Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 9cP{u$
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 iz`>'wpC
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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 @!!u>1
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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 ki@C}T5
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分页支持类: l$9k:#\FD
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java代码: nf"#F@dk
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package com.javaeye.common.util; 5yoi;$~}_0
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import java.util.List; _%D7D~2r|
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publicclass PaginationSupport { 6#CswSpS
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publicfinalstaticint PAGESIZE = 30; }l$zZ>.\H
} (-9d
privateint pageSize = PAGESIZE; N'EZJoH
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privateList items; dB4ifeT]
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privateint totalCount; p$1 'e,G
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privateint[] indexes = newint[0]; |*g#7YL
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privateint startIndex = 0; p+]S)K GZw
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public PaginationSupport(List items, int [=jZP,b&),
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totalCount){ EDgtn)1
setPageSize(PAGESIZE); >VIFQ\
setTotalCount(totalCount); C$+Q,guM
setItems(items); zMP6hn
setStartIndex(0); N^oP,^+U
} CS~onf<xz
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public PaginationSupport(List items, int ,%IP27bPW
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totalCount, int startIndex){ iEtR<R>=
setPageSize(PAGESIZE); ~\NQkaBkY
setTotalCount(totalCount); ~v2(sRJ
setItems(items); q`2dL)E
setStartIndex(startIndex); }9\6!GY0
} "]]LQb$
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public PaginationSupport(List items, int unn2I|XH
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totalCount, int pageSize, int startIndex){ ]aF;
setPageSize(pageSize); *Ts$Hj[
setTotalCount(totalCount); COHBjufmR
setItems(items); -avxH?;?7
setStartIndex(startIndex); zx\-He
} xgIb6<qwY
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publicList getItems(){ +:jonN9d
return items; oA-,>:}g{
} +?"F=.SZ
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publicvoid setItems(List items){ _w?!Mu
this.items = items; G5U?]& I8
} X5.9~
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publicint getPageSize(){ `O2P&!9&
return pageSize; d6tv4Cf
} (,o@/ -o
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publicvoid setPageSize(int pageSize){ hE=xS:6
this.pageSize = pageSize; #p*uk
}
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publicint getTotalCount(){ 4bL *7bA
return totalCount; dcmf~+T
} g4,ldr"D
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publicvoid setTotalCount(int totalCount){ .E^w, o
if(totalCount > 0){ +zch e
this.totalCount = totalCount; %JSRC<,a
int count = totalCount / ["&{^
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pageSize; H:hM(m0?q
if(totalCount % pageSize > 0) cd1-2-4U
count++; P]^OSPRg
indexes = newint[count]; D%3$"4M7!
for(int i = 0; i < count; i++){ L$O\fhO?
indexes = pageSize * Ua|iAD1
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} b1#C,UWK
}else{
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this.totalCount = 0; zOSUYn
} <S7SH-{_\
} C@ q#s
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publicint[] getIndexes(){ dDl+
return indexes; *V:U\G
} IxUj(l1Fm
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publicvoid setIndexes(int[] indexes){ xa'U_]m
this.indexes = indexes; 3YLfh`6
} &uE )Vr4 R
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publicint getStartIndex(){ 46)[F0,$r
return startIndex; NvIg,@}
} V*s\ ~h)
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publicvoid setStartIndex(int startIndex){ \; '#8
if(totalCount <= 0) %fS1gSfh
this.startIndex = 0; ".|8 (Y
elseif(startIndex >= totalCount) ^kcuRJ0*$
this.startIndex = indexes [g@qZ5I.
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[indexes.length - 1];
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elseif(startIndex < 0) J&h59dm-
this.startIndex = 0; Xp<O
else{ PtUS7[]
this.startIndex = indexes 'MYKAnZ-i
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[startIndex / pageSize]; <`Fl Igo
} 8g{Mv#b%
} R?lTB3"
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publicint getNextIndex(){ "dv\
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int nextIndex = getStartIndex() + LEnv/t6U
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pageSize; e^~dx}X
if(nextIndex >= totalCount) rC|nE=i
return getStartIndex(); L=Aj+
else +|S)Mm8-
return nextIndex; J_&cI%.
} ts[8;<YD
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publicint getPreviousIndex(){ )cQ KR4x0^
int previousIndex = getStartIndex() - *$VeR(QN
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pageSize; -ys/I,}<
if(previousIndex < 0) V+>RF
return0; D8w.r"ne
else 0[
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return previousIndex; lws.;abm%n
} 7?k3jDK
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} *dB3Gu{
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抽象业务类 ~a7@O^q4
java代码: b?Q$UMAbH
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/** V0,5c`H c
* Created on 2005-7-12 G^ <m0ew|
*/ m>[G-~0?kI
package com.javaeye.common.business; z/5TYv)S
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import java.io.Serializable; ${. :(z
import java.util.List; H<^3H
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import org.hibernate.Criteria; e5FF'~A%]
import org.hibernate.HibernateException; U[yA`7Zs}
import org.hibernate.Session; <|WXFjn
import org.hibernate.criterion.DetachedCriteria; Q-s5-&h(
import org.hibernate.criterion.Projections; hQzT
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import 3,#qt}8`
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org.springframework.orm.hibernate3.HibernateCallback; %ID48_>*
import XI ><;#
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org.springframework.orm.hibernate3.support.HibernateDaoS =y?Aeqq\fl
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upport; ow,! 7|m
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import com.javaeye.common.util.PaginationSupport; |t$%kpp
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public abstract class AbstractManager extends qMO(j%N5
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HibernateDaoSupport { rP(;^8l"
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privateboolean cacheQueries = false; r5lPO*?Df
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privateString queryCacheRegion; z^KBV^n
! v%%_sRV
publicvoid setCacheQueries(boolean
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cacheQueries){ gZz5P>^
this.cacheQueries = cacheQueries; (r.y
} +9;6]4
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publicvoid setQueryCacheRegion(String e/)Vx'd`+
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queryCacheRegion){ 0w2<2grQ
this.queryCacheRegion = \%W"KLP
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queryCacheRegion; u3 4.
} +=kz".$
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publicvoid save(finalObject entity){ pe\]}&
getHibernateTemplate().save(entity); #("E)P
} N71%l
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publicvoid persist(finalObject entity){ NdI~1kemr
getHibernateTemplate().save(entity); @7?L+.r$9
} ^
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publicvoid update(finalObject entity){ UtB~joaR
getHibernateTemplate().update(entity); EBUCG"e
} YipL_&-
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publicvoid delete(finalObject entity){ ?[X^'zz}
getHibernateTemplate().delete(entity);
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} 2B=BRVtSs
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publicObject load(finalClass entity, >
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finalSerializable id){ jxgs!B>
return getHibernateTemplate().load 0{47TX*YX
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(entity, id); MF5o\-&dN
}
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publicObject get(finalClass entity, KA9v?_@{ F
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finalSerializable id){ p}a0z?
return getHibernateTemplate().get `+T"^{
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(entity, id); &>Nw>V
} 843O}v'
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publicList findAll(finalClass entity){ mA\}zLw+r9
return getHibernateTemplate().find("from {60U6n
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" + entity.getName()); hyC]{E
} 9.l*#A^
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publicList findByNamedQuery(finalString ;v%f +
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namedQuery){ 03dmHg.E!E
return getHibernateTemplate B5/"2i
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().findByNamedQuery(namedQuery); t$ 3/ZTx
}
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publicList findByNamedQuery(finalString query, ,uCgC4EP
/
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finalObject parameter){ N9BfjT}
return getHibernateTemplate )8JM.:,
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().findByNamedQuery(query, parameter); 9<1dps=c
} C\gKJW^]y@
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publicList findByNamedQuery(finalString query, 2X@" #wIg
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finalObject[] parameters){ h%>yErs
return getHibernateTemplate zIbrw9G
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().findByNamedQuery(query, parameters); Fz@9
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} +Z=DvKsTJ
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publicList find(finalString query){ nm]m!.$d
return getHibernateTemplate().find J*+[?FXRL
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(query); &[y+WrGG
} ({WV<T&
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publicList find(finalString query, finalObject t`E e/L%
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parameter){ Eanwk` Rx
return getHibernateTemplate().find EEj.Kch}4
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(query, parameter); Oc%W_Gb7
} Z90]I<a~
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public PaginationSupport findPageByCriteria ibh,d.*~g
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(final DetachedCriteria detachedCriteria){ !p{CsR8c
return findPageByCriteria 1SSS0 &
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); y=SVS3D
} g,s^qW0vds
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public PaginationSupport findPageByCriteria )_SpY\J
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(final DetachedCriteria detachedCriteria, finalint !TLJk]7uC
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startIndex){ U[W &D%'
return findPageByCriteria >Xw0i\G
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(detachedCriteria, PaginationSupport.PAGESIZE, e@7UL|12
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startIndex); 1G)I|v9R
} QM@zy
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public PaginationSupport findPageByCriteria w$"^)EG,7
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(final DetachedCriteria detachedCriteria, finalint Lwn
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pageSize, cc 0Tb
finalint startIndex){ o2!wz8
return(PaginationSupport) }!V-FAL
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getHibernateTemplate().execute(new HibernateCallback(){ Y-lTPR<Eq
publicObject doInHibernate i@mS8%|l
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(Session session)throws HibernateException { 2WC$r8E
Criteria criteria = 7QRkXs
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detachedCriteria.getExecutableCriteria(session); `RXlqj#u
int totalCount = 3%)@c P:?
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((Integer) criteria.setProjection(Projections.rowCount YP>J'{?b*"
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()).uniqueResult()).intValue(); Ko0?c.l
criteria.setProjection J vq)%t8q>
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(null); VxtX%McK
List items = knHrMD;
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criteria.setFirstResult(startIndex).setMaxResults `LIlR8&@aX
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(pageSize).list(); C'l\4ij)7
PaginationSupport ps = { i3x\|
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new PaginationSupport(items, totalCount, pageSize, TQ/#
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startIndex); "Ya;&F.'
return ps; CnY dj~
} n
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}, true); F3Vvqt*2
} e2;=OoBK
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public List findAllByCriteria(final >/@Q7V99{
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DetachedCriteria detachedCriteria){ biffBC:q
return(List) getHibernateTemplate 5HvYy
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().execute(new HibernateCallback(){ <bv9X?U
publicObject doInHibernate p<@+0Uw2
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(Session session)throws HibernateException { "6?Y$y/wm
Criteria criteria = E*9W'e~=
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detachedCriteria.getExecutableCriteria(session); kwt;pxp i
return criteria.list(); "bO]AG
} f%YD+Dt_V
}, true); tE=$#
} 9B3}LVg\
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public int getCountByCriteria(final *;.:UR[i
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DetachedCriteria detachedCriteria){ ! -gOqo
Integer count = (Integer) sD<8-n
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getHibernateTemplate().execute(new HibernateCallback(){ ~BI! l
publicObject doInHibernate -f(<2i
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(Session session)throws HibernateException { -32.g\]
Criteria criteria = )#cGePA
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detachedCriteria.getExecutableCriteria(session); pC)S9Kl
return +(hr5
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criteria.setProjection(Projections.rowCount GwlAEh P
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()).uniqueResult(); /#?i +z
} g\,HiKBXd
}, true); s|8_R;
return count.intValue(); &nF7CCF
} 7Rom#Kl:
} #1f8A5<
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用户在web层构造查询条件detachedCriteria,和可选的 mh`VZQ@
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 =u`^QE
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PaginationSupport的实例ps。 >U$,/_uMNW
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ps.getItems()得到已分页好的结果集 #r)c@?T@j
ps.getIndexes()得到分页索引的数组 u_U51C\rb
ps.getTotalCount()得到总结果数 6*2z^P9FRj
ps.getStartIndex()当前分页索引 N5[fwz
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ps.getNextIndex()下一页索引 TNC,{sM
ps.getPreviousIndex()上一页索引
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 `7|v
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 L+s,,k
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一下代码重构了。 TlZ|E '_C
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我把原本我的做法也提供出来供大家讨论吧: 4jrY3gyBX
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首先,为了实现分页查询,我封装了一个Page类: ^r$P&}Z\b
java代码: e p;_'
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/*Created on 2005-4-14*/ X4Eq/q"
package org.flyware.util.page;
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/** dM 7-,9Vc
* @author Joa f|_iHY
* }dE0WJcO
*/ UMw1&"0:
publicclass Page { %Sfew/"R0
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/** imply if the page has previous page */ SUfl`\O
privateboolean hasPrePage; pVPCxP
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/** imply if the page has next page */ O%y.
privateboolean hasNextPage; x2[A(O=
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/** the number of every page */ aDTNr/I
privateint everyPage; ,)nO
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/** the total page number */ Y+syc dq
privateint totalPage; F%t`dz!L
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/** the number of current page */ R-"A*/A 2
privateint currentPage; Y dmYE$
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/** the begin index of the records by the current 4WZ:zr N
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query */ ?A;x%8}
privateint beginIndex; 1p<m>s=D=e
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/** The default constructor */ *pCT34'--
public Page(){ dQQh$*IL?{
{ ,qm=Xjq
} &aqF||v%)
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/** construct the page by everyPage r'#5ncB
* @param everyPage HP^<2?K
* */ ,8nu%zcVn
public Page(int everyPage){ F$7>q'#
this.everyPage = everyPage; K2<"O qp_W
} V6B`q;lA
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/** The whole constructor */ %{WS7(si
public Page(boolean hasPrePage, boolean hasNextPage, Eq=~S O%
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int everyPage, int totalPage, GuPxN}n
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int currentPage, int beginIndex){ (-viP
this.hasPrePage = hasPrePage; SKt&]H
this.hasNextPage = hasNextPage; }lt5!u~}
this.everyPage = everyPage; N"1o>
!
this.totalPage = totalPage; y_boJ
this.currentPage = currentPage; $L7Z_JD5
this.beginIndex = beginIndex; p'{B|ujj6
}
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/** viB'ul7o
* @return `Y>'*4a\
* Returns the beginIndex. vqO d`_)
*/ R8LJC]6Bh
publicint getBeginIndex(){ 3m%oXT
return beginIndex; j5\z7
} 3,`I\>No
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/** 'EzKu~*
* @param beginIndex )!z4LE
* The beginIndex to set. E2dl}S zp
*/ ymH>]
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publicvoid setBeginIndex(int beginIndex){ <@:RS$"i
this.beginIndex = beginIndex; 4JQd/;
} ?APzb4f^W
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/** Uh[MBwK
* @return nA owFdCD
* Returns the currentPage. +4L]Z;k
*/ m\zCHX#n
publicint getCurrentPage(){ /q1k)4?E
return currentPage; DVJuX~'|!
} ^wass_8
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/** O>R@Xj)M
* @param currentPage _2Zc?*4
* The currentPage to set. oYx4+xH/
*/ [0bp1S~
publicvoid setCurrentPage(int currentPage){ 6JgbJbUi
this.currentPage = currentPage; hMCf|
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} oU l0w~Xn
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/** hy&WG&qf
* @return d9iVuw0u<
* Returns the everyPage. !LR9}Xon
*/ dzk1 !yy
publicint getEveryPage(){ FPb4VJ|xm
return everyPage; `y3*\l
} OYyF*F&S[
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/** ]qb>O:T
* @param everyPage *j~ObE_y
* The everyPage to set. ?`=
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*/ =Q,D3F
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publicvoid setEveryPage(int everyPage){ kfY. 9$(d
this.everyPage = everyPage; (}RTHpD
} h[bC#(
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/** Xv+!)j<
* @return (%j V[Q
* Returns the hasNextPage. g#Z7ReMw
*/ yxtfyf|9 '
publicboolean getHasNextPage(){ 6&"*{E
return hasNextPage; ug_c}Nv=Y
} Z*R~dHr
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/** !q~f;&rg
* @param hasNextPage Cp?6vu|RA
* The hasNextPage to set. \WqC^Di
*/ '%&-`/x
publicvoid setHasNextPage(boolean hasNextPage){ 5g`J}@"k
this.hasNextPage = hasNextPage; gj7'43
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} ]DUmp6
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/** +y_V$q$G
* @return "yK)9F[9Mo
* Returns the hasPrePage. ?pdN!zOeL
*/ }Ui)xi:8
publicboolean getHasPrePage(){ 4av
return hasPrePage; b\^1P;!'W
} pxI[/vS
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/** T2A74>Nw
* @param hasPrePage e< G[!m
* The hasPrePage to set. /g1;`F(MS/
*/ L<G6)'5W
publicvoid setHasPrePage(boolean hasPrePage){ \'X-><1
this.hasPrePage = hasPrePage; _7R6%^
} 1]W8A.ZS
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/** l$!Z};mw0E
* @return Returns the totalPage. ('`mPD,
* l}FA&c"
*/ z<s~`
publicint getTotalPage(){ 1lsg|iVz
return totalPage; Oiw!d6"Ovq
} %C)|fDwN
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/** F)50 6
* @param totalPage H:t2;Z'
* The totalPage to set. QZ5%nJme_
*/ Q@s G6iz
publicvoid setTotalPage(int totalPage){ ;`Sn66&
this.totalPage = totalPage; C@MJn)$4
} {!t6&
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} ZV!*ZpTe~
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 oTeQY[%$
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个PageUtil,负责对Page对象进行构造: 3UcOpq2i\
java代码: YY$O"!."
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/*Created on 2005-4-14*/ Ucj>gc=
package org.flyware.util.page; w.Kp[
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import org.apache.commons.logging.Log; n(\VP!u5r
import org.apache.commons.logging.LogFactory; 6
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/** 3
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* @author Joa ~
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* .7H*F9
*/ t2z@"e
publicclass PageUtil { p B79#4
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privatestaticfinal Log logger = LogFactory.getLog +C(/.X
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(PageUtil.class); K/LoHWy+n*
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/** =A^VzIj(
* Use the origin page to create a new page 6H!"oC&
* @param page (2%z9W
* @param totalRecords b %I2ig
* @return 4";[Xr{pW
*/ L3X[; |v}
publicstatic Page createPage(Page page, int ,9ZN k@q
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totalRecords){ ESv&x6H
return createPage(page.getEveryPage(), 9@z"~H
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page.getCurrentPage(), totalRecords); !4
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} sMAu*
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/** V$<5`
* the basic page utils not including exception $v+t~b
qQUCK
handler -AxO1
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* @param everyPage D.R 7#^.
* @param currentPage *f$wmZ5A
* @param totalRecords 6'qC *r
* @return page \LpR7D
*/ Ta3qEV s
publicstatic Page createPage(int everyPage, int -V)DKf"f
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currentPage, int totalRecords){ *R6Ed
everyPage = getEveryPage(everyPage); rSvQarT
currentPage = getCurrentPage(currentPage); $Y5m"wySZ
int beginIndex = getBeginIndex(everyPage, Grw|8xN0t
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currentPage); $.2#G"|
int totalPage = getTotalPage(everyPage, h|j$Jy
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totalRecords); zn'F9rWx>
boolean hasNextPage = hasNextPage(currentPage, 5J4'\M
8vLaSZ="[
totalPage); t$lO~~atr
boolean hasPrePage = hasPrePage(currentPage); yy%'9E ldc
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returnnew Page(hasPrePage, hasNextPage, $kA'9Y
everyPage, totalPage, 6RLYpQ$+
currentPage, ?(4E le
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beginIndex); V6C*d:
} %|:Gn) 8
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privatestaticint getEveryPage(int everyPage){ ,MxTT!9Su
return everyPage == 0 ? 10 : everyPage; .MzVc42<
} \Y0o~JD
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privatestaticint getCurrentPage(int currentPage){ oK5"RW
return currentPage == 0 ? 1 : currentPage; oWu2}#~z_
} 7)`U%}R
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privatestaticint getBeginIndex(int everyPage, int d@a FW
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currentPage){ XvU^DEfW
return(currentPage - 1) * everyPage;
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} *oC],4y~D
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privatestaticint getTotalPage(int everyPage, int 'Olp2g8=
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totalRecords){ sw={bUr6G`
int totalPage = 0; hGPo{>xR
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if(totalRecords % everyPage == 0) /A8ua=Kn
totalPage = totalRecords / everyPage; J|9kWjOf+i
else -bN;nSgb
totalPage = totalRecords / everyPage + 1 ; Z r}5)ZR.
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return totalPage;
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} #Sxk[[KwH*
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privatestaticboolean hasPrePage(int currentPage){ r\OunGUP
return currentPage == 1 ? false : true; e;+6U"Jx*
}
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privatestaticboolean hasNextPage(int currentPage, c>_tV3TDA
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int totalPage){ O%g
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return currentPage == totalPage || totalPage == |[)k5nUQ|
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0 ? false : true; ',7LVT7
} 4LEWOWF}
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} nx
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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。 zBQV2.@
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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 Oe)d|6=
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做法如下: >>cb0fH5
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 i\zVP.c])*
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的信息,和一个结果集List: `D%U5Jb
java代码: w#XD4kwQG
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cs
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/*Created on 2005-6-13*/ \aN*x
package com.adt.bo; z#[PTqD-_
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import java.util.List; NihUCj"
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import org.flyware.util.page.Page; yTxrbE
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/** ,qT^e8E+
* @author Joa 5%_aN_1?ef
*/ K8=jkU
publicclass Result { b8
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{;L,|(o^
private Page page; Ka_g3
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private List content; "5!T-Z+F
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/** 3;O4o]`
* The default constructor 8FIk|p|l^
*/ mDXG~*1
public Result(){ H%b c.c
super(); ~n~j2OE
} !(F?Np Am
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/** SHYbQF2
* The constructor using fields lhC^Upqw
* noso* K7
* @param page |vw],r6
* @param content X<D fzd oI
*/ jL7r1pu5
public Result(Page page, List content){ mKqXB\<
this.page = page; VRZqY7j}g
this.content = content; Q Hr'r/0
} hD[r6c
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/** 5WA:gy gB&
* @return Returns the content. (HXKa][T
*/ UcKVLzKs
publicList getContent(){ Qr_0
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return content; x_x_TEyy h
} GkIhPn(d
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/** }[=)sb_
* @return Returns the page. B]NcY&A
*/ ${rWDZ0Z
public Page getPage(){ *8_Dn}u?Jx
return page; lcLDCt?
} tDavp:M1v
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/** C=(Q0-+L|
* @param content p>i8aN
* The content to set. +_k A&Q(t
*/ omGzyuPF
public void setContent(List content){ P*B@it
this.content = content; -LT!LBnEkf
} HI{h>g T
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/** OSfT\8YA
* @param page m+(g.mvK>
* The page to set. _!VtM#G[
*/ U?d
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publicvoid setPage(Page page){ P(FlU]q
this.page = page; /qJC p![X
} Mtv{37k~
} n.qT7d(
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