Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Q*hXFayx
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ;Z9(ll:<$
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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 J$U_/b.mk
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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 KE6XNG3
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分页支持类: c#f@v45
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java代码: $*:g~#bh
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package com.javaeye.common.util; e{H(
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import java.util.List; uu.}<VM.1
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publicclass PaginationSupport { sDY+J(Z
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publicfinalstaticint PAGESIZE = 30; z+{xW7
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privateint pageSize = PAGESIZE; gT(8.<h8
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privateList items; iuA_Jr
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privateint totalCount; K
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privateint[] indexes = newint[0]; Q/q>mN"#1
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privateint startIndex = 0; .K]Uk/W
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public PaginationSupport(List items, int E
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totalCount){ \8g=
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setPageSize(PAGESIZE); W4bN']?
setTotalCount(totalCount); ;E,i
setItems(items); *
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setStartIndex(0); gWL`J=DiU
} :G#+5 }
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public PaginationSupport(List items, int
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totalCount, int startIndex){ &KY!a0s
setPageSize(PAGESIZE); a;v4R[lQ
setTotalCount(totalCount); ;!C_}P
setItems(items); +&dkJ 4g[
setStartIndex(startIndex); {5fL!`6w
} O~v~s
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public PaginationSupport(List items, int %P{3c~?DH
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totalCount, int pageSize, int startIndex){ S{3c}>n
setPageSize(pageSize); J"Fp),
setTotalCount(totalCount); 7<Qmpcp =
setItems(items); Yep~C%/}
setStartIndex(startIndex); hzU(XW
} ExMd$`gW
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publicList getItems(){ T|0+o+i
return items; ]1pB7XL
} 1w,34*- }
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publicvoid setItems(List items){ t-5Y,}j
this.items = items; D1$ER>
} ~L>86/hP,N
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publicint getPageSize(){ >t<\zC|~w
return pageSize; r6R@"1/
} m;A[2 6X
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publicvoid setPageSize(int pageSize){ E N CWOj
this.pageSize = pageSize; AWE ab
} awI{%u_(nA
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publicint getTotalCount(){ 8O$LY\G
return totalCount; 3m9b
} L|}s Z\2!
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publicvoid setTotalCount(int totalCount){ V#b=mp
if(totalCount > 0){ @OGG]0
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this.totalCount = totalCount; fUGappb
int count = totalCount / YaL:6[6
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pageSize; (Q @'fb9z
if(totalCount % pageSize > 0) x$bUd 9
count++; r/HCWs|
indexes = newint[count]; 7(oA(l1V
for(int i = 0; i < count; i++){ `R>z{-@=
indexes = pageSize * TVx
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i; {~uTi>U
} d=n{Wn{C
}else{ b$%Kv(
this.totalCount = 0; M0~%[nX
} W&:0J
} F>3 o0ke}
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publicint[] getIndexes(){ E1tCY.N{
return indexes; T1*.3_wtP
} k].swvIi
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publicvoid setIndexes(int[] indexes){ 2%L`b"9}V
this.indexes = indexes; >;'0ymG.`
} 9cUa@;*1
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publicint getStartIndex(){ |Tc4a4 jS
return startIndex; Nh_\{
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} >*VvV/UU
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publicvoid setStartIndex(int startIndex){ >X
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if(totalCount <= 0) ,ofE*Wt
this.startIndex = 0; 'vZIAnB8
elseif(startIndex >= totalCount) DyCzRkH
this.startIndex = indexes R y#C#0
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[indexes.length - 1]; 86N,04
elseif(startIndex < 0) fZ5 UFq_~s
this.startIndex = 0; 83SK<V6
else{ IQ~qiFCf
this.startIndex = indexes 9#@s(s
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[startIndex / pageSize]; u~j
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} R:YVmqd
} %),u0:go
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publicint getNextIndex(){ lTP#6zqfv
int nextIndex = getStartIndex() + Xd5s8C/}
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pageSize; t@9-LYbL
if(nextIndex >= totalCount)
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return getStartIndex(); Y`(Ri-U4
else 77yYdil^W+
return nextIndex; iiMS3ueF
} bTmhz
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publicint getPreviousIndex(){ n#b{
int previousIndex = getStartIndex() - Wp8>Gfb2
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pageSize; !ess.U&m'
if(previousIndex < 0) f"P866@oWn
return0; ?o?$HK
else D@gC(&U/6
return previousIndex; ~M-L+XZl(
} 3&7? eO7*
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} &C+2p
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抽象业务类 69)"T{7
java代码: xZ P
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/** yzp#
* Created on 2005-7-12 r8:"\%"f>
*/ #f24a?n|
package com.javaeye.common.business; v$Fz^<Na
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import java.io.Serializable; K+!e1
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import java.util.List; 4Ii5V
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import org.hibernate.Criteria; _Ffg"xoC
import org.hibernate.HibernateException; "WQ6[;&V
import org.hibernate.Session; >pLJ ,Z
import org.hibernate.criterion.DetachedCriteria; /~w*)e)
import org.hibernate.criterion.Projections; r^}0qO,XM
import B
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org.springframework.orm.hibernate3.HibernateCallback; {%u^O/M
import j67ppt
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org.springframework.orm.hibernate3.support.HibernateDaoS 5)T[ha77u
c, .@Cc2
upport; G6zFQ\&f
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import com.javaeye.common.util.PaginationSupport; (LmU\ Pe%
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public abstract class AbstractManager extends mI,lW|/l,
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HibernateDaoSupport { zgEN2d
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privateboolean cacheQueries = false; AZc=Bbh
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privateString queryCacheRegion; EA>.SSs!
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publicvoid setCacheQueries(boolean C{85#`z`
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cacheQueries){ Vf pT5W<
this.cacheQueries = cacheQueries; ydYsmTr
} r/'!#7dLG-
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publicvoid setQueryCacheRegion(String ~k"b"+2
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queryCacheRegion){ 7Qd$@ m
this.queryCacheRegion = xH:L6K/c
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queryCacheRegion; ]VKQm(,0
} A)"L+Yu5
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publicvoid save(finalObject entity){ s=(q#Z
getHibernateTemplate().save(entity); HL4=P,'
} PB$beQ
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publicvoid persist(finalObject entity){ jOzXy Dq
getHibernateTemplate().save(entity); x;yvv3-$
} L5I!YP#v
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publicvoid update(finalObject entity){ 0}NDi|o
getHibernateTemplate().update(entity); 4;Ucas6
} _-y1>{]H
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publicvoid delete(finalObject entity){ SXqB<j$.;
getHibernateTemplate().delete(entity); /i>n1>~yn
} V /2NIh
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publicObject load(finalClass entity, CdRJ@Lf
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finalSerializable id){ 6WZffB{-TK
return getHibernateTemplate().load \f^xlX3&`
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;
(entity, id); &mVClq
} e`g+Jf`AT
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publicObject get(finalClass entity, u:|^L]{
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finalSerializable id){ $+GDPYm'
return getHibernateTemplate().get }wiyEVAh{
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(entity, id); 8b'@_s!_
} \DujF>:
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publicList findAll(finalClass entity){ tNr'@ls
return getHibernateTemplate().find("from bI:W4y>I=
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" + entity.getName()); |3e+ K.
} v2rO>NY4
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publicList findByNamedQuery(finalString <{k{Coy
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namedQuery){ \h=*pAf
return getHibernateTemplate \OkZ\!<hg
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().findByNamedQuery(namedQuery); <">epbV6
} C3W4:kbau
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publicList findByNamedQuery(finalString query, M;y*`<x
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finalObject parameter){ Up?RN %gq
return getHibernateTemplate <!>\
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().findByNamedQuery(query, parameter); P#V!hfM
} G1jj:]1
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publicList findByNamedQuery(finalString query, 46NuT]6/4
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finalObject[] parameters){ hJ xL|5Uo
return getHibernateTemplate MwRLv,&"
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().findByNamedQuery(query, parameters); RN-gZ{AW
} .8s-)I
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publicList find(finalString query){ %f&Y=
return getHibernateTemplate().find YOLzCnI4
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(query); [5L?#Y
} C `_/aR6
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publicList find(finalString query, finalObject Hh;lT
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parameter){ *tj(,:!
return getHibernateTemplate().find >R]M:Wx
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(query, parameter); 4@fv%LOQo
} .%n_{ab1
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public PaginationSupport findPageByCriteria #<[&Lw
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(final DetachedCriteria detachedCriteria){ ^7+;XUyg
return findPageByCriteria fdKE1,;
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); EP@u4F
} ![K\)7 iKo
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public PaginationSupport findPageByCriteria QG?!XWz
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(final DetachedCriteria detachedCriteria, finalint lFt!
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startIndex){
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return findPageByCriteria 0yC~"u[N Y
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(detachedCriteria, PaginationSupport.PAGESIZE, a~jb%i_
)M0(vog
startIndex); Q/?`);
} R
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public PaginationSupport findPageByCriteria 1ygEyC[1
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(final DetachedCriteria detachedCriteria, finalint BH {z]a
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pageSize, 'qT;Eht5
finalint startIndex){ 5&Yt=)c\
return(PaginationSupport) zs]ubJC@
>&;J/ME
getHibernateTemplate().execute(new HibernateCallback(){ J@/4CSCR]
publicObject doInHibernate xwZ1Q,'C
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(Session session)throws HibernateException { 18NnXqe-m
Criteria criteria = ")MHP~ ?
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detachedCriteria.getExecutableCriteria(session); 95#]6*#[4!
int totalCount = J8S$YRZ_
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((Integer) criteria.setProjection(Projections.rowCount >xo<i8<Miv
1 jB0gNe
()).uniqueResult()).intValue(); dj(&"P
criteria.setProjection VC/n}7p
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(null); 4dFr~ {
List items = {2:baoG-
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criteria.setFirstResult(startIndex).setMaxResults QEqYqAGzu|
Mu`_^gG
(pageSize).list(); TM6wjHFm
PaginationSupport ps = /~'C!so[v
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new PaginationSupport(items, totalCount, pageSize, +I5\`By=
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startIndex); ]'xci"qV`
return ps; gBV4IQ
} S\N l|U[
}, true); " J9
} BN]o!Y
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public List findAllByCriteria(final f3!Oc
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DetachedCriteria detachedCriteria){ N~/X.D4e#
return(List) getHibernateTemplate rR@]`@9
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().execute(new HibernateCallback(){ ?@@$)2_*u
publicObject doInHibernate }Y!V3s1bm
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(Session session)throws HibernateException { )wjpxr
Criteria criteria = i695P}J2
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detachedCriteria.getExecutableCriteria(session); mr}o0@5av
return criteria.list(); WDxcV%
} vT{(7m!Ra
}, true); no-";{c
} XHJdynt/
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public int getCountByCriteria(final e}2?)B`[
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DetachedCriteria detachedCriteria){ N:3=G`Ws
Integer count = (Integer) Pn^:cr|
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getHibernateTemplate().execute(new HibernateCallback(){ *%jXjTA0D
publicObject doInHibernate U>!TM##1QD
k8ILo)
(Session session)throws HibernateException { aoW2 c1`?Z
Criteria criteria = 3"Oipt+
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detachedCriteria.getExecutableCriteria(session); R-pON4D"*
return 1d49&-N
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criteria.setProjection(Projections.rowCount zZ-/S~l
aO1.9!<v
()).uniqueResult(); /xgC`]-
} Vr1r2G2
}, true); bl!pKOY
return count.intValue(); 4IZAJqw(*
} E^n!h06~G
} @dK_w'W
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用户在web层构造查询条件detachedCriteria,和可选的 :f Rta[
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 #"A`:bjG
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PaginationSupport的实例ps。 .mrv"k\<
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ps.getItems()得到已分页好的结果集 > Q=e9L=
ps.getIndexes()得到分页索引的数组 n>JJ Xw,,
ps.getTotalCount()得到总结果数 hH>a{7V
ps.getStartIndex()当前分页索引 kygj" @EX
ps.getNextIndex()下一页索引 T@vE@D
ps.getPreviousIndex()上一页索引 B7C<;`5TiD
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^WWr8-
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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 >9nVR
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一下代码重构了。 ~g[D!HV|yu
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我把原本我的做法也提供出来供大家讨论吧: `TF3Ho\MC
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首先,为了实现分页查询,我封装了一个Page类: sDgo G
java代码: ec^{ez@`
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/*Created on 2005-4-14*/ s!gVY!0
package org.flyware.util.page; F_@`
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/** cc=_KYZ1k
* @author Joa Pt-mLINvG
* :k_)Bh?+
*/ #Z]Cq0=
publicclass Page { )=glN<*?
?:GrM!kq76
/** imply if the page has previous page */ {1UU `d
privateboolean hasPrePage; [xfg6
M4?>x[Pw
/** imply if the page has next page */ nRq[il0 `i
privateboolean hasNextPage; #.]W>hN8\
x=K'Jj
/** the number of every page */ a]V#mF |{
privateint everyPage; ]EN&EA"<
5't9/8i
/** the total page number */ k<fR)o
privateint totalPage; t,w/L*r+w
v8uUv%Hkd
/** the number of current page */ !f!YMpN
privateint currentPage; ]*$o qn=m
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/** the begin index of the records by the current gi:M=
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query */ e=jtF"&
privateint beginIndex; qoph#\
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/** The default constructor */ 9*"K+t:
public Page(){ Q.8^F
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} |Cfo(]>G
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/** construct the page by everyPage HF&dHD2f
* @param everyPage i)'u!V
* */ (Ze\<Y#cv
public Page(int everyPage){ `"~ X1;
this.everyPage = everyPage; Zia6m[ ^Q
} ex|)3|J
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/** The whole constructor */ v+C D{Tc
public Page(boolean hasPrePage, boolean hasNextPage, ~d3BVKP5
e \kR/<L
&&}c R:U,
int everyPage, int totalPage, )OlYz!#?
int currentPage, int beginIndex){ ;%>X+/.y0
this.hasPrePage = hasPrePage; %74f6\
this.hasNextPage = hasNextPage; ]/R>nT
this.everyPage = everyPage; q{yzux
this.totalPage = totalPage; >X>]QMfh
this.currentPage = currentPage; @X/-p3729
this.beginIndex = beginIndex; [ifQLsHA
} OWN|W,
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/** A}"uEk(R
* @return oY@]&A^ah
* Returns the beginIndex. m1 p%,
*/ hB:+_[=Kj.
publicint getBeginIndex(){ K^I$05idi
return beginIndex; )gR3S%Ju
} [h\_yU[P
7vH4}S\
q
/** 2NL|_W/
* @param beginIndex ;ov}%t>UD
* The beginIndex to set. DEv,!8
*/ _B ]Bd@<w
publicvoid setBeginIndex(int beginIndex){ 3
}rx(
this.beginIndex = beginIndex; ,.gI'YPQC
} 4x/u$Ixzh=
H/G;hk
/** 3bugVJ93
* @return i)ibDrX!I
* Returns the currentPage. J2`OJsMwWe
*/ +A_jm!tJS(
publicint getCurrentPage(){ 1@<>GDB9
return currentPage; B7'2@+(
} *EtC4sP
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/** aUBu"P$J
* @param currentPage OBP iLCq
* The currentPage to set. twTRw:.!f
*/ 5bWy=Xk
B
publicvoid setCurrentPage(int currentPage){ {\=NZ\
this.currentPage = currentPage; XoiZ"zE
} nm,Tng
oj
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^
/** afcyAzIB&
* @return 1Imb"E
* Returns the everyPage. 0*u X2*
*/ JDMsco+j5
publicint getEveryPage(){ Od]wh
return everyPage; sy9Yd PPE
} Y9(BxDP_+Y
Yr:$)ap
/** piiO5fK|
* @param everyPage _lk5\bu
* The everyPage to set. |VoYFoiQ
*/ Qc:Sf46O
publicvoid setEveryPage(int everyPage){ a@gm r%C
this.everyPage = everyPage; RKz _GEH)
} y|D-W>0cX3
C_hIPMU=
/** odq3@
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* @return l_=kW!l
* Returns the hasNextPage. gem+$TFq
*/ n<sA?T
publicboolean getHasNextPage(){ h1?.x
return hasNextPage; rg+3pX\{
} ]h&?^L<.
z: W1(/W~
/** ~leLQsZ
* @param hasNextPage ;W#/;C
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* The hasNextPage to set. '#8;bU
*/ AzBpQb*
publicvoid setHasNextPage(boolean hasNextPage){ c6pGy%T-
this.hasNextPage = hasNextPage; }(if|skau
} E{|n\|
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/** P~*v}A
* @return V -9z{
* Returns the hasPrePage.
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*/ /K#J63 ,
publicboolean getHasPrePage(){ :!g zx n
return hasPrePage; t~]oJ5%
} e%DF9}M
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/** d`Em)3v
* @param hasPrePage b(gcnSzM2
* The hasPrePage to set. m-!z(vcn
*/ ]r1C
publicvoid setHasPrePage(boolean hasPrePage){ 2$%0~Z5
this.hasPrePage = hasPrePage; \~q cYp
} o!t1EPJE*
vui{["
/** wZUR
* @return Returns the totalPage. 3H47 vm(`
* m4@w M?
*/ &($Zs'X
publicint getTotalPage(){ ('pxX+
return totalPage; pDx}~IB
} z'}?mE3i
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/** Aonq;} V e
* @param totalPage
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* The totalPage to set. ud.Bzg:/
*/ 1&}^{ Ys
publicvoid setTotalPage(int totalPage){ V5ihplAk
this.totalPage = totalPage; h?:Y\DlU'
} pNzGpCk
DK;/eZe
} 0CO6-&F9n
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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 EMejvPnZO
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个PageUtil,负责对Page对象进行构造: P X<,/6g z
java代码: Mky8qVQ2
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5Gsj;
/*Created on 2005-4-14*/ { n%U2LVL
package org.flyware.util.page; f?C !Br}
Q-N.23\1
import org.apache.commons.logging.Log;
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import org.apache.commons.logging.LogFactory; YB} _zuZ4&
Pjff%r^
/** t`mLZ
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* @author Joa T{lJ[M
* rzqUI*4%
*/ Z;mDMvIu (
publicclass PageUtil { ZvO:!u0+"
uQ.VW/>
privatestaticfinal Log logger = LogFactory.getLog BPd]L=,/
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zv
(PageUtil.class); Fk,3th
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/** T;< >"" T
* Use the origin page to create a new page 93(
* @param page }a_: oR
* @param totalRecords m"vV=6m|\
* @return t(MlZ>H
*/ 0,;FiOp
publicstatic Page createPage(Page page, int jr:LLn#}
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totalRecords){ .9g\WH#qD|
return createPage(page.getEveryPage(), c~|/,FZU'
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page.getCurrentPage(), totalRecords); &[KFCn
} -}juj;IVv
GO wd=]e
/** S["
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* the basic page utils not including exception i9)y|
\9/n~/{
handler yK&)H+v
* @param everyPage q+o(`N'~G
* @param currentPage MU&5&)m
* @param totalRecords wL 5).`oq
* @return page O'-lBf+<
*/ 1|cmmUM-'v
publicstatic Page createPage(int everyPage, int u-k?ef
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currentPage, int totalRecords){ ~ab"q%
everyPage = getEveryPage(everyPage); oci-[CI,
currentPage = getCurrentPage(currentPage); 9HEc=,D|
int beginIndex = getBeginIndex(everyPage, +V8yv-/{
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currentPage); R4JO)<'K&
int totalPage = getTotalPage(everyPage, l>&)_:\
a4: PufS
totalRecords); *G~c6BZ
boolean hasNextPage = hasNextPage(currentPage, a<gzI
n(f&uV_):
totalPage); a3lo;Cfp
boolean hasPrePage = hasPrePage(currentPage); :({lXGc}4?
p-;]O~^
returnnew Page(hasPrePage, hasNextPage, %e1vq
everyPage, totalPage, x{ZVq 4
currentPage, u X0wg
cdIy[
1
beginIndex); xSOL4
} {@,
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privatestaticint getEveryPage(int everyPage){ $~~=SOd0
return everyPage == 0 ? 10 : everyPage;
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} d=4MqX r
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privatestaticint getCurrentPage(int currentPage){ "|Q&
return currentPage == 0 ? 1 : currentPage; ;LrKXp
} kkOYC?zE?
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privatestaticint getBeginIndex(int everyPage, int w pCS]2
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currentPage){ ?I@3`?'
return(currentPage - 1) * everyPage; wc,y+C#V
} In;z\"NN4
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privatestaticint getTotalPage(int everyPage, int Jc%>=`f
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totalRecords){ !J6s^um
int totalPage = 0; CWN=6(y
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if(totalRecords % everyPage == 0) (wY%$kW4
totalPage = totalRecords / everyPage; gCm?nb)
else 7e=a D~f
totalPage = totalRecords / everyPage + 1 ; \qTn"1bQ
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return totalPage; &'](T9kg=
} Nm081ic2<
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privatestaticboolean hasPrePage(int currentPage){ ckP3[@Su {
return currentPage == 1 ? false : true; ca-n:1
} u('OHPqq
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privatestaticboolean hasNextPage(int currentPage, bA^a@ lv a
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int totalPage){ n `Xz<Q!
return currentPage == totalPage || totalPage == 2E1TJ.[BS
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0 ? false : true; vaxg^n|v9
} G[^G~U\+!
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} IGqmH=-
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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。 &+^
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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 P3
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做法如下: Zn} )&Xt
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 =!c+|X`
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的信息,和一个结果集List: gdZVc9_
java代码: i;xMf5Jz
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/*Created on 2005-6-13*/ SWGa%6|
package com.adt.bo; j`GbI0,bT
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import java.util.List; Q+Fw =Xw
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import org.flyware.util.page.Page; A X#!9-m3
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/** a?MtY
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* @author Joa 2&d&$Jg
*/ W.R'2R#
publicclass Result { Rp|&1nS
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private Page page; o'4@]ae
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private List content; M0e|G.S&_
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/** T??aVe]c
* The default constructor M^f1D&A