Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 1Z?uT[kR
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 8B+C[Q:+'
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 %qqCpg4
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 KXz7l\1Gb
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分页支持类: 9]T61Z{OW1
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java代码: jZ"j_=o@
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package com.javaeye.common.util; H>D?
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import java.util.List; ;FuST
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publicclass PaginationSupport { uwi.Sg11
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publicfinalstaticint PAGESIZE = 30; Mcz;`h|EW
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privateint pageSize = PAGESIZE; Rxr?T-
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privateList items; [ns==gDD
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privateint totalCount; *q\>DE=7
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privateint[] indexes = newint[0]; fGA#0/_`
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privateint startIndex = 0; .=yv m
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public PaginationSupport(List items, int "E4CQL'U
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totalCount){ hhWy-fP#
setPageSize(PAGESIZE); WAtv4
setTotalCount(totalCount); vxi_Y\r=T
setItems(items); e\-,e+
setStartIndex(0); "
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} L?M
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public PaginationSupport(List items, int
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totalCount, int startIndex){ b5.]}>]t
setPageSize(PAGESIZE); cdGBo4
setTotalCount(totalCount); )_>'D4l?
setItems(items); 92C; a5s
setStartIndex(startIndex); rf`xY4I\
} dK8dC1@,X;
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public PaginationSupport(List items, int =HV${+K=~
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totalCount, int pageSize, int startIndex){ WCk. K
setPageSize(pageSize); .r-Zz3
setTotalCount(totalCount); UKTfLh
setItems(items); Nq6;
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setStartIndex(startIndex); @)!N{x?
} `}L{gssv
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publicList getItems(){ $Xu/P5
return items; qu'D"0
} ([^f1;ncm
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publicvoid setItems(List items){ YdIZikF#
this.items = items; z;/8R7L&
} DSq?|H
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publicint getPageSize(){ =[Z3]#h
return pageSize; @SaxM4
} Hr7pcz/#l
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publicvoid setPageSize(int pageSize){ <9:~u]ixt
this.pageSize = pageSize; 5')]Y1J
} 1;B&R89}
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publicint getTotalCount(){ })?-)fFD
return totalCount; !mB
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} bR:hu}YS
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publicvoid setTotalCount(int totalCount){ IGlyx'\_
if(totalCount > 0){ F~7TE91C
this.totalCount = totalCount; KDV.ZSF7
int count = totalCount / 7[K3kUm[
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pageSize; M"qS#*{
if(totalCount % pageSize > 0) N>Uxq&)!
count++; }s6Veosl
indexes = newint[count]; F0r2=f(?
for(int i = 0; i < count; i++){ wa`c3PQGu
indexes = pageSize * SkCux
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} 23,pVo
}else{ myqwU`s
this.totalCount = 0; D:z_FNN
} WB<MU:.Vc
} FgrVXb_q
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publicint[] getIndexes(){ {X_I>)Wg
return indexes; Xh3b=i|K
} 0 VG;z#{J
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publicvoid setIndexes(int[] indexes){ bu $u@:q 6
this.indexes = indexes; R?2HnJh
} WiQVZ{
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publicint getStartIndex(){ y9LO;{(
return startIndex; DnG9bVm>
} 19pFNg'kA
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publicvoid setStartIndex(int startIndex){ %W=BdGr[8z
if(totalCount <= 0) C@zG(?X
this.startIndex = 0; ._<,
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elseif(startIndex >= totalCount) ~Cg7
this.startIndex = indexes H8HVmfM
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[indexes.length - 1]; ]>*VEe}hJ
elseif(startIndex < 0) i:jB
this.startIndex = 0; }; M@JMu,
else{ P>_9>k@;Q
this.startIndex = indexes [F;\NJp6?^
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[startIndex / pageSize]; uqa
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} )UTjP/\gN
} iVf7;M8O
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publicint getNextIndex(){ Hvy$DX|p
int nextIndex = getStartIndex() + mO(Y>|mm
ka ;=%*7T
pageSize; A"s?;hv\fS
if(nextIndex >= totalCount) =n_z `I
return getStartIndex(); x*=m'IM[
else JP5en
return nextIndex; Sl'$w4s
} a\oz-`ESa
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publicint getPreviousIndex(){ ~ qaT
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int previousIndex = getStartIndex() - G51-CLM,
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pageSize; pFZ$z?lI
if(previousIndex < 0)
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return0; J=(i0A
else }|N88PN
return previousIndex; .J&89I]U
} ["Tro;K#
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} ZU`~@.`i
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抽象业务类 >, 'guaa
java代码: )'e1@CR
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/** v.vkQQ0[9
* Created on 2005-7-12 8t, &dq
*/ m_Z(osoE#W
package com.javaeye.common.business; % WXl*
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import java.io.Serializable; Ui9;rh$1eU
import java.util.List; NZADHO@0
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import org.hibernate.Criteria; 8'bZR]
import org.hibernate.HibernateException; U 0~BcFpD
import org.hibernate.Session; F9r/
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import org.hibernate.criterion.DetachedCriteria; @JLN3
import org.hibernate.criterion.Projections; "Ms{c=XPK
import h8Oj
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org.springframework.orm.hibernate3.HibernateCallback; \ Ucv<S
import V>E7!LIn.
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org.springframework.orm.hibernate3.support.HibernateDaoS l,(:~KH|
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upport; nnE'zk<"
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import com.javaeye.common.util.PaginationSupport; `'EG7
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public abstract class AbstractManager extends =A{'57yP
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HibernateDaoSupport { NG:4Q.G1g
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privateboolean cacheQueries = false; ;#IrHR*Bk
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privateString queryCacheRegion; QlR~rFs9t
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publicvoid setCacheQueries(boolean LikCIO
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cacheQueries){ #Z
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this.cacheQueries = cacheQueries; 5M #',(X
} :"Tkl$@,
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publicvoid setQueryCacheRegion(String YDYNAOThnb
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queryCacheRegion){ /-^J0f+l3
this.queryCacheRegion = 'W54 T
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queryCacheRegion; {%^4%Eco
}
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publicvoid save(finalObject entity){ @W
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getHibernateTemplate().save(entity); KU0Ad);e
} DcM/p8da
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publicvoid persist(finalObject entity){ P_8!Gp
getHibernateTemplate().save(entity); -O=xgvh"
} T3"'`Sd9;
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publicvoid update(finalObject entity){ 8f)pf$v`
getHibernateTemplate().update(entity); 7^M$u\a)U
} yENAc sv
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publicvoid delete(finalObject entity){ .H qJ)OH
getHibernateTemplate().delete(entity); gp $Rf9\
} :7obxW1X
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publicObject load(finalClass entity, gae=+@z
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finalSerializable id){ #6[F&
return getHibernateTemplate().load o]qwN:8^
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(entity, id); Xppb|$qp4H
} r%X
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publicObject get(finalClass entity, #=ij</
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finalSerializable id){ FU .%td=:
return getHibernateTemplate().get 'X6Y!VDd
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(entity, id); k W
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} [cznhIvyO
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publicList findAll(finalClass entity){ 5|Z8UzL
return getHibernateTemplate().find("from E?KPez
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" + entity.getName()); vRf$#fBEQ
} Yjd/
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publicList findByNamedQuery(finalString -m>3@"q
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namedQuery){ }oSgx
return getHibernateTemplate A8ef=ljM?
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().findByNamedQuery(namedQuery); S+wT}_BQ
} >b5 ;I1o=y
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publicList findByNamedQuery(finalString query, $Zw+"AA
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finalObject parameter){ kw gLK@@%1
return getHibernateTemplate Zz/p'3?#
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().findByNamedQuery(query, parameter); (&r`
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} =2NrmwWZs
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publicList findByNamedQuery(finalString query, T{`VUS/
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finalObject[] parameters){ 7I&o
return getHibernateTemplate N81M9#,["~
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().findByNamedQuery(query, parameters); l Ib
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} a8ouk7G
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publicList find(finalString query){ 2cIKph
return getHibernateTemplate().find Kn= EDtg
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(query); F.1u9)
} 2QAP$f0Ln
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publicList find(finalString query, finalObject qnWM %k
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parameter){ ='4)E6ea?
return getHibernateTemplate().find .QZjJ9pvK
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(query, parameter); |mRlP5
} AJ&j|/
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public PaginationSupport findPageByCriteria /je
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(final DetachedCriteria detachedCriteria){ 4KR`
return findPageByCriteria 19y,O0# _
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); bolG3Tf|
} b6Z3(!]
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public PaginationSupport findPageByCriteria (s&]V49
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(final DetachedCriteria detachedCriteria, finalint 'xG J;pY
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startIndex){ H&p:
return findPageByCriteria 6S_mfWsi
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(detachedCriteria, PaginationSupport.PAGESIZE, "JLE
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startIndex); qGMU>J.;c
} {,h_T0D^j
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public PaginationSupport findPageByCriteria jN*wbqL
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(final DetachedCriteria detachedCriteria, finalint 00dY?d{[D
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pageSize, 32SkxcfrCK
finalint startIndex){ M/9[P*
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return(PaginationSupport) mTWd+mx
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getHibernateTemplate().execute(new HibernateCallback(){ x7<l*WQ
publicObject doInHibernate rCczQ71W
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(Session session)throws HibernateException { Qb>("j~Z
Criteria criteria = Db*b"/]
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detachedCriteria.getExecutableCriteria(session); AA=rjB9
int totalCount = u pUJF`3
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((Integer) criteria.setProjection(Projections.rowCount G/#<d-}_
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()).uniqueResult()).intValue(); SG\ /m'F
criteria.setProjection 0)b1'xt',
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(null); xZ`vcS(
List items = Y%eW6Y#
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criteria.setFirstResult(startIndex).setMaxResults p=> +3
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(pageSize).list(); Q$]1juqg
PaginationSupport ps = uuF~+=.|
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new PaginationSupport(items, totalCount, pageSize, c U(z5th
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startIndex); >yT1oD0+x
return ps; .*oL@iX
} ^mFsrw
}, true); 8,RqhT)2#
} h>[ qXz
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public List findAllByCriteria(final aBY&]6^-
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DetachedCriteria detachedCriteria){ a`^$xOK,
return(List) getHibernateTemplate 4 Sk@ v
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().execute(new HibernateCallback(){ w%)RX<h dI
publicObject doInHibernate C Q iHk
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(Session session)throws HibernateException { L?0IUGY
Criteria criteria = d#bg(y\G|
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detachedCriteria.getExecutableCriteria(session); o_Y?s+~i[/
return criteria.list(); #Y-_kQV*
} wG)[Ik6:
}, true); Z>Rshtg
} LCA+y1LP-_
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public int getCountByCriteria(final <'sm($.2
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DetachedCriteria detachedCriteria){ !XI9evJw
Integer count = (Integer) z4(\yx
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getHibernateTemplate().execute(new HibernateCallback(){ BOM0QskLf
publicObject doInHibernate 9lGa*f)
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(Session session)throws HibernateException { 4K`b?{){+a
Criteria criteria = KOXG=P0
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detachedCriteria.getExecutableCriteria(session); [U^Cz{G
return _G<Wq`0w)
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criteria.setProjection(Projections.rowCount ]=xX_
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()).uniqueResult();
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} hmuhq:<f
}, true); x]%,?Vd?
return count.intValue(); N z=P1&G'
} edlf++r~
} :cXN
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用户在web层构造查询条件detachedCriteria,和可选的 >zfx2wh\a
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 !-%%94 Q
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PaginationSupport的实例ps。 yn(bW\
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ps.getItems()得到已分页好的结果集 tr/.pw6
ps.getIndexes()得到分页索引的数组 +s`cXTlFrk
ps.getTotalCount()得到总结果数 6iEg]FI
ps.getStartIndex()当前分页索引 K~3Y8ca
ps.getNextIndex()下一页索引 vAeVQ~
ps.getPreviousIndex()上一页索引 unz~vG1Tn
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 4,Uqcw?!F'
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 V;J3lV<
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一下代码重构了。 ~P~q'
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我把原本我的做法也提供出来供大家讨论吧: }rs>B,=*k
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首先,为了实现分页查询,我封装了一个Page类: /?TR_>
java代码: Up_"qD6
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/*Created on 2005-4-14*/ eC6wrpZO
package org.flyware.util.page; I};*O6D`
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/** fuF{8-ua
* @author Joa U+E9l?4R
* H5UF r,t
*/ 4)'U!jSb
publicclass Page { "*MF=VB1
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/** imply if the page has previous page */ V 7ZGT
privateboolean hasPrePage; uNw9g<g:V[
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/** imply if the page has next page */ "o_'q@.}
privateboolean hasNextPage; AA=eWg
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/** the number of every page */ <Kl$ek8
privateint everyPage; %@TC-
xx
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/** the total page number */ ),xD5~_=q
privateint totalPage; zf^|H%
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/** the number of current page */ asCcBp
privateint currentPage; rQ U6*f
tp&|*M3
/** the begin index of the records by the current ja&m-CFK
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query */ b&LAk-}[
privateint beginIndex; L2~'Z'q
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/** The default constructor */ u-mD"
public Page(){ n%4/@M
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} rcY &n^:
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/** construct the page by everyPage *0Fz." v
* @param everyPage R-1MD
* */ ReA-.j_2@
public Page(int everyPage){ &Vgpv#&Cfx
this.everyPage = everyPage; |(PS
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} *vvm8ik
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/** The whole constructor */ urCTP.F
public Page(boolean hasPrePage, boolean hasNextPage, zEukEA^9`
8]R{5RGy
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int everyPage, int totalPage, _5x]BH6f
int currentPage, int beginIndex){ `r~3Pf).4
this.hasPrePage = hasPrePage; Zzz94`
this.hasNextPage = hasNextPage; 1KBGML-K3
this.everyPage = everyPage; <yBa5m@/
this.totalPage = totalPage; W-/V5=?
this.currentPage = currentPage; Qf}.= (
this.beginIndex = beginIndex; o;
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} lmD[Cn
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w
/** -V[x
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* @return N0vECk
* Returns the beginIndex. n^O!93a
*/ FoH1O+e
publicint getBeginIndex(){ Q>rr?L`
return beginIndex; jvL!pEC!
} (}.MB3`#C
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/** `.3@Ki~$#
* @param beginIndex SPt/$uYJ
* The beginIndex to set. Qx8(w"k*
*/ =+ >>l0=_v
publicvoid setBeginIndex(int beginIndex){ xSSEDfq
this.beginIndex = beginIndex; kw]?/s`
} 83gWA>Odh
3JBXGT0gJ
/** '=#fELMW
* @return `8RKpZv&
* Returns the currentPage. ~!8j,Bqs+z
*/ ubOXEkZ8N
publicint getCurrentPage(){ m_@XoS
yxI
return currentPage; "* F`,I3
} : MjDcI~
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/** c"Vp5lo0
* @param currentPage jnTTj l
* The currentPage to set. W{tZX^|
*/ GQ7uxdqWBQ
publicvoid setCurrentPage(int currentPage){ =W:=}ODD
this.currentPage = currentPage; rVl 8?uy
} hd~#I<8;2
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/** ,qv\Y]
* @return \U>&W
* Returns the everyPage. {tY1$}R
*/ [xr^t1
publicint getEveryPage(){ |l+5E
return everyPage; U$& '> %#
} !|H,g wqU
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/** [X!w@d= i
* @param everyPage HdB>CVuh
* The everyPage to set. }^&f {
*/ 'o#oRK{#
publicvoid setEveryPage(int everyPage){ Rk3
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this.everyPage = everyPage; /]!2k9u\
} yxp,)os:
^4^N} 7>5
/** It&CM,=t
* @return ~i>DF`w$
* Returns the hasNextPage. 5}ftiy[Yc
*/ 3-{BXht)
publicboolean getHasNextPage(){ DR}I+<*%aD
return hasNextPage; &|#[.ti1
} Q'Osw"
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/** 3J
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* @param hasNextPage 9|Jv>Ur=)2
* The hasNextPage to set. Z,E$4Z
*/ FrXP"U}Y
publicvoid setHasNextPage(boolean hasNextPage){ Z}uY%]
this.hasNextPage = hasNextPage; |zpy!X 3
} wb?k
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/**
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* @return L4m Vk
* Returns the hasPrePage. Rq5'=L
*/ bN zb#P#hP
publicboolean getHasPrePage(){ >aO.a[AM
return hasPrePage; i`r`Fj}-S-
} W?.469yy
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/** ^WO3,
* @param hasPrePage iv *$!\Cd
* The hasPrePage to set. _90D4kGU
*/ }]o8}$&(
publicvoid setHasPrePage(boolean hasPrePage){ 018SFle
this.hasPrePage = hasPrePage; WT<}3(S'?
} 1~L;S
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/** l1DJ<I2
* @return Returns the totalPage. ;kk[x8$
* .b3h?R*&
*/ *O~y6|U?
publicint getTotalPage(){ >80k5$t
return totalPage; Qq`S=:}~x
} :kR>wX
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/** iF^qbh%%E
* @param totalPage /f1]U
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* The totalPage to set. W-s 6+DY
*/ Gg'!(]v
publicvoid setTotalPage(int totalPage){ HfVHjF)
this.totalPage = totalPage; A,<5W }
} *HR
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} Unb2D4&'
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 Hh^ "c}
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个PageUtil,负责对Page对象进行构造: W:RjWn @<
java代码: }g/u.@E
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/*Created on 2005-4-14*/ p$\>3\
package org.flyware.util.page; _s5^\~ao
6U ! P8q
import org.apache.commons.logging.Log; r5~W/eE
import org.apache.commons.logging.LogFactory; dB_0B.
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/** e|{R2z"^
* @author Joa IADHe\.
* OWewV@VXR
*/ Wz'!stcp
publicclass PageUtil { hEB5=~A_
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privatestaticfinal Log logger = LogFactory.getLog b~vV++ou_
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(PageUtil.class); o+Jnn"8
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/** I*N"_uKU
* Use the origin page to create a new page _dm0*T ?
* @param page Z>`\$1CI
* @param totalRecords BjfVNF;hk:
* @return cK1^jH<|
*/ T>asH
publicstatic Page createPage(Page page, int <{cY2cx~3
S&}7XjY
totalRecords){ QZ&(e2z
return createPage(page.getEveryPage(), *,Bm:F<m
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page.getCurrentPage(), totalRecords); Z}$sY>E
} kaCN^yQ
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/**
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* the basic page utils not including exception !=:>y WQ
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handler +4%~.,<_to
* @param everyPage Hq}g1?b
* @param currentPage ndLEIqOY
* @param totalRecords i-wRwl4aEF
* @return page by>%}#M
*/ t?>}0\1
publicstatic Page createPage(int everyPage, int k";dK*hD,
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currentPage, int totalRecords){ ^!S4?<v
everyPage = getEveryPage(everyPage); zj r($?
currentPage = getCurrentPage(currentPage); sR9$=91`
int beginIndex = getBeginIndex(everyPage, ,<L4tp+y0
&'/"=lK
currentPage); 06&;GW!-
int totalPage = getTotalPage(everyPage, ura&9~
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totalRecords); c]Epg)E
boolean hasNextPage = hasNextPage(currentPage, twr{jdY9
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totalPage); ?sQg{1"Zr
boolean hasPrePage = hasPrePage(currentPage); )L9eLxI
+
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returnnew Page(hasPrePage, hasNextPage, .F7?}8>Z
everyPage, totalPage, V|
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currentPage, ;t +p2i
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beginIndex); 5Yv*f:
} AVjRhe
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privatestaticint getEveryPage(int everyPage){ W\Pd:t
return everyPage == 0 ? 10 : everyPage; !LH;K
} OT\D;Z"__I
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privatestaticint getCurrentPage(int currentPage){ 0\!Bh^++1
return currentPage == 0 ? 1 : currentPage; &C
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} q*lk9{>
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privatestaticint getBeginIndex(int everyPage, int
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currentPage){ *66EkCj
return(currentPage - 1) * everyPage; E&J<qTH9
} K7C
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privatestaticint getTotalPage(int everyPage, int :i>LESJq
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totalRecords){ ?:/J8s
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int totalPage = 0; 4OM
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if(totalRecords % everyPage == 0) $DH/
totalPage = totalRecords / everyPage; @XG1d)sE
else WrwbLl E
totalPage = totalRecords / everyPage + 1 ; EB&hgz&_
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return totalPage; 'KmM%tN
} >AV9 K
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privatestaticboolean hasPrePage(int currentPage){ l1zPL3"u_^
return currentPage == 1 ? false : true; G$YF0Nc
} ^) s6`:
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privatestaticboolean hasNextPage(int currentPage, 'exR;q\
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int totalPage){ 2Ax(q&`9
return currentPage == totalPage || totalPage == Ke^/aGi}O
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0 ? false : true; I|*<[/)]y
} Z .`+IN(>E
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} 6$PQ$
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 |LIcq0Z
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 qtVgjT2#H
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做法如下: xPF.c,6b4=
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 X..M!3W
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的信息,和一个结果集List: &K