Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 c=Y8R/G<
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 /'uFX,
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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 /N?vVp
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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 d(>
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分页支持类: Xj+oV
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java代码: RLtIn!2OU
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package com.javaeye.common.util; mE+
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import java.util.List; `*to(
)
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publicclass PaginationSupport { xO nW~Z
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publicfinalstaticint PAGESIZE = 30; ``j8T[g
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privateint pageSize = PAGESIZE; z')zVoW,
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privateList items; ^>H+#@R
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privateint totalCount; SF#Rc>v
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privateint[] indexes = newint[0]; +CF"Bm8@
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privateint startIndex = 0; :lGH31GG
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public PaginationSupport(List items, int <Z6tRf;B
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totalCount){ qV`JZ\n
setPageSize(PAGESIZE); `OP?[
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setTotalCount(totalCount); v7kR]HU[y
setItems(items); sKLH.@
setStartIndex(0); S7_^E
} 2*<'=*zaQ
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public PaginationSupport(List items, int 3jG
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totalCount, int startIndex){ pHpHvSI
setPageSize(PAGESIZE); @T6Z3Zj}
setTotalCount(totalCount); G>q16nS~KP
setItems(items); 5HAIKc
setStartIndex(startIndex); 1FO T
} <y30t[.E6
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public PaginationSupport(List items, int Y3J;Kk#AH
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totalCount, int pageSize, int startIndex){ 14,Pf`5Sz
setPageSize(pageSize); 'z}Hg
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setTotalCount(totalCount); }CyS_Tc
setItems(items); 6-w'? G37
setStartIndex(startIndex); 8iDg2_l`G
} -<0PBl
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publicList getItems(){ i$Sq.NU
return items; J/o$\8tiMw
} J"TM[4^\Y
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publicvoid setItems(List items){ E*F)jP,yo
this.items = items; ^ew<|J2,B
} n!*uv~%$
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publicint getPageSize(){ d'yA"b]
return pageSize; X%>Sio
} ~il{6Z+#n
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publicvoid setPageSize(int pageSize){ ?(!<m'jEy
this.pageSize = pageSize; @^)aUOe
} xa?#wY
b
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publicint getTotalCount(){ -#nfO*H}
return totalCount; ERE1XOe=D
} jW G=k#WN
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publicvoid setTotalCount(int totalCount){ `S{Blv
if(totalCount > 0){ R1%2]?
this.totalCount = totalCount; 22<T.c
int count = totalCount / u?>]C6$
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pageSize; vj23j[!|
if(totalCount % pageSize > 0) |4F3Gu
count++; kK]^q|vb6
indexes = newint[count]; {D( _"
for(int i = 0; i < count; i++){ d5x>kO'[l
indexes = pageSize * 'xC83}!k
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i; /W6r{Et
} b(Ev :
}else{ 3/w) mY-o
this.totalCount = 0; >WsRCBA
} f#W5Nu'*!
} DjX*2O
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publicint[] getIndexes(){ tv+H4/
return indexes; ~alC5|wCUQ
} gD\ =
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publicvoid setIndexes(int[] indexes){ {[&_)AW6m%
this.indexes = indexes; -[I}"Glz:
} dUTF0U
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publicint getStartIndex(){ AV0C9a/td
return startIndex; 1f"LAs`%
} ZXf^HK
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publicvoid setStartIndex(int startIndex){ -cjwa-9
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if(totalCount <= 0) F_Q?0 Do0'
this.startIndex = 0; $=?CW(
elseif(startIndex >= totalCount) :PrQ]ss@C5
this.startIndex = indexes _l`s}yC
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[indexes.length - 1]; "o*zZ;>^
elseif(startIndex < 0) 3KF[ v{
this.startIndex = 0; k]n=7vw;
else{ +;}XWV
this.startIndex = indexes <V3N!H_d
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[startIndex / pageSize]; jZm57{C#*?
} %mhnd):
} Y2DR
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publicint getNextIndex(){ K,>D%mJ
int nextIndex = getStartIndex() + ?5%|YsJP_
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pageSize; %#.HFK
if(nextIndex >= totalCount) 4DL;/Z:
return getStartIndex(); .Jt&6N
else =Of!1TR(
return nextIndex; *N0R3da
} b ;Vy=f
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publicint getPreviousIndex(){ Ba$Ibq,r/
int previousIndex = getStartIndex() - #K3A{
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pageSize; {5f?y\Z
if(previousIndex < 0) #Fua^]n
return0; }NMkL l]J
else [8k7-}[
return previousIndex; B}.G(-u?7
} 2Et7o/\<
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} Tm8c:S^uq)
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抽象业务类 \(lt [=
java代码: lg0iNc!
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/** gJNp]I2R
* Created on 2005-7-12 pcM'j#;
*/ d1c_F~h<
package com.javaeye.common.business; W*q[f!@
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import java.io.Serializable; OBF2?[V~
import java.util.List; %bnDxCj"
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import org.hibernate.Criteria; P5+FZzQ
import org.hibernate.HibernateException; 0Ts[IHpg&E
import org.hibernate.Session;
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import org.hibernate.criterion.DetachedCriteria; tQy@d_a=y
import org.hibernate.criterion.Projections; (mvAEN+y
import Azrc+ k
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org.springframework.orm.hibernate3.HibernateCallback; Nb[z+V{=
import 7Q<xC
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org.springframework.orm.hibernate3.support.HibernateDaoS z G
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upport; &Bbs\
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import com.javaeye.common.util.PaginationSupport; a*d>WN.;U
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public abstract class AbstractManager extends eu(1bAfS&T
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HibernateDaoSupport { 5$Yt@8;
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privateboolean cacheQueries = false; 6]dK,
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privateString queryCacheRegion; L;=<d
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publicvoid setCacheQueries(boolean u4L&8@
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cacheQueries){ &|7pu=
this.cacheQueries = cacheQueries; b$P=rIB
} .~0A*a
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publicvoid setQueryCacheRegion(String ;T! mNKl
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queryCacheRegion){ sgDlT=c'
this.queryCacheRegion = 7d?'~}j
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queryCacheRegion; 5taYm'
} xBhfC!AK}
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publicvoid save(finalObject entity){ 9l?#ZuGXp
getHibernateTemplate().save(entity); O $uXQ.r
} B:=*lU.n
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publicvoid persist(finalObject entity){ s@C@q(i6
getHibernateTemplate().save(entity); i,BE]w
} IZczHHEL`b
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publicvoid update(finalObject entity){ $u`y
getHibernateTemplate().update(entity); ~Rx[~a
} y&NO[
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publicvoid delete(finalObject entity){ =$UDa`}D
getHibernateTemplate().delete(entity); Kw}-<y
} 4,kT4_&,
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publicObject load(finalClass entity, 'G3B02*
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finalSerializable id){ LuS]D%
return getHibernateTemplate().load %ci/(wL
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(entity, id); s5>=!yX
} -.:[a3c?
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publicObject get(finalClass entity, dOArXp`s
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finalSerializable id){ ?<\K!dA
return getHibernateTemplate().get $VYMAk&\
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(entity, id); <;:M:{RZY
} WC,&p
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publicList findAll(finalClass entity){ 'u$e2^
return getHibernateTemplate().find("from s4bLL
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" + entity.getName()); |a#4
} QT /TZ:
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publicList findByNamedQuery(finalString }zi:nSpON
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namedQuery){ =h^cfyj
return getHibernateTemplate JK.lL]<p i
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().findByNamedQuery(namedQuery); q
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} w
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publicList findByNamedQuery(finalString query, y\b.0-z
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finalObject parameter){ MK7S*N1
return getHibernateTemplate IB:Wh;_x
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().findByNamedQuery(query, parameter); > bWsUG9
} >}h/$bU
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publicList findByNamedQuery(finalString query, ce&)djC7U
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finalObject[] parameters){ 09`5<9/
return getHibernateTemplate %B`MO-
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().findByNamedQuery(query, parameters); RG|]Kt8
} ?V%x94B
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publicList find(finalString query){ :^FOh*H
return getHibernateTemplate().find 1SeDrzLA
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(query); ?U:?o_w
} O.CRF-`t
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publicList find(finalString query, finalObject j8nG
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)nyud$9w'
parameter){ $A)i}M;uK
return getHibernateTemplate().find w~QUG^0Fx
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(query, parameter); M%+l21&
} ~hPp)-A
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public PaginationSupport findPageByCriteria g![]R-$
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(final DetachedCriteria detachedCriteria){ z-K?AkB1
return findPageByCriteria kPF[E5
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); *;. l/
} oHdss;q
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public PaginationSupport findPageByCriteria g
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(final DetachedCriteria detachedCriteria, finalint 4(Gs$QkSo|
" &'Jw
startIndex){ 'F^nW_ryW
return findPageByCriteria :ak D
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(detachedCriteria, PaginationSupport.PAGESIZE, Q[`J=
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startIndex); DesvnV'{`
} %m1k^
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public PaginationSupport findPageByCriteria 1[o] u:m9U
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(final DetachedCriteria detachedCriteria, finalint {C Qo}@.7
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pageSize, '$*d:1
finalint startIndex){ V*xT5TljS-
return(PaginationSupport) |rkj$s,
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getHibernateTemplate().execute(new HibernateCallback(){ EU.vw0}u8
publicObject doInHibernate j7=I!<w V
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(Session session)throws HibernateException { _XIls*6AK
Criteria criteria = T1m'+^?"
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detachedCriteria.getExecutableCriteria(session); Z{RRhJ
int totalCount = mz;S*ONlV
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((Integer) criteria.setProjection(Projections.rowCount Ac!,#Fq
)[Bwr
bn
()).uniqueResult()).intValue(); ~fB}v
criteria.setProjection _,(]T&j #2
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(null); ]uO 8
List items = | iEhe
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criteria.setFirstResult(startIndex).setMaxResults Bt4
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(pageSize).list(); fBS`b[x
PaginationSupport ps = b;K>Q!(|
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new PaginationSupport(items, totalCount, pageSize, !4d6wp"
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startIndex); PI~LbDE
return ps; pvM;2
} :L<$O7
}, true); i|+ EC_^<
} tyFhp:ZB
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public List findAllByCriteria(final dP[l$/
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DetachedCriteria detachedCriteria){ itb0dF1G
return(List) getHibernateTemplate MJ'|$b}
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().execute(new HibernateCallback(){ r1&b#r>
publicObject doInHibernate -]c5**O}
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(Session session)throws HibernateException { k .? aq
Criteria criteria = wOQ-sp0q0
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detachedCriteria.getExecutableCriteria(session); dO.?S89L
return criteria.list(); hWpn~q
} '(A)^K>+
}, true); &\8.y2=9p
} *m:h0[[J
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public int getCountByCriteria(final c\~H_ ~F
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DetachedCriteria detachedCriteria){ !PUbaF-.6
Integer count = (Integer) .kh%66:
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getHibernateTemplate().execute(new HibernateCallback(){ S@]7
publicObject doInHibernate ~8~B VwZ_
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(Session session)throws HibernateException { rhY>aj
Criteria criteria = d&'z0]mOe
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detachedCriteria.getExecutableCriteria(session); %:^,7
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return Ai\"w 0
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criteria.setProjection(Projections.rowCount v<iMlOEt
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()).uniqueResult(); yO.3~H)c
} +;SQ}[
}, true); 7cin?Z1
return count.intValue(); Vr/UbgucJ
} 3nv7Uz
} iK{q_f\"
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用户在web层构造查询条件detachedCriteria,和可选的 rm2"pfs
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 /!ZeMY:x
,?i^i#Wqzg
PaginationSupport的实例ps。 ~d6_
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ps.getItems()得到已分页好的结果集 q:sDNj)R\
ps.getIndexes()得到分页索引的数组 6W$ #`N>
ps.getTotalCount()得到总结果数 "Q9S<O8)
ps.getStartIndex()当前分页索引 NhQIpzL)
ps.getNextIndex()下一页索引 b $x<7l5C
ps.getPreviousIndex()上一页索引 @
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 8}h ^Frh
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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 hKjvD.6]%
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一下代码重构了。 WmLl.Vv=
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我把原本我的做法也提供出来供大家讨论吧: Yu=4j9e_mG
vfzGRr
首先,为了实现分页查询,我封装了一个Page类: Ga~N7
java代码: _H^Ij
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/*Created on 2005-4-14*/ g6EdCG.V
package org.flyware.util.page; xG0IA 7
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/** YXXUYi~!f
* @author Joa Z:aDKAboU
* nMc3.fM
*/ OqUEj 0X
publicclass Page { wqBGJ
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/** imply if the page has previous page */ [bkMl+:/HG
privateboolean hasPrePage; C3-l(N1O{
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/** imply if the page has next page */ R[
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privateboolean hasNextPage; !e6;@ *
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/** the number of every page */ VpMpZ9oM<
privateint everyPage; m
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/** the total page number */ *2crhI*@>
privateint totalPage; >JS\H6
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/** the number of current page */ V`~$|
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privateint currentPage; /tA$'tZ
M]!\X6<_
/** the begin index of the records by the current w<j6ln+nM
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query */ g.f!Uc{
privateint beginIndex; @;_r`AT7
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/** The default constructor */ :Oo
public Page(){ "-XL Y_
aAO[Y"-:,Y
} qhVDC
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/** construct the page by everyPage N^q*lV#kob
* @param everyPage +xRja(d6
* */ 3O%[k<S\VO
public Page(int everyPage){ liFNJd`|o+
this.everyPage = everyPage; : Ey
} Nt67Ye3;
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/** The whole constructor */ srx`"
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public Page(boolean hasPrePage, boolean hasNextPage, wM (!9Ws3
{.SN
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int everyPage, int totalPage, Svn|vH
int currentPage, int beginIndex){ J/w?Fa<
this.hasPrePage = hasPrePage; a}#[mw@m=
this.hasNextPage = hasNextPage; <VB
this.everyPage = everyPage; 'mpY2|]\$
this.totalPage = totalPage; <;#d*&]
this.currentPage = currentPage; J5k\R+\H
this.beginIndex = beginIndex; h3aHCr E
} 9?gLi!rd
/MsXw/],
/** ~^"
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* @return ;E:ra_l
* Returns the beginIndex. ?v#t{e0eQ
*/ n?&G>`u*
publicint getBeginIndex(){ x ' 3<F
return beginIndex; fS-#dJC";`
} !40{1U&@a`
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/** ;z#D%#Ztq
* @param beginIndex Ia)wlA02S
* The beginIndex to set. j9%u&
*/ G9 z Q{E
publicvoid setBeginIndex(int beginIndex){ 0KnlomuH2
this.beginIndex = beginIndex; g6Qzkvw)
} :g'"*VXYB
z1f~:AdL
/** /-E>5 w U
* @return ]N-K`c]
* Returns the currentPage. |k)h' ?
*/ Gw!jYnU
publicint getCurrentPage(){ B^U5=L[:p
return currentPage; :~:(49l
} Y1{6lhxgE
E8jdQS|i
/** &AGV0{NMh]
* @param currentPage &k&tkE
* The currentPage to set. nE]R0|4h
*/ gsc/IUk
publicvoid setCurrentPage(int currentPage){ %,a.431gi
this.currentPage = currentPage; :CSys62
} mn*.z!N=
q ]rsp0P2
/** -{pcb7.xuv
* @return E~2}rK+#)
* Returns the everyPage. 3RscuD&
*/ q{@>2AlK
publicint getEveryPage(){ o?$D09j;;
return everyPage; A[XEbfDO
} PLg`\|
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/** p4<&N MG
* @param everyPage )oG_x{
* The everyPage to set. |?V6__9
*/ T$GhE
publicvoid setEveryPage(int everyPage){ $Xk1'AzB8
this.everyPage = everyPage; )eY3[>`
} cliP+#
n1DD+@
/** n0@e%=H)I
* @return W)<us?5Ec5
* Returns the hasNextPage. $4 >K2
*/ p:k>!8.Qho
publicboolean getHasNextPage(){ O]m,zk
return hasNextPage; 2<fG= I8
} ?b2"~A
-nN }8&l
/** s4;SA
* @param hasNextPage q3T'rw%Eh
* The hasNextPage to set. ?5'UrqYSW
*/ <bXfjj6YJ@
publicvoid setHasNextPage(boolean hasNextPage){ "1&C\}.7
this.hasNextPage = hasNextPage; #]:yCiA
} TTmNPp4q
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/** G~8C7$0z
* @return ~7 C` a$
* Returns the hasPrePage. rh${pHl
*/ vov"60K
publicboolean getHasPrePage(){ -2K`:}\y&
return hasPrePage; 9w}A7('
} 8D)*~C'85E
6Ei>VcN4a
/** $?(fiFC
* @param hasPrePage ss236&
* The hasPrePage to set.
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*/ '2/48j X5
publicvoid setHasPrePage(boolean hasPrePage){ }7X85@jC
this.hasPrePage = hasPrePage; ]|Vm*zO
} wB?;3lTS
7od!:<v/
/** {#zJx(2yG
* @return Returns the totalPage. C \H%4p1r
* fE|([` !
*/ M!,$i
publicint getTotalPage(){ O>Xyl4U
return totalPage; $a(wM1S4
} 'S)}mG_
.B"h6WMz
/** ].
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* @param totalPage (VWTYG7
* The totalPage to set. U:#9!J?41
*/ mUm9[X~'
publicvoid setTotalPage(int totalPage){ @;G}bYq^(I
this.totalPage = totalPage; Tr(w~et
} j Bl I^
+g/y)] AP
} |B;:Ald
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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 X@\rg}kP
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个PageUtil,负责对Page对象进行构造: zo7Hm]W`
java代码: rts@1JY[
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/*Created on 2005-4-14*/ ZxwI< T:&
package org.flyware.util.page; = =cAL"Z
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import org.apache.commons.logging.Log; i?A4uyYwS
import org.apache.commons.logging.LogFactory; :jT1=PfL
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/** ](aXZ<,
* @author Joa DdN{=}A
* 0%cbno@1V
*/ <I&X[Sqp
publicclass PageUtil { ?Sh]m/WZd[
=xw) [
privatestaticfinal Log logger = LogFactory.getLog ,~hvFTJI
&+xNR2";
(PageUtil.class); p4fU/
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/** (VI4kRj
* Use the origin page to create a new page * A@~!@XE4
* @param page /Pxt f~$
* @param totalRecords *=$Jv1"Q
+
* @return dArg'Dc4
*/ bfVKf}
publicstatic Page createPage(Page page, int X) owj7U;
) 'j7Ra
totalRecords){ l7Zqk GG]
return createPage(page.getEveryPage(), cD YKvrPY
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page.getCurrentPage(), totalRecords); cE$<6&0
} ^{DXin 1O`
dli?/U@hO
/** Ww{bh-nyq
* the basic page utils not including exception ,?3r-bM
&j<B22t!
handler ?rKewdGY
* @param everyPage ,j:`yB]4,
* @param currentPage 0/6f9A
* @param totalRecords yrSmI)&%
* @return page Z]@my,+Z;
*/ ey _3ah3x
publicstatic Page createPage(int everyPage, int ,ZHIXylZ
7YV}F9h4
currentPage, int totalRecords){ dAh&Z:86\
everyPage = getEveryPage(everyPage); eBFsKOtu
currentPage = getCurrentPage(currentPage); %|*tL7
int beginIndex = getBeginIndex(everyPage, sy.FMy+
etMQy6E\
currentPage); FMc$?mm
int totalPage = getTotalPage(everyPage, I%ivY
mp*&{[XoVC
totalRecords); Q_$aiE
boolean hasNextPage = hasNextPage(currentPage, ]o$aGrZ
% r`hW\4{
totalPage); TTZb.
boolean hasPrePage = hasPrePage(currentPage); C*a>B,H
]u?|3y^(
returnnew Page(hasPrePage, hasNextPage, _/;vsQB
everyPage, totalPage, =2F;'T\6
currentPage, bJ4} )P&
*P7 H=Yf&
beginIndex); h64<F3}
} !i,Eo-[Z
)"/.2S;
privatestaticint getEveryPage(int everyPage){ v-B{7
~=#Z
return everyPage == 0 ? 10 : everyPage; mSm:>hBd
} 8oK*NB29
?1T)cd*
privatestaticint getCurrentPage(int currentPage){ j^;f {0f
return currentPage == 0 ? 1 : currentPage; I<L
} 1xP*
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privatestaticint getBeginIndex(int everyPage, int _C2iP[YwQ{
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currentPage){ aZn]8jC%
return(currentPage - 1) * everyPage; K~$A2b95
} hfE5[
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privatestaticint getTotalPage(int everyPage, int {e~#6.$:
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totalRecords){ i/E"E7
int totalPage = 0; Y)H~*-vGu
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if(totalRecords % everyPage == 0)
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totalPage = totalRecords / everyPage; s;e%*4
else w%~UuJ#i
totalPage = totalRecords / everyPage + 1 ; JN)@bP
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return totalPage; iY?J3nxD-:
} f@yInIzRJ
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privatestaticboolean hasPrePage(int currentPage){ VUnO&zV{
return currentPage == 1 ? false : true; _^w&k{T
} {P')$f)
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privatestaticboolean hasNextPage(int currentPage, (SGX|,5X7
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int totalPage){ !xcLJ5^W
return currentPage == totalPage || totalPage == Oxsx\f_
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0 ? false : true; D=1:-aLP7
} ~/^q>z!\4
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} #djby}hi
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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 Fi)(~ji:
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做法如下: jKr\mb
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 P^[eTR*?
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的信息,和一个结果集List: o-I:p$B -
java代码: >|zMN$:
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/*Created on 2005-6-13*/ B703{k
package com.adt.bo; sU Er?TZ
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import java.util.List; C(CwsdlP
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import org.flyware.util.page.Page; 56w uk
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/** QNbV=*F?
* @author Joa Ls<^z@I
*/ \!LIqqX
publicclass Result { /U26IbJ
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private Page page; 6}l[%8
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private List content; z@I'Ryalyc
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/** jYUN:
* The default constructor L:j3
*/ d!{]CZ"@
public Result(){ %(&$CmS@
super(); j%+>y;).
} \)$:
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/** 5(5:5q.A/D
* The constructor using fields -\<\OV:c*
* CS'LW;#[
* @param page U7#C. Z
* @param content Gr-~&pm
*/ j+9;Rvt2
public Result(Page page, List content){
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this.page = page; @eJ6UML"
this.content = content; w**~k]In
} 5o6X.sC8e
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/** ]f{3_M[
* @return Returns the content. HmiG%1+{A
*/ %@9c'6
publicList getContent(){ v}LI-~M>U
return content; :
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} qCkC 2Fy(
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/** "%}24t%
* @return Returns the page. iD*21c<