pojo到數據表映射文件

CODE:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"[url]http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd[/url]">
<!-- 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>


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9. 開始配置compass，首先是compass的系統配置文件 mycompass.cfg.xml

CODE:

<?xml version="1.0" encoding="UTF-8"?>
<compass-core-config
xmlns="[url]http://www.opensymphony.com/compass/schema/core-config[/url]"
xmlns:xsi="[url]http://www.w3.org/2001/XMLSchema-instance[/url]"
xsi:schemaLocation="[url]http://www.opensymphony.com/compass/schema/core-config[/url]
[url]http://www.opensymphony.com/compass/schema/compass-core-config.xsd[/url]">

<compass name="default"> <!—這個名字隨你取了，但它是必須的-->

<connection>
<file path="target" /> <!—這裏是索引文件的存放路徑，我們設置的是當前工程的相對路徑target-?
</connection>

<searchEngine>
<!-- 因是使用自己的分詞算法，所以這裏的類型必須是CustomAnalyzer -->
<analyzer name="MMAnalyer" type="CustomAnalyzer" analyzerClass="jeasy.analysis.MMAnalyzer">
<stopWords>
<stopWord value="test" />
</stopWords>
</analyzer>
</searchEngine>

</compass>
</compass-core-config>

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在上面的配置中，我們使用的我們選用的一箇中文分詞算法庫，你可以用compass自帶的。具體compass提供了哪些分詞算法，請查閱compass的手冊。


10. 然後是mycompass.cmd.xml

CODE:

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

<compass-core-meta-data>

<!-- 定義一個實體和字段組-->
<meta-data-group id="mycompass" displayName="My Compass">

<description>Mycompass Meta Data</description>
<uri>[url]http://com/darkhe/sample/mycompass</uri>[/url]


<!-- 申明所有需要檢索的實體-->
<alias id="Article" displayName="Article">
<description>Article alias</description>
<uri>[url]http://com/darkhe/sample/mycompass/alias/Article</uri>[/url]
<name>Article</name>
</alias>

<!-- 申明所有需要檢索的屬性或者字段，而不管這些屬性或者字段是哪個實體的 -->
<meta-data id="ArticleTitle" displayName="ArticleTitle">
<description>ArticleTitle</description>
<uri>[url]http://com/darkhe/sample/mycompass/alias/ArticleTitle</uri>[/url]
<name>ArticleTitle</name>
</meta-data>

<meta-data id="PublishDate" displayName="PublishDate">
<description>PublishDate</description>
<uri>[url]http://com/darkhe/sample/mycompass/alias/PublishDate</uri>[/url]
<name format="yyyy-MM-dd hh:mm:ss">date</name>
</meta-data>

<meta-data id="Summary" displayName="Summary">
<description>Summary</description>
<uri>[url]http://com/darkhe/sample/mycompass/alias/Summary</uri>[/url]
<name>Summary</name>
</meta-data>

<meta-data id="Content" displayName="Content">
<description>Content</description>
<uri>[url]http://com/darkhe/sample/mycompass/alias/Content</uri>[/url]
<name>Content</name>
</meta-data>

<meta-data id="KeyList" displayName="KeyList">
<description>KeyList</description>
<uri>[url]http://com/darkhe/sample/mycompass/alias/KeyList</uri>[/url]
<name>KeyList</name>
</meta-data>

</meta-data-group>

</compass-core-meta-data>

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11. 再是mycompass.cpm.xml

CODE:

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

<!-- 這裏的包名必須和pojo的包名一致 -->
<compass-core-mapping package="com.darkhe.sample.mycompass">

<!-- 定義實體及其字段的對應關係 -->

<!-- 注意實體及其字段的名稱的大小寫應當與pojo對象一致，而不是與數據庫一致
關於pojo與數據庫的對應表的一致性關係由hibernate的映謝文件定義，而不是這個文件
當前映射文件只定義compass與hibernate的關係 -->

<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>


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12. log4j.properties

CODE:

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

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13. jdbc.properties

CODE:

# 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

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14. 最後是applicationContext-hibernate.xml，這裏集中配置了compass如何與spring與hibernate結合的。

CODE:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "[url]http://www.springframework.org/dtd/spring-beans.dtd[/url]">

<!--
- 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 <!-- 這裏是hibernate裏需要的數據映射文件 -->
</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> <!-- 這裏是compass所需要的兩個關於數據項的配置文件 -->
<value>classpath:mycompass.cpm.xml</value>
</list>
</property>
<property name="configLocation">
<value>classpath:mycompass.cfg.xml</value> <!-- 這裏是compass的系統配置文件的路徑 -->
</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>

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15. 注意上面的所以配置文件，根據我們上面的配置，都應當放到classpath的根路徑。
16. 建立工具類，用來進行spring引擎的初始化工作。

CODE:

/**
* <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);
}

}


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17. 建立索引程序，用來數據庫中的建立索引

CODE:

/*
* 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 {

// 加裁自定義詞典
DictionaryUtils.loadCustomDictionary();

ApplicationContext context = IOC.getContext();

// 得到spring環境中已經配置和初始化好的compassGps對象
CompassGps compassGps = (CompassGps) context.getBean("compassGps");
// 調用index方法建立索引
compassGps.index();

}

}

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18. 建立搜索程序，檢證compass的應用。

CODE:

/*
* 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 {

// 加裁自定義詞典
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("大頭人");

System.out.println("Found [" + hits.getLength()
+ "] hits for [大頭人] 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("");
}
}


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19. 工具類DictionaryUtils是用來管理我們自己採用的中文分詞算法的加載自定義詞典的。

CODE:

/**
* Copyright (c) 2005-2006 重慶人月科技發展有限公司
*
* ------------------------------------------------------------------------------
* @(#) 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 {
// 靜態變量
private static boolean isInit = false;

// 靜態初始化

// 靜態方法
public static void loadCustomDictionary() throws FileNotFoundException {

if (isInit == false) {

// 添加我們自己的詞典
FileReader fr = new FileReader(new File("dict.txt"));
MMAnalyzer.addDictionary(fr);

//System.out.println("添加我們自己的詞典");

isInit = true;
}
}
}

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20. 執行Indexer，再執行Seracher後控制檯信息如下：

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


具體結果和你的數據表中的內容有別。

21. 這樣，我們便實現瞭如何利用compass構建我們自己的搜索引擎的一個簡單實現。

[url]http://blog.csdn.net/songbaojie/archive/2007/03/26/1541376.aspx[/url]