compass学习笔记

以下是鄙人在学习compass所做的笔记（如果鄙人写的不是很清楚的话，可以从电驴或者迅雷上搜索v521刘伟老师的compass学习视频）。系统框架采用Struts2.1.6+Spring2.5.4+Hibernate3+compass2.1.0，JDK版本采用6.0的。

首先，需要将将SSH整合好。具体的我不在此说明，可以在google上进行搜索。我将重点说明compass如何与SSH进行整合。

使用compass框架，首先需要进行compass关于实体类的映射。compass在其文档中说明，一般是在实体类相对应的*.cpm.xml中进行配置的。但是在开发中，我们可以借助jdk关于标注的新特性，将此文件省略。具体代码如下所示：

package com.zhou.model;   
  
  
import java.io.Serializable;   
  
import org.compass.annotations.Searchable;   
import org.compass.annotations.SearchableId;   
import org.compass.annotations.SearchableProperty;   
  
@Searchable  
public class Product implements Serializable {   
  
  
    private static final long serialVersionUID = -3148838659193709682L;   
       
    //Field   
       
    @SearchableId  
    private String id;   
    @SearchableProperty(name="name")   
    private String name;   
    @SearchableProperty(name="price")   
    private Integer price;   
    @SearchableProperty(name="brand")   
    private String brand;   
    @SearchableProperty(name="description")   
    private String description;   
  
    // Constructors   
  
    /** default constructor */  
    public Product() {   
    }   
  
    /** full constructor */  
    public Product(String name, Integer price, String brand, String description) {   
        this.name = name;   
        this.price = price;   
        this.brand = brand;   
        this.description = description;   
    }   
  
    // Property accessors   
  
    public String getId() {   
        return this.id;   
    }   
  
    public void setId(String id) {   
        this.id = id;   
    }   
  
    public String getName() {   
        return this.name;   
    }   
  
    public void setName(String name) {   
        this.name = name;   
    }   
  
    public Integer getPrice() {   
        return this.price;   
    }   
  
    public void setPrice(Integer price) {   
        this.price = price;   
    }   
  
    public String getBrand() {   
        return this.brand;   
    }   
  
    public void setBrand(String brand) {   
        this.brand = brand;   
    }   
  
    public String getDescription() {   
        return this.description;   
    }   
  
    public void setDescription(String description) {   
        this.description = description;   
    }   
  
}  

如代码所示，实体类的类声明和属性声明分别加入了相应的标注。public class前面的“@Searchable”表示此类可以被索引，也就是此类对应的数据库可以被索引。属性id前的“@SearchableId”表示索引建立的id。其他属性前面的“@SearchableProperty(name="name")”表示此字段可以被索引、被检索。name=“name”表示此字段被索引后的名称。在检索类中，可以根据此名字指定搜索的字段名称。

建立索引的类（CompassIndexBuilder.java）

package com.zhou.service.impl;   
  
import java.util.Date;   
  
import org.compass.gps.CompassGps;   
import org.springframework.beans.factory.InitializingBean;   
  
public class CompassIndexBuilder implements InitializingBean {   
    private boolean buildIndex = false;   
  
    private int lazyTime = 5;   
    private CompassGps compassGps;   
    private Thread indexThread = new Thread() {   
        public void run() {   
            try {   
                Thread.sleep(lazyTime * 1000);   
                System.out.println("begin compass index...");   
                long beginTime = System.currentTimeMillis();   
                compassGps.index();   
                long costTime = System.currentTimeMillis() - beginTime;   
                System.out.println("compss index finished.");   
                System.out.println("costed " + costTime + " milliseconds");   
            } catch (InterruptedException e) {   
                e.printStackTrace();   
            }   
        }   
    };   
  
    public void afterPropertiesSet() throws Exception {   
        System.out.println(new Date()+"调用");   
        if (buildIndex) {   
            indexThread.setDaemon(true);   
            indexThread.setName("Compass Indexer");   
            indexThread.start();   
        }   
    }   
  
    public void setBuildIndex(boolean buildIndex) {   
        this.buildIndex = buildIndex;   
    }   
  
    public void setLazyTime(int lazyTime) {   
        this.lazyTime = lazyTime;   
    }   
  
    public void setCompassGps(CompassGps compassGps) {   
        this.compassGps = compassGps;   
    }   
  
}  

详细的解释可以观看视频，在此不再说明。

将compass的配置写在同一个文件（applicationContext-compass）中，以便同一管理。内容如下：

<?xml version="1.0" encoding="UTF-8"?>  
  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xsi:schemaLocation=" http://www.springframework.org/schema/beans  http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"  
    default-lazy-init="true">  
  
       <!--  如果使用jdk标注新特性，此处必须有的  -->  
    <bean id="annotationConfiguration" class="org.compass.annotations.config.CompassAnnotationsConfiguration">  
    </bean>  
  
  
    <bean id="compass" class="org.compass.spring.LocalCompassBean">  
        <property name="resourceDirectoryLocations">  
            <list>  
                <value>classpath:com/zhou</value>  
            </list>  
        </property>  
        <property name="connection">  
            <value>/lucene/indexes</value>  
        </property>  
  
  
        <property name="classMappings">  
            <list>  
                <value>com.zhou.model.Product</value>  
            </list>  
        </property>  
        <property name="compassConfiguration"  
            ref="annotationConfiguration" />  
  
        <property name="compassSettings">  
            <props>  
                <prop key="compass.transaction.factory">  
                    org.compass.spring.transaction.SpringSyncTransactionFactory   
                </prop>  
                <prop  
                    key="compass.engine.analyzer.MMAnalyzer.CustomAnalyzer">  
                    net.paoding.analysis.analyzer.PaodingAnalyzer   
                </prop>  
                <prop  
                    key="compass.engine.highlighter.default.formatter.simple.pre">  
                    <!--[CDATA[<font color="red"><b>]]>  
                </prop>  
                <prop  
                    key="compass.engine.highlighter.default.formatter.simple.post">  
                    <![CDATA[</b></font>]]-->  
                </prop>  
            </props>  
        </property>  
  
        <property name="transactionManager" ref="transactionManager" />  
    </bean>  
  
  
    <bean id="hibernateGpsDevice"  
        class="org.compass.gps.device.hibernate.HibernateGpsDevice">  
        <property name="name">  
            <value>hibernateDevice</value>  
        </property>  
        <property name="sessionFactory" ref="sessionFactory" />  
        <property name="mirrorDataChanges">  
            <value>true</value>  
        </property>  
    </bean>  
    <!-- 同步更新索引 -->  
    <bean id="compassGps" class="org.compass.gps.impl.SingleCompassGps"  
        init-method="start" destroy-method="stop">  
        <property name="compass" ref="compass" />  
        <property name="gpsDevices">  
            <list>  
                <bean  
                    class="org.compass.spring.device.SpringSyncTransactionGpsDeviceWrapper">  
                    <property name="gpsDevice" ref="hibernateGpsDevice" />  
                </bean>  
            </list>  
        </property>  
    </bean>  
  
  
    <bean id="compassTemplate"  
        class="org.compass.core.CompassTemplate">  
        <property name="compass" ref="compass" />  
    </bean>  
  
    <!-- 定时重建索引(利用quartz)或随Spring ApplicationContext启动而重建索引 -->  
    <bean id="compassIndexBuilder"  
        class="com.zhou.service.impl.CompassIndexBuilder" lazy-init="false">  
  
        <property name="compassGps" ref="compassGps" />  
  
        <property name="buildIndex" value="true" />  
        <property name="lazyTime" value="5" />  
    </bean>  
  
</beans>  

在业务层进行数据检索的代码如下：

public List<Product> searchProducts(String queryString) {   
  
    List<Product> products = new ArrayList<Product>();   
  
    Compass compass = compassTemplate.getCompass();   
    CompassSession session = compass.openSession();   
  
    CompassHits hits = session.queryBuilder().queryString(   
            "name:" + queryString).toQuery().hits();   
    System.out.println("---------------------------------------------");   
    System.out.println("queryString=" + queryString);   
    System.out.println("结果个数=" + hits.length());   
  
    for (int i = 0; i < hits.length(); i++) {   
        Product hit = (Product) hits.data(i);   
  
        String ht = hits.highlighter(i).fragment("name");   
        if (null != ht) {   
            hit.setName(ht);   
        }   
        products.add(hit);   
    }   
  
    return products;   
}  

以上是关键部分的说明。在bs层中的检索方法searchProducts(String queryString)中，有很多地方需要深入的思考一下。比如：在“CompassHits hits = session.queryBuilder().queryString("name:" + queryString).toQuery().hits();”中的“name”就是至前面实体类中的“@SearchableProperty(name="name")”中“name”的值，表示只对该字段进行检索。又比如涉及到结果分页显示的话，该如何封装返回的结果。究竟是一次全部封装到List中还是每页显示n条就封装n条，翻页的时候继续hit呢？有待深入思考。

附件为样例程序，但是相关的jar包太大了，无法上传！需要自己查找。