Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Y`v&YcX;
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 _'Z@ < ,L
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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 S6uBk"V!
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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 `B~%TEvMh
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分页支持类: Z q)A"'Y
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java代码: n$>H } #q
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package com.javaeye.common.util; 9S}PCAA;
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import java.util.List; q%l<Hw6{z
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publicclass PaginationSupport { />$kDe
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publicfinalstaticint PAGESIZE = 30; %rkUy?=vu
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privateint pageSize = PAGESIZE; H3JWf
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privateList items; f-PDgs
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privateint totalCount;
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privateint[] indexes = newint[0];
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privateint startIndex = 0; 0>vm&W<?)
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public PaginationSupport(List items, int zK}.Bhj#
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totalCount){ -<.>jX
setPageSize(PAGESIZE); x~
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setTotalCount(totalCount); RSy1 wp4W
setItems(items); 4&tY5m>
setStartIndex(0); )<+Z,6
}
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public PaginationSupport(List items, int *ood3M[M^
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totalCount, int startIndex){ qzq>C"z\Y$
setPageSize(PAGESIZE); u
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setTotalCount(totalCount); FYzl- 7!Y
setItems(items); Q-AN~k8+)[
setStartIndex(startIndex); 7kO
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} K-K+%U
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public PaginationSupport(List items, int I3$v-OiL
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totalCount, int pageSize, int startIndex){ &iTsuA/7
setPageSize(pageSize); rkVZP!7!
setTotalCount(totalCount); F4*f_lP
setItems(items); 9K)2OX;$w
setStartIndex(startIndex); hsi#J^n{
} =fm/l-P@
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publicList getItems(){ _uDtRoI8
return items; @qeI4io-n
} !5ppA
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publicvoid setItems(List items){ Q16RDQ*
this.items = items; lgU7jn
} H}A67J9x
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publicint getPageSize(){ 'EXp[*
return pageSize; )V3G~p=0
} kIQMIL0+
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publicvoid setPageSize(int pageSize){ }ZV$_
this.pageSize = pageSize; X)\t=><<
} <[(xGrEZV
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publicint getTotalCount(){ 9n1O@~
return totalCount; =>&d[G[m!
} 'Kl} y,
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publicvoid setTotalCount(int totalCount){ (g5T2(_6L
if(totalCount > 0){ 6ZX{K1_q
this.totalCount = totalCount; d^4!=^HN
int count = totalCount / V;9.7v
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pageSize; uV{cvq$jy
if(totalCount % pageSize > 0) y/E%W/3
count++; q^EG'\<^
indexes = newint[count]; .7{,u1N'
for(int i = 0; i < count; i++){ IpHGit28
indexes = pageSize * iielAj*b
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} [i\K#O +f
}else{ 2wikk]Z
this.totalCount = 0; K-sJnQ23'
} g\d|/HVK
} ge*f<#|0U-
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publicint[] getIndexes(){ (FP-
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return indexes; !M\8k$#"n
} XNsMXeO]&
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publicvoid setIndexes(int[] indexes){ XXvM*"3D5
this.indexes = indexes; 1ih|b8)Dn
} 7iT#dpF/A
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publicint getStartIndex(){ QrDI$p7;'
return startIndex; *$Bx#0J8
} qo/`9%^E?
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publicvoid setStartIndex(int startIndex){ /aNlr>^
if(totalCount <= 0) +uLl3(ml
this.startIndex = 0; }mz@oEB#vF
elseif(startIndex >= totalCount) _I+QInD ;)
this.startIndex = indexes [Q6PFdQ_JT
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[indexes.length - 1]; $zKf>[K
elseif(startIndex < 0) AKu]c-
this.startIndex = 0; *7FtEk/l
else{ Gu-6~^Km9
this.startIndex = indexes "K;f[&xO,o
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[startIndex / pageSize]; Onz@A"
} M*$#j|
} \$$DM"+:;H
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publicint getNextIndex(){ S8 .1%sw
int nextIndex = getStartIndex() + yp9vgUs
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pageSize; '9.L5*wh]
if(nextIndex >= totalCount) \AQ*T`Dq
return getStartIndex(); B _k+Oa2!
else ,=jwQG4wq
return nextIndex; bdbTK8-
} i_Ol vuy~
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publicint getPreviousIndex(){ a'r8J~:jy
int previousIndex = getStartIndex() - usc"m huQ
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pageSize; g:8k,1y5
if(previousIndex < 0) v)1@Ew=Y%
return0; &P' d&B1
else 6 b-'Hu i+
return previousIndex; wkc)2z
} z>}H[0[#
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} }6b" JoC
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抽象业务类 yI$KBx/]n
java代码: WstX>+?'
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/** E &G]R!
* Created on 2005-7-12 dT?mMTKn+
*/ 3'2>3Y/7Bb
package com.javaeye.common.business; `cgyiJ
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import java.io.Serializable; <Ukeq0
import java.util.List; rJtpTV@.
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import org.hibernate.Criteria; cb82k[L6
import org.hibernate.HibernateException; ?vh1 >1D
import org.hibernate.Session; %^pm~ck!
import org.hibernate.criterion.DetachedCriteria; GBSuTu8
import org.hibernate.criterion.Projections; tqk^)c4FF(
import *E.uqu>I
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org.springframework.orm.hibernate3.HibernateCallback; }-/oL+j
import 0(qtn9;=2
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org.springframework.orm.hibernate3.support.HibernateDaoS ;r?s7b/>
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upport; Ky[s&>02
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import com.javaeye.common.util.PaginationSupport; sU7fVke1
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public abstract class AbstractManager extends :6TLT-B
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HibernateDaoSupport { ,eSII2,r4
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privateboolean cacheQueries = false; pgd9_'[5
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privateString queryCacheRegion; 2=,O)g
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publicvoid setCacheQueries(boolean hm,H3pN
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cacheQueries){ <g$b M;6%
this.cacheQueries = cacheQueries; thLx!t
} z?<Xx?Kk
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publicvoid setQueryCacheRegion(String &0x;60b
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queryCacheRegion){ HC!5AJ&+}v
this.queryCacheRegion = 7<0oK|~c#
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queryCacheRegion; blx"WVqo
} B,b^_4XX$
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publicvoid save(finalObject entity){ BN1,R] *;
getHibernateTemplate().save(entity); eNDc220b
} K?@x'q1
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publicvoid persist(finalObject entity){ w!r.MWE
getHibernateTemplate().save(entity); !ZS5}/ZU
} L'HO"EZFj
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publicvoid update(finalObject entity){ )0o|u >
getHibernateTemplate().update(entity); XyYP!<].C
} K!a7Hg
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publicvoid delete(finalObject entity){ NCp]!=uM;
getHibernateTemplate().delete(entity); (j&7`9<5
} f?lnBvT|b
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publicObject load(finalClass entity, %Y=
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finalSerializable id){ ~,m5dP#[bV
return getHibernateTemplate().load Um!LF"Z
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(entity, id); t vp kc;
} 8vx#QU8E/
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publicObject get(finalClass entity, jwp?eL!7
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finalSerializable id){ CqLAtS X7
return getHibernateTemplate().get 8Xa{.y"
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(entity, id); lm8<0*;,
} ({<qs}H"
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publicList findAll(finalClass entity){ UYH&x:WEd
return getHibernateTemplate().find("from o4H'
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" + entity.getName()); 9gFfbvd
} 5Z_aN|Xn
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publicList findByNamedQuery(finalString Q"k #eEA
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namedQuery){ i\zN1T_
return getHibernateTemplate MZt&HbD-
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().findByNamedQuery(namedQuery); b
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} &4m;9<8\
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publicList findByNamedQuery(finalString query, \ccCrDz
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finalObject parameter){ T^@P.zX
return getHibernateTemplate `aL4YH-v
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().findByNamedQuery(query, parameter); |?LUt@r;
} VrKFpFd
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publicList findByNamedQuery(finalString query, Mb+CtI_'
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finalObject[] parameters){ :@,UPc-+
return getHibernateTemplate ui&^ m,
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().findByNamedQuery(query, parameters); %(~8a
} b/UjKNf@
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publicList find(finalString query){ l j %k/u
return getHibernateTemplate().find `7Dj}vVu
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(query); yb-/_{Y
} eR!K8W
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publicList find(finalString query, finalObject #1[Q?e4,0
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parameter){ eB5<N?;s
return getHibernateTemplate().find tVHQ$jJY%
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(query, parameter); IWnyqt(k
} k(wJ6pc
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public PaginationSupport findPageByCriteria |dqvv
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(final DetachedCriteria detachedCriteria){ QW>(LG G=
return findPageByCriteria h<FEe~
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); E akS(Q?
} oT^r
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public PaginationSupport findPageByCriteria l 5z8]/
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(final DetachedCriteria detachedCriteria, finalint du^r EMb%
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startIndex){ Cz#3W8jV
return findPageByCriteria M5l*D'GE]
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(detachedCriteria, PaginationSupport.PAGESIZE, \\,z[C
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startIndex); jIL$hqo
} LJBDB6
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public PaginationSupport findPageByCriteria @-BgPDi.Z
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(final DetachedCriteria detachedCriteria, finalint ,E8~^\HV
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pageSize, 9p9-tJfH.
finalint startIndex){ R,ddH[3
return(PaginationSupport)
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getHibernateTemplate().execute(new HibernateCallback(){ x^JjoI2vf
publicObject doInHibernate }NETiJ"6
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(Session session)throws HibernateException { Mta;6<
Criteria criteria = ]@7]mu:oL
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detachedCriteria.getExecutableCriteria(session); K7$Vl"l
int totalCount = !FR1yO'd>
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((Integer) criteria.setProjection(Projections.rowCount t+BLO<
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()).uniqueResult()).intValue(); IP+1 :M
criteria.setProjection x_|: 3I
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(null); LdY aJh~h
List items = |h65[9DMP
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criteria.setFirstResult(startIndex).setMaxResults YK|Y^TU^
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(pageSize).list(); /yj-^u\R
PaginationSupport ps = .
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new PaginationSupport(items, totalCount, pageSize, i4oBi]$T
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startIndex); 3a#j&]
return ps; 9@|X~z5E
} b3!,r\9V
}, true); hX@.k|Yd
} bNO/CD4
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public List findAllByCriteria(final IWcYa.=tZ
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DetachedCriteria detachedCriteria){ zwKm;;v8
return(List) getHibernateTemplate i iZK^/P$
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().execute(new HibernateCallback(){ IRQ3> 4hI
publicObject doInHibernate u3H2\<
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(Session session)throws HibernateException { VClw!bm
Criteria criteria = dc0Ro,
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detachedCriteria.getExecutableCriteria(session); 6axmH~_
return criteria.list(); kV Z5>D$
} ywV8s|o
}, true); c/57_fOK
} 20f):A6
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public int getCountByCriteria(final l7r!fAV-f
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DetachedCriteria detachedCriteria){ `-N&cc
Integer count = (Integer) ?$^qcpJCp
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getHibernateTemplate().execute(new HibernateCallback(){ A
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publicObject doInHibernate KCed!OJ+
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(Session session)throws HibernateException { B1A5b=6G<
Criteria criteria = +xlxhF
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detachedCriteria.getExecutableCriteria(session); `$\Y,9E}x
return @.X}S"yr
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criteria.setProjection(Projections.rowCount c#e_Fs
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()).uniqueResult(); ft[g1
} %?EOD=e=
}, true); *<! W k\
return count.intValue(); =`X@+~%-
} G
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} f. =4p^
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用户在web层构造查询条件detachedCriteria,和可选的 G JItGq`)
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 m!:7ur:Y
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PaginationSupport的实例ps。 3Fn26Rij
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ps.getItems()得到已分页好的结果集 y=\jQ6Fc
ps.getIndexes()得到分页索引的数组 BifA&o%
ps.getTotalCount()得到总结果数 ~&~%q u
ps.getStartIndex()当前分页索引 .so{ RI
ps.getNextIndex()下一页索引 ?8(`tS(_?
ps.getPreviousIndex()上一页索引 S~F:%@,*
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 )B*?se]LJ
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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
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一下代码重构了。 ZZE
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我把原本我的做法也提供出来供大家讨论吧: ooIMN =
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首先,为了实现分页查询,我封装了一个Page类: ),\>'{~5&
java代码: `z)!!y
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/*Created on 2005-4-14*/ ^;s`[f|w
package org.flyware.util.page; {7eKv+30
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/** Xx|&%b{{r
* @author Joa ^l^_ K)tw*
* #s#z@F
*/ G-3.-
publicclass Page { #K!Df%,<
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/** imply if the page has previous page */ *!9/`zW
privateboolean hasPrePage; :/vB,JC
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/** imply if the page has next page */ !icpfxOpjQ
privateboolean hasNextPage;
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/** the number of every page */ kM3BP&
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privateint everyPage; k #*|-?
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/** the total page number */ yekIw
privateint totalPage; I I>2\d|
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/** the number of current page */ $xu?zd"
privateint currentPage; ;wQWt_OtuJ
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/** the begin index of the records by the current `FJnR~d
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query */ `8dE8:#Y
privateint beginIndex; Xp} vJl
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@IiT8B
/** The default constructor */ HnP;1Gi
public Page(){ oLr"8R\d>t
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} 4(aesZ8h
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/** construct the page by everyPage 0dcXgP
* @param everyPage {my=Li<