Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 n5s2\(
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 "fN=Y$G
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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 `E:&a]ul
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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?yrx6
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分页支持类: 4uy:sCmu
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java代码: !HCuae3_
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package com.javaeye.common.util; ({!S!k
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import java.util.List; }[mLtv%&
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publicclass PaginationSupport { Z(wj5;[G
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publicfinalstaticint PAGESIZE = 30; MfG8=H2#|
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privateint pageSize = PAGESIZE; ["N_t:9I
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privateList items; +rWcfXOHM
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privateint totalCount; F\Q X=n
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privateint[] indexes = newint[0]; 7N4)T'B
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privateint startIndex = 0; n"g)hu^B
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public PaginationSupport(List items, int aNDpCpy
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totalCount){ W'!
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setPageSize(PAGESIZE); 35 d:r:
setTotalCount(totalCount); Q$58K9
setItems(items); K*9~g('
setStartIndex(0); q~6a$8+t
} }CGA)yK~3
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public PaginationSupport(List items, int sDl@
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totalCount, int startIndex){ 3{H&{@Q
setPageSize(PAGESIZE); e#!,/pE
setTotalCount(totalCount); =HHtLW.|,
setItems(items); hEMS
setStartIndex(startIndex); j^6,V\;l
} BK)3b6L=%
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public PaginationSupport(List items, int ]47!Zo,
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totalCount, int pageSize, int startIndex){ ZO8r8
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setPageSize(pageSize); 'BX
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setTotalCount(totalCount); D $&6 8
setItems(items); B+4WnR1%T
setStartIndex(startIndex); )~be<G( a
} $Y?[[>u
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publicList getItems(){ 1qm
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return items; {xu~Dx
} o7kQ&w
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publicvoid setItems(List items){ J*D3=5&
this.items = items; l&{+3 aC:
} @B9O*x+n:
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publicint getPageSize(){ Y$0K}`{
return pageSize; [oG
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} d$B+xW
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publicvoid setPageSize(int pageSize){ 3eN(Sw@p
this.pageSize = pageSize; <RCeY(1
} AsO)BeUD
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publicint getTotalCount(){ Q`!<2i;
return totalCount; M,sZ8eeq
} \2[sUY<W
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publicvoid setTotalCount(int totalCount){ PwC^
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if(totalCount > 0){ Jix;!("
this.totalCount = totalCount; ODCv^4}9
int count = totalCount / lS |:4U.
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pageSize; 0,1)Sg*
if(totalCount % pageSize > 0) UL0n>Wa5
count++; iJSyi;l|
indexes = newint[count]; K`8$+JDP+
for(int i = 0; i < count; i++){ m+3]RIr&A
indexes = pageSize * 51'{Jx8
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} RU+F~K<
}else{ ^ 2LqKo\T
this.totalCount = 0; nVoP:FHH
} xG:7AGZ$[
} oH1]-Nl$
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publicint[] getIndexes(){ UUEbtZH;
return indexes; j"9Zaq_
} \4Z"s[8}
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publicvoid setIndexes(int[] indexes){ 4\y>pXML-U
this.indexes = indexes; DAQozhP8
} N4w&g-
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publicint getStartIndex(){ g-<[* nF
return startIndex; 6.6x$y3v
} yX1OJg[s,
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publicvoid setStartIndex(int startIndex){ +m4?a\U
if(totalCount <= 0) x }i'2
this.startIndex = 0; 7'RU\0QG
elseif(startIndex >= totalCount) )TOKHN
this.startIndex = indexes /vAA]n8
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[indexes.length - 1]; \
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elseif(startIndex < 0) ~' q&rvk`
this.startIndex = 0; 15ImwQ
else{ <ELqj2`c
this.startIndex = indexes O6]X\Cwj%
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[startIndex / pageSize]; ~`<_xIvrq
} 23'Ac,{
} Bi|-KS.9
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publicint getNextIndex(){ %:Y'+!bX
int nextIndex = getStartIndex() + W <M\b#
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pageSize; UQ~gjnb[c
if(nextIndex >= totalCount) 3$PGLM
return getStartIndex(); pXf5/u8&
else S<>u
return nextIndex; VE*&t>I
} -9yWf8;
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publicint getPreviousIndex(){ Vc&xXtm[v
int previousIndex = getStartIndex() - D`NQEt"(
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pageSize; crU]P $a
if(previousIndex < 0) :JCe,1!3@
return0; ]lA.?
else CM
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return previousIndex; rQ&F Gb
} )P9&I.a8
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} g&d
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抽象业务类 M(.Up
java代码: C[nacAi
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/** `:5W1D(
* Created on 2005-7-12 HfA@tZ5q|U
*/ U_AmRiy
package com.javaeye.common.business; :{x
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import java.io.Serializable; Rs53R$PIR
import java.util.List; xB,(!0{`
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import org.hibernate.Criteria; WGI4DzKa
import org.hibernate.HibernateException; CxJH)H$
import org.hibernate.Session; mH7Mch|
m
import org.hibernate.criterion.DetachedCriteria; h;t5v6["
import org.hibernate.criterion.Projections; b0[H{q-z{X
import yA^+<uz}
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org.springframework.orm.hibernate3.HibernateCallback; eG%Q
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import =R0#WMf$@
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org.springframework.orm.hibernate3.support.HibernateDaoS dwmZ_m.
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upport; o'!WW
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import com.javaeye.common.util.PaginationSupport; Tw!_=zy(Gw
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public abstract class AbstractManager extends (kZ2D
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HibernateDaoSupport { u;=a=>05IR
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privateboolean cacheQueries = false; !KmSLr7xU
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privateString queryCacheRegion; H(ds
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publicvoid setCacheQueries(boolean 9Xeg&Z|!
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cacheQueries){ $s!2D"wl n
this.cacheQueries = cacheQueries; K)TMr"j\
} 8aa`0X/6
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publicvoid setQueryCacheRegion(String Q5/BEUkC
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queryCacheRegion){ >kG: MJj
this.queryCacheRegion = zM++Z*
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queryCacheRegion; mE3M$2}
} ec"+Il
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publicvoid save(finalObject entity){ 4'U #<8
getHibernateTemplate().save(entity); Wf5ohXm>
} m7NrS?7
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publicvoid persist(finalObject entity){ jt4c*0z
getHibernateTemplate().save(entity); <hmRr
} KcF#c_f
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publicvoid update(finalObject entity){ AJR`ohh
getHibernateTemplate().update(entity);
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} FdMxw*}
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publicvoid delete(finalObject entity){ 1bpjj'2%x
getHibernateTemplate().delete(entity); B&4NdL/
} 9xIz[`)i.
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publicObject load(finalClass entity, ff.;6R\
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finalSerializable id){ [5$Y>Tr!
return getHibernateTemplate().load 'I1^70bB
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(entity, id); \EOPlyf8x
} U+'h~P'4
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publicObject get(finalClass entity, U8icP+Y
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finalSerializable id){ $C~OV@I
return getHibernateTemplate().get x/xd
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(entity, id); rT{+ h}vO
} Z{spo=
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publicList findAll(finalClass entity){ OAd}#R\U
return getHibernateTemplate().find("from Uh8c!CA8:\
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" + entity.getName()); \1cJ?/$_Of
} DW.vu%j^[
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publicList findByNamedQuery(finalString V
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namedQuery){ y%=t((.Z
return getHibernateTemplate Cz]NSG 5
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().findByNamedQuery(namedQuery); >r~!'Pd!
} Gs)2HR@>
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publicList findByNamedQuery(finalString query, mQy!*0y
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finalObject parameter){ ={gf x;
return getHibernateTemplate E G3?C
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().findByNamedQuery(query, parameter); |*-&x:p7O
} =}7[ypQM`]
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publicList findByNamedQuery(finalString query, Zm~oV?6
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finalObject[] parameters){ mq*Efb)!
return getHibernateTemplate +-+%6O<C
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().findByNamedQuery(query, parameters); +YK/^;Th
} gdkQ
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publicList find(finalString query){ hRKA,u/G
return getHibernateTemplate().find T`gR&n<D
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(query); 1T@#gE["Ic
} n#lZRwhq
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publicList find(finalString query, finalObject ^ ;XJG9a0\
?7"6dp_K
parameter){ =w <;tb
return getHibernateTemplate().find sGs_w:Hn
7.N~e}p8
(query, parameter); YdNmnB%J
} | Xv]s61
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public PaginationSupport findPageByCriteria )S2GPn7
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(final DetachedCriteria detachedCriteria){ |SfmQ;
return findPageByCriteria 9et%Hn.K'
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); @XRN#_{
} 7C"&f *lEi
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public PaginationSupport findPageByCriteria n~|sMpd,M1
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(final DetachedCriteria detachedCriteria, finalint a-<&(jV
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startIndex){ eW>Y*l%B
return findPageByCriteria E|K~WO]>o
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(detachedCriteria, PaginationSupport.PAGESIZE, suP/I?4'@
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startIndex); 'ZboLoS*-
} 12JmSvD
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public PaginationSupport findPageByCriteria XFv) ]_G
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(final DetachedCriteria detachedCriteria, finalint ub,GF?9
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pageSize, [9U::
finalint startIndex){ |MQ_VZ{6
return(PaginationSupport) e[)oT
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getHibernateTemplate().execute(new HibernateCallback(){ y(w&6:
publicObject doInHibernate Zj]jE%AT
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(Session session)throws HibernateException { ]6BV`r]
Criteria criteria = ^;@Q3~DpP%
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detachedCriteria.getExecutableCriteria(session); Pv3rDQ/Yt|
int totalCount = lI"~*"c`
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((Integer) criteria.setProjection(Projections.rowCount @W+m;4 HH
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()).uniqueResult()).intValue(); :,'yHVG\
criteria.setProjection ]W9 {<+&
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(null); HJ]9e
List items = U6/$CH<pe
#o/
criteria.setFirstResult(startIndex).setMaxResults #D2.RN
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(pageSize).list(); X}@'FxIF
PaginationSupport ps = )=]u]7p}
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new PaginationSupport(items, totalCount, pageSize, ;[,r./XmH
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startIndex); T4lE-g2%M
return ps; cU
} c ?H@HoF
}, true);
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} (n+FEE<
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public List findAllByCriteria(final jMV9r-{*+
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DetachedCriteria detachedCriteria){ 94CHxv
return(List) getHibernateTemplate #i1z&b#@
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().execute(new HibernateCallback(){ "gCqb;^
publicObject doInHibernate CL)*cu6zG
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(Session session)throws HibernateException { 9-(
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Criteria criteria = ]QJWqY
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detachedCriteria.getExecutableCriteria(session); 2C59fXfd
return criteria.list(); alV{| Vf[6
} WnkI i,<
}, true); \]y /EOT
} =)Z~w`
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public int getCountByCriteria(final s-"oT=
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DetachedCriteria detachedCriteria){ |[B JZ
Integer count = (Integer) 8uD%
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getHibernateTemplate().execute(new HibernateCallback(){ ];63QJU
publicObject doInHibernate 'n dXM
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(Session session)throws HibernateException { QGoBugU
Criteria criteria = %%h0 H[5*
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detachedCriteria.getExecutableCriteria(session); IL&;2%
return 'i5,2vT0
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criteria.setProjection(Projections.rowCount hqwDlapTt
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j
()).uniqueResult(); ?Zv>4+Y'
} ["7]EW\!:
}, true); >)6d~
return count.intValue(); lVra&5
} p/WE[8U
} N*NGC!p`N
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用户在web层构造查询条件detachedCriteria,和可选的 >tQ$V<YB
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 h(MNH6B1
`\Ye:$q
PaginationSupport的实例ps。 ]~d!<x#+
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ps.getItems()得到已分页好的结果集 /)/>/4O
ps.getIndexes()得到分页索引的数组 &(/QJ `*8
ps.getTotalCount()得到总结果数 7S.E,\Tws
ps.getStartIndex()当前分页索引 $s`#&.>c-
ps.getNextIndex()下一页索引 ,he1WjL
ps.getPreviousIndex()上一页索引 Cak-J~=
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 A=bBI>GEYP
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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 oF {u
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一下代码重构了。 O&@pi-=o
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我把原本我的做法也提供出来供大家讨论吧: .0b4"0~T6
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首先,为了实现分页查询,我封装了一个Page类: yDmx)^En
java代码: \l71Q/y6u`
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/*Created on 2005-4-14*/ k?VH4yA
package org.flyware.util.page; Kk|4
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/** O;H|nW}
* @author Joa m>&:)K}m
* * G0I2
*/ $-p#4^dg
publicclass Page { kpLx?zW--q
TJ+,G4z
/** imply if the page has previous page */ >^TcO
privateboolean hasPrePage; 6H'W]T&
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/** imply if the page has next page */ JGG (mrvR
privateboolean hasNextPage; 7L !$hk
;+(EmD:Q
/** the number of every page */ . g8db d
privateint everyPage; r";;Fk#5
y|2y!&o,!
/** the total page number */ MCO`\"`l
privateint totalPage; ~Sc{\ZJl
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/** the number of current page */ X|Rw;FY
privateint currentPage; ;q&2$Mb
kH" >(f
/** the begin index of the records by the current e763yd
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query */ 9?.
privateint beginIndex; AEE&{_[S
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/** The default constructor */ k r ga!,I
public Page(){ )Nnrsa
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} .
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/** construct the page by everyPage +(/' b'*
* @param everyPage N"-U)d-.
* */ K6G+sBw[
public Page(int everyPage){ !.@F,wZvY
this.everyPage = everyPage; x03@} M1
} =BroH\
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/** The whole constructor */ RZbiiMC>
public Page(boolean hasPrePage, boolean hasNextPage, *RJiHcII
~jDf,a2
5h@5.-}
int everyPage, int totalPage, _qvzZ6
int currentPage, int beginIndex){ Sgq" 3(+%,
this.hasPrePage = hasPrePage; |DkK7gw
this.hasNextPage = hasNextPage; M&J$9X
this.everyPage = everyPage; 'h3yxf}\
this.totalPage = totalPage; ?~=5x
this.currentPage = currentPage; HC(7,3
this.beginIndex = beginIndex; <Wa7$ h F
} \Y^GA;AMQQ
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/** ~U+W4%f8
* @return e!oL!Zg
* Returns the beginIndex. ]*TW%mY
*/ xV>sc;PEb
publicint getBeginIndex(){ {pz7ADK<
return beginIndex; J?_-Dg(=
} 82KWe=
/4{IxQk
/** vu|-}v?:
* @param beginIndex -h%1rw
* The beginIndex to set. 4gh`
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*/ l9vJ]
publicvoid setBeginIndex(int beginIndex){ V(P 1{g
this.beginIndex = beginIndex; "5b4fQ;x
} s}g3*_"
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/** "] [u
* @return 4;V;8a\A
* Returns the currentPage. NEW0dF&)
*/ qx";G
publicint getCurrentPage(){ t-?#x
return currentPage; w"
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} 8T}Dn\f
h)h%y)1
/** ra}t#Xt`
* @param currentPage Q=h37]U+
* The currentPage to set. Rgb&EnVW
*/ =i:,")W7=
publicvoid setCurrentPage(int currentPage){ {+jO/ZQu5
this.currentPage = currentPage; Q3rLCg,;
} @j'GcN vs
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/** 1{.5X8y1x
* @return i#:M2&twE
* Returns the everyPage. J!d=aGY0-
*/ 9T%b#~?3P
publicint getEveryPage(){ ",P?jgs^g5
return everyPage; H?wf%0
} EqF>=5*
h.4FY<
/** `i)Pf WdBN
* @param everyPage >6Ody<JPHP
* The everyPage to set. q_z ;kCHM
*/ =h,J!0Y
publicvoid setEveryPage(int everyPage){ BY>]6SrP
this.everyPage = everyPage; hUe\sv!x?
} ;! ,I1{`
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/** (N?nOOQ
* @return *X8Pa;x
* Returns the hasNextPage. EL(BXJrx{
*/ .\mkgAlyaM
publicboolean getHasNextPage(){ o,[Em<
return hasNextPage; ~mC>G 4y$a
} Dn:1Mtj-
_71&".A
/** Q=t_m(:0
* @param hasNextPage cf%aOHYI*
* The hasNextPage to set. E'^ny4gL
*/ 8u7QF4
Id
publicvoid setHasNextPage(boolean hasNextPage){ 9gac7(2`)
this.hasNextPage = hasNextPage; He1~27+99
} 3hfv^H
o ]@'R<F(u
/** =}'7}0M_=
* @return 2?kVbF
* Returns the hasPrePage. D*t[5,~j
*/ 58t~? 2E
publicboolean getHasPrePage(){ h(p cGE
return hasPrePage; O:Wd
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} p<c1$O*
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/** S2:G#%EAa
* @param hasPrePage bK k7w#y
* The hasPrePage to set. iz3Hoj
*/ uLr-!T
publicvoid setHasPrePage(boolean hasPrePage){ 8\rAx P}=
this.hasPrePage = hasPrePage; k,LaFe`W
} 7ea%mg\
&(h@]F!
/** L~*nI d
* @return Returns the totalPage. T@mYHKu
* Mo]aB:a
*/ !im%t9
publicint getTotalPage(){ wU-Cb<^
return totalPage; zICAV -&
} DaqlL
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/** jJAr #|
* @param totalPage CEJqo8ds
* The totalPage to set. >=/DCQ$
*/ 0Ok[`r`
publicvoid setTotalPage(int totalPage){ 2]V8-
this.totalPage = totalPage; o.wXaS8
} WF-^pfRq~
f('##pND@
} BO0Y#fs
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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 c=aVYQ"2
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个PageUtil,负责对Page对象进行构造: >nO[5
java代码: ! q+>'Mt
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/*Created on 2005-4-14*/ c=<^pCa9t1
package org.flyware.util.page; \6!s";=hQ
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import org.apache.commons.logging.Log; \O)u' Bu
import org.apache.commons.logging.LogFactory; 2{S*$K[M
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/** \zzPsnFIg
* @author Joa c
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* q#`;G,rs
*/ 99~ZZG
publicclass PageUtil { QB*n
[(?
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privatestaticfinal Log logger = LogFactory.getLog j.:f=`xf
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(PageUtil.class);
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/** %>t4ib_8
* Use the origin page to create a new page *_"lXcG.
* @param page orhzeOi\
* @param totalRecords 0oo_m6ie&
* @return m}+_z^@j9
*/ 4"eeEs h
publicstatic Page createPage(Page page, int hA+;eXy/
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totalRecords){ tDtqTB}
return createPage(page.getEveryPage(), Qm4cuV-0{
5Zl7crA [
page.getCurrentPage(), totalRecords); 1~vv<`-
} ZVz*1]}
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/** n"<'F4r
* the basic page utils not including exception X
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Tvw(Sq};
handler y2Vc[o(NP
* @param everyPage yppXecFJ
* @param currentPage 2>.>q9J(
* @param totalRecords 0$|wj^?U
* @return page soqnr"
1
*/ wD SSgk
publicstatic Page createPage(int everyPage, int i~tps
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currentPage, int totalRecords){ q,]57s
everyPage = getEveryPage(everyPage); L>!MEMqm
currentPage = getCurrentPage(currentPage); 1wW4bg 5
int beginIndex = getBeginIndex(everyPage, c}w[T
[yVcH3GcjI
currentPage); 'h 7n}
int totalPage = getTotalPage(everyPage, cyWDtq
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totalRecords); Ps~)l#gue
boolean hasNextPage = hasNextPage(currentPage, bjFND]p?w
$B`bsJ
totalPage); )T@+"Pw8t
boolean hasPrePage = hasPrePage(currentPage); \p\rPfY{>
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returnnew Page(hasPrePage, hasNextPage, IXsOTBM
everyPage, totalPage, "~T06!F45
currentPage, <"`P;,S
D 66!C{
beginIndex); rm,h\
} `(8RK
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privatestaticint getEveryPage(int everyPage){ ,J'@e+jV
return everyPage == 0 ? 10 : everyPage; qb5IpI{U
} o
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privatestaticint getCurrentPage(int currentPage){ @fd{5 >\
return currentPage == 0 ? 1 : currentPage; F=yE>[! LB
} ~PC S_
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privatestaticint getBeginIndex(int everyPage, int /
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currentPage){ h3;RVtS
return(currentPage - 1) * everyPage; c1StA
} G[!<mh4h|
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privatestaticint getTotalPage(int everyPage, int =4Wjb
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totalRecords){ G_?qY#"(
int totalPage = 0; 'deqF|Iox
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if(totalRecords % everyPage == 0) {1W,-%
totalPage = totalRecords / everyPage; %$F\o1S
else sUsIu,1Q
totalPage = totalRecords / everyPage + 1 ; V_pKe~
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return totalPage; BO;LK-V
} I^S{V^Ty
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privatestaticboolean hasPrePage(int currentPage){ 9|//_4]
return currentPage == 1 ? false : true; YQ5d!a.
} [RHji47
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privatestaticboolean hasNextPage(int currentPage, XwdehyPhT2
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int totalPage){ E)F"!56lV
return currentPage == totalPage || totalPage == If(IG]>`D
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0 ? false : true; ~kPZh1n`
} LzkwgcR
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} pw1&WP&?3
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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。 z=VL|Du1OT
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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 yy|F6Pq3`
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做法如下: @KC;"u'C
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 R8R,!3 N
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的信息,和一个结果集List: \+sP<'~M
java代码: :KJZo,\
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/*Created on 2005-6-13*/ X.!|#FWb+
package com.adt.bo; e5fzV.' 5
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import java.util.List; 00@y,V_]
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import org.flyware.util.page.Page; @60/IE{-v
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/** q3R?8Mb
* @author Joa kc70HrG
*/ 4f>
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publicclass Result { %q
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private Page page; h^"OC$
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private List content; :0B'
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/** G=%SMl>[
* The default constructor mmrz:_
*/ >vY5%%}
public Result(){ ]AzDkKj
super(); uPtS.j=
} "+:IA|1wD
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/** "#a,R^J
* The constructor using fields DnW*q/=w
* _m|Tr*i8
* @param page l@ W?qw
* @param content @.h|T)Zyr
*/ ?_7^MP>
public Result(Page page, List content){ itW~2#nJz
this.page = page; 4Fpu68y
this.content = content; Vtr5<:eEx
}
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/** YE\s<$
* @return Returns the content. |*WE@L5
*/ IQ"9#{o
publicList getContent(){ !o&