Ehcache学习笔记(二) 根据条件筛选缓存中的数据

Ehcache学习笔记(二)  根据条件筛选缓存中的数据

 

Ehcache提供了很方便的索引机制，有的时候我们需要根据一些其他的条件对缓存中的数据进行索引，而不是简单根据KEY来进行索引。

 

这是实体类 没什么好说的

package com.epkj.test;

import java.util.Date;

public class User implements java.io.Serializable {

    private int id;
    
    private String name;
    
    private int age;
    
    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    private Date brithray;
    
    private double money;

    public User() {
        super();
    }

    public User(int id, String name, int age, Date brithray, double money) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
        this.brithray = brithray;
        this.money = money;
    }

    @Override
    public String toString() {
        return this.id + "====" + this.age;
    }
    
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Date getBrithray() {
        return brithray;
    }

    public void setBrithray(Date brithray) {
        this.brithray = brithray;
    }

    public double getMoney() {
        return money;
    }

    public void setMoney(double money) {
        this.money = money;
    }
}

 主要看XML

<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="http://ehcache.org/ehcache.xsd"
         updateCheck="true" monitoring="autodetect"
         dynamicConfig="true">
         
    <diskStore path="F:/"/>
    
    <cache 
        name="sampleCache" 
        maxElementsInMemory="1000"
        eternal="false"
        timeToIdleSeconds="120"
        timeToLiveSeconds="120"
        memoryStoreEvictionPolicy="LRU"
    >
        <searchable>
            <searchAttribute name="name"/>
            <searchAttribute name="age" expression="value.getAge()"/>
        </searchable>
    </cache>
    
    <!-- 
        //定义查询的属性 可以有多重方式,这里不一一举例
        <searchable>
            <searchAttribute name="name"/>
            <searchAttribute name="age" expression="value.getAge()"/>
        </searchable>
        
        <searchable>
            <searchAttribute name="age" expression="value.person.getAge()"/>
        </searchable>
        
        <searchable>
             <searchAttribute name="name" expression="element.toString()"/>
          </searchable>
     -->
</ehcache>

 查询的代码

package com.epkj.test;

import java.util.Date;
import java.util.List;

import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Ehcache;
import net.sf.ehcache.Element;
import net.sf.ehcache.search.Attribute;
import net.sf.ehcache.search.Query;
import net.sf.ehcache.search.Result;
import net.sf.ehcache.search.Results;

public class SerachTest {

    /**
     * @param args
     */
    public static void main(String[] args) {
        
        CacheManager manager = CacheManager.getInstance();
        
        Ehcache cache = manager.getCache("sampleCache");
        //创建测试数据放入缓存
        for (int i = 0; i < 50; i++) {
            Element element = null;
            if(i <= 20) {
                element = new Element(i, new User(1, "Txxxxxx" + i, i, new Date(), 3500));
            } else {
                element = new Element(i, new User(1, "Yxxxxxx" + i, i, new Date(), 3500));
            }
            cache.put(element);
        }
        
        //创建Query接口 用法跟hibernate的Query类似
        Query query = cache.createQuery();
        //取得属性
        Attribute<Integer> age = cache.getSearchAttribute("age");
        
        Attribute<String> name = cache.getSearchAttribute("name");
        
        //可以任务组合查询条件
        query.addCriteria(name.ilike("T*").and(age.between(10, 20)));
        
        //根据查询的条件 引入结果集
        query.includeValues().end();
        
        Results results = query.execute();
        
        List<Result> list = results.all();
        
        for (Result result : list) {
            System.out.println(result.getValue());
        }
    }

}

以上是对Ehcache缓存元素的条件查询的一个总结。