java - How to use cache with queries on different fields/keys? -

i implementing spring mvc based web application have added caching, face problem in terms of how operate on cache when changes applied underlying database.

i have been studying documentation available @ ehcache (http://ehcache.org/documentation), failed find examples solve problem.

let's have dao class have chosen apply cache on 2 methods return list of objects (non-compileable pseudocode):

@repository public class myentitydao {     @autowired    datasource ds;     @autowired    ehcachecachemanager cachemanager;     @autowired    cachekeygenerator keygenerator;     @cacheable("myentitycache")    public list<myentity> findbyfieldalpha(string fieldalpha) {        return ds.query("select * myentity fieldalpha = #fieldalpha").execute();    }     @cacheable("myentitycache")    public list<myentity> findbyfieldbeta(string fieldbeta) {        return ds.query("select * myentity fieldbeta = #fieldbeta").execute();    }     public void deletebyfieldalpha(string fieldalpha) {       ds.query("delete myentity fieldalpha = #fieldalpha").execute();    }     public void deletebyfieldbeta(string fieldbeta) {       ds.query("delete myentity fieldbeta = #fieldbeta").execute();    }     public void store(myentity myentity) {       ds.insert(myentity).execute();    } } 

i using custom keygenerator, know how keys when calling method generated:

public class cachekeygenerator implements keygenerator {     @override    public object generate(final object target, final method method, final object... params) {        return generatecachekey(method.getname(), params);    }     public string generatecachekey(final string methodname, final object... params) {        stringbuilder key = new stringbuilder();        key.append(methodname);        (object o : params) {           key.append("_").append(o.tostring());        }        return key.tostring();    } } 

the obvious problem need solve how should implement cache modification policy when data added or removed underlying database.

for store method find problem quite trivial solve:

 ...   public void store(myentity myentity) {     boolean success = ds.insert(myentity).execute();     if (success) {        cache cache = cachemanager.getcache("myentitycache")         string keyfieldalpha = keygenerator.generatecachekey("findbyfieldalpha", myentity.getfieldalpha());        list cachelistfieldalpha = (list) cache.get(keyfieldalpha).getobjectvalue();        cachelistfieldalpha.add(myentity);         string keyfieldbeta = keygenerator.generatecachekey("findbyfieldbeta", myentity.getfieldbeta());        list cachelistfieldbeta = (list) cache.get(keyfieldbeta).getobjectvalue();        cachelistfieldbeta.add(myentity);     }  } 

but delete-methods things more complicated.

this 1 implementation have come far, seems far more complicated (costly) should be. have valuable input if design patterns correct, or if should solve problem in other way?

public void deletebyfieldalpha(string fieldalpha) {   list<myentity> myentititestobedeleted = this.findbyfieldalpha(fieldalpha);   boolean success = ds.query("delete myentity fieldalpha = #fieldalpha").execute();   if (success) {      cache cache = cachemanager.getcache("myentitycache")       string keyfieldalpha = keygenerator.generatecachekey("findbyfieldalpha", fieldalpha);      cache.remove(keyfieldalpha);       (myentity myentity : myentititestobedeleted) {         string keyfieldbeta = keygenerator.generatecachekey("findbyfieldbeta", myentity.getfieldbeta());         list cachelistfieldbeta = (list) cache.get(keyfieldbeta).getobjectvalue();         cachelistfieldbeta.remove(myentity);       }   } } 

perhaps correct way of solving it? haven't stumbled upon recipes solves these problems @ best guess here.

i'll give opinion. seems (almost) correct aproach. think after delete operation should empty cache , start again. usualy, after data changing operations cache reset. that's done because of table joins. doesn't seem case because have 2 queries , no joins, usualy cache cleaned , restarted. doing way don't need scan on cache refers "fieldbeta" after changes in "fieldalfa". hope somethig you. btw, mybatis works way.