Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 O?CdAnhQc`
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .>}BNy
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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 (Aorx #z
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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 G'u|Q
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分页支持类: z&O#v9.NE|
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java代码: # Mu<8`T-
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package com.javaeye.common.util; 13H;p[$
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import java.util.List; Hb+X}7c$
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publicclass PaginationSupport { z)
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publicfinalstaticint PAGESIZE = 30; ymYBm:"
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privateint pageSize = PAGESIZE; 1Pm4.C)
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privateList items; jgG$'|s}
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privateint totalCount; /hL\,x2
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privateint[] indexes = newint[0]; E, GN| l
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privateint startIndex = 0; ["u#{>(X
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public PaginationSupport(List items, int OZf6/10O/
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totalCount){ k0JW[04j
setPageSize(PAGESIZE); S<"oUdkz
setTotalCount(totalCount); %)?`{O~ h
setItems(items); zVw:7-
setStartIndex(0); Or7
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} EkjgNEXq
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public PaginationSupport(List items, int RND9D\7
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totalCount, int startIndex){ Fk{J@Y
setPageSize(PAGESIZE); e4DMO*6
setTotalCount(totalCount); nob0T5G
setItems(items); 8f|98T"
setStartIndex(startIndex); j
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} 5MR,UgT
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public PaginationSupport(List items, int V7EQ4Om:It
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totalCount, int pageSize, int startIndex){ +y/ 55VLq
setPageSize(pageSize); \|.7-X
setTotalCount(totalCount); ,beS0U]
setItems(items); QOH<]~3J
setStartIndex(startIndex); `rlk|&T1
} vy[C'a
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publicList getItems(){ +>SRrIi
return items; ZIDbqQu
} _|A+) K
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publicvoid setItems(List items){ {WQq}-(
this.items = items; y \D=Z
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} <.bRf
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publicint getPageSize(){ Od##U6e`
return pageSize; &l m#
} )"|||\Iv
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publicvoid setPageSize(int pageSize){ MG{l~|\x)
this.pageSize = pageSize; Y1)!lTG
} ^AL2H'
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publicint getTotalCount(){ bWmw3w
return totalCount; j/KO|iNL2
} po7>IQS]
* ?]~
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publicvoid setTotalCount(int totalCount){ =^tA_AxVw
if(totalCount > 0){ iX "C/L|JN
this.totalCount = totalCount; U>a\j2I
int count = totalCount / Jxa4hM0
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pageSize; g9~]s9
if(totalCount % pageSize > 0) pDl3!m
count++; @kxel`,$e
indexes = newint[count]; IeP
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for(int i = 0; i < count; i++){ TB!(('
indexes = pageSize * T^:fn-S}=
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i; O"Q7Rx
} ) #+^
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}else{ l63hLz
this.totalCount = 0; vUesV%9hq
} _las;S'oa
} ~b)74M/
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publicint[] getIndexes(){ ,R2U`EO;
return indexes; =a}b+(R
} "N5!mpD"
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publicvoid setIndexes(int[] indexes){ E\U`2{^.
this.indexes = indexes; 2oCkG~j
} _zMgoc7
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publicint getStartIndex(){ U*)m',
return startIndex; Iz@)!3h
} =d)-Fd2li
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publicvoid setStartIndex(int startIndex){ j Ux
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if(totalCount <= 0) +>\id~c(
this.startIndex = 0; MTOy8 Im
elseif(startIndex >= totalCount) eE@&ze>X
this.startIndex = indexes }4//@J?:
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[indexes.length - 1]; AUe# RP
elseif(startIndex < 0) ~1L:_Sg*
this.startIndex = 0; OLC{iD#
else{ 7.g[SBUOG
this.startIndex = indexes t2BL(yB
,|kDsR!
[startIndex / pageSize]; 6#@ f'~s
} om h{0jA0
} 7U|mu~$.!
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publicint getNextIndex(){ ,yd= e}lQx
int nextIndex = getStartIndex() + _zWfI.o
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pageSize; hrGH}CU"
if(nextIndex >= totalCount) hC <O`|lF
return getStartIndex(); Pr ]Ka
else =#gEB#$x:
return nextIndex; NMOut@
} QPtGdd
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publicint getPreviousIndex(){ c%m3}mrb
int previousIndex = getStartIndex() - U.!lTLjfLz
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pageSize; ,#?uJTLH
if(previousIndex < 0) T"7~AbgNU
return0; $(e#aHB
else X;v$5UKU
return previousIndex; '6y}ZE[
} MY#
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} UFAL1c<V
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抽象业务类 V'*~L\;pU
java代码: !`41q=r
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/** %\|'%/"`2(
* Created on 2005-7-12 o6
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*/ Jc&y9]
package com.javaeye.common.business; QTX8
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import java.io.Serializable; 4lhw3,5
import java.util.List; @Z>ZiU,^
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import org.hibernate.Criteria; w}Uhd,
import org.hibernate.HibernateException; o*U]v
import org.hibernate.Session; s*U1
import org.hibernate.criterion.DetachedCriteria; $un?0S
import org.hibernate.criterion.Projections; `Qr%+OD
import J]f3CU,<N
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org.springframework.orm.hibernate3.HibernateCallback; _4^R9Bt
import l2N]a9bq@
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org.springframework.orm.hibernate3.support.HibernateDaoS \%^%wXfp
]BR,M4
upport; U!U$x74D5
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import com.javaeye.common.util.PaginationSupport; {ZY+L;eg1
P) 3mX.(}
public abstract class AbstractManager extends U- )i+}Ng
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HibernateDaoSupport { E4m`
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privateboolean cacheQueries = false; (=~&+z
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privateString queryCacheRegion; ,^#yo6-
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publicvoid setCacheQueries(boolean y~()|L[
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cacheQueries){ _6ay-u
this.cacheQueries = cacheQueries; RV@*c4KvO+
} lz1wO5%h
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publicvoid setQueryCacheRegion(String E@7J:|.)R
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queryCacheRegion){ Um&(&?Xf
this.queryCacheRegion = J9~g|5
{e|[%reSkg
queryCacheRegion; Z+@2"%W
} E Cyyl
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publicvoid save(finalObject entity){ +TXX$)3%
getHibernateTemplate().save(entity); K tNY_&xd
} )7h$G-fe
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publicvoid persist(finalObject entity){ 6{txm+U
getHibernateTemplate().save(entity); itC-4^
} Ja9e^`i;
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publicvoid update(finalObject entity){ s6>ZREf#J
getHibernateTemplate().update(entity); =:~R=/ZXk
} KEWTBBg
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publicvoid delete(finalObject entity){ jy'13G/b\
getHibernateTemplate().delete(entity); z[Xd%mhjO
} P#AW\d^"B
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publicObject load(finalClass entity, >y,-v:Vy
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finalSerializable id){ D-c`FG'
return getHibernateTemplate().load 'q`^3&E
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(entity, id); 1YH+d0UGn
} MG.`
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publicObject get(finalClass entity, Dd\jHF>u
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finalSerializable id){ rW=Z>1
return getHibernateTemplate().get I"GB<oB
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(entity, id); +llR204
} !jTcsN%
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publicList findAll(finalClass entity){ "men
return getHibernateTemplate().find("from &G-!qxe
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" + entity.getName()); /{&tY:;m
} bD?VU<)3
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publicList findByNamedQuery(finalString #)nSr
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namedQuery){ s=;uc]9g
return getHibernateTemplate u?}(P_9
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().findByNamedQuery(namedQuery); ynQ: >tw
} P09;ng67
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publicList findByNamedQuery(finalString query, ZusEfh?
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finalObject parameter){ \RG8{G,
return getHibernateTemplate bJX)$G
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().findByNamedQuery(query, parameter); @"^0%/2-
} tIuCct-
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publicList findByNamedQuery(finalString query, W>j !Q^?
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finalObject[] parameters){ ]jo1{IcI
return getHibernateTemplate 0E3[N:s
)84 ~ugs
().findByNamedQuery(query, parameters); l`f/4vy
} I+tb[*X+
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publicList find(finalString query){ vbyH<LPz5
return getHibernateTemplate().find lIW
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(query); =ACVE;L?
} 24z< gO
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publicList find(finalString query, finalObject zN^n]N_?
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parameter){ Gz,i~XX
return getHibernateTemplate().find {?:X8&Sf
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(query, parameter); $\X[@E S0
} ~?K ~L~f5
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public PaginationSupport findPageByCriteria )-a'{W/t
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(final DetachedCriteria detachedCriteria){ ewctkI$,5
return findPageByCriteria tFp Ygff<
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); K<>oa[B9
} XovRg,
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public PaginationSupport findPageByCriteria nU7>uU
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(final DetachedCriteria detachedCriteria, finalint i3@)W4{
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startIndex){ w9< R#y[A
return findPageByCriteria &L'Dqew,*
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Y
(detachedCriteria, PaginationSupport.PAGESIZE, >n'o*gZM
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startIndex); '"SEw
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} l`#4KCL(
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public PaginationSupport findPageByCriteria r]:(Vk]|F
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(final DetachedCriteria detachedCriteria, finalint H4:`6 PSL
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pageSize, /|C*
finalint startIndex){ -zOdU}91Ao
return(PaginationSupport) l]Ax : Z
}fb#G<3
getHibernateTemplate().execute(new HibernateCallback(){ +BETF;0D
publicObject doInHibernate Lr$go6s
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(Session session)throws HibernateException { pNepC<rY
Criteria criteria = xhVO3LW'
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detachedCriteria.getExecutableCriteria(session); v0z5j6)-1
int totalCount = vHryPl+
}$SavB#SBP
((Integer) criteria.setProjection(Projections.rowCount (l^3Z3zf&
,,%i;
()).uniqueResult()).intValue(); gQ Fjr_IS#
criteria.setProjection D$
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(null); /:~\5}tW
List items = 6e9,PS
+6HVhoxU#
criteria.setFirstResult(startIndex).setMaxResults MQ5R O;RY
T@2#6Tffo
(pageSize).list(); #`CA8!j!!
PaginationSupport ps = f$e[u
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new PaginationSupport(items, totalCount, pageSize, Dfg2`l
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startIndex); 6Ypc`
return ps; We$:&K0
} E ~Sb
}, true); ,?8qpEG~#+
} $q6BP'7
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public List findAllByCriteria(final )h"<\%LU
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DetachedCriteria detachedCriteria){ uwzvb gup?
return(List) getHibernateTemplate [$0p+1
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().execute(new HibernateCallback(){ \?[v{WP)
publicObject doInHibernate -]/I73!b
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(Session session)throws HibernateException { ^Cu\VV
Criteria criteria = ?pr9f5
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detachedCriteria.getExecutableCriteria(session); K1mPr^3rC
return criteria.list(); *"?l ]d
} K28+]qy[
}, true); K2M~-S3
} qLn/2
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public int getCountByCriteria(final U`R5'Tf;
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DetachedCriteria detachedCriteria){ `Nz/Oh7
Integer count = (Integer) /oR0+sH]
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getHibernateTemplate().execute(new HibernateCallback(){ 2|3)S`WZl
publicObject doInHibernate RQ vft
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(Session session)throws HibernateException { UW N*j_9i
Criteria criteria = PDJr<E?
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detachedCriteria.getExecutableCriteria(session); H$=e
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return QLXN*c
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criteria.setProjection(Projections.rowCount HG^B#yX
.{ocV#{s
()).uniqueResult(); Wvbf"hq
} kpJ@M%46
}, true); UtPLI al
return count.intValue(); !}YAdZJ
} %`>nS@1zp
} ?I6fye7
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用户在web层构造查询条件detachedCriteria,和可选的 f!\lg
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 WKC.$[T=
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PaginationSupport的实例ps。 f\]sz?KY
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ps.getItems()得到已分页好的结果集 $+P>~X)
ps.getIndexes()得到分页索引的数组 ?oVx2LdD|
ps.getTotalCount()得到总结果数 S=5<^o^h3
ps.getStartIndex()当前分页索引 OVm\
ps.getNextIndex()下一页索引 X &uTSgN
ps.getPreviousIndex()上一页索引 AJh w
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 JLnH&(O
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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 >"|B9Woc
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一下代码重构了。 iX0i2ek
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我把原本我的做法也提供出来供大家讨论吧: 4lr(,nPRD
n"c)m%yZ
首先,为了实现分页查询,我封装了一个Page类: S)cLW~=z
java代码: $w)!3c4
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/*Created on 2005-4-14*/ NG--6\
package org.flyware.util.page; 2;zb\d
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/** igkYX!0#8O
* @author Joa 1Yq?X:
* 8B/\U'
*/ e5* ni/P
publicclass Page { S]bmS6#
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/** imply if the page has previous page */ \#f<!R4
privateboolean hasPrePage; UYk/v]ZA
K?[q%W]%
/** imply if the page has next page */ xDG2ws=@D
privateboolean hasNextPage; 4i6q{BeHn
u$>4F|=T
/** the number of every page */ /RNIIY~w
privateint everyPage; kW*f.!
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/** the total page number */ dYG,_ji
privateint totalPage; v'U{/ ,x
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/** the number of current page */ :Pvzl1
privateint currentPage; =:&ly'QB&
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/** the begin index of the records by the current 4.Q} 1%ZN
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query */ )[PtaPWeT
privateint beginIndex; v>$'iT~ l
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/** The default constructor */ fI{E SXU
public Page(){ tasIDoo+!J
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} IEXt:
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/** construct the page by everyPage UELy"z
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* @param everyPage x,rlrxI
* */ >64P6P;S
public Page(int everyPage){ uEktQ_u[
this.everyPage = everyPage; +@94;me
} 8"U. Hnu
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/** The whole constructor */ <L"GqNuRQ
public Page(boolean hasPrePage, boolean hasNextPage, v{(^1cX
7uKNd
*%
{ &"CH]r
int everyPage, int totalPage, spdvZU=}
int currentPage, int beginIndex){ qT%FmX
this.hasPrePage = hasPrePage; I$<<(VWH
this.hasNextPage = hasNextPage; ;g @4|Ro
this.everyPage = everyPage; eZSNNgD<:
this.totalPage = totalPage; =osv3>&q
this.currentPage = currentPage; &7`^i.fh)
this.beginIndex = beginIndex; YpH&<$x:
} S'4(0j
rf?qdd(~cH
/** yUZb#%n
* @return O!P H&;H
* Returns the beginIndex. y`F3Hr c
*/ U&Wt%U{
publicint getBeginIndex(){ F@mQQ
return beginIndex; r~/
} rf>0H^r
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/** _J Hd9)[
* @param beginIndex VtnRgdJ
* The beginIndex to set. `+o2DA)#(
*/ cl]Mi
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publicvoid setBeginIndex(int beginIndex){ 5_- (<B
this.beginIndex = beginIndex; v*r7Zz6l
} ToJ$A`_!`
z.kvX+7'
/** b6U2GDm\s
* @return Y&S24aql
* Returns the currentPage. l8I /0`_
*/ swK-/$#
publicint getCurrentPage(){ F({HP)9b
return currentPage; Fh`~`eog
} /W>iJfx
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/** #~7ip\Uf[
* @param currentPage Bwa'`+bC
* The currentPage to set. KVn []@#
*/ i+p^ ^t\
publicvoid setCurrentPage(int currentPage){ ,cB\
this.currentPage = currentPage; mS~o?q-n
} *v9 2
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/** K
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* @return yf[~Yl>Ogw
* Returns the everyPage. -=~| ."O
*/ ~$)2s7
O
publicint getEveryPage(){ {OXFN;2
return everyPage; ,q}MLTSi
} H@q?v+2
U*22h` S
/** ujlY!-GM
* @param everyPage @JD;k>
* The everyPage to set. QR%mj*@Wle
*/ ;_rF;9z9
publicvoid setEveryPage(int everyPage){ ,1 [q^-9
this.everyPage = everyPage; }T&iewk
} NYrQ$N"
v6>_ j
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/** | # 47O
* @return {u#;?u=|
* Returns the hasNextPage. +kzo*zW$L
*/ j@SQ~AS
publicboolean getHasNextPage(){ $npT[~U5
return hasNextPage; Dp)=0<$y
} sg$rzT-S4
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/** V:VO[e<e
* @param hasNextPage m9.{[K"
* The hasNextPage to set. 9%B\/&f
*/ (NF~Ck$#q
publicvoid setHasNextPage(boolean hasNextPage){ _3TY,l~
this.hasNextPage = hasNextPage; )N7Y^CN~
} 4\Tl\SZ?
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/** mt,OniU= Q
* @return 0=AVW`J
* Returns the hasPrePage. BT}!W`
*/ 3E!|<q$z
publicboolean getHasPrePage(){ 1Cv-
return hasPrePage; ?u "
4@
} 7f0lQ
K`u(/kz/<
/** `HZ;NRr
* @param hasPrePage |}(`kW
* The hasPrePage to set. FaDjLo2'o
*/ mP0yk|
publicvoid setHasPrePage(boolean hasPrePage){ m^ tFi7c
this.hasPrePage = hasPrePage; y:~ZLTAv
} rA%usaW
-o$QS,
/** '}B+r@YCN
* @return Returns the totalPage. Cjc6d4~
* Gn ~6X-l
*/ G!>z;5KuS
publicint getTotalPage(){ e\!0<d
return totalPage; t!r A%*
} j4|N-:
Kx;eaz:gx
/** eHn7iuS8
* @param totalPage <vONmE a
* The totalPage to set. jRJn+
*/ 0n;<
ge&~R
publicvoid setTotalPage(int totalPage){ ;" dV"W
this.totalPage = totalPage; -f% '
} q*_/to
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} 925|bX6I
}BZ"S-hZ
C71qPb|$R
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 BD_Iz A<wK
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个PageUtil,负责对Page对象进行构造: WtG~('g>&
java代码: >8WP0Qx/
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C8Qa$._
/*Created on 2005-4-14*/ 2+QY hdw
package org.flyware.util.page; i rU 6D
Y
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import org.apache.commons.logging.Log; ow_W%I=6
import org.apache.commons.logging.LogFactory; {2=jAz'?
A OISs4
/** mH%yGBp_
* @author Joa = \'}g?
* n
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*/ b:lP%|7
publicclass PageUtil { jL%x7?*U0
8Kg n"M3
privatestaticfinal Log logger = LogFactory.getLog *h!28Ya(~
r+":' /[x
(PageUtil.class); rH_\d?b
nqI@Y)
/** Cd,jDPrw
* Use the origin page to create a new page FbS|~Rp~
* @param page gW>uR3Ca4
* @param totalRecords gQ'zW
* @return oU056
*/ g!lWu[d
publicstatic Page createPage(Page page, int $Tu61zq
gl\\+VyU
totalRecords){ /?@3.3sl_
return createPage(page.getEveryPage(), pGJ>O/%
%?}33yV
page.getCurrentPage(), totalRecords); i~I%D%;
} 2NC.Z;
bCo7*<I4
/** fZ0M%f
* the basic page utils not including exception =G7m)!
cq}EZ@ .
handler `A w^H!
* @param everyPage d:BG#\e]v
* @param currentPage AK'[c+2[
* @param totalRecords Fq|Ni$
* @return page z\K"Rg~J
*/ yE:+Lo`>
publicstatic Page createPage(int everyPage, int ;j[>9g
h"X;3b^ m
currentPage, int totalRecords){ .E`\MtA
everyPage = getEveryPage(everyPage); |bTPtrT8
currentPage = getCurrentPage(currentPage); G`cHCP_n
int beginIndex = getBeginIndex(everyPage, ZrPbl"`7
KN<S}3MN
currentPage); /N =b\-]
int totalPage = getTotalPage(everyPage, 6 :b!F
qTdh eX/
totalRecords); TE3lK(f
boolean hasNextPage = hasNextPage(currentPage, d,+Hd2o^X
B2>H_dmQ
totalPage); ;LcZ`1
boolean hasPrePage = hasPrePage(currentPage); 0z1ifg&
U'H$`$Ov
returnnew Page(hasPrePage, hasNextPage, U{2BVqM
everyPage, totalPage, J!c)s!`w
currentPage, $xzAv{
I'A_x$ib6
beginIndex); ojaws+(& y
} >_[9t
t^+ik1.
privatestaticint getEveryPage(int everyPage){ \pPY37l
return everyPage == 0 ? 10 : everyPage; X <f8,n
} [xSF6
B
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privatestaticint getCurrentPage(int currentPage){ zr-*$1eu
return currentPage == 0 ? 1 : currentPage; tXNm$Cq.|
} !%CWZZ 6u
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privatestaticint getBeginIndex(int everyPage, int s'!Cp=xQF"
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currentPage){ S0zD"T
return(currentPage - 1) * everyPage; ]~9tYn
} ZGexdc%
wxKX{Bs
privatestaticint getTotalPage(int everyPage, int ?qPo=~y01
f.D?sH An
totalRecords){ MqW7cjg
int totalPage = 0; TrlZ9?3#D
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if(totalRecords % everyPage == 0) ;&9)I8Us
totalPage = totalRecords / everyPage; "|EM;o
else ]D?"aX'q>
totalPage = totalRecords / everyPage + 1 ; ")SFi^]
T1 ut"Zu
return totalPage; |n2qVR,
} ) pzy
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privatestaticboolean hasPrePage(int currentPage){ dMh:ulIY>
return currentPage == 1 ? false : true; 3eb%OEMYk
} 2L3)#22m*
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privatestaticboolean hasNextPage(int currentPage, sd*p/Q|4
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k]
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int totalPage){ 9B{k , 1
return currentPage == totalPage || totalPage == i+A3~w5c
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0 ? false : true; c23oCfB>
} VLOO8N[o
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} Kz~ps
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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。 ,vr? 2k
HJ9Kz^TnC
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 t_o['F
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做法如下: bp*
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1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 \d6C%S!
= I:.X ;
的信息,和一个结果集List: urbp#G/>
java代码: 51#_Vg
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/*Created on 2005-6-13*/ dzARI`
package com.adt.bo; =b%MXT
1a?!@g)
import java.util.List; $|L
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import org.flyware.util.page.Page; qB~rQPa
,kiv>{
/** q3mJ782p]
* @author Joa v_BcTzQ0S
*/ @:j}Jmg
publicclass Result { 8NxM4$nQX
B}n,b#,*
private Page page; |9u OUE
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private List content; 8*W#DH!
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/** ^hG-~z<
* The default constructor UvJ}b
*/ @'w"R/,n-@
public Result(){ :G [|CPm-
super(); QqDC4+p"
} VyXKZ%\dQ/
y0Fb_"}
/** &:;:"{t}Do
* The constructor using fields ~FZ&.<s
* xu>9(,l
* @param page V_R@o3kv;
* @param content xR-%L
*/ F0pir(n-
public Result(Page page, List content){ hcgMZT!<5
this.page = page; 9%k2'iV7
this.content = content; zpzK>DH(
} Cl5uS%g
zvvhFN2s
/** o15-ZzE-
* @return Returns the content. "~#3&3HVS
*/ N,`$M.|?
publicList getContent(){ ,KF'TsFf
return content; #pT"BSz]
} Vrjc~>X
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/** viW!,QQ(S
* @return Returns the page. ({
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*/ Ar%%}Gx/
public Page getPage(){ .?D7dyU l1
return page; `n.5f[wC
} %oF}HF.
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/** _ q(ko/T
* @param content 61Bwb]\f/|
* The content to set. }d[ kxo
*/ bbtGXfI+SB
public void setContent(List content){ 18)'c?^.
this.content = content; +dWDxguE{w
} Y4OPEo 5o
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/** rDD:7*z
* @param page ")_|69 VX
* The page to set.
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*/ l\E%+?K+^
publicvoid setPage(Page page){ ",p;Sd
this.page = page; 0QBiC]9
} %r<rcY
} NC8t)
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S(o#K|)>
9?A)n4b;
ko5 @qNq
2. 编写业务逻辑接口,并实现它(UserManager, #Z}Rfk(~
Bz_^~b7
UserManagerImpl) }Q)#[#e
java代码: ~t@cO.c
\6S7T$$ 1m
Km%]1X7T6
/*Created on 2005-7-15*/ P!~MZ+7#&
package com.adt.service; &LmJ!^#
4ae`pAu
import net.sf.hibernate.HibernateException; ?# Mr
8/DS:uM
import org.flyware.util.page.Page; QsGiclU
3RiWZN
import com.adt.bo.Result; H;D>|q
Qwz}B
/** v&Ii^?CvO
* @author Joa f&