Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 u ExLj6
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 g/?Vl2W
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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 @uSO~.7
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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 |jsI-?%8J
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分页支持类: B`pBIUu
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java代码: UhB+c
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package com.javaeye.common.util; ,f03TBD}
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import java.util.List; 8jK=A2pTa
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publicclass PaginationSupport { eSPS3|YYn
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publicfinalstaticint PAGESIZE = 30; +]l?JKV
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privateint pageSize = PAGESIZE; M-WSdG[AJ
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privateList items; SH*'<
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privateint totalCount; /E>;O47a
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privateint[] indexes = newint[0]; Gz`Jzh
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privateint startIndex = 0; cIug~ x>
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public PaginationSupport(List items, int KdNo'*;U]_
(}#&HE<
totalCount){ b,~'wm8:A
setPageSize(PAGESIZE); IRW0.'Dn
setTotalCount(totalCount); b1xE;0uR
setItems(items); Y;af|?U*6:
setStartIndex(0); KFM[caKeJO
} q4BXrEOw
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public PaginationSupport(List items, int ]dycesc'
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totalCount, int startIndex){ _KRnx-
setPageSize(PAGESIZE); * :"*'
setTotalCount(totalCount); YznL+TD
setItems(items); _/[qBe
setStartIndex(startIndex); +|?a7qM
} &BVUK"}P
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public PaginationSupport(List items, int ui]iOp
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totalCount, int pageSize, int startIndex){ 4S(G366
setPageSize(pageSize); 6v@Prw@.b
setTotalCount(totalCount); R P{pEd
setItems(items); Owp]>e
setStartIndex(startIndex); f,YORJ
} L1IF$eC
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publicList getItems(){ A-x^JC=
return items; T*p7[}#
} j;$f[@0o
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publicvoid setItems(List items){ (o>N*?,}
this.items = items; -J]?M
} %6ckau1_;
}3
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publicint getPageSize(){ J~x]~}V&
return pageSize; t!D'ZLw
} XT0-"-q
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publicvoid setPageSize(int pageSize){ ;5X6`GlS#5
this.pageSize = pageSize; +;,{`*W+N
} '[
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publicint getTotalCount(){ AA-$;s
return totalCount; $$AZ)#t[
} ?MDo. z3
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publicvoid setTotalCount(int totalCount){ p5In9s
if(totalCount > 0){ BDt$s(
\
this.totalCount = totalCount; 4Q+ ,_iP
int count = totalCount / _0[z
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NK-}[!f
pageSize; v9T3=
if(totalCount % pageSize > 0) hyxv+m[
count++; \ZnA%hC
indexes = newint[count]; `=Mk6$%Cs
for(int i = 0; i < count; i++){ 5|0}bv O
indexes = pageSize * CI+)0=`<1B
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i; ;apLMMsWC
} g.\b@0Uy'
}else{ AB
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this.totalCount = 0; (~@.9&cBD
} S1k*"><
} Q_T,=y
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publicint[] getIndexes(){ %>&~?zrq
return indexes; ImQ-kz?b
} y0O(n/
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publicvoid setIndexes(int[] indexes){ hGFi|9/-u
this.indexes = indexes; b$w66q8
} 7L+Wj }m
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publicint getStartIndex(){ 7]@M
return startIndex; l>jrY1u
} %2RXrH2&H
zGe =l;
publicvoid setStartIndex(int startIndex){ hz bvR~rn
if(totalCount <= 0) QM!UMqdj
this.startIndex = 0; M"mvPr9
elseif(startIndex >= totalCount) \*PE#RB#6
this.startIndex = indexes ks$5$,^T2o
yI=nu53BV
[indexes.length - 1]; n4?;!p<F
elseif(startIndex < 0) F_u?.6e]
this.startIndex = 0; nUY)LnI
else{ =Q"thsR
this.startIndex = indexes j % MY6"
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[startIndex / pageSize]; 2C0j.Ib
} @"cnPLh&
} UB] tKn
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publicint getNextIndex(){ Z$0mKw
int nextIndex = getStartIndex() + w8>lWgN
6
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pageSize; %to.'R
if(nextIndex >= totalCount) =M{&g
return getStartIndex(); KW0KXO06a
else E=v4|/['N
return nextIndex; cLp9|y0r
} }zo-%#
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publicint getPreviousIndex(){ fk#Ggp<
int previousIndex = getStartIndex() - .>`7d=KT
WUDXx %
pageSize; Pi&\GMzd
if(previousIndex < 0) !/F-EJOH6C
return0; B_r:da CS:
else DL_M#c`<
return previousIndex; $~EY:
} Cn9MboXX
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} e?aSM
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抽象业务类 +c'I7bBr
java代码: ]sI{+$~:c
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/** ht)KS9Xu
* Created on 2005-7-12 @iz6)2z
*/ -}JRsQ+rgM
package com.javaeye.common.business; avv/mEf-f
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import java.io.Serializable; Bq:: 5,v
import java.util.List; B415{
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import org.hibernate.Criteria; 64!V8&Ay
import org.hibernate.HibernateException; 5.)/gK2$
import org.hibernate.Session; *!(?=9[
import org.hibernate.criterion.DetachedCriteria; l\-(li
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import org.hibernate.criterion.Projections; Z$@ XMq!
import "Zicac@N
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org.springframework.orm.hibernate3.HibernateCallback; Xp3cYS*u
import Neb%D8/Kn
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org.springframework.orm.hibernate3.support.HibernateDaoS {Q~A;t
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upport; vCNYqa)m:
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import com.javaeye.common.util.PaginationSupport; ;c>Rjg&[
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public abstract class AbstractManager extends Ie;}k;?-
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HibernateDaoSupport { My'6yQL
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privateboolean cacheQueries = false; 4B8{\"6
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privateString queryCacheRegion; &"svt2
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publicvoid setCacheQueries(boolean ZjJEjw
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cacheQueries){ - r82'3]
this.cacheQueries = cacheQueries; ex2*oqAdX
} Ih95&HsdC
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publicvoid setQueryCacheRegion(String LNU9M>
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queryCacheRegion){ = %7:[#n
this.queryCacheRegion = "|"bo5M:
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queryCacheRegion; WYE[H9x1?
} Im_`q\i
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publicvoid save(finalObject entity){ qx/GioPU
getHibernateTemplate().save(entity); HgX4RSU
} akQtre`5sd
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publicvoid persist(finalObject entity){ oZ~M`yOz.
getHibernateTemplate().save(entity); ^\\cGJ&8c
} T3{qn$t8
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publicvoid update(finalObject entity){ $wVY)p9Q
getHibernateTemplate().update(entity); c>3W1"
} Wcn^IQ
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publicvoid delete(finalObject entity){ B: uW(E
getHibernateTemplate().delete(entity); 'gE_xn7j
} G";yqG
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publicObject load(finalClass entity, W"WvkW>-
)5X7|*LP
finalSerializable id){ ?z60b=f8
return getHibernateTemplate().load ^IM;D)X&:
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(entity, id); \Jv6Igu
} PHD$E s
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publicObject get(finalClass entity, _Oq (&I
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finalSerializable id){ c66Iy"
return getHibernateTemplate().get :/Nz' n
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(entity, id); D1lHq/
} bd<zn*HZ*
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publicList findAll(finalClass entity){ J2H8r 'T
return getHibernateTemplate().find("from J(-#(kMyf
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" + entity.getName()); Fu m1w
} ^ yu^Du
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publicList findByNamedQuery(finalString qx53,^2
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namedQuery){ /)y~%0
return getHibernateTemplate /{1 xpR
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().findByNamedQuery(namedQuery); 4k$BqM1
} r"rID
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publicList findByNamedQuery(finalString query, $K8ZxH1z@
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finalObject parameter){ m.EWYO0XQ
return getHibernateTemplate m(Bv}9
})bTQj7
().findByNamedQuery(query, parameter); 0 x"3
} f+$/gz
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publicList findByNamedQuery(finalString query, c6dL
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finalObject[] parameters){ .6OE8w
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return getHibernateTemplate o~^hsm[44J
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().findByNamedQuery(query, parameters); CWI(Q`((>
} P RX:*0
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publicList find(finalString query){ C2eei're
return getHibernateTemplate().find j|HOry1E &
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(query); 8 s:sMU:Q
}
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publicList find(finalString query, finalObject %wvSD&oz
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parameter){ jPA?0h
return getHibernateTemplate().find NY1olnI
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(query, parameter); |n~,$
} |$9k
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public PaginationSupport findPageByCriteria xp>ra2A
UO<%|{W+
(final DetachedCriteria detachedCriteria){ jr@<-.
return findPageByCriteria )+mbR_@,O6
5oWR}qqFK
(detachedCriteria, PaginationSupport.PAGESIZE, 0); -jFt4Q7}8
} 7=mU["raz`
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public PaginationSupport findPageByCriteria {b+!0[
](-:l6
(final DetachedCriteria detachedCriteria, finalint bv$)^
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startIndex){ +~02j1Jx
return findPageByCriteria 01#a
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(detachedCriteria, PaginationSupport.PAGESIZE, @;d(>_n
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startIndex); aeE9dV~
} T3)/?f?|
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public PaginationSupport findPageByCriteria A^
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(final DetachedCriteria detachedCriteria, finalint nY}Ep\g
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pageSize, Gv6EJV1i
finalint startIndex){ ],&WA?>G
return(PaginationSupport) hq$:62NYg
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getHibernateTemplate().execute(new HibernateCallback(){ qeSxE`E"
publicObject doInHibernate Uq0RJ<n
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(Session session)throws HibernateException { i4v7x;m_p
Criteria criteria = [D?RL`ZF
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detachedCriteria.getExecutableCriteria(session); *)U=ZO6S
int totalCount = SG;]Vr
Nm:nSqc
((Integer) criteria.setProjection(Projections.rowCount xAQ=oF
+
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()).uniqueResult()).intValue(); *w59BO&M4
criteria.setProjection 0b~5i-zM/
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(null); {Qg"1+hhM
List items = E,u@,= j
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criteria.setFirstResult(startIndex).setMaxResults EM;]dLh
u0#q)L8
(pageSize).list(); 2|kx:^D p
PaginationSupport ps = qA#!3<
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new PaginationSupport(items, totalCount, pageSize, ZVVK:dDgt
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startIndex); G;qC&7T
return ps; @q],pD
} *" >ek k
}, true); kdITh9nx<r
} S;MS,R
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public List findAllByCriteria(final iAbtv^fn
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DetachedCriteria detachedCriteria){ 6#K1LY5 }
return(List) getHibernateTemplate {SbA(a?B
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().execute(new HibernateCallback(){ h$G&4_O
publicObject doInHibernate 9L]x9lI;
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(Session session)throws HibernateException { j$n[;\]n
Criteria criteria = wz$1^ml
/^
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detachedCriteria.getExecutableCriteria(session); yfnqu4Cn
return criteria.list(); uK="#1z cC
} +kd88Fx
}, true); e$4 5 OL
} Ma:xxsH.
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public int getCountByCriteria(final S`5^H~
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DetachedCriteria detachedCriteria){ q!$?G]-%
Integer count = (Integer) lnEc5J@c>i
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getHibernateTemplate().execute(new HibernateCallback(){ Ef;_im
publicObject doInHibernate ~ 61O
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(Session session)throws HibernateException { ^g$k4
Criteria criteria = DAj@wn3K?
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detachedCriteria.getExecutableCriteria(session); z0t6}E<VIR
return nG1mx/w
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{
criteria.setProjection(Projections.rowCount d>M&jSCL
;m,lS_[c
()).uniqueResult(); MP-A^QT
} `f}}z5
}, true); Pv1C o:
return count.intValue(); =4/LixsV|
} {W62%>v
} qDxz`}Ly=
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用户在web层构造查询条件detachedCriteria,和可选的 ja$ e)
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 KM*sLC#
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PaginationSupport的实例ps。 KwlN
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ps.getItems()得到已分页好的结果集 :CV!:sUm
ps.getIndexes()得到分页索引的数组 T?I&n[Y|
ps.getTotalCount()得到总结果数 36s[hg
ps.getStartIndex()当前分页索引 .;u(uB;J6
ps.getNextIndex()下一页索引 &n|#jo(gS
ps.getPreviousIndex()上一页索引 Wct
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9 %4Pt=v~d
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 y,tA~
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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 7 6~x|6)
"!i7U2M'
一下代码重构了。 :c"J$wT/
c@1C|
我把原本我的做法也提供出来供大家讨论吧: 8c\mm 0n
L01R.3Z+
首先,为了实现分页查询,我封装了一个Page类: 5YUn{qtD
java代码: #IDDKUE
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/*Created on 2005-4-14*/ *r!1K!c
package org.flyware.util.page; wh
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j
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/** ;TD<\1HJT=
* @author Joa >V;JI;[
* XtRfzqg?K
*/ AMA:hQ
publicclass Page { 1!/cd;{B
;LELC5[*s
/** imply if the page has previous page */ yHLclv
privateboolean hasPrePage; >P/kb fPA
A0# K@
/** imply if the page has next page */ WM}:%T-
privateboolean hasNextPage; )zlksF
-iGt]mbJkP
/** the number of every page */ M6vW}APH[n
privateint everyPage; zkYlIUD
g-U'{I5F
/** the total page number */ 7Av/ZS
privateint totalPage; d i`}Y&
=L{lt9qQz
/** the number of current page */ _SjS^z~
privateint currentPage; #dE#w#=r
J\b,rOI f
/** the begin index of the records by the current \/$T 3f`x
ptQr8[FA
query */ =\e}fyuK
privateint beginIndex; 2w)0>Y(_
}P#%aE&-
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/** The default constructor */ T9jp*
public Page(){ s$YKdtR
3}= .7qm
} :T"!6;
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/** construct the page by everyPage Wz nz
* @param everyPage )TJz'J\*
* */ a8rsF
public Page(int everyPage){ hi"[R@UG
this.everyPage = everyPage; "Y}f"X|
} ?t$sju(\
X?z5IL;rt
/** The whole constructor */ zLc.4k
public Page(boolean hasPrePage, boolean hasNextPage, 1GN>,Lb:o
[bUM x
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int everyPage, int totalPage, P5* :r3>
int currentPage, int beginIndex){ ZZA!Y9ia2
this.hasPrePage = hasPrePage; xY(+[T!OF
this.hasNextPage = hasNextPage; kXzm
this.everyPage = everyPage; g2L
this.totalPage = totalPage; AT}}RE@vq
this.currentPage = currentPage; H"WkZX
this.beginIndex = beginIndex; fc._*y#AS
} #`RYKQwB
=xQ7:TB
/** fs&J%ku\
* @return A9qCaq{
* Returns the beginIndex. ,w; ~R4x
*/ VQU [5C
publicint getBeginIndex(){ C6,GgDH`
return beginIndex; p18-yt;
1
} D-9zg\\'`
OYzt>hdH
/** #B8`qFpQC
* @param beginIndex }oigZI(1
* The beginIndex to set. !;{@O`j?b
*/ vD D !.i
publicvoid setBeginIndex(int beginIndex){ m8n!<_NFt(
this.beginIndex = beginIndex; Y;6<AIx>
} #QXv[%k
[&|Le;h
/** 0){%4
* @return 2hEB?ZAQZ
* Returns the currentPage. (9*s:)zD-
*/ @ \J R xJ
publicint getCurrentPage(){ /%po@Pm#I
return currentPage; kFgN^v^t
} 6[$kEKOY=
wYSvI
/** 4q/E7n
* @param currentPage Fkuq'C<|Y
* The currentPage to set. Wa
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*/ Hj
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publicvoid setCurrentPage(int currentPage){ V]L$`7G
this.currentPage = currentPage; 2FD[D`n]f
} tBtJRi(
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/** </t_<I0{
* @return T?!^-PD9*
* Returns the everyPage. C, n]9
*/ ogs9obbZ!
publicint getEveryPage(){ uYIw ?fXy
return everyPage; 1)/B V{n
} kMKI=>s+
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/** ?Pw#!t
* @param everyPage V[wEn9
* The everyPage to set. H1| -f]!
*/ :{h,0w'd
publicvoid setEveryPage(int everyPage){ $ ;>,
this.everyPage = everyPage; J9)wt ?%j
} =vT3SY
n}
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/** ?)<zrE5p
* @return aw/Y#
* Returns the hasNextPage. 4D"IAI
*/ |}^[f]
publicboolean getHasNextPage(){ 6R%c+ok8i
return hasNextPage; ~^lQ[ x
} ?*u)T%S
-kZz,pNQ,
/** $1H?k
* @param hasNextPage "sz LTC]*6
* The hasNextPage to set. Yk(OVl T
*/ Z%Y=Lx
publicvoid setHasNextPage(boolean hasNextPage){ j8?$Hk
this.hasNextPage = hasNextPage; W0tBF&E"
} 7
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/** H|0B*i@81
* @return <E$P
* Returns the hasPrePage. +6*oO|
*/ lk \|EG
publicboolean getHasPrePage(){ 6ecr]=Cv
return hasPrePage; KZ ?<&x
} 6Kh:m-E9
}CsUZ&* &
/** 5U|f"3&8
* @param hasPrePage ij r*_=
* The hasPrePage to set. [4kx59J3b
*/ :|<D(YA
publicvoid setHasPrePage(boolean hasPrePage){ lcJ`OLG
this.hasPrePage = hasPrePage; ll1?I8}5|
} vMzR3@4e
$MKx\qx}
/** 1(w0*`
* @return Returns the totalPage. JQ+4 SomK
* zN].W\("\
*/ P{(m: `N
publicint getTotalPage(){ bsM`C]h&
return totalPage; Br]VCp
} X_HR$il
hz Vpv,|G
/** PHDKx+$
* @param totalPage s[nOB0
* The totalPage to set. 1:My8
*/ cIl^5eE^Pq
publicvoid setTotalPage(int totalPage){ `!qWHm6I*
this.totalPage = totalPage; ?-#w [J'6
} j0=`Jf
wa<@bub
} )#ic"UtR
jV:U%
8f,jC+(
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bT[Q:#GL
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 @)<uQ S
%E1~I\n:F
个PageUtil,负责对Page对象进行构造: ?j8CkqX!
java代码: 1Na CGD"
'9auQ(2
t@}<&{zk
/*Created on 2005-4-14*/ *Ei~2O}
package org.flyware.util.page; |YZ`CN<
QV{Nq=%]
import org.apache.commons.logging.Log; <FS/'[P
import org.apache.commons.logging.LogFactory; l:+tl/
SnQ$
/** d#ld*\|
* @author Joa 8k_,Hni
* SwC,=S
*/ *sAoYx
publicclass PageUtil { wjS3ItB
l-t:7`=|
privatestaticfinal Log logger = LogFactory.getLog YvBUx#\
1(q!.lPc
(PageUtil.class); H1\~T
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/** of+$TKQNpN
* Use the origin page to create a new page k B2+ Tr
* @param page jf/;`br
* @param totalRecords D-ug$ZRg
* @return 5 Nl>4d`
*/ %=#&\ldPS
publicstatic Page createPage(Page page, int hJFQ/(
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totalRecords){ He#+zE;
return createPage(page.getEveryPage(), _<t3~{qUT
Q=e?G300#L
page.getCurrentPage(), totalRecords); 71K6] ~<
} ]PUyX8'~
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/** yaR|d3ef?4
* the basic page utils not including exception U?#6I-
0>Mm |x*5
handler QREIr |q'
* @param everyPage ]NTHit^EX
* @param currentPage kdxs{b"t
* @param totalRecords >#!n"i;
* @return page gkBat(Uc
*/ H[-zQ#I9
publicstatic Page createPage(int everyPage, int O,^,G<`
?[XH`c,
currentPage, int totalRecords){ 50_%Tl[
everyPage = getEveryPage(everyPage);
vf5[x!4
currentPage = getCurrentPage(currentPage); !29
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int beginIndex = getBeginIndex(everyPage, xFg=Tyq:
L?al2aopF
currentPage); ~0/=5 dC
int totalPage = getTotalPage(everyPage, Onot<}K
*:YW@Gbm
totalRecords); SvI
boolean hasNextPage = hasNextPage(currentPage, 3kKXzIh
-MB,]m
totalPage); b?w4Nx#
boolean hasPrePage = hasPrePage(currentPage); .>}we ~O
I9Z8]Q+2"
returnnew Page(hasPrePage, hasNextPage, \BJnJk!%
everyPage, totalPage, w'L;`k;Q
currentPage, &X|z(vSJ$
u;=("S{"0
beginIndex); YJ3970c/M
} @&,r|-
"}PmAr e
privatestaticint getEveryPage(int everyPage){ "B+M5B0Z
return everyPage == 0 ? 10 : everyPage; -$e\m]
}Z
} _ZR2?y-M
bZ3CJ f&mE
privatestaticint getCurrentPage(int currentPage){ |$1j;#h
return currentPage == 0 ? 1 : currentPage; g{<3*,
} Lo;T\CN
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privatestaticint getBeginIndex(int everyPage, int 7Kh+m@q.
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currentPage){ pdtK3Pf
return(currentPage - 1) * everyPage; +d#ZSNu/
} v t(kL(}v
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privatestaticint getTotalPage(int everyPage, int zEks4yd
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totalRecords){ _Z8zD[l
int totalPage = 0; N|7._AR2
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if(totalRecords % everyPage == 0) Nk^#Sa?
totalPage = totalRecords / everyPage; u!g<y
else VK$+Nm)
totalPage = totalRecords / everyPage + 1 ; N:&^ql4
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return totalPage; V2.MZ9
} {0Leua
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privatestaticboolean hasPrePage(int currentPage){ b,SY(Ce~g
return currentPage == 1 ? false : true; )ZiJl5l@
} {H0B"i
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privatestaticboolean hasNextPage(int currentPage, t%8*$"~X
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int totalPage){ `D?vmSQ
return currentPage == totalPage || totalPage == (a)d7y.oo
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0 ? false : true; YpNTq_S1,
} IClnh1=
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} E-!`6
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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。 wt)tLMEv
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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 meIY00
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做法如下: $=H\#e)]Ug
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 N^`F_R1Z
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的信息,和一个结果集List: 8[zP2L!-
java代码: ]1p&*xX:Bj
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/*Created on 2005-6-13*/ wAy;ZNu
package com.adt.bo; ^iTjr$hQ;
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import java.util.List; srC'!I=s>8
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import org.flyware.util.page.Page; ~0worI?
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/** ^*Rr x
* @author Joa 'MsxZqW"~
*/ mtJI#P
publicclass Result { \Dr@n^hk@[
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private Page page; *[_?4*F
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private List content; v( (fRX.`
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/** 3:);vh!
* The default constructor \_BaV0<
*/ %]
public Result(){ 8tPq5i
super(); Q=w\)qJ
} x{&