Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 BLD gt~h#
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 H"WprHe
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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 XlR@pr6tw
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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 E hMNap}5"
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分页支持类: mc\"yC^s
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java代码: }-=|^
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package com.javaeye.common.util; 5$C-9
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import java.util.List; Btcy)LRk
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publicclass PaginationSupport { $qj2w"'
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publicfinalstaticint PAGESIZE = 30; Ig>(m49d
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privateint pageSize = PAGESIZE; /%io+94
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privateList items; ~Z'?LV<t
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privateint totalCount; qlPT Ll
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privateint[] indexes = newint[0]; FU4L6n
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privateint startIndex = 0; )lDD\J7
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public PaginationSupport(List items, int 'TB2:W3
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totalCount){ z~s PXGb
setPageSize(PAGESIZE); 13x p_j
setTotalCount(totalCount); `VguQl_,gA
setItems(items); b4N[)%@
setStartIndex(0); 7B66]3v
} #o#H?Vo9b
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public PaginationSupport(List items, int fe_5LC"
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totalCount, int startIndex){ Slc\&Eb
setPageSize(PAGESIZE); om:VFs\U
setTotalCount(totalCount); "VMz]ybi^
setItems(items); 6(-N FnT
setStartIndex(startIndex); K[zVa
} AH~E )S
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public PaginationSupport(List items, int SOA,kwHRe
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totalCount, int pageSize, int startIndex){ c@L< Z` u
setPageSize(pageSize); U| R_OLWAg
setTotalCount(totalCount); H0vfUF53l
setItems(items); 8Z=R)asGS
setStartIndex(startIndex); |M;7>'YNC*
} =[ 7A v>
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publicList getItems(){ +9sQZB# (
return items; [j+sC*
} l9Q-iJ
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publicvoid setItems(List items){ (X*^dO
this.items = items; 1T
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} ?(_08O
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publicint getPageSize(){ 1EX;MW-p<T
return pageSize; E}Uc7G
} *MW\^PR?
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publicvoid setPageSize(int pageSize){ &s>Jb?_5Mx
this.pageSize = pageSize; S)"Jf?
} ,f?*{Q2
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publicint getTotalCount(){ k)TpnH! "
return totalCount; aV0"~5
} +^F Zq$NP
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publicvoid setTotalCount(int totalCount){
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if(totalCount > 0){ [AJJSd/:
this.totalCount = totalCount; nQ3A~ ()
int count = totalCount / &q*Aj17
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pageSize; V0 a3<6@4
if(totalCount % pageSize > 0) w7&A0M
count++; k$:|-_(w
indexes = newint[count]; ~6md !o%i
for(int i = 0; i < count; i++){ )NT*bLRPQ
indexes = pageSize * (A.C]hD
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} ]A_`0"m.U
}else{ j3ls3H&
this.totalCount = 0; 0jWVp-y
} 4E}Yt$|
} 2y1Sne=<Kb
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publicint[] getIndexes(){ lPAQ3t!,
return indexes; `){.+S(5C
} :\_ 5oVb
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publicvoid setIndexes(int[] indexes){ buHJB*?9
this.indexes = indexes; \a3+rNdj
} j.=
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publicint getStartIndex(){ 1X1dG#:
return startIndex; *|HY>U.
} )0k53-h&
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publicvoid setStartIndex(int startIndex){ J]r^W)O
if(totalCount <= 0) bpa?C
this.startIndex = 0; <(! :$
elseif(startIndex >= totalCount) |k00Z+O(
this.startIndex = indexes z\4.Gm-
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[indexes.length - 1]; 1G`Pmh@
elseif(startIndex < 0) <wHP2|<l*
this.startIndex = 0; }Ou}+^Bc
else{ + LJ73
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this.startIndex = indexes bW+:C5'
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[startIndex / pageSize]; GTxk%
} KqP#6^ _
} 4Wp=y
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publicint getNextIndex(){ *qpSXmOz
int nextIndex = getStartIndex() + M )(DZ}
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pageSize; LFV%&y|L
if(nextIndex >= totalCount) +
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return getStartIndex(); b\,+f n
else tX~w{|k
return nextIndex; wb ;xRP"w
} qmP].sA
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publicint getPreviousIndex(){ K:WDl;8(d
int previousIndex = getStartIndex() - 'Z]w^<
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pageSize; X5w$4Kj&4l
if(previousIndex < 0) JlJ a
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return0; o5)<$P43
else e+=K d+:k
return previousIndex; iN.n8MN=I
} $<OD31T
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} HK%7g
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抽象业务类 l}P=/#</T
java代码: u$`a7Lp,n
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/** EiaW1Cs
* Created on 2005-7-12 wdoR%b{M
*/ qxJ\ye+'*
package com.javaeye.common.business; dD@(z:5M\
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import java.io.Serializable; _(zG?]y0P
import java.util.List; G KeU%x
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import org.hibernate.Criteria; DW3G
import org.hibernate.HibernateException; og>uj>H&
import org.hibernate.Session; <{cQ2
import org.hibernate.criterion.DetachedCriteria; Gp\
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import org.hibernate.criterion.Projections; A/?7w
import 7PF%76TO
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org.springframework.orm.hibernate3.HibernateCallback; 5E
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import :fJN->wY^s
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org.springframework.orm.hibernate3.support.HibernateDaoS q0\6F^;M
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upport; ]JR +ayk7
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import com.javaeye.common.util.PaginationSupport; OB}Ib]
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public abstract class AbstractManager extends B|X!>Q<g
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HibernateDaoSupport { {7pli{`
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privateboolean cacheQueries = false; ~bpgSP"
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privateString queryCacheRegion; ]]Ufas9
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publicvoid setCacheQueries(boolean Yoll?_k+
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cacheQueries){ 8a"%0d#
this.cacheQueries = cacheQueries; e8b:)"R
} 6d~'$<5on
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publicvoid setQueryCacheRegion(String N4HqLh23H
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queryCacheRegion){ Z$? #
this.queryCacheRegion = ^d73Ig:8q
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queryCacheRegion; Jfl!#UAD|n
} 7cMv/g^h@
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publicvoid save(finalObject entity){ An/|+r\
getHibernateTemplate().save(entity); >c}u>]D
} AkiDL=;w
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publicvoid persist(finalObject entity){ J4U1t2@)9
getHibernateTemplate().save(entity); 2I{"XB
} ;]:@n;c\
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publicvoid update(finalObject entity){ h!9ei6
getHibernateTemplate().update(entity); _u9Jxw?F@Y
} }l9llu
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publicvoid delete(finalObject entity){ )Xyn
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getHibernateTemplate().delete(entity); Yz)qcU
} J<lO=
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publicObject load(finalClass entity, f(7GX3?
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finalSerializable id){ Fv`,3aNB
return getHibernateTemplate().load sW8dPw
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(entity, id); Q=yg8CQ
} ;YL i{
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publicObject get(finalClass entity, B4 }bVjs
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finalSerializable id){ ^T-V^^#(
return getHibernateTemplate().get R0-j5&^jju
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(entity, id); K!l5coM
} a7%]Y}$
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publicList findAll(finalClass entity){ ;i+#fQO7Q
return getHibernateTemplate().find("from 8DaL,bi*.
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" + entity.getName()); lks!w/yCF
} 8, >P
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publicList findByNamedQuery(finalString QkC(uS
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namedQuery){ ;gr9/Vl
return getHibernateTemplate IIx#2r
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().findByNamedQuery(namedQuery); 7. ;3e@s
} y"wShAR
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publicList findByNamedQuery(finalString query, )w%!{hn
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finalObject parameter){ S|+o-[e8O
return getHibernateTemplate 4H]L~^CD
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().findByNamedQuery(query, parameter); u,4eCxYE$
} nzeX[*
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publicList findByNamedQuery(finalString query, jo@J}`\Zt
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finalObject[] parameters){ >[*qf9$
return getHibernateTemplate bA->{OPkT
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().findByNamedQuery(query, parameters); Yg1X
} !g2+w$YVa
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publicList find(finalString query){ 2jhxQL
return getHibernateTemplate().find cYt!n5w~W
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(query); 4HA<P6L
} ?FcAXA/J{
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publicList find(finalString query, finalObject *;*r8[U}q
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parameter){ um0N)&iY
return getHibernateTemplate().find P";'jVcR
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(query, parameter); s->^=dy
} TRq6NB
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public PaginationSupport findPageByCriteria L;I]OC^J
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(final DetachedCriteria detachedCriteria){ DR<9#RRD
return findPageByCriteria G'A R`"F
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); b SU~XGPB
} =C.$
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public PaginationSupport findPageByCriteria ~Jz6O U*z
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(final DetachedCriteria detachedCriteria, finalint z' >_Mc6
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startIndex){ oILZgNe'
return findPageByCriteria E~oOKQ5W
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(detachedCriteria, PaginationSupport.PAGESIZE, @I!0-OjL
*!7O~yQ
startIndex); N<injx
} \P`hq^;
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public PaginationSupport findPageByCriteria &KRX[2
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(final DetachedCriteria detachedCriteria, finalint ^.NU|NQi'
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pageSize, Q$@I"V&G.
finalint startIndex){ *bA.zmzM
return(PaginationSupport) "1M[5\Ax
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getHibernateTemplate().execute(new HibernateCallback(){ jtc]>]6i
publicObject doInHibernate NHZz _a=
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(Session session)throws HibernateException { JnM["Q=`
Criteria criteria = v^ VitLC
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detachedCriteria.getExecutableCriteria(session); wDe& 1(T^
int totalCount = z ~/` 1
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((Integer) criteria.setProjection(Projections.rowCount :&9s,l
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()).uniqueResult()).intValue(); 81
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criteria.setProjection v,>Dbxn
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(null); Z}Ft:7
List items = W v+?TEP
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criteria.setFirstResult(startIndex).setMaxResults
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(pageSize).list(); :! !at:>
PaginationSupport ps = Qn)a/w-
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new PaginationSupport(items, totalCount, pageSize, UrEs4R1#
:E )>\&
startIndex);
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return ps; bAtSV u
} *wB1,U{
}, true); 5taT5?n2
}
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public List findAllByCriteria(final ExL0?FemWV
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DetachedCriteria detachedCriteria){ -4{<=y?"a
return(List) getHibernateTemplate LuvY<~u
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().execute(new HibernateCallback(){ .jjG(L
publicObject doInHibernate H]Z$OpI
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(Session session)throws HibernateException { t=W}SH
Criteria criteria = mb^~qeRQ
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detachedCriteria.getExecutableCriteria(session); 0{}8(
return criteria.list(); fSvM(3Y<Qh
} _5Ct]vy
}, true); >V8-i`
} )cMh0SGcM1
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public int getCountByCriteria(final Wf>R&o6tr
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DetachedCriteria detachedCriteria){ 68C%B9.b'
Integer count = (Integer) |"CZ T#
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getHibernateTemplate().execute(new HibernateCallback(){ <&g,Nc'5C
publicObject doInHibernate PmEsN&YP]
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(Session session)throws HibernateException { 6)
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Criteria criteria = XrGglBIV
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detachedCriteria.getExecutableCriteria(session); gu.}M:u
return v\%HPMlh
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criteria.setProjection(Projections.rowCount hH8oyIC
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()).uniqueResult(); ['tY4$L(
} SP_75BJ
}, true); ywmo#qYe
return count.intValue(); 6HWE~`ok6
} `%"\@<
} i#Bf"W{F
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用户在web层构造查询条件detachedCriteria,和可选的 6wjw ^m0
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 LxSpctiNx
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PaginationSupport的实例ps。 h_3E)jc
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ps.getItems()得到已分页好的结果集 W/bQd)Jvk
ps.getIndexes()得到分页索引的数组 Ee%%d
ps.getTotalCount()得到总结果数 `MN4uC
ps.getStartIndex()当前分页索引 ,77d(bR<
ps.getNextIndex()下一页索引 _FU_Ubkr
ps.getPreviousIndex()上一页索引 $AjHbU.I{
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 BLf>_bUk
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 g63(E,;;J
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一下代码重构了。 -4IE]'##
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我把原本我的做法也提供出来供大家讨论吧: i0kak`x0
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首先,为了实现分页查询,我封装了一个Page类: }9# r0Vja
java代码: pis`$_kmwV
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/*Created on 2005-4-14*/ S8wLmd>
package org.flyware.util.page; N&+x+;Kx
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/** :tB1D@Cb6
* @author Joa c&?m>2^6
* /}fHt^2H
*/ 8hz^%vm
publicclass Page { kY|utoAP
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/** imply if the page has previous page */ GxI!{oi2
privateboolean hasPrePage; U}e!Wjrc
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/** imply if the page has next page */ K6/Q}W
privateboolean hasNextPage; CR`Q#Yi
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/** the number of every page */ t?-n*9,#S
privateint everyPage; 5z8d}
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/** the total page number */ P%:wAYz1^O
privateint totalPage; ~"&|W'he[
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/** the number of current page */ n,V[eW#m'L
privateint currentPage; c"n\cNP<
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/** the begin index of the records by the current r?lf($D*
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query */ ^w@%cVh
privateint beginIndex; t?x<g <PJ4
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/** The default constructor */ Yz/md1T$
public Page(){ +`7i'ff
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} ^& tZ
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/** construct the page by everyPage n.`($yR_
* @param everyPage h-#6av:
* */ p$NQyS5C"S
public Page(int everyPage){ hOu3 bA
this.everyPage = everyPage; :0j?oY~e
} ,.83m%i
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/** The whole constructor */ "3)C'WlEy/
public Page(boolean hasPrePage, boolean hasNextPage, hl7bzKO*w
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int everyPage, int totalPage, b8`)y<