Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 /)Weg1b
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 f_. 0 uM
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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 d&DQ8Gm ^
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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 /XuOv(j
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分页支持类: c#fSt}J>C
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java代码: Sjmq\A88dc
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package com.javaeye.common.util; 2<_|1%C
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import java.util.List; gYw=Z_z
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publicclass PaginationSupport { 6s:
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publicfinalstaticint PAGESIZE = 30; P`n"E8"ab<
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privateint pageSize = PAGESIZE; -wnBdL
PW*[(VX
privateList items; qD}O_<_1ym
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privateint totalCount; AT"!Ys|
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privateint[] indexes = newint[0]; *nY$YwHB
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privateint startIndex = 0; `{nzw $
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public PaginationSupport(List items, int Vf$q3X
B,{Q[
totalCount){ [g lhru=+
setPageSize(PAGESIZE); 3=^B
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setTotalCount(totalCount); v*@R U
setItems(items); kE{-h'xADD
setStartIndex(0); K=J">^uW
} 3TT?GgQ
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public PaginationSupport(List items, int \'P79=AU
v-}D>)M^W
totalCount, int startIndex){ t,yMO
setPageSize(PAGESIZE); D{]9s
setTotalCount(totalCount); $4>x4*
setItems(items); J/A UOInh
setStartIndex(startIndex); dYp} R>+
} BbNl:`
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public PaginationSupport(List items, int t[bZg9;
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totalCount, int pageSize, int startIndex){ X}]g;|~SN
setPageSize(pageSize); FzQ6UO~'
setTotalCount(totalCount); Z}r9jM
setItems(items); 9Ui|8e~=
setStartIndex(startIndex); .:TSdusr~
} BHIC6i%
m/1;os5+8
publicList getItems(){ R-BN}ZS
return items; m)xz_Plc
} !;&{Q^}
l|
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publicvoid setItems(List items){ PA${<wyBR_
this.items = items; +C`zI~8
} R"{oj]d;$F
,) 3Eog\-
publicint getPageSize(){ 0d #jiG
return pageSize; EceD\}
} A@
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publicvoid setPageSize(int pageSize){ kwpbg Q
this.pageSize = pageSize; G/_9!lE
} 1(m[L=H5>
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publicint getTotalCount(){ .^!uazPE0
return totalCount; s!j vBy
} a^Lo;kHY
[7=?I.\Cr7
publicvoid setTotalCount(int totalCount){ rPoq~p[Y
if(totalCount > 0){ N5@l[F7I
this.totalCount = totalCount; sFonc
int count = totalCount / <FU1|
=_9grF-
pageSize; 4*_. m9{
if(totalCount % pageSize > 0) $or8z2d1
count++; 9{n?Jy
indexes = newint[count]; |Ht~o(]&&/
for(int i = 0; i < count; i++){ fTV}IP
indexes = pageSize * ?8@EBPpC
kk7M$)>d
i; E'F87P ^>
} H mVpxD+
}else{ 5?C) v}w+
this.totalCount = 0; P#ot$@1v
} sn:wLc/GAd
} >$N ?\\#
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publicint[] getIndexes(){ &s_)|K
return indexes; eR:!1z_h
} "| KD$CY
DzG$\%G2R}
publicvoid setIndexes(int[] indexes){ +p_>fO
this.indexes = indexes; mpDQhD[n
} aA&}=lm
=F90SyzTy
publicint getStartIndex(){ E|omC_h
return startIndex; =&v&qne9
} }#QYZ nR
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publicvoid setStartIndex(int startIndex){ Q%^!j_#
if(totalCount <= 0) .V\:)\<|
this.startIndex = 0; Tq!.M1{&
elseif(startIndex >= totalCount) s_Gf7uC
this.startIndex = indexes jL9to6 Hmr
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[indexes.length - 1]; Y|N.R(sAs&
elseif(startIndex < 0) w2o5+G=
this.startIndex = 0; 2f7]=snCG
else{ zUd{9B$
this.startIndex = indexes zFeo8S
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[startIndex / pageSize]; R7~#7qKQB
} X1~ WQ?ww
} k5]`:k6
5Ak6 q(\
publicint getNextIndex(){ KeE)9e
int nextIndex = getStartIndex() + Y@R9+7!
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pageSize; =@0/.oSD
if(nextIndex >= totalCount) qr_:zXsob_
return getStartIndex(); 'AJlkLqm#>
else .z&,d&E
return nextIndex; <B3$ODGJp
} ?9m@ S#@
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publicint getPreviousIndex(){ $WHmG!)*
int previousIndex = getStartIndex() - B0eKj=y;
qB44;!(
pageSize; 8:)itYE
if(previousIndex < 0) eJtfQ@?
return0; (b>B6W\&
else x#,nR]C
return previousIndex; "qv J-Y
} W<s5rM x
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} Q=Y1kcTOn
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?wYvBFRn7"
抽象业务类 K1*]6x,
java代码: 3lD1G~
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/** ^TCgSi7k`L
* Created on 2005-7-12 qJPEq%'Q
*/ w.6 Gp;O
package com.javaeye.common.business; %q)*8
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import java.io.Serializable; a2\r^fY/
import java.util.List; 52>,JHq
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import org.hibernate.Criteria; yi$ Jk}w
import org.hibernate.HibernateException; ohj(1jt
import org.hibernate.Session; |B/A)(c
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import org.hibernate.criterion.DetachedCriteria; AEr8^6
import org.hibernate.criterion.Projections; !$5.\D
import F F7
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org.springframework.orm.hibernate3.HibernateCallback; !<I3^q
import rLzN#Zoi
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org.springframework.orm.hibernate3.support.HibernateDaoS '2BE"e
( 17=|s
upport; {#X]D~;s+
.|Zt&5osI
import com.javaeye.common.util.PaginationSupport; A,'JmF$d
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public abstract class AbstractManager extends 1hnw+T<<W
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HibernateDaoSupport { 3iC$ "9!p
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privateboolean cacheQueries = false; i`)h~V|G
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privateString queryCacheRegion; r^,XpRe&M
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publicvoid setCacheQueries(boolean BqA
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cacheQueries){ Gcz@z1a=n
this.cacheQueries = cacheQueries; 4OOH
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} pk,]yi,ZF
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publicvoid setQueryCacheRegion(String GIGC,zP@k
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queryCacheRegion){
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this.queryCacheRegion = bO2s'!x
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queryCacheRegion; S_ Pa .
} hwR_<'!
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publicvoid save(finalObject entity){
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getHibernateTemplate().save(entity); a.O pxd
} p^uX{!
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publicvoid persist(finalObject entity){ jR[3{ Reo
getHibernateTemplate().save(entity); :s5wFumD
} tUPdq 0%t[
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publicvoid update(finalObject entity){ +>uiI4g
getHibernateTemplate().update(entity); 2GRdfX
} +.u)\'r;h
Z+G.v=2q<
publicvoid delete(finalObject entity){ &+v!mw >
getHibernateTemplate().delete(entity); Z:2a_Atm
} BD(Y=g
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publicObject load(finalClass entity, dvl'Sq<
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finalSerializable id){ [_pw|BGp
return getHibernateTemplate().load Wu!s
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(entity, id); n8dJ6"L<"
} i6@c@n
qP}187Q1
publicObject get(finalClass entity, UHh7x%$n
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finalSerializable id){ AJ0
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return getHibernateTemplate().get hN3*]s;/6z
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(entity, id); `3C dW
} UbnX%2TW
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publicList findAll(finalClass entity){ Z@G[\"
return getHibernateTemplate().find("from H>qw@JiO!
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" + entity.getName()); 7l~d_<h
} \pVmSac,
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publicList findByNamedQuery(finalString P,}cH;w6Ck
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namedQuery){ 5>e#SW
return getHibernateTemplate DQ86(4e*g#
,_N+t:*#0
().findByNamedQuery(namedQuery); pmIOV~K
} $:i%\7=
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publicList findByNamedQuery(finalString query, Q/[g|"
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finalObject parameter){ ?m(]@6qa
return getHibernateTemplate PXRkK63
a
At<36{?
().findByNamedQuery(query, parameter); )#H&lH
} T.}wcQf&*
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publicList findByNamedQuery(finalString query, UBm L:Qv
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finalObject[] parameters){ !'jZ
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return getHibernateTemplate Xj Rk1~
+~x'1*A_
().findByNamedQuery(query, parameters); %lbDcEsf9
} A%[BCY_
g"dq;H
publicList find(finalString query){ hp$/O4fD
return getHibernateTemplate().find .yF@Ow
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(query); zarxv|
}$
} BWWO=N
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publicList find(finalString query, finalObject v/m} {&K
)9]DJ!]&Q"
parameter){ .S{FEV
return getHibernateTemplate().find l
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QH d^?H*
(query, parameter); GI[TD?s
} O?=YY@j
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public PaginationSupport findPageByCriteria O)jpnNz
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(final DetachedCriteria detachedCriteria){ X9-WU\?UC
return findPageByCriteria
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); nZbINhls
} W0 n?S
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public PaginationSupport findPageByCriteria V`WSZ
y v58~w*"
(final DetachedCriteria detachedCriteria, finalint I,lX;~xb
@7? O#WmL
startIndex){ Xt.ca,`U
return findPageByCriteria #hZ`r5GvTj
E-`3}"{
(detachedCriteria, PaginationSupport.PAGESIZE, p=jpk@RX
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startIndex); li37*
} s?5vJ:M
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public PaginationSupport findPageByCriteria Ct<]('Hm(
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(final DetachedCriteria detachedCriteria, finalint
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pageSize, WR<?_X_
finalint startIndex){ ?]AF?
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return(PaginationSupport) gr^TL1(
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getHibernateTemplate().execute(new HibernateCallback(){ `w_%HVw>"
publicObject doInHibernate &Yklf?EZ>Q
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(Session session)throws HibernateException { Mgp+#w+,
Criteria criteria = L[cP2X]NQ
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detachedCriteria.getExecutableCriteria(session); rHa*WA;TE
int totalCount = B6 yTD7
11((b
((Integer) criteria.setProjection(Projections.rowCount WbWEgd%8.
}WV}in0
()).uniqueResult()).intValue(); bk=ee7E7>
criteria.setProjection >\o._?xSA
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In\,x
(null); ;I/ A8<C
List items = i,B<k 0W9
{ew;
/;
criteria.setFirstResult(startIndex).setMaxResults 4o<rj4G>
#I"s{*
(pageSize).list(); [0n[ \&
0
PaginationSupport ps = jcbq#
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new PaginationSupport(items, totalCount, pageSize, 5~[m]
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startIndex); TYKs2+S6
return ps; 9Wv}g"KY0
} q|g>;_
}, true); 8CUlE-R5
} bP Q=88*
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public List findAllByCriteria(final ^~;"$=Wf
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DetachedCriteria detachedCriteria){ Ii&\LJ
return(List) getHibernateTemplate Z0[d;m*
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().execute(new HibernateCallback(){ ueyQ&+6r
publicObject doInHibernate ntntB{t
,
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(Session session)throws HibernateException { !<3!ORFO
Criteria criteria = 0Lf4^9N
RKPX*(i~
detachedCriteria.getExecutableCriteria(session); U38~m}c
return criteria.list(); :Y Ki
} !pZ<{|cH
}, true); b]gVZ-
} RcC5_@W
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public int getCountByCriteria(final hXh nJ
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DetachedCriteria detachedCriteria){ 4a=QTq0p
Integer count = (Integer) aka)#0l .
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getHibernateTemplate().execute(new HibernateCallback(){ Xp.$FJ1)
publicObject doInHibernate w{*PZb4
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(Session session)throws HibernateException { E&N~h|CL
Criteria criteria = 9:P\)'y?
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detachedCriteria.getExecutableCriteria(session); MD^,"!A
return 5eiKMKW[
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criteria.setProjection(Projections.rowCount N8iLI`
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()).uniqueResult(); a4[t3U
} Q5b9q$L$
}, true); >xXC=z+g]
return count.intValue(); KM+[1Ze$
} Z(t7QFd
} !FwNq'Q8$
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& 'CUc/,
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用户在web层构造查询条件detachedCriteria,和可选的 uM\5GK
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 {_mVfFG
G
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PaginationSupport的实例ps。 gyb99c,)
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ps.getItems()得到已分页好的结果集 d_Jj&:"l
ps.getIndexes()得到分页索引的数组 "BVp37m;?
ps.getTotalCount()得到总结果数 ve+bR
ps.getStartIndex()当前分页索引 zW\s{
ps.getNextIndex()下一页索引 fTso[r:F.
ps.getPreviousIndex()上一页索引 mPhu#oK'f
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ps;d bY*s6
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 $
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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 YS#*#!ZMn?
)Gm9x]SVl
一下代码重构了。 BA2J dU
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我把原本我的做法也提供出来供大家讨论吧: d@ >i=l [
1Au+X3
首先,为了实现分页查询,我封装了一个Page类: Xo:Mar
java代码: 2e-`V5{)b
x0b=r!Duu
zO---}[9a
/*Created on 2005-4-14*/ h5rR44
package org.flyware.util.page; BN `2UVH
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/** r^a:s]
* @author Joa T-#4hY`
* `/Rqt+C
*/ ,/%'""`w
publicclass Page { <=V{tl
`KN>0R2k
/** imply if the page has previous page */ O5aXa_A_u
privateboolean hasPrePage; @gfW*PNjlP
lKB9n}P
/** imply if the page has next page */ X i1|%
privateboolean hasNextPage; `IEA
haY]gmC
/** the number of every page */ _-lE$
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privateint everyPage; =kfa1kD&{
)|v y}Jf7
/** the total page number */ s[sv4hq
privateint totalPage; 14"57Jt8
J
jm={+@+
/** the number of current page */ eZ+6U`^t
privateint currentPage; .>eR X%
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/** the begin index of the records by the current P1Z"}Qw
/OWwC%tM/
query */ xnt) 1Q
privateint beginIndex; ;Y[D#Ja-
^~.AV]t|
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/** The default constructor */ [{Jo(X
public Page(){ :-5[0Mx=
/IG{j}
} ROmmak(y8
-2; 6Pwmv
/** construct the page by everyPage 6^WNwe\
* @param everyPage bY2R/FNL=
* */ 3i7EF.
public Page(int everyPage){ w;gk=<_
this.everyPage = everyPage; tc0;Ake-&
} q~b# ml2QS
uE41"?GS
/** The whole constructor */ In^mE(8YO
public Page(boolean hasPrePage, boolean hasNextPage, >7PQOQMW'
MzX&|wimb
=T,Q7Dh
int everyPage, int totalPage, 9-/q-,
int currentPage, int beginIndex){ aTTkj\4
this.hasPrePage = hasPrePage; RARA _tii
this.hasNextPage = hasNextPage; 50QDqC-]XS
this.everyPage = everyPage; ,puoq{
this.totalPage = totalPage; 5, ,~k=
this.currentPage = currentPage; |y[I!JdR
this.beginIndex = beginIndex; V:GypY)
} v>#Njgo
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/** fJ[ ^_,O
* @return m~5 unB9
* Returns the beginIndex. Cd_@<
*/ Ai1"UYk\\Y
publicint getBeginIndex(){ 9gcW;
return beginIndex; XZb=;tYo
} o6px1C:
@T~XwJ~
/** dazNwn
* @param beginIndex
LNWS
* The beginIndex to set. "t&=~eOe3
*/ -0d9,,c
publicvoid setBeginIndex(int beginIndex){ eO <N/?t
this.beginIndex = beginIndex; 'EiCTl
} L@{'J
s|e.mZk/
/** ud r\\5
* @return Yi%lWbr
* Returns the currentPage. (|K+1R
*/ nsRCDUCi
publicint getCurrentPage(){ oI{.{]
return currentPage; =|]h-[P'
} 5[jcw`
.oyAi||
/** T0tX%_6`
* @param currentPage Y2x|6{ #
* The currentPage to set. Gu*y7I8
*/ z3uR1vF'
publicvoid setCurrentPage(int currentPage){ S-S%IdL
this.currentPage = currentPage; C P}fxDW
} A7Ql%$v7^
ICN>kJ\;M
/** q*UHzE:LI
* @return bW6| &P}X
* Returns the everyPage. ~i"=:D
*/ F<,pAxl~@
publicint getEveryPage(){ *~)6 sm
return everyPage; T;92M}\
} uaF-3
oZiW4z*Wh
/** k~8-Eu1
* @param everyPage ik(Du/
* The everyPage to set. /P*XB%y
*/ t2o{=!$WH
publicvoid setEveryPage(int everyPage){ Oj c Tu
this.everyPage = everyPage; Vc(4d-d5
} gB'ajX=OA/
y''~j<'
/** ayA;6Qt
* @return w0_P9g:
* Returns the hasNextPage. V1]GOmXz
*/ B?z2@,
publicboolean getHasNextPage(){ 1?Y>Xz
return hasNextPage; O JcS%-~
} /aI@2] |~
yjjq&Cn
/** .7.lr[$g
* @param hasNextPage .t_t)'L
* The hasNextPage to set. 5G`HJ6
*/ hI:.Qp`r
publicvoid setHasNextPage(boolean hasNextPage){ ']1n?K=A
this.hasNextPage = hasNextPage; IE`3I#v
} ]3O&8,
/*qRbN
/** Mk}T
* @return 7
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* Returns the hasPrePage. _"1RidhH
*/ [<#jK}g
publicboolean getHasPrePage(){ ='h2z"}\Bn
return hasPrePage; NfvPE ]S
} !q2zuxq!R
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/** Q/S ^-&~
* @param hasPrePage -{\(s=%
* The hasPrePage to set. #%"G[B
*/ Zk=,`sBC
publicvoid setHasPrePage(boolean hasPrePage){ iwK.*07+
this.hasPrePage = hasPrePage; <gF]9%2E
} k_7m[o
;7P'>j1?U
/** )dkU4]
* @return Returns the totalPage. #dZs[R7h
* 1C<cwd;9
*/ CeYhn\m5K0
publicint getTotalPage(){ 4-yK!LR
return totalPage; CVfV
} e34>q:#5l
:0r,.)
/** /f#b;qa,
* @param totalPage OIP]9lM$nC
* The totalPage to set. A<+Dx
*/ 2`4m"D tA
publicvoid setTotalPage(int totalPage){ eN=jWUoCh
this.totalPage = totalPage; 3YvKHn|V"
} ~m6=s~Vn
gK rUv0&F
} = QBvU)Ki
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 .TGw+E1k
(DiduSJ
个PageUtil,负责对Page对象进行构造: ?@'&<o0p#
java代码: 4CM'I~
RCWmdR#}V
RNk|h
/*Created on 2005-4-14*/ >jI.$%L$
package org.flyware.util.page; |n26[=\B
VRd7H.f,A6
import org.apache.commons.logging.Log; sSW'SE?,<
import org.apache.commons.logging.LogFactory; 17s~mqy
1@|+l!rYF
/** j.q}OK
* @author Joa 3uuIISK
* m{Q
#f\<
*/ ;xwcK-A
publicclass PageUtil { $XF$ n#ua
PT~htG<Fw
privatestaticfinal Log logger = LogFactory.getLog pkn^K+<n,
HA,o2jZ?In
(PageUtil.class); ~XOmxz0
v #+ECx
/** tAv3+
* Use the origin page to create a new page I\mF dE
* @param page QC+
Z6WS;
* @param totalRecords &r1(1<
* @return ,CqWm9
*/ "`% ,l|D
publicstatic Page createPage(Page page, int [M\ an6h6O
3x[Cpg,
totalRecords){ \BnU?z
return createPage(page.getEveryPage(), :c/54Ss~
uBlPwb,V
page.getCurrentPage(), totalRecords);
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} G8av5zR
2{=]Pf
/** ]E/0iM5
* the basic page utils not including exception =%W:N|k
&aRL}#U
handler 0ID9=:J
* @param everyPage Z*k(Q5&U
* @param currentPage 4}H+hk8-
* @param totalRecords V%8(zt
* @return page njs:
*/ dxX`\{E
publicstatic Page createPage(int everyPage, int wK(]E%\
V9) /
currentPage, int totalRecords){ gcA:Q4
everyPage = getEveryPage(everyPage); `]KX`xGK
currentPage = getCurrentPage(currentPage); -pC'C%Q
int beginIndex = getBeginIndex(everyPage,
|3]/CrR_
eAlOMSL\
currentPage); \;&;K'
int totalPage = getTotalPage(everyPage, &E&~9"^hQL
Pe@#6N`
totalRecords); Y9^l|,bm5
boolean hasNextPage = hasNextPage(currentPage, &s".hP6
zH]oAu=H
totalPage); e0P[,e*0
boolean hasPrePage = hasPrePage(currentPage); q/b+V)V
IhNX~Jg'^
returnnew Page(hasPrePage, hasNextPage, K%J?'-
everyPage, totalPage, -.h)CM@L
currentPage, vD#U+
(=!At)O
beginIndex); l eC!Yj
} R/~!km
vfkF@^D
privatestaticint getEveryPage(int everyPage){ 2d.$V,U<
return everyPage == 0 ? 10 : everyPage; *Ypn@YpSp
} "
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( cs
privatestaticint getCurrentPage(int currentPage){ I-R7+o
return currentPage == 0 ? 1 : currentPage;
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} M@.l#
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privatestaticint getBeginIndex(int everyPage, int :+"4_f0
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currentPage){ l2LQV]l
return(currentPage - 1) * everyPage; $)#orZtzr
} x$d[Ovw-
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privatestaticint getTotalPage(int everyPage, int n#P>E(K
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totalRecords){ t<v.rb
int totalPage = 0; .)
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if(totalRecords % everyPage == 0) A]bQUWt2
totalPage = totalRecords / everyPage; dEk#"cvg
else ;U'\"N9
totalPage = totalRecords / everyPage + 1 ; 4;YP\{u
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return totalPage; 2_wpj;E
} J@-'IJ
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privatestaticboolean hasPrePage(int currentPage){ 77M!2S_E
return currentPage == 1 ? false : true; 2'fd4rE5
} qraXAQ
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privatestaticboolean hasNextPage(int currentPage, LaJvPOQ
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int totalPage){ V48_aL
return currentPage == totalPage || totalPage == ?$/::uo
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0 ? false : true; ZjxF@`H
} jemb/:E
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} #mU\8M,
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 WXxnOLJr
2Z{?3mAb;
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 4XAB_Q
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做法如下: C|]c#X2t3
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 VrW]|jIu*
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的信息,和一个结果集List: Cj>HMB}
java代码: Zz} o t
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/*Created on 2005-6-13*/ q_[y|ETJ]
package com.adt.bo; ]+e
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import java.util.List; 5J`w8[;
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import org.flyware.util.page.Page; '
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/** )cH\i91
* @author Joa O]XRalkEM
*/ 7Q!ksp
publicclass Result { [7><^?t
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private Page page; #f(a,,Uu'
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private List content; BQfnoF
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/** L!JC)p.
* The default constructor ;.jj>1=Tnl
*/ R_j.k3r4d
public Result(){ yM 7{v$X0
super(); L$Z!
} Nd( I RsH(
UI=v|<'-
/** _7N?R0j^9N
* The constructor using fields {U-z(0
* UovN"8W+
* @param page T4W20dxL7
* @param content NzZ(Nz5
*/ p{oz}}
public Result(Page page, List content){ pq0Z<b;2
this.page = page; iU+SXsXLR4
this.content = content; ir'<H<t2
} &7'=t6
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/** FqJd
* @return Returns the content. qVU<jt
*/ O\7x+^.
publicList getContent(){ Q7u|^Gu,5
return content; #c:@oe4v
} =H7p&DhD