java 缓存框架java caching system使用示例
要使用java caching system，需要下面这几个包：jcs.jar，concurrent.jar,commons-logging.jar, commons-lang.jar,commons-collection.jar这几个包，在java工程里面，
首先新建一个使用jcs的配置文件：cache.ccf，文件名不能改。
# DEFAULT CACHE REGION # sets the default aux value for any non configured caches jcs.default= jcs.default.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes jcs.default.cacheattributes.MaxObjects=2000 jcs.default.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache jcs.default.elementattributes.IsEternal=false jcs.default.elementattributes.MaxLifeSeconds=3600 jcs.default.elementattributes.IdleTime=1800 jcs.default.elementattributes.IsSpool=true jcs.default.elementattributes.IsRemote=true jcs.default.elementattributes.IsLateral=true # CACHE REGIONS AVAILABLE # Regions preconfigured for caching jcs.region.bookCache= jcs.region.bookCache.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes jcs.region.bookCache.cacheattributes.MaxObjects=1200 jcs.region.bookCache.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache jcs.region.bookCache.elementattributes.IsEternal=false jcs.region.bookCache.elementattributes.MaxLifeSeconds=7200 jcs.region.bookCache.elementattributes.IdleTime=1800 jcs.region.bookCache.elementattributes.IsSpool=true jcs.region.bookCache.elementattributes.IsRemote=true jcs.region.bookCache.elementattributes.IsLateral=true # AUXILIARY CACHES AVAILABLE # Primary Disk Cache -- faster than the rest because of memory key storage jcs.auxiliary.DC=org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCacheFactory jcs.auxiliary.DC.attributes=org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCacheAttributes jcs.auxiliary.DC.attributes.DiskPath=/usr/opt/bookstore/raf jcs.auxiliary.DC.attributes.MaxPurgatorySize=10000 jcs.auxiliary.DC.attributes.MaxKeySize=10000 jcs.auxiliary.DC.attributes.OptimizeAtRemoveCount=300000 jcs.auxiliary.DC.attributes.MaxRecycleBinSize=7500
然后新建两个类，
import java.io.Serializable;
import java.util.List;
public class Student implements Serializable{
/**
*
*/
public static final long serialVersionUID = 1L;
public int sno;
public String sname;
public Student()
{}
public int getSno(){
return this.sno;
}
public void setSno(int no){
this.sno=no;
}
public String getSname(){
return this.sname;
}
public void setSname(String name){
this.sname=name;
}
}
import org.apache.jcs.JCS;
public class StuObjManager {
private static StuObjManager instance;
private static int checkedOut=0;
public static JCS stuCache;
private StuObjManager()
{
try
{
stuCache=JCS.getInstance("stuCache");
}
catch(Exception e)
{
e.printStackTrace();
}
}
public static StuObjManager getInstance()
{
synchronized(StuObjManager.class)
{
if(instance==null)
{
instance=new StuObjManager();
}
}
synchronized(instance)
{
instance.checkedOut++;
}
return instance;
}
public Student getStu(int sno)
{
return getStu(sno,true);
}
public Student getStu(int sno,boolean a)
{
Student stu=null;
if(a)
{
stu=(Student)stuCache.get("Stu"+sno);
}
if(stu==null)
{
stu=loadStu(sno);
}
return stu;
}
public Student loadStu(int sno)
{
Student stu=new Student();
stu.sno=sno;
try
{
boolean found=false;
found=true;
if(found)
{
stuCache.put("Stu"+sno, stu);
}
}
catch(Exception e)
{System.out.println("又报错了!");}
return stu;
}
public void storeStu(Student stu)
{
try
{
if(stu.sno!=0)
{
stuCache.remove("Stu"+stu.sno);
}
stuCache.put("Stu"+stu.sno, stu);
}
catch(Exception e)
{}
}
public static void main(String [] args)
{
long last=System.currentTimeMillis();
StuObjManager stu=StuObjManager.getInstance();
for(int i = 0; i < 2000; i++){
stu.loadStu(i);
}
Student stu1=stu.getStu(8,true);
System.out.println(stu1.sno);
System.out.println("所需时间："+(System.currentTimeMillis()-last));
}
}
运行类StuObjManager里面的main函数，结果如下：
8
所需时间：1250
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