Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 kl1Y] ?z}
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .[DthEF
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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 zH=!*[d8
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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 1\dn1Hh
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。 /w]&t\]*
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分页支持类: "0jJh^vk
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java代码: +*&cz
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package com.javaeye.common.util; rZbEvS
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import java.util.List; ">dq0gD
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publicclass PaginationSupport { I~'*$l
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publicfinalstaticint PAGESIZE = 30; &"uV~AM
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privateint pageSize = PAGESIZE; ,]Zp+>{
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privateList items; |0bc$ZY:
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privateint totalCount; BbJkdt7
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privateint[] indexes = newint[0]; %K 4
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privateint startIndex = 0; ZF#Rej?
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public PaginationSupport(List items, int Bk|K%K
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totalCount){ >s*Drf X6
setPageSize(PAGESIZE); <
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setTotalCount(totalCount); Mo|wME#M
setItems(items); v4*rPGv
setStartIndex(0); % U`xu.
} ~3WL)%
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public PaginationSupport(List items, int `GQ{*_-
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totalCount, int startIndex){ 6R}j-1
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setPageSize(PAGESIZE); S+x_c4 T
setTotalCount(totalCount); 3$M3Q]z
setItems(items); 0? Yz]+{C
setStartIndex(startIndex); E\2Ml@J
} 8{&["?
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public PaginationSupport(List items, int ^9"KTZc-*
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totalCount, int pageSize, int startIndex){ Mxz,wfaH>
setPageSize(pageSize); L x|',6S
setTotalCount(totalCount); d-!<C7O}
setItems(items); 8zQfY^/{M
setStartIndex(startIndex); !ZtSbOC '
} V*jsq[q=
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publicList getItems(){ Q]JX`HgPaU
return items; &hZwZgV+3
} B(HT.%r^A
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publicvoid setItems(List items){ t
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this.items = items; &m{'nRU}c
} 8KjRCm,I
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publicint getPageSize(){ ysXx%k
return pageSize; B0mLI%B
} gb-{2p>}
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publicvoid setPageSize(int pageSize){ @Gjny BJ
this.pageSize = pageSize; X,fu!
} A[/I#Im7
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publicint getTotalCount(){ 2z2`
return totalCount; |w)5;uQ&\
} 2wh#$zGy
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publicvoid setTotalCount(int totalCount){ o<VP'F{p
if(totalCount > 0){ !Rw&DFU
this.totalCount = totalCount; 8:g!w:$x
int count = totalCount / -wr(vE,
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pageSize; -Wo15O"
if(totalCount % pageSize > 0) Y_H/3?b%
count++; *{/@uO
indexes = newint[count]; F&@ |M(
for(int i = 0; i < count; i++){ ]A:( L9
indexes = pageSize * K84&sSi
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} f~\Xg7<
}else{ 6M><(1fT
this.totalCount = 0; $-G`&oT
} Lar r}o=
} ^Vo"fI`=C
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publicint[] getIndexes(){ IcoowZZ
return indexes; Q-('5a19J
} n9}RW;N+u
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publicvoid setIndexes(int[] indexes){ H7e /
this.indexes = indexes; ?JqjYI{$
} E$S`6+x`:a
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publicint getStartIndex(){ O~'FR[J
return startIndex; {\We72!
} !t-K<'
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publicvoid setStartIndex(int startIndex){ :EB,{|m
if(totalCount <= 0) dB)[O9K)
this.startIndex = 0; %,? vyY
elseif(startIndex >= totalCount) #<#%>Y^
this.startIndex = indexes ZgF/;8!~V-
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[indexes.length - 1]; 1_3?R}$Wl
elseif(startIndex < 0) .uDM_ 34
this.startIndex = 0; fv==Gu%{
else{ 1P5LH5
this.startIndex = indexes !J#.!}3
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[startIndex / pageSize]; BI/y<6#rR
} ~gt3Omh
} ZLJNw0!=|t
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publicint getNextIndex(){ |cu`f{E2]
int nextIndex = getStartIndex() + oyQ0V94j
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pageSize; M:|/ijpN
if(nextIndex >= totalCount) Yw^ Gti'<
return getStartIndex(); 3]S`|#J
else l\aUresm
return nextIndex; d pn3 (
} .eTk=i[N-
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publicint getPreviousIndex(){ wP`sXPSmIu
int previousIndex = getStartIndex() - coAW9=o}
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pageSize; kH2oK:lN
if(previousIndex < 0) m<FK;
return0; hho%~^bn(
else 4WG=m}X
return previousIndex; (6-y+LG
} 0x#E4v(UA
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} sY^lQN
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抽象业务类 dJE`9$jN
java代码: %yhI;M^
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/** LaT8l?q q
* Created on 2005-7-12 v>:=w|.HC
*/ ?%;B`2 nDR
package com.javaeye.common.business; L5C2ng>
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import java.io.Serializable; o'^phlX
import java.util.List; Z"N(=B
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import org.hibernate.Criteria; id4]|jb
import org.hibernate.HibernateException; qm}\?_
import org.hibernate.Session; 5%'S
import org.hibernate.criterion.DetachedCriteria; V^vLN[8_\
import org.hibernate.criterion.Projections; g
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import z+Z%H#9e
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org.springframework.orm.hibernate3.HibernateCallback;
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import xv&S[=Dt
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org.springframework.orm.hibernate3.support.HibernateDaoS %t{Sb4XZ4k
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upport; xfes_v""
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import com.javaeye.common.util.PaginationSupport; 6d};|#}
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public abstract class AbstractManager extends v*Xk WH5
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HibernateDaoSupport {
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privateboolean cacheQueries = false; K+-z Y[3
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privateString queryCacheRegion; *LEu=3lp%>
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publicvoid setCacheQueries(boolean *bU% @O
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cacheQueries){ ?4MSgu
this.cacheQueries = cacheQueries; <oZ(n g@X
} Vp\80D&
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publicvoid setQueryCacheRegion(String o[n<M>@
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queryCacheRegion){ !^]q0x
this.queryCacheRegion = +#9xA6,AE
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queryCacheRegion; l_ZO^E~D_
} >^;(c4C
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publicvoid save(finalObject entity){ U(P:J e
getHibernateTemplate().save(entity); Dl&PL
} xg{VP7
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publicvoid persist(finalObject entity){ K:uQ#W.&
getHibernateTemplate().save(entity); f%L:<4
} %kJh6J
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publicvoid update(finalObject entity){ prqT (1
getHibernateTemplate().update(entity); u*U_7Uw$
} A%P 8c
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publicvoid delete(finalObject entity){ gu^_iU
getHibernateTemplate().delete(entity); sD2*x T
} :wSJ-\'$
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publicObject load(finalClass entity, uvR0TIF4
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finalSerializable id){ U{HyxZ|q<
return getHibernateTemplate().load WI0QLR'
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(entity, id); h)7v1,;w'
} +<GrRYbC
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publicObject get(finalClass entity, 3_C98ClE
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finalSerializable id){ =obt"K%n
return getHibernateTemplate().get PIgGXNo
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(entity, id); 9)jo7,VM
} @>+^W&
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publicList findAll(finalClass entity){ YfV"_G.ad|
return getHibernateTemplate().find("from =jsx(3V
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" + entity.getName()); =kwb`
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} 7Y%!,ff
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publicList findByNamedQuery(finalString !?S5IGLOj
FK-}i|di
namedQuery){ wEZ,49
return getHibernateTemplate >-UD]?>
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().findByNamedQuery(namedQuery); \)uy"+ Z`
} 7E;>E9 '
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publicList findByNamedQuery(finalString query, W]} #\\$z
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finalObject parameter){ 9)#gtDM%J
return getHibernateTemplate Ewa[Y=+tx
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().findByNamedQuery(query, parameter); +dDJes!]
} <m~T>Ql1
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publicList findByNamedQuery(finalString query, @=02
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finalObject[] parameters){ /;zZnF\e
return getHibernateTemplate 37%`P\O;s
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().findByNamedQuery(query, parameters); p
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} t^`<*H
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publicList find(finalString query){ We[<BJo4
return getHibernateTemplate().find |3s.;wK
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(query); eUX@9eML
} C}x4#bNK
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publicList find(finalString query, finalObject 2q2p=H>&
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parameter){ &gY;`*<
return getHibernateTemplate().find THrc
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(query, parameter); EG'7}W
} U;x99Go:
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public PaginationSupport findPageByCriteria .q
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(final DetachedCriteria detachedCriteria){ s#'|{
return findPageByCriteria \9dz&H
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Y9z:xE
} 0S)"Q^6ny
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public PaginationSupport findPageByCriteria nEjo,
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(final DetachedCriteria detachedCriteria, finalint u.ULS3`C/X
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startIndex){ !Ei Ze.K
return findPageByCriteria AlPL;^Y_l
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(detachedCriteria, PaginationSupport.PAGESIZE, P^'>dOI0w
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startIndex); *Y|lO
} jUV#HT
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public PaginationSupport findPageByCriteria (H|%?F;{l
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(final DetachedCriteria detachedCriteria, finalint 8eg2o$k_,#
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pageSize, 17MN8SfQ
finalint startIndex){ )W_ Y3M,
return(PaginationSupport) ,*9#c*'S
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getHibernateTemplate().execute(new HibernateCallback(){ ;/6:lL
publicObject doInHibernate {,nd_3"Vq
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(Session session)throws HibernateException { @j)f(Zlu#
Criteria criteria = /NPl2\ o.
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detachedCriteria.getExecutableCriteria(session); E-*>f"<h
int totalCount = *g/I&'^
ND)M3qp2(
((Integer) criteria.setProjection(Projections.rowCount I(iGs I
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()).uniqueResult()).intValue(); &;uGIk>s
criteria.setProjection baO&n
VNOK>+
(null); M8^ziZY
List items = m \R@.jkZ
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criteria.setFirstResult(startIndex).setMaxResults Q!BkS=H30K
#/&q
(pageSize).list(); JsAb q
PaginationSupport ps = YQfZiz}Fv
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new PaginationSupport(items, totalCount, pageSize, r`mzsO-'
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startIndex); A61-AwvF8-
return ps; *`\4j*$^
} 0*]<RM
}, true); <9MQ
} n]6w)wE(
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public List findAllByCriteria(final 9e :d2
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DetachedCriteria detachedCriteria){ MRxo|A{
return(List) getHibernateTemplate Vt$ $ceu
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().execute(new HibernateCallback(){ 5BGv^Qb_2
publicObject doInHibernate <try%p|f
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(Session session)throws HibernateException { E`sapk
Criteria criteria = l#J>It\
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detachedCriteria.getExecutableCriteria(session); ;#Crh}~
return criteria.list(); :` !mCW`Q-
} 2-B8>-
}, true); g'l7Jr3
} (t]R#2{
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public int getCountByCriteria(final "VhrsVT
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DetachedCriteria detachedCriteria){ eT
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Integer count = (Integer) Y@xeyMzE
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getHibernateTemplate().execute(new HibernateCallback(){ GoGgw]h>x
publicObject doInHibernate "h|0]y^2
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(Session session)throws HibernateException { k.VOS0
Criteria criteria = K":tr~V;
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detachedCriteria.getExecutableCriteria(session); *" +cP!
return rb4g<f|
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criteria.setProjection(Projections.rowCount ]uXsl0'`V
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()).uniqueResult(); Aba%Gh
} /-9+(
}, true); {}2p1-(
return count.intValue(); m|?J^_
} o*S $j Cf?
} rm;"98~zJ?
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用户在web层构造查询条件detachedCriteria,和可选的 69w"$Vk
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ph+tk5k
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PaginationSupport的实例ps。
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ps.getItems()得到已分页好的结果集 T`G"2|ISS
ps.getIndexes()得到分页索引的数组 y`dzo`f
ps.getTotalCount()得到总结果数 [Y~ s
ps.getStartIndex()当前分页索引 Kt0Tuj@CY
ps.getNextIndex()下一页索引 CplRnKra
ps.getPreviousIndex()上一页索引 SZ){1Hu
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 !X_~|5.
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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 s]>%_(5
hdb4E|'A
一下代码重构了。 c^k.
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我把原本我的做法也提供出来供大家讨论吧: g{(nt5|^l
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首先,为了实现分页查询,我封装了一个Page类: r/ f;\w7
java代码: z$b!J$A1
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/*Created on 2005-4-14*/ 5w9<_W0d
package org.flyware.util.page; {xH@8T$DX
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/** n5/Q)*e0'#
* @author Joa V|`|CVFo]
* Zv93cv
*/ VV0$L=mo
publicclass Page { +Eg# 8/q
*
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/** imply if the page has previous page */ Hq$|j,&?
privateboolean hasPrePage; 2T9Z{v
4r&~=up]
/** imply if the page has next page */ W
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privateboolean hasNextPage; ],|B4\b ;
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/** the number of every page */ b.&YUg[#
privateint everyPage; cO9Aw !
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/** the total page number */ a6_`V;
privateint totalPage; VXS9E383
3}+
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/** the number of current page */ Ok!{2$P8U9
privateint currentPage; rv:O|wZ
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/** the begin index of the records by the current TF>F7v(,45
\ :.p8`
query */ M;R>]wP"V
privateint beginIndex;
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/** The default constructor */ 0ZN/-2c A#
public Page(){ ,U}8(D~:
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} al/~
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/** construct the page by everyPage S5JnJkNn
* @param everyPage v]v f(]""
* */ 3-'|hb
public Page(int everyPage){ aF:LL>H
this.everyPage = everyPage; {8Ll\j@ "
} X9 R-GT
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/** The whole constructor */ C;` fOCz^
public Page(boolean hasPrePage, boolean hasNextPage, CJ_B.
4/b#$o<I?
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int everyPage, int totalPage, '5%DKz
int currentPage, int beginIndex){ ?k#%AM
this.hasPrePage = hasPrePage; L@wnzt
this.hasNextPage = hasNextPage; MEu-lM7v
this.everyPage = everyPage; KGIz)/eSg
this.totalPage = totalPage; (\j<`"n
this.currentPage = currentPage; vzL>ZBeZ
this.beginIndex = beginIndex; kQ +
} ]zO]*d=m
g!$
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/** bpkn[K"(
* @return 99 ["I:
* Returns the beginIndex. ;$Y?j8g
*/ 04s N4C
publicint getBeginIndex(){ &("?6%GC
return beginIndex; &7 ,wdG
} Hl#o& *Ui"
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/**
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* @param beginIndex =c|Bu^(Ctw
* The beginIndex to set. =xgW$c/yB
*/ I
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publicvoid setBeginIndex(int beginIndex){ o}T]f(>}
this.beginIndex = beginIndex; IAfYlS#<yD
} 1g;3MSn~
7cC$)
/** L@/+u+j0
* @return HV}NT~
* Returns the currentPage. C oaqi`v4T
*/ 2dC)%]aLme
publicint getCurrentPage(){ f:TW<
return currentPage; v#~,)-D&
} V#=N?p
kz#DBh!&
/** r
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* @param currentPage KT3[{lr
* The currentPage to set. ?}W:DGudZ
*/ H:|yu
publicvoid setCurrentPage(int currentPage){ 2]@U$E='s
this.currentPage = currentPage; Ss8`;>
} c6e?)(V>
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/** CSs3l
* @return u",
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* Returns the everyPage. &P\T{d2"
*/ f`?|A
publicint getEveryPage(){ 3,pRmdC
return everyPage; &oT]ycz%
} UOa{J|k>h
ztu N0}'
/** [9w8oNg0
* @param everyPage c0tv!PSw
* The everyPage to set. A>X#[qx
*/ RNm/&F1C$
publicvoid setEveryPage(int everyPage){ b+w|3bQa
this.everyPage = everyPage; wt-)5f'{
} J&lQ,T!?B
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/** =s;7T!7!
* @return k+_pj k
* Returns the hasNextPage. :g][99
*/ {uq
publicboolean getHasNextPage(){ ."9v1kW
return hasNextPage; [^aow-4z
} SC'fT!
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/** '#^ONn STn
* @param hasNextPage ~]}7|VN.}
* The hasNextPage to set. PE3l2kr
*/ i/~A7\:8%
publicvoid setHasNextPage(boolean hasNextPage){ x#'#
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this.hasNextPage = hasNextPage; /I="+
} =EFF2M`F
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/** $l Y
* @return a:1-n%&F
* Returns the hasPrePage. j:rGFd
*/ $
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publicboolean getHasPrePage(){ 5r@x$* >e
return hasPrePage; "(/.3`g
} )|3?7?X
mL ]zkD_
/** Ow<=K:^
* @param hasPrePage $5:j" )$,
* The hasPrePage to set. waldLb>7D
*/ 98G>I(Cw%
publicvoid setHasPrePage(boolean hasPrePage){ HjLY\.S
this.hasPrePage = hasPrePage; L=
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} @MTm8E6au
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/** ,LX]
* @return Returns the totalPage. =fEn h'KE
* RY/9Ku `
*/ Yaht<Hy
publicint getTotalPage(){ B xq(+^T
return totalPage; ^lf{IM-Y
} <t&0[l
)y_MI
r
/** eA4@)6W P(
* @param totalPage an=8['X
* The totalPage to set. ~[t%g9
*/ b v~"_)C
publicvoid setTotalPage(int totalPage){ k#&d`?X
this.totalPage = totalPage; wm!Y5
} BH0].-)[y!
YR^J7b\
} ma,H<0R
NvQN
7vubkj&
K#kU6/
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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
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个PageUtil,负责对Page对象进行构造: :[?hU}9
java代码: a)/!ifJ;
d@JjqE[
p~6/
/*Created on 2005-4-14*/ { owK~
package org.flyware.util.page; fKb8)PDP
Z`Rrv$M!
import org.apache.commons.logging.Log; Nyip]VwMJ
import org.apache.commons.logging.LogFactory; uPQ:}zL2
^giseWR(
/** '1_CMr
* @author Joa $OldHe[p
* tI ~.3+F
*/ 3o5aB1
publicclass PageUtil { CI{? Kb
_ ?]bd-E
privatestaticfinal Log logger = LogFactory.getLog pqmtN*zV
1Ue)&RW
(PageUtil.class); :q/%uca9
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/** UOC>H%r~M?
* Use the origin page to create a new page SvLI%>B=9
* @param page ,4M7:=gf
* @param totalRecords Nr8#/H2f
* @return Nk*d=vj
*/ $aDAD4mmm
publicstatic Page createPage(Page page, int \R\?`8Orz
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totalRecords){ XEl-5-M"
return createPage(page.getEveryPage(), ;89 `!V O
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page.getCurrentPage(), totalRecords); h fZY5+Z<
} a|S6r-_;s
VZF;
/** n .is+2t
* the basic page utils not including exception Wg{ 9X#|
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handler o?5m^S14[1
* @param everyPage W'lejOiw
* @param currentPage |z1er"zR)
* @param totalRecords 89n\$7Ff9
* @return page &Z'3n9zl
*/ ETZE.a
publicstatic Page createPage(int everyPage, int x9\z^GU%H
e7tp4M9!%
currentPage, int totalRecords){ ,6VY S\a3
everyPage = getEveryPage(everyPage); iF,%^95=
currentPage = getCurrentPage(currentPage); TP3KT)
int beginIndex = getBeginIndex(everyPage, Ql>bsr}
9B3+$uP
currentPage); tBUn
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int totalPage = getTotalPage(everyPage, k4T`{s}e
HE!"3S2S&+
totalRecords); 0MpZdJ
boolean hasNextPage = hasNextPage(currentPage, =)b!M^=X-a
@~7y\G
totalPage); F-R5Ib-F*A
boolean hasPrePage = hasPrePage(currentPage); )O+V ft
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returnnew Page(hasPrePage, hasNextPage, Mbm'cM&}
everyPage, totalPage, !#&`1cYX
currentPage, xu%_Zt2/?j
POXd ,ON9
beginIndex); xQUskjv/
} ^k J>4
[/=Z2mtA
privatestaticint getEveryPage(int everyPage){ 'Nkd *
return everyPage == 0 ? 10 : everyPage; -XASS%
} kF]sy8u]
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privatestaticint getCurrentPage(int currentPage){ ,{6Vf|?
return currentPage == 0 ? 1 : currentPage; )x5t']w`K
} 4yK{(!&i+
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privatestaticint getBeginIndex(int everyPage, int +h]~m_O
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currentPage){ Z1}@N/>>
return(currentPage - 1) * everyPage; iWGn4p'
} o[^nmHrM2
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privatestaticint getTotalPage(int everyPage, int 3s\}|LqX#
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totalRecords){ t1`.M$
int totalPage = 0; 1S+lHG92I
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if(totalRecords % everyPage == 0) +7\"^D
totalPage = totalRecords / everyPage; L}=DC =E
else I|x?
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totalPage = totalRecords / everyPage + 1 ; 'vwu^u?
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return totalPage; O2qy[]km
} 6n A/LW\x
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privatestaticboolean hasPrePage(int currentPage){ V1#:[o63+
return currentPage == 1 ? false : true; N&yr?b'!-*
} m)l'i!Y
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privatestaticboolean hasNextPage(int currentPage, Y'y
yrn}
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int totalPage){ nV:RL|p2jw
return currentPage == totalPage || totalPage == "l 8YD&q
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0 ? false : true; ?zuKVi?I
} ^ 0.` 1$
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} 'iWDYZ?
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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。 T' =6_?7K4
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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 yUjkRT&h
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做法如下: ,!O]c8PcU
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 4V&(w,zl
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的信息,和一个结果集List: dv Vz#
java代码: <v6W
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/*Created on 2005-6-13*/ k4PXH
package com.adt.bo; <Nk:C1Op}
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import java.util.List; ^[&,MQU{7
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import org.flyware.util.page.Page; Q?V+
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*/HW]x|?V~
/** sd9b9?qiu
* @author Joa "$/1.SX;]
*/ p9 G{Q
publicclass Result { /|8rVYSs
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private Page page; J4x|Af p
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private List content; uPy5<