Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @(Ou;Uy
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 e][U ;
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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 5cgDHs
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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 ~naL1o_FZ
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分页支持类: VoWlBH
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java代码: 5Ee%!Pk
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package com.javaeye.common.util;
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import java.util.List; 29 Yg>R!/
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publicclass PaginationSupport { p_)V@7
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publicfinalstaticint PAGESIZE = 30; vv"_u=H
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privateint pageSize = PAGESIZE; ,g6w2y7 ]
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privateList items; k^S=i_ U
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privateint totalCount; |.)oV;9
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privateint[] indexes = newint[0]; JN$v=Ox{
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privateint startIndex = 0; m/Q@ -
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public PaginationSupport(List items, int op/HZa
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totalCount){ g"FG7E&
setPageSize(PAGESIZE); w(eAmN:zR
setTotalCount(totalCount); nQa5e_q!u
setItems(items); F(Pe@ #)A
setStartIndex(0); (UAa
} fJH09:@^%
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public PaginationSupport(List items, int c'vxT<8fWW
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totalCount, int startIndex){ ic%<39
setPageSize(PAGESIZE); +5JCbT@y
setTotalCount(totalCount); nws '%MK)
setItems(items); =%%\b_\L
setStartIndex(startIndex); SWNi@
} |ITp$_S
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public PaginationSupport(List items, int (/a2#iW
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totalCount, int pageSize, int startIndex){ o
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setPageSize(pageSize); ug.mY= n'
setTotalCount(totalCount); 1y2D]h /'
setItems(items); J{
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setStartIndex(startIndex); k?;A#L~
} JN .\{ Y
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publicList getItems(){ &BY%<h0c
return items; ryB^$Kh,,
} eB%KXPhMm
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publicvoid setItems(List items){ pEuZsQ
this.items = items; '_lyoVP
} [ >O4hifq
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publicint getPageSize(){ 5x(`z
return pageSize; gPSUxE`O.
} IL 'i7p
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publicvoid setPageSize(int pageSize){ Dd-;;Y1C
this.pageSize = pageSize; HJhPd#xCW
} m2E$[g
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publicint getTotalCount(){ }fpK{db
return totalCount; %6+J]U
} orVsMT[A
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publicvoid setTotalCount(int totalCount){ 4.I6%Bq$
if(totalCount > 0){ q#:,6HDd
this.totalCount = totalCount; ZF"f.aV8)
int count = totalCount / WPygmti}Be
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pageSize; P~Q5d&1SO
if(totalCount % pageSize > 0) uSLO"\zysX
count++; dIQ7u
indexes = newint[count]; XKp.]c wP
for(int i = 0; i < count; i++){ "u~l+aW0
indexes = pageSize * Tf7$PSupP
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} ]W7(}~m
}else{ a/;u:"
this.totalCount = 0; Y]/(R"-2G
} v_)a=I%o&2
} IMIZ#/
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publicint[] getIndexes(){ .=~beTS'Vo
return indexes; /d=i0E3
} /+l3
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publicvoid setIndexes(int[] indexes){ {Z 3t0F
this.indexes = indexes; 3G9"La,b
} Genk YtS
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publicint getStartIndex(){ R$'4 d
return startIndex; !4GGq
} -CfGWO#Gbx
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publicvoid setStartIndex(int startIndex){ R#i|n<x
if(totalCount <= 0) 0@d )DLM?
this.startIndex = 0; xx0s`5
elseif(startIndex >= totalCount) [hTGWT3
this.startIndex = indexes Vo}3E]
|};]^5s9
[indexes.length - 1]; @P#uH5U
elseif(startIndex < 0) #mlTN3
this.startIndex = 0; i#$9>X
else{ -FytkM^]6
this.startIndex = indexes +5H9mk
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[startIndex / pageSize]; 8:;_MBt
} bq[j4xH0X
} *(YtO
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publicint getNextIndex(){ }dw`[{cm
int nextIndex = getStartIndex() + z"*X/T
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pageSize; ;"SnCBt:>
if(nextIndex >= totalCount) $3S6{"
return getStartIndex(); j89|hG)2
else tRRPNY
return nextIndex; LuY`mi
} ?Y+xuY/t
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publicint getPreviousIndex(){ H1_XEcaM+*
int previousIndex = getStartIndex() - ]vJZ v"ACn
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pageSize; p8K4^H
if(previousIndex < 0) *cxmQ
return0; >Z?fX
else `)e;bLP
return previousIndex; : Q X~bq
} V#[I/D
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} 0cZyO$.
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抽象业务类 9C}Ie$\
java代码: <h|XB}s+
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/** u8qL?Aj^
* Created on 2005-7-12 R 5 47
*/ %])-+T
package com.javaeye.common.business; 21D4O,yCe
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import java.io.Serializable; JPfNf3<@My
import java.util.List; Ze~$by|9f
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import org.hibernate.Criteria; W[PZQCL}K)
import org.hibernate.HibernateException; ;~T)pG8IS
import org.hibernate.Session; -/|O*oZ
import org.hibernate.criterion.DetachedCriteria; fv$Y&_,5
import org.hibernate.criterion.Projections; \DBoe:0~
import !t "uNlN
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org.springframework.orm.hibernate3.HibernateCallback; XRXKO>4q
import %Q5D#d"p`
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org.springframework.orm.hibernate3.support.HibernateDaoS J0zudbP
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upport; 6G6Hg&B
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import com.javaeye.common.util.PaginationSupport; XSt5s06TM
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public abstract class AbstractManager extends q# gZ\V$I
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HibernateDaoSupport { UXD?gK1
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privateboolean cacheQueries = false; )?~3fb6^
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privateString queryCacheRegion; wpu]{~Y
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publicvoid setCacheQueries(boolean Ht?
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cacheQueries){ SdC505m0*
this.cacheQueries = cacheQueries; @3wI(l[
} :Q2\3
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publicvoid setQueryCacheRegion(String I=D{(%+^d
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queryCacheRegion){ 6yk
this.queryCacheRegion = L`FsK64@
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queryCacheRegion; }#zE`IT
} K4SR`Q
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publicvoid save(finalObject entity){ PN/2EmwtC
getHibernateTemplate().save(entity); I@cKiB
} D}"\nCz}y&
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publicvoid persist(finalObject entity){ ^T'+dGU`
getHibernateTemplate().save(entity); g _;5"
} J x-^WB
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publicvoid update(finalObject entity){ vq$%Ug/B
getHibernateTemplate().update(entity); 9Q=g]int u
} <9-tA\`8N
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publicvoid delete(finalObject entity){ o]n5pZ\\W<
getHibernateTemplate().delete(entity); ;G!X?(%+
} Wr`=P,
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publicObject load(finalClass entity, *Dh.'bB!
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finalSerializable id){ /.'1i4Xa1P
return getHibernateTemplate().load S)VuT0
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(entity, id); A42At]
} fouy??
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publicObject get(finalClass entity, U,iTURd
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finalSerializable id){ wVE"nN#
return getHibernateTemplate().get C'n 9n!hR
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(entity, id); !SJmu}OB]
} :KX/`
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publicList findAll(finalClass entity){ i=o>Bl@f
return getHibernateTemplate().find("from Y141Twjvd
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" + entity.getName()); >z^T~@m7l
} @GnsW;$*~.
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publicList findByNamedQuery(finalString +Ya-h~7;g#
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namedQuery){ /6gRoQ%j
return getHibernateTemplate bL0+v@(r
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().findByNamedQuery(namedQuery); 3M1(an\nW
} k[v n:
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publicList findByNamedQuery(finalString query, 2"__jp:(
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finalObject parameter){ oAvJ"JH@i
return getHibernateTemplate RtqW!ZZ:H
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().findByNamedQuery(query, parameter); L~mL9[( ,
} r<|\4zIo/
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publicList findByNamedQuery(finalString query, D^&!
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finalObject[] parameters){ %mcuYR'D}
return getHibernateTemplate }kOhwT8sI
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().findByNamedQuery(query, parameters); UBU(@T(
} $%t{O[(
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publicList find(finalString query){ a,j!B
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return getHibernateTemplate().find D 'u+3
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(query); iww h,(
} ;3?M?E/$s
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publicList find(finalString query, finalObject hh8UKEM-
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parameter){ t]@Zd*
return getHibernateTemplate().find Y]Fq)-
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(query, parameter); \`XJz{Lm]
} w}(xs)`num
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public PaginationSupport findPageByCriteria =Q|}7g8o
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(final DetachedCriteria detachedCriteria){ =}q4ked/
return findPageByCriteria kfVG@ o?o
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); -p;oe}|
} r2<+ =INn
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public PaginationSupport findPageByCriteria Wh<lmC50(
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(final DetachedCriteria detachedCriteria, finalint (la
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startIndex){ pUwX
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return findPageByCriteria b\+|g9Tm
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(detachedCriteria, PaginationSupport.PAGESIZE, 5m bs0GL
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startIndex); >3kR~:;
} C=m Y
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public PaginationSupport findPageByCriteria 9D|
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(final DetachedCriteria detachedCriteria, finalint Mu (Y6
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pageSize, e7?W VV,
finalint startIndex){ >4VU
return(PaginationSupport) p}.b#{HJ
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getHibernateTemplate().execute(new HibernateCallback(){ S]o
publicObject doInHibernate _Pz3QsV9
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(Session session)throws HibernateException { \|pAn
Criteria criteria = v\k,,sI
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detachedCriteria.getExecutableCriteria(session); "@?|Vv,vn
int totalCount = xh6x
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((Integer) criteria.setProjection(Projections.rowCount 0B4(t6o
=5/;h+bk+3
()).uniqueResult()).intValue(); PVU"oz&T
criteria.setProjection _Ry.Wth
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(null); CU;nrd "
List items = =zjUd 5
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8
criteria.setFirstResult(startIndex).setMaxResults :I'Ezxv|
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(pageSize).list(); D+)=bPMe
PaginationSupport ps = ThlJhTh<%4
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new PaginationSupport(items, totalCount, pageSize, /kA19E4
<ut DZ#k
startIndex); D,n}Qf!GYk
return ps; U&n>fXTHn
} zn
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}, true); a-E-hX2
} e]
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public List findAllByCriteria(final 3NN'E$"3
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DetachedCriteria detachedCriteria){ o1WidJ"
return(List) getHibernateTemplate kxW>Da<6
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().execute(new HibernateCallback(){ Jo3(bl%u
publicObject doInHibernate >NRz*h #
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(Session session)throws HibernateException { "x;k'{S
Criteria criteria = m_$I?F0
5;
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detachedCriteria.getExecutableCriteria(session); @7s,|\
return criteria.list(); 3Y{)(%I
} !e'0jf-~
}, true); A<Z5
} B`B%:#
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public int getCountByCriteria(final 2ly,l[p8
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DetachedCriteria detachedCriteria){ 9V;$v
Integer count = (Integer) EotwUT|
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getHibernateTemplate().execute(new HibernateCallback(){ `GQiB]Z
publicObject doInHibernate F[kW:-ne@Z
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(Session session)throws HibernateException { k&A7alw
Criteria criteria = 6"i{P
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detachedCriteria.getExecutableCriteria(session); VS9]po>=
return qggk:cN1
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criteria.setProjection(Projections.rowCount qEJ8o.D-=
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()).uniqueResult(); 1/2V.:bg
} l+2cj?X
}, true); [vWkAJ'K
return count.intValue(); >7nV$.5S
} $>r>0S#+\&
} #*$_S@
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用户在web层构造查询条件detachedCriteria,和可选的 {}_ Nep/;
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 heL$2dZ5H
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PaginationSupport的实例ps。 ,-(T"Ph<
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ps.getItems()得到已分页好的结果集 v/R[?H)
ps.getIndexes()得到分页索引的数组 U*3AM_w
ps.getTotalCount()得到总结果数 sI&i{D
ps.getStartIndex()当前分页索引 VG_uxKY
ps.getNextIndex()下一页索引 \3Dk5cSDk+
ps.getPreviousIndex()上一页索引 C8IkpAD
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 *16<M)7
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 F9(._ow[
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一下代码重构了。 M.>^{n$
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我把原本我的做法也提供出来供大家讨论吧: yND"bF9
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首先,为了实现分页查询,我封装了一个Page类: #6Jc}g<?g
java代码: w8O" =},
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/*Created on 2005-4-14*/ ?4XnEDAm
package org.flyware.util.page; HTmI1
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/** M!1U@6n!=)
* @author Joa |%
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* ? ^M
/[@
*/ kv6Cp0uFg
publicclass Page { 1y
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/** imply if the page has previous page */ @@I7$*
privateboolean hasPrePage; m9in1RI%
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/** imply if the page has next page */ {RC&Ub>
privateboolean hasNextPage; ?/q\S
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/** the number of every page */ $pJw
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privateint everyPage; d1';d6.u\
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/** the total page number */ -pW*6??+?
privateint totalPage; &4{!5r
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/** the number of current page */ ipC
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privateint currentPage; 722:2 {
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/** the begin index of the records by the current \l1==,wk
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query */ TW6F9}'f&
privateint beginIndex; +~$pkxD"
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/** The default constructor */ G@zJf)u}
public Page(){ +_1sFH`
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} >%H(0G#X
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/** construct the page by everyPage /B<QYvv
* @param everyPage an2Yluc;
* */ <q&4Y+b
public Page(int everyPage){ Rga
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this.everyPage = everyPage; .: k6Kg
} ;EQ7kuJQ?
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/** The whole constructor */ _<KUa\
public Page(boolean hasPrePage, boolean hasNextPage, ;;|.qgxc~
4L_)@n}
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int everyPage, int totalPage, _FxeZ4\
int currentPage, int beginIndex){ @{"?fqo
this.hasPrePage = hasPrePage; Lp)P7Yt-
this.hasNextPage = hasNextPage; 66-tNy
this.everyPage = everyPage; `|2g&Vn
this.totalPage = totalPage; ^yX >^1
this.currentPage = currentPage; S ,x';"
this.beginIndex = beginIndex; ;0lY_ii
} G#fF("Ndu`
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/** DTlId~Dyq
* @return ( 8X^pL
* Returns the beginIndex. ,KCxNdg^#-
*/ 6Ey@)p..E
publicint getBeginIndex(){ waU2C2!w
return beginIndex; h[mJ=LIrg
} (K_{a+$[
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/** c \;_jg
* @param beginIndex O-huC:zZh
* The beginIndex to set. m}7Nu
*/ cn Ohj
publicvoid setBeginIndex(int beginIndex){ A*g-pJh
this.beginIndex = beginIndex; msY6zJc`
} "W~vSbn7
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/** >p'{!k
* @return K^
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* Returns the currentPage. S=j
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*/ JvK]EwR
;
publicint getCurrentPage(){ _+X-D9j(l
return currentPage; _u]%K-_
} CeeAw_*@
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/** b:cy(6G(
* @param currentPage BO WOH
* The currentPage to set. %/ctt_p0x
*/ B77`azwF
publicvoid setCurrentPage(int currentPage){ G\o9mEzQ
this.currentPage = currentPage; %lD+57=
} #qFY`fVf1
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/** S9{A}+"K
* @return jtUqrJFlQ
* Returns the everyPage. o{hX?,4i
*/ B$n 1k45
publicint getEveryPage(){ SgYMPBh
return everyPage; &B]1 VZUp
} 9VanR
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/** 3I(;c ,S
* @param everyPage K:^0*5Y-k
* The everyPage to set. `2hg?(ul
*/ w {"1V7|
publicvoid setEveryPage(int everyPage){ 0?}n( f!S
this.everyPage = everyPage; &36SX<vZ
} G{I),Y~IF
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/** p!5'#\^f
* @return [(gXjt-
* Returns the hasNextPage. BNj_f
*/ YRo,wsj
publicboolean getHasNextPage(){ <#RVA{
return hasNextPage; C$0g2X
} ~d].<Be
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/** #wo
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* @param hasNextPage \h_q]
* The hasNextPage to set. xH&hs$=
*/ wJNm}Wf
publicvoid setHasNextPage(boolean hasNextPage){ !-.GfI:q
this.hasNextPage = hasNextPage;
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} *AYq:n6
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/** ;1s+1G}_z
* @return #n}~u@,o_
* Returns the hasPrePage. kY @(-
*/ z DU=2c4W9
publicboolean getHasPrePage(){ loO"[8i.k
return hasPrePage; 6JDaZh"=K
} n_3R Q6
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/** uKd4+Km
* @param hasPrePage L,[Q{:C S
* The hasPrePage to set. ]8}51y8
*/ yu)^s!UY;
publicvoid setHasPrePage(boolean hasPrePage){ AYgXqmH~+
this.hasPrePage = hasPrePage; u*TC8!n
} Dnl<w<}ZU:
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/** D}q"^"#T
* @return Returns the totalPage. "4;nnq
* 8!rdqI
*/ ICvV}%d
publicint getTotalPage(){ pF4Z4?W
return totalPage; :nQlS
} i'7+
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/** LP=j/qf|
* @param totalPage Ps74SoD-
* The totalPage to set. ,/D}a3JD
*/ Xv|=RNz
publicvoid setTotalPage(int totalPage){ @phVfP"M
this.totalPage = totalPage; \ l#eW
x
} 5&V=$]t
ocFk#FW
} z
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8.[F3Tk=
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 v6s,lC5qR
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个PageUtil,负责对Page对象进行构造: 0Gc@AG{
java代码: d<6F'F^w.7
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/*Created on 2005-4-14*/ I5_HaC>
package org.flyware.util.page; /\c'kMAW!
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import org.apache.commons.logging.Log; <;6{R#Tuh
import org.apache.commons.logging.LogFactory; @ M]_],
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/** ,|{`(y/v
* @author Joa Bchv1KF
* I I+y
*/ ;^5k_\
publicclass PageUtil { yGdX>h
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privatestaticfinal Log logger = LogFactory.getLog IHni1
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(PageUtil.class); N)H "'#-
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/** lL:a}#qxU
* Use the origin page to create a new page N2v/<
* @param page |QDoi[
*
* @param totalRecords m$fEk,d
* @return (-21h0N[V
*/ .9rYBy
publicstatic Page createPage(Page page, int sD:o
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totalRecords){ Lwr's'ao.
return createPage(page.getEveryPage(), #$I@V4O;#
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page.getCurrentPage(), totalRecords); Uj):}xgi'
} `m7<_#Y
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/** %.Ma_4o
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* the basic page utils not including exception -B
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handler >
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* @param everyPage q 84*5-
* @param currentPage mG jB{Q+
* @param totalRecords *M1GVhW(+
* @return page :V(LBH0
*/ 0O9b
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publicstatic Page createPage(int everyPage, int C#kE{Qw10r
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currentPage, int totalRecords){ #ES[),+|mB
everyPage = getEveryPage(everyPage); !6KX^j-
currentPage = getCurrentPage(currentPage); Y%XF64)6
int beginIndex = getBeginIndex(everyPage, *siX:?l
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currentPage); |O{N_-];.
int totalPage = getTotalPage(everyPage, &-3e3)
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totalRecords); a!9'yc
boolean hasNextPage = hasNextPage(currentPage, b=,BLe\
mn7I# ~
totalPage); R2,9%!iiX
boolean hasPrePage = hasPrePage(currentPage); m+<&NDj.
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returnnew Page(hasPrePage, hasNextPage, T/_u;My;
everyPage, totalPage, =AIFu\9#a`
currentPage, QK]P=pE'C
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beginIndex); ;W,* B.~
} [';o -c"!
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privatestaticint getEveryPage(int everyPage){ x+X@&S
return everyPage == 0 ? 10 : everyPage; r#sg5aS7O|
} jeu'K vhe
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privatestaticint getCurrentPage(int currentPage){ FDMQLx f
return currentPage == 0 ? 1 : currentPage; Z hfp>D
} Uwc%'=@
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privatestaticint getBeginIndex(int everyPage, int .z>/A/&+
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currentPage){ j&8YE7
return(currentPage - 1) * everyPage; 6}^x#9\
} sL$sj|" S
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privatestaticint getTotalPage(int everyPage, int -9b=-K.y
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totalRecords){ Jt_=aMY:7
int totalPage = 0; 6] x6FeuS
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if(totalRecords % everyPage == 0) N]P~`)
totalPage = totalRecords / everyPage; gP%<<yl
else 3:,%>#"
totalPage = totalRecords / everyPage + 1 ; !> sA.L&=
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return totalPage; suN6(p(.
} [vi
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privatestaticboolean hasPrePage(int currentPage){ qs]W2{-4~
return currentPage == 1 ? false : true; E`)e
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} )s!A\a`vEd
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privatestaticboolean hasNextPage(int currentPage, +^AdD8U
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int totalPage){ /TMVPnvz.
return currentPage == totalPage || totalPage == 'V&g"Pb
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0 ? false : true; )G2Bx+Z;L
} Ne
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} f#s 6 'g
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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。 (Y~/9a4X
59.$;Ip;g
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 ]3v)3Wp
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做法如下: C. .| O
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 L1kn="5
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的信息,和一个结果集List: Z\0wQ;}
java代码: |j+JLB
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/*Created on 2005-6-13*/ ]-wyZ +a
package com.adt.bo; {MtJP:8Jp
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import java.util.List; \#[DZOI~
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import org.flyware.util.page.Page;
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/**
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* @author Joa (6fD5XtS
*/ -c>3|bo
publicclass Result { ndQw>
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private Page page; Y$OE[nGi%X
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private List content; W%rUa&00
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/** N1Y
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* The default constructor @.L#u#
*/ ^C
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public Result(){ J{4=:feIC?
super(); ZKI8x1>Iq
} Q%6zr9
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/** >FeCa
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* The constructor using fields 56Lxr{+X
* !~zn*Hm
* @param page O
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* @param content LDegJer-v
*/ o"qxR'V
public Result(Page page, List content){ O=K0KOj
this.page = page; \>\ERVEd
this.content = content; z&9ljQ
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} m2m
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/** -medD G
* @return Returns the content. $\m:}\%p
*/ h8WM4
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publicList getContent(){ X!V#:2JY
return content; GYtgw9 "Y
} )-I/ej^
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/** {JdXn
* @return Returns the page. {yNeZXA>
*/ hcW>R
public Page getPage(){ zSA"f_e
return page; Q)E3)),
} [VX5r1-F
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/** /QB;0PrE
* @param content LmY[{.'tX
* The content to set. Swf%WuDj
*/ (<.\v@7HC
public void setContent(List content){ QUkP&