Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 %ou@Y`
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 b@ OF
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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 fp2uk3Bm[
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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 @XN*H- |
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。
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分页支持类: 4=C7V,a
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java代码: k{E!X
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package com.javaeye.common.util; gT#hF]c:
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import java.util.List; '"]QAj?N
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publicclass PaginationSupport { ;GZ/V;S
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publicfinalstaticint PAGESIZE = 30; >"<<hjKJ
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privateint pageSize = PAGESIZE; '=cAdja
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privateList items; /(?,S{]
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privateint totalCount; ^ SW!S_&Z2
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privateint[] indexes = newint[0]; *s (L!+
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privateint startIndex = 0; aSQvtv)91
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public PaginationSupport(List items, int B;^YHWJ6i
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totalCount){ /YD2F
setPageSize(PAGESIZE); #GIjU1-
setTotalCount(totalCount); )|IMhB+4
setItems(items); Tu7sA.73k
setStartIndex(0); *7^w}v+.
} U{Moyj
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public PaginationSupport(List items, int 7cV
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totalCount, int startIndex){ +|6 u
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setPageSize(PAGESIZE); xL\R-H^c]
setTotalCount(totalCount); e3}o3c_
setItems(items); m!^z{S
setStartIndex(startIndex); qExmf%q:q
} dobqYd4`
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public PaginationSupport(List items, int YHfk; FI
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totalCount, int pageSize, int startIndex){ U_
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setPageSize(pageSize); <BhNmEo)2
setTotalCount(totalCount); E2yL9]K2
setItems(items); =6< Am
setStartIndex(startIndex); t[HA86X
} %C~LKs5oH
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publicList getItems(){ !R3ZyZcX
return items; TY]-L1$
} ),&tF_z:
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publicvoid setItems(List items){ ??h4qJ
this.items = items; WQ)vu&;
} &v.Nj9{zi
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publicint getPageSize(){ +w9X$<?_
return pageSize; %tT=q^%5
} ~v^I*/uY
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publicvoid setPageSize(int pageSize){ X'.*I])
this.pageSize = pageSize;
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} &]P1IQ
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publicint getTotalCount(){ q.Vcb!*$
return totalCount; ]}s'`44J9e
} 4A\>O?\
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publicvoid setTotalCount(int totalCount){ ))eQZ3ap9
if(totalCount > 0){
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this.totalCount = totalCount; Nk@a g)
int count = totalCount / N9X`81)t
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pageSize; z3(:a'
if(totalCount % pageSize > 0) ,R5z`O
count++; 'o% .Qx
indexes = newint[count]; b,o@m
for(int i = 0; i < count; i++){ khS >
indexes = pageSize * boWaH}?0'
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} ,'^^OLez
}else{ j6r.HYX!
this.totalCount = 0; I>(-&YbC
} 5#hsy;q;[
} iqTGh*k
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publicint[] getIndexes(){ i5G"@4(
return indexes; lMRy6fzI
} *$EcP`K$
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publicvoid setIndexes(int[] indexes){ X+;{&Efrl
this.indexes = indexes; ^rIe"Kx
} x>*#cOVz;C
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publicint getStartIndex(){ M?m)<vMr*
return startIndex; .C?rToCY
} 9w08)2$Na
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publicvoid setStartIndex(int startIndex){ 8V(-S,
if(totalCount <= 0) $<v{$UOh
this.startIndex = 0; $5S/~8g(
elseif(startIndex >= totalCount) 8*m=U@5]
this.startIndex = indexes 3*;S%1C^
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[indexes.length - 1]; ,V{Cy`bi
elseif(startIndex < 0) ;+Uc}=
this.startIndex = 0; +u]L#].;
else{ HVkq{W|w
this.startIndex = indexes %MUh_63bB
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[startIndex / pageSize]; XX;MoE~MM
} XTPf~Te,=
} 2nA/{W\ hC
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publicint getNextIndex(){ -eSZpz p
int nextIndex = getStartIndex() +
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pageSize; aH+n]J]
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if(nextIndex >= totalCount) 0Er;l|
return getStartIndex(); CHo(:A.U>
else !3T,{:gyrI
return nextIndex; ,~^BoH}
} {c\KiWN
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publicint getPreviousIndex(){ o u*`~K|R
int previousIndex = getStartIndex() - jg+q{ ^
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pageSize; 1KWGQJ%%s
if(previousIndex < 0) R#w9%+
return0; Y~C;M6(P
else q>H f2R
return previousIndex; [G>U>[u|
} . L'eVLQe
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} +ZU@MOni
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抽象业务类 ^DWhIxBh
java代码: :jUu_s}
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/** NNM+Z:
* Created on 2005-7-12 *^_ywqp
*/ DgiMMmpE
package com.javaeye.common.business; #mvOhu
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import java.io.Serializable; v#WD$9QWs
import java.util.List; q/l@J3p[qm
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import org.hibernate.Criteria; Al 1BnFB
import org.hibernate.HibernateException; *&A/0]w
import org.hibernate.Session; !3 j@gi2
import org.hibernate.criterion.DetachedCriteria; pXBlTZf
import org.hibernate.criterion.Projections; Z{gJ m9
import 7m+d;x2
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org.springframework.orm.hibernate3.HibernateCallback; F4`5z)<*
import ]f<H?
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org.springframework.orm.hibernate3.support.HibernateDaoS ;;;{<GEQ
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upport; UxS@]YC
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import com.javaeye.common.util.PaginationSupport; (iO8[
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public abstract class AbstractManager extends c[RkiV3
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HibernateDaoSupport { ^KO=8m( )J
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privateboolean cacheQueries = false; E`aAPk_y
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privateString queryCacheRegion; '}|sRuftb
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publicvoid setCacheQueries(boolean ]pi8%.d
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cacheQueries){ @M!WosRk
this.cacheQueries = cacheQueries; uv$t>_^
} 7UzbS,$x
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publicvoid setQueryCacheRegion(String gk.c"$2
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queryCacheRegion){ ?9)-?tZ^Q
this.queryCacheRegion = f4Yn=D=_
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queryCacheRegion; |9X$@R
} L9Gxqw
}%;o#!<N(@
publicvoid save(finalObject entity){ ;>z.wol
getHibernateTemplate().save(entity); \ $PB~-Z
} Q{~ WWv
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publicvoid persist(finalObject entity){ -/O_wqm#
getHibernateTemplate().save(entity); :s}6 a23
} IJ`%Zh{f
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publicvoid update(finalObject entity){ ,+gU^dc|hq
getHibernateTemplate().update(entity); Rz Os,
} P&s-U6
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publicvoid delete(finalObject entity){ 0E5"}8
getHibernateTemplate().delete(entity); )Uk!;b
} 1@}`dc
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publicObject load(finalClass entity, b85r=tm
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finalSerializable id){ c8^M::NI
return getHibernateTemplate().load j<HBzqP%6
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(entity, id); 4NY}=e5
} i Sm
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publicObject get(finalClass entity, nF Mc'm
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finalSerializable id){ w6RB|^
return getHibernateTemplate().get _>G.
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(entity, id); iE~][_%U
} g p2S
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publicList findAll(finalClass entity){ r}-si^fo;
return getHibernateTemplate().find("from 8R) 0|v&;
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" + entity.getName()); *WHQ1geI8
} _{]\} =@
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publicList findByNamedQuery(finalString &$1ifG
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namedQuery){ ]WsQ=
return getHibernateTemplate #GJ{@C3H8Q
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().findByNamedQuery(namedQuery); \-]zXKl2k
} al<;*n{/
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publicList findByNamedQuery(finalString query, VIXY?Ua
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finalObject parameter){ fI_I0dc.p
return getHibernateTemplate @d+NeS
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().findByNamedQuery(query, parameter); !iys\ AV
} D<16m<b
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publicList findByNamedQuery(finalString query, wX!q dII)
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finalObject[] parameters){ !T'`L{Sj
return getHibernateTemplate R/_bk7o]H
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().findByNamedQuery(query, parameters); l"{1v~I
} DV8b<)
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publicList find(finalString query){ k%|Sl>{Ir
return getHibernateTemplate().find 8p;|&7
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(query); <-]qU}-
} c*k%r2'
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publicList find(finalString query, finalObject b-`=^ny)K
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parameter){ M MQ^&!H
return getHibernateTemplate().find Un~8N
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(query, parameter); !:GlxmtoW?
} N4xCZb
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public PaginationSupport findPageByCriteria C'wRF90
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(final DetachedCriteria detachedCriteria){ Ue=Je~Ri;9
return findPageByCriteria +=V[7^K;
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); $$5E+UDOs
} Ik\n/EE
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public PaginationSupport findPageByCriteria S.I3m-
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(final DetachedCriteria detachedCriteria, finalint j6JK4{
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startIndex){ Rs +),
return findPageByCriteria _oILZ,
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(detachedCriteria, PaginationSupport.PAGESIZE, YcmLc)a7
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startIndex); t++
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} !bq3c(d
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public PaginationSupport findPageByCriteria UyUz_6J
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(final DetachedCriteria detachedCriteria, finalint HkL:3 E.
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pageSize, 'bb*$T0=
finalint startIndex){ :;g7T -_q
return(PaginationSupport) nj(\+l5
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getHibernateTemplate().execute(new HibernateCallback(){ [wO|P{8\"
publicObject doInHibernate blk4@pg
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(Session session)throws HibernateException { <b,oF]+;z
Criteria criteria = \Qgc7ev
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detachedCriteria.getExecutableCriteria(session); ,O'#7Dj
int totalCount = 0# d:<+4D
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((Integer) criteria.setProjection(Projections.rowCount 6 6%_p]U
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()).uniqueResult()).intValue(); 'O+)[D
criteria.setProjection j`o_Stbg
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(null); F*, e,s
List items = KB$SB25m
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criteria.setFirstResult(startIndex).setMaxResults Pe,:FIp,
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(pageSize).list();
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PaginationSupport ps = t9\}!{<s
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new PaginationSupport(items, totalCount, pageSize, 2N}U B=J
t8?$q})RL
startIndex); ^D5+S`V
return ps; tZL {;@
} nc[Kh8N9
}, true); xo.k:F
} &*YFK/ ]
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public List findAllByCriteria(final y7ZYo7avg
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DetachedCriteria detachedCriteria){ _wp_y-"
return(List) getHibernateTemplate EZee
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().execute(new HibernateCallback(){ 6g-Q
publicObject doInHibernate >At* jg48
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(Session session)throws HibernateException { 3Jh!YzI8
Criteria criteria = l8~s#:v6X
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detachedCriteria.getExecutableCriteria(session); Ef]<0Tm]:
return criteria.list(); 6.'j\
} bP)(4+t~
}, true); RA$%3L[A!
} c2RQwtN|
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public int getCountByCriteria(final dI?x(vw
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DetachedCriteria detachedCriteria){ *w`_(Xf
Integer count = (Integer) s|[CvjL#0
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getHibernateTemplate().execute(new HibernateCallback(){ *w
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publicObject doInHibernate I
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(Session session)throws HibernateException { yBl9 a-2A
Criteria criteria = |r+w(TG
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detachedCriteria.getExecutableCriteria(session); BS|$-i5L
return d^+0=_[PmK
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criteria.setProjection(Projections.rowCount Kn*LwWne
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()).uniqueResult(); <f9a%`d
} 3]li3B'
}, true); <]f{X<ef
return count.intValue(); X#<+D1P
} !!+LFe4su
} ;wa#m1
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用户在web层构造查询条件detachedCriteria,和可选的 .(%]RSBY
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 O~#A )d6
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PaginationSupport的实例ps。 <)a7Nrc\T
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ps.getItems()得到已分页好的结果集 +n>p"+c
ps.getIndexes()得到分页索引的数组 ]NyN@9u@(
ps.getTotalCount()得到总结果数 Ke^9R-jP
ps.getStartIndex()当前分页索引 #+ Y%Bxf
ps.getNextIndex()下一页索引 6&;h+;h
ps.getPreviousIndex()上一页索引 D!V~g72j
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 :?j]W2+kR
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 wv
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一下代码重构了。 zSagsH |W
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我把原本我的做法也提供出来供大家讨论吧: '<U4D
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首先,为了实现分页查询,我封装了一个Page类: ,B#*<_?E5
java代码: [D"5@
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/*Created on 2005-4-14*/ ct@3]
package org.flyware.util.page; XzBlT( `w
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/** O4cBn{Dq9
* @author Joa sD$K<nyz
* `LNKbTc[m
*/ b$sT`+4q
publicclass Page { |j4p
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/** imply if the page has previous page */ ?-'GbOr!
privateboolean hasPrePage; <m,bP
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/** imply if the page has next page */ v0( _4U]/
privateboolean hasNextPage; >*EJ6FPO
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/** the number of every page */ BP@V:z
privateint everyPage; 0jt@|3
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/** the total page number */ ?e\u_3-9
privateint totalPage; ]:}7-;$V
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/** the number of current page */ ; o(:}d
privateint currentPage; qIxe)+.
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/** the begin index of the records by the current yQ!keGj
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query */ xyHv7u%*
privateint beginIndex; R;uP^
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/** The default constructor */ '*t<g@2$
public Page(){ @V+KL>Qw
@V@<j)3P
} 6;Mv)|FJF
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/** construct the page by everyPage rP/W,!
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* @param everyPage &ha<pj~
* */ T( k:\z/
public Page(int everyPage){ ZS@R ?
this.everyPage = everyPage; I;9DG8C&v*
} JD AX^]
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/** The whole constructor */ nE:Wl
public Page(boolean hasPrePage, boolean hasNextPage, Tc|+:Usy
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int everyPage, int totalPage, N'|9rB2e
int currentPage, int beginIndex){ /)rv Ndn
this.hasPrePage = hasPrePage; pvRa
this.hasNextPage = hasNextPage; "\M3||.!
this.everyPage = everyPage; 1J&hm[3[K
this.totalPage = totalPage; u:,B&}j
this.currentPage = currentPage; SV^[)p)
this.beginIndex = beginIndex; wB<