Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 /W9(}Id6
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 GZH{"_$
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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^GfZ
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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 n&OM~Vs
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分页支持类: ;`Nh@*_
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java代码: 6S`0<Z;;/
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package com.javaeye.common.util; VKV
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import java.util.List; h4Wt
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publicclass PaginationSupport { B6=?Qp/f
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publicfinalstaticint PAGESIZE = 30; &^2SdF
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privateint pageSize = PAGESIZE; J0V`sK
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privateList items; Y<L35
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privateint totalCount; 'X<4";$mU
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privateint[] indexes = newint[0]; ]
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privateint startIndex = 0; @}=(4%
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public PaginationSupport(List items, int u
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totalCount){ X NgcBSD
setPageSize(PAGESIZE); i.k7qclL`
setTotalCount(totalCount); 8EI9&L>
setItems(items); 8~tX>q<@q
setStartIndex(0); K!]a+M]>
} k&2=-qgVR
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public PaginationSupport(List items, int G54J'*Z
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totalCount, int startIndex){ ~)^'5^
setPageSize(PAGESIZE); 8N%nG(
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setTotalCount(totalCount); |BbzRis
setItems(items); )adV`V%=>
setStartIndex(startIndex); `^52IkM)
} [Ur\^wS
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public PaginationSupport(List items, int x-"8V(
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totalCount, int pageSize, int startIndex){ 0z'GN#mT5
setPageSize(pageSize); (`S^6-^
setTotalCount(totalCount); ia7<AwV
setItems(items); 9.8%Iw
setStartIndex(startIndex); vfc:ok 1
} XEQTT D<
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publicList getItems(){ |GtvgvO,
return items; V(_1q
} B*N1)J\5
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publicvoid setItems(List items){ lDTHK2f
this.items = items; -QroT`gy
} ,Cb3R|L8
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publicint getPageSize(){ /TyGZ@S>m
return pageSize; <XIIT-b[
} /M_$4O;*@
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publicvoid setPageSize(int pageSize){ )rq |t9kix
this.pageSize = pageSize; MC* Hl`C
} ^cm]
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publicint getTotalCount(){ T9C_=0(hn
return totalCount; 0^lWy+
} CmZayV
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publicvoid setTotalCount(int totalCount){ CuWJai:nQ;
if(totalCount > 0){ fC[za,PXaE
this.totalCount = totalCount; EHk\Q\
int count = totalCount / Gq^vto
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pageSize; H_X^)\oJ
if(totalCount % pageSize > 0) B1V{3
count++; ovdJ[bO
indexes = newint[count]; hbJ>GSoZ,
for(int i = 0; i < count; i++){ VG);om7`PD
indexes = pageSize * N-gYamlQ
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i; 5~|{:29X
} Snx!^4+MF
}else{ aYWWln
this.totalCount = 0; }(oeNPM8
} s
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} "j@\a)a
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publicint[] getIndexes(){ )h8}{*
return indexes; bC/":+s& p
} !cwZ*eM
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publicvoid setIndexes(int[] indexes){ Upe}9xf
this.indexes = indexes; ]mTBD<3\
} >2'"}np*
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publicint getStartIndex(){ c+ oi8G
return startIndex; TmsIyDcD~
} cJ;Nh>ey
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publicvoid setStartIndex(int startIndex){ j*jUcD*
if(totalCount <= 0) *.DC(2:o!
this.startIndex = 0; ilA45@
elseif(startIndex >= totalCount) =]Vz=<
this.startIndex = indexes J@s>Pe)
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[indexes.length - 1]; j]Jgz<
elseif(startIndex < 0) BAf$tyh
this.startIndex = 0; XBQt:7[<
else{ !+eH8
this.startIndex = indexes S/nPK,^d2
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[startIndex / pageSize]; CD$#}Id
} ^"WVE["
} c0qp-=^&.
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publicint getNextIndex(){ K~N$s"Qx
int nextIndex = getStartIndex() + &mwd0%4
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pageSize; .ZpOYhk
if(nextIndex >= totalCount) i%hCV o
return getStartIndex(); ?sf<cFF
else 1E+12{~m"i
return nextIndex; g!'R}y
} gcJ!_KZK
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publicint getPreviousIndex(){ ~r1pO#r-
int previousIndex = getStartIndex() - &Y{^yb
T @ c~ql
pageSize; 0j.K?]f)h
if(previousIndex < 0) E}@C4pS
return0; RkF#NCnL;
else >STtX6h
return previousIndex; jD:
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} ]A*}Dem*5
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} '![oLy
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抽象业务类 xa>| k>I
java代码: =>jp\A
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/** yvAO"43
* Created on 2005-7-12 [q<'ty
*/ BR,-:?z
package com.javaeye.common.business;
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import java.io.Serializable; ^L[:DB{Z
import java.util.List; 1F@k9[d~
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import org.hibernate.Criteria; <W4F`6`x
import org.hibernate.HibernateException; iUx\3d,
import org.hibernate.Session; ,eXtY}E
import org.hibernate.criterion.DetachedCriteria; h>N}M}8
import org.hibernate.criterion.Projections; GG}%
import 8y;Rw#Dz
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org.springframework.orm.hibernate3.HibernateCallback; 79\wjR!T
import AK:cDKBO
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org.springframework.orm.hibernate3.support.HibernateDaoS Y'v[2s
NGx3f3 9
upport; rQ;w{8J\t
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import com.javaeye.common.util.PaginationSupport; HA6tGZP*L
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public abstract class AbstractManager extends ?t#wK}d.
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HibernateDaoSupport { sX>u.
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privateboolean cacheQueries = false; =2Y;)wrF
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privateString queryCacheRegion; ><V*`{bD9)
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publicvoid setCacheQueries(boolean A1WUK=P
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cacheQueries){ d*(aue=
this.cacheQueries = cacheQueries; .tBlGMcN
} 0-.
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publicvoid setQueryCacheRegion(String `Q]N]mK
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queryCacheRegion){ U1RU2M]v
this.queryCacheRegion = 91-bz^=xO
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queryCacheRegion; Bo 35L:r|
} L@}PW)#
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publicvoid save(finalObject entity){ v^|U?
getHibernateTemplate().save(entity); ,:_c-d#
} $=aO*i
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publicvoid persist(finalObject entity){ 5&]5*;Bv J
getHibernateTemplate().save(entity); mH*ldf;J;=
} =ily=j"hK
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publicvoid update(finalObject entity){ IqOg{#sm
getHibernateTemplate().update(entity); l_B735
} Fq9YhR
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publicvoid delete(finalObject entity){ sI ,!+
getHibernateTemplate().delete(entity); $Y/9SD
} 0;Z|:\P\=
hI[}
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publicObject load(finalClass entity, &2'-v@kK
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finalSerializable id){
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return getHibernateTemplate().load uuzV,q
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(entity, id); Z6!Up1
} B#sCB&(
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publicObject get(finalClass entity, N Ob`)qb
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finalSerializable id){ T j$'B[cv
return getHibernateTemplate().get !avol/*
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(entity, id); bO~y=Pa\
} mHD_cgKN
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publicList findAll(finalClass entity){ J-W9B amx
return getHibernateTemplate().find("from ou,[0B3n0
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" + entity.getName()); l|5 h
} xtV+Le%
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publicList findByNamedQuery(finalString j"W>fC/u
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namedQuery){ W4^L_p>Tm^
return getHibernateTemplate 6FS%9.Ws
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().findByNamedQuery(namedQuery); XS<>0YM
} LoF/45|-<
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publicList findByNamedQuery(finalString query, ?R`S-
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finalObject parameter){ WBe0^=x
return getHibernateTemplate 4GYi'
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().findByNamedQuery(query, parameter); %6K7uvTq
} t)SZ2G1r
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publicList findByNamedQuery(finalString query, r]B8\5|<d
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finalObject[] parameters){ 0G%9
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return getHibernateTemplate s!6lZ mPM
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().findByNamedQuery(query, parameters); ;(Yb9Mr)z
} n@p]v*
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publicList find(finalString query){ So%X(,
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return getHibernateTemplate().find Ee>VA_ss
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(query); z]7 WC
} A(Ct^/x-
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publicList find(finalString query, finalObject
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parameter){ 1{uxpYAP=
return getHibernateTemplate().find Ple.fKu
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(query, parameter); B|`?hw@g+
} 5epI'D
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public PaginationSupport findPageByCriteria %VHy?!/
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(final DetachedCriteria detachedCriteria){ Iix,}kzss
return findPageByCriteria r&=ulg
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ct+F\:e
} R'c*CLaiE
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public PaginationSupport findPageByCriteria %G?@Hye3
*)^6'4=
(final DetachedCriteria detachedCriteria, finalint
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startIndex){ srS!X$cec
return findPageByCriteria !Vpi1N\
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(detachedCriteria, PaginationSupport.PAGESIZE, U32$9"
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startIndex); "&(/bdah?&
} H4M=&"ll}
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public PaginationSupport findPageByCriteria 4KPnV+h"b
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(final DetachedCriteria detachedCriteria, finalint (3e.q'
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pageSize, 3Tr,waV
finalint startIndex){ ammi4k/
return(PaginationSupport) fe .=Z&
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getHibernateTemplate().execute(new HibernateCallback(){ }G4I9Py
publicObject doInHibernate If'q8G3]-
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(Session session)throws HibernateException { xU'z>y4V$
Criteria criteria = 2H%9l@}u
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detachedCriteria.getExecutableCriteria(session); H3wJ5-q(
int totalCount = q@.>eB'92P
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((Integer) criteria.setProjection(Projections.rowCount jN6V`Wh_
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()).uniqueResult()).intValue(); u%-]-:c
criteria.setProjection A}fm).Wp@
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(null); -jQ*r$iRE
List items = hqRC:p#9
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criteria.setFirstResult(startIndex).setMaxResults 4*_jGw
{7y;s
(pageSize).list(); lpi"@3
PaginationSupport ps = M)13'B.
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new PaginationSupport(items, totalCount, pageSize, ?NE/}?a
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startIndex); i)l0[FNI}
return ps; iXWzIb}CJ-
} Om.%K>V
}, true); ]9!y3"..W{
} SIK:0>yK"
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public List findAllByCriteria(final pq*e0uW
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DetachedCriteria detachedCriteria){ 4!sK>l!
return(List) getHibernateTemplate {S0-y
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().execute(new HibernateCallback(){ ~[=<Os
publicObject doInHibernate S1|5+PPs
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(Session session)throws HibernateException { w!lk&7Q7Z
Criteria criteria = zJXK:/
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detachedCriteria.getExecutableCriteria(session); ):N#X<b':
return criteria.list(); ?HG[N7=j
} Wvl~|Sx]
}, true); Q{~g<G
} !mv5i%3
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public int getCountByCriteria(final ByY^d#oE
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DetachedCriteria detachedCriteria){ 2n.HmS
Integer count = (Integer) F{mUxo#T
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getHibernateTemplate().execute(new HibernateCallback(){ #91^1jyMf
publicObject doInHibernate yPE3Awh5
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(Session session)throws HibernateException { k A=5Kc
Criteria criteria = kq| !{_
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detachedCriteria.getExecutableCriteria(session); yjT>bu]
return DN:|
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criteria.setProjection(Projections.rowCount 20I`F>-*
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()).uniqueResult(); )>2L(~W
} n1%2sV)>
}, true); a&{Y~Og?%
return count.intValue(); ZH~bY2^;
} BP..p ^EPN
} k'r} @-X
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用户在web层构造查询条件detachedCriteria,和可选的 _1[Wv?
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 gaN/
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PaginationSupport的实例ps。 Muwlehuq
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ps.getItems()得到已分页好的结果集 ![Qi+xyc
ps.getIndexes()得到分页索引的数组 xHt7/8wF
ps.getTotalCount()得到总结果数 4Q !A w
ps.getStartIndex()当前分页索引 m 3UK`~ji
ps.getNextIndex()下一页索引 \k5"&]I3
ps.getPreviousIndex()上一页索引 {9(0s| pr
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 %Bw:6Y4LZ
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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 q\@_L.tc[
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一下代码重构了。 Ck#e54gJX
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我把原本我的做法也提供出来供大家讨论吧: i&m_G5u88
2.WI".&y=
首先,为了实现分页查询,我封装了一个Page类: %16Lo<DPm
java代码: WOZuFS13
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/*Created on 2005-4-14*/ d<d3j9u(#
package org.flyware.util.page; CNb(\]
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/** ,c:NdY(,)
* @author Joa zg3kU65PJE
* uD@ZM
*/ msxt'-$M
publicclass Page { 7tWC<#
wH8J?j"5>
/** imply if the page has previous page */ pl%!AY'oE>
privateboolean hasPrePage; T^Ia^B-%}g
T/E=?kBR
/** imply if the page has next page */ T#Q7L~?zY
privateboolean hasNextPage; <oJ?J^
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/** the number of every page */ #w.0 Cc
privateint everyPage; hu$eO'M_
>%;i@"
/** the total page number */ ?PWg
privateint totalPage; K ,NmDc^
8Azh&c
/** the number of current page */ ,r*Kxy
privateint currentPage; EF!J#N2
sJx_X8
/** the begin index of the records by the current fD@d.8nXd
{[#)Q.2
query */ F(n<:TvlK
privateint beginIndex; ;U>nj],uv
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/** The default constructor */ [L X/O@
public Page(){ &V1d"";SZ
la<.B^
} _^Q!cB'~/`
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/** construct the page by everyPage x?o#}:S
* @param everyPage RAl/p9\A+
* */ ?:3hp2k<
public Page(int everyPage){ R_B0CM<!
this.everyPage = everyPage; o)XrC
} !.,J;Qt
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/** The whole constructor */ 6&0@k^7~
public Page(boolean hasPrePage, boolean hasNextPage, 5@+?{Cl
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int everyPage, int totalPage, d)1gpRp
int currentPage, int beginIndex){ AE>W$x8P
this.hasPrePage = hasPrePage; Bk\Y v0
this.hasNextPage = hasNextPage; Wz.iDRFl
this.everyPage = everyPage; w\s`8S
this.totalPage = totalPage; ;Tr,BfV|Bf
this.currentPage = currentPage; 5e.aTW;U
this.beginIndex = beginIndex; >BO$tbU5b
} |hxiARr4
ld]*J}cw
/** :0:Tl/))
* @return ?'0!>EjY"
* Returns the beginIndex. xjr4')h
*/ T`wDdqWbEG
publicint getBeginIndex(){ SI~jM:S}
return beginIndex; jbipNgxkr
} vN^.MR+<
V3ht:>c9qs
/** ~D3S01ecM
* @param beginIndex s>o#Ob@4'
* The beginIndex to set. )KE
*/ %\
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publicvoid setBeginIndex(int beginIndex){ ^O*-|ecA
this.beginIndex = beginIndex; tnobqL'
} iGSJ\
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/** FA*$ dwp
* @return P9yMf~
* Returns the currentPage. =gI41Y]
*/ OJpfiZ@Q_
publicint getCurrentPage(){ [TOo 9W
return currentPage; l+@;f(8}
} iOg4(SPci
]uox ^HC
/** x3&gB`j-
* @param currentPage GGEM&0*
* The currentPage to set. iGhvQmd(/*
*/ qZ^
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publicvoid setCurrentPage(int currentPage){ 0\:=KIY.
this.currentPage = currentPage; x7/Vf,N
} _l9fNf!@
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/** QO}~"lMj
* @return g6%]uCFB
* Returns the everyPage. ,Tr&`2w
*/ N_bgW QY
publicint getEveryPage(){ xH\\#4/
return everyPage; j%s,%#al
} lo>9 \ Po
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/** ;Va(l$zD
* @param everyPage V?S}%-a
* The everyPage to set. IOZw[9](+
*/ C33Jzn's
publicvoid setEveryPage(int everyPage){ ^nNY|
*
this.everyPage = everyPage; buX(mj:&
} bUS:c
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/** d[9{&YnH !
* @return S'34](9n6
* Returns the hasNextPage. d.+
*/ Pv5S k8
publicboolean getHasNextPage(){ I>FL&E@K
return hasNextPage; e2c'Wab
} AVQcD`V3B
<&b,%O
/** G,!j P2S
* @param hasNextPage ^ slIR!L
* The hasNextPage to set. LSc^3=X
*/ ^WB[uFt-
publicvoid setHasNextPage(boolean hasNextPage){ ,nYa+e
this.hasNextPage = hasNextPage; ?I^$35
} h@R n)D
OU%"dmSDk
/** ^$P_B-C N
* @return s?}qia\~m
* Returns the hasPrePage. #B~;j5
*/ fQib?g/G
publicboolean getHasPrePage(){ Xw9]WJc
return hasPrePage; ]2m=lt1
} NW6;7nWb
gS<p~LPf
/** t RU/[?!
* @param hasPrePage >97YK =
* The hasPrePage to set. CbM~\6R
*/ NOs00 H
publicvoid setHasPrePage(boolean hasPrePage){ u W,J5!
this.hasPrePage = hasPrePage; e*T^:2oRl
} aQmS'{d?^
CrI<rD%'
/** &'12,'8
* @return Returns the totalPage. }Q: CZ
* Zuzwc [Z1
*/ xBxiBhqzF
publicint getTotalPage(){ L;:PeYPL
return totalPage; m#BXxS#B<_
} ,|RKM
[xM&Jdf8
/** ,M`1 k
* @param totalPage uq]=L
* The totalPage to set. Q<6* UUQm
*/ +ZjDTTk
publicvoid setTotalPage(int totalPage){ 25Z}.))
this.totalPage = totalPage; W]Xwt'ABz
} %R4 \[e
MMrN#&r
} @Pc7$ qD %
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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 eMdP4<u
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个PageUtil,负责对Page对象进行构造: m<j;f
java代码: n#"G)+h3#
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/*Created on 2005-4-14*/ ?a,#p
package org.flyware.util.page; 6P@K]jy& n
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import org.apache.commons.logging.Log; W[I[Xg&
import org.apache.commons.logging.LogFactory; Q3i\`-kbb
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/** . h)VR
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* @author Joa mQVlE__ub
* ,1 H|{ <
*/ 1ik.|T<f0
publicclass PageUtil { &I
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{=?[:5
privatestaticfinal Log logger = LogFactory.getLog ?;Sg,.J
XS2/U<sd
(PageUtil.class); x$jLB&+ICz
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/** rCqwJoC`v
* Use the origin page to create a new page a\m=E#G
* @param page =4+2y '
* @param totalRecords y`m0/SOT
* @return ASEKP(]v
*/ \h[*oeh
publicstatic Page createPage(Page page, int RU/WI<O
=g6~2p=H
totalRecords){ yD\Kn{
return createPage(page.getEveryPage(), &^&0,g?To
p&\QkI=
page.getCurrentPage(), totalRecords); l@w\
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} ?r|iZKa
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/** <z60EvHg
* the basic page utils not including exception T*B`8P
JO]?u(m01
handler 19R~&E's
* @param everyPage &to~#.qc
* @param currentPage b"o\-iUioe
* @param totalRecords I3.JAoB>!
* @return page XjzGtZ#6
*/ g3'dkS!
publicstatic Page createPage(int everyPage, int PfYeV/M|
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currentPage, int totalRecords){ "MzBy)4Q
everyPage = getEveryPage(everyPage); H;a) `R3
currentPage = getCurrentPage(currentPage); D
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int beginIndex = getBeginIndex(everyPage, *>aVU'
@ukL!AV?Y
currentPage); ~)pZ5%C
int totalPage = getTotalPage(everyPage, o:UNSr
)RFY2}
totalRecords); %! Sjbh
boolean hasNextPage = hasNextPage(currentPage, lhE]KdE3
"}0QxogYE
totalPage); l(QntP
boolean hasPrePage = hasPrePage(currentPage); (i{ZxWW&
WUYU\J&q3
returnnew Page(hasPrePage, hasNextPage, rUV'DC?eE
everyPage, totalPage, u*\QVOF
currentPage, dw}ge,bBic
Tl"r#
beginIndex); vfT
@;`
} iX2exJto
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privatestaticint getEveryPage(int everyPage){
m5J@kE%
return everyPage == 0 ? 10 : everyPage; 7ko}X,aC
} TRgj`FG
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privatestaticint getCurrentPage(int currentPage){ ~|~ 2B$JeV
return currentPage == 0 ? 1 : currentPage; lGT[6S\as
} Zl#';~9W
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privatestaticint getBeginIndex(int everyPage, int :`BG/
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currentPage){ b~ig$!N]
return(currentPage - 1) * everyPage; @QpL*F
} { .i^&
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privatestaticint getTotalPage(int everyPage, int ooa"Th<
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totalRecords){ 6R3/"&P(/#
int totalPage = 0; Y*jkUQ
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if(totalRecords % everyPage == 0) OWr\$lm@z$
totalPage = totalRecords / everyPage; IWddJb~hu
else %Y.@AiViz
totalPage = totalRecords / everyPage + 1 ; {6)H.vpP
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return totalPage; tG"EbWi
} Y2uy@j*N
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privatestaticboolean hasPrePage(int currentPage){ hE,-CIRg
return currentPage == 1 ? false : true; ^8ilUu
} E_D@7a
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privatestaticboolean hasNextPage(int currentPage, ^5!"[RB\
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int totalPage){ Ly`.~t(~l
return currentPage == totalPage || totalPage == MnY}U",
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0 ? false : true; r;waT@&C
} {A MAQ
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} s<C66z
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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。 LmR OG-9
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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 R6o07.]
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做法如下: k^UrFl
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ^D
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的信息,和一个结果集List: bC&xN@4
java代码: d$MewDWUN
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/*Created on 2005-6-13*/ uF*tlaV6
package com.adt.bo; :G<~x8]k0
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import java.util.List; wD pL9 q
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import org.flyware.util.page.Page; NQbgk+&wD
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/** EF6"PH+J@
* @author Joa mFC9\
*/ @G>&Gu;5
publicclass Result { Oh1a'&
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private Page page; &xFs0Ri(
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private List content; 8;,(D#p
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/** \xk8+= /A
* The default constructor 3=lQZi<]%
*/ cn$0^7?
public Result(){ p!LaR.8]
super(); u&Xn#fh
} a/q8v P
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/** +227SPLd
* The constructor using fields Uv:NY1(3!
* AT^MQvn
* @param page kqS_2[=]
* @param content TGG-rA6@Lx
*/ Bp=BRl
public Result(Page page, List content){ n]_<6{: U
this.page = page; wcDb| H&
this.content = content; +oa>k
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} <;E>1*K}8
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/** Oufdi3h
* @return Returns the content. G8hDR^ra
*/ rEsGf+4
publicList getContent(){ -hO[^^i9
return content; ='.G,aJ9
} -~=:tn)0
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/** hL/
* @return Returns the page. lHoV>k
*/ c6F8z75U
public Page getPage(){ \8 -PCD
return page; m-|~tve
} F!6;<!&