Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 c!wRq4
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 CALD7qMK
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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 *!BQ1] G
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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 047PlS
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分页支持类: ,P`G IGvkA
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java代码: SIR2 Kc0
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package com.javaeye.common.util; Hmhsb2`\
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import java.util.List; z2,NWmP|w
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publicclass PaginationSupport { w ~crj$UM
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publicfinalstaticint PAGESIZE = 30; 1pDU}rPJ.
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privateint pageSize = PAGESIZE; tK{#kApHGG
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privateList items; _4SZ9yu
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privateint totalCount; u^E0u^
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privateint[] indexes = newint[0]; E)jd>"
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privateint startIndex = 0; (,+#H]L
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public PaginationSupport(List items, int +N+117m
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totalCount){ <im}R9eJ1
setPageSize(PAGESIZE); e<`?$tZ3
setTotalCount(totalCount); W
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setItems(items); k$J!,!q
setStartIndex(0); /=9dX;
#
} KV&6v`K/N
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public PaginationSupport(List items, int Wrp+B[{r\
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totalCount, int startIndex){ }u0&> k|y
setPageSize(PAGESIZE); fiSX( 9
setTotalCount(totalCount); _]Ob)RUVH
setItems(items); qyKR]%yzi
setStartIndex(startIndex); =+DhLH}8
} P2s\f;Dwr
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public PaginationSupport(List items, int f8r7SFwUv
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totalCount, int pageSize, int startIndex){ f!5w+6(
setPageSize(pageSize); BU>R<A5h
setTotalCount(totalCount); 4o@:+T:1
setItems(items); P()W\+",n
setStartIndex(startIndex); I D-I<Ev
} hDUU_.q)D
Y|hd!C-x
publicList getItems(){ ks%;_~b
return items; -p7
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} 3&M0@/
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publicvoid setItems(List items){ w7pX]<?R"
this.items = items; edlf++r~
} J
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publicint getPageSize(){ j%]sym
return pageSize; R! X+-
} gCkR$.-E
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publicvoid setPageSize(int pageSize){ Q\xDAOEL
this.pageSize = pageSize; G
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} 3bo
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publicint getTotalCount(){ ;KmrBNF
return totalCount; (0_zp`)
} IIBS:&;+-
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publicvoid setTotalCount(int totalCount){ k_?OEkgUh
if(totalCount > 0){ | lzcyz
this.totalCount = totalCount; a[}?!G-Wt|
int count = totalCount / +`B^D
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pageSize; {dE(.Z?]!#
if(totalCount % pageSize > 0) PGYx]r
count++; +tg${3ti_
indexes = newint[count]; Rm$( X5x>o
for(int i = 0; i < count; i++){ @/$i
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indexes = pageSize * !>Q\Y`a,*
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i; ? }`mQ <~
} ==%5Ci7qMy
}else{ e8(Qx3T?b
this.totalCount = 0; j*f\Z!EeZ
} uXUuA/O5-
} 7'{Vh{.
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publicint[] getIndexes(){ y
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return indexes; SXJjagAoML
} 7,alZ"%W
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publicvoid setIndexes(int[] indexes){ {36N=A
this.indexes = indexes; {:n1|_r4Z
} seP h%Sa_
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publicint getStartIndex(){ @"^7ASd%
return startIndex; JdWav!PYm
} {'{9B
m,]9\0GUd
publicvoid setStartIndex(int startIndex){ 9p^gF2?k
if(totalCount <= 0) ZIh)D[n
this.startIndex = 0; ^4<&"aoo
elseif(startIndex >= totalCount) }mUb1b
this.startIndex = indexes h>!9N
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[indexes.length - 1]; e$`hRZ%
elseif(startIndex < 0) WW^+X~Y
this.startIndex = 0; `P:[.hRu
else{ H<?s[MH[
this.startIndex = indexes hK{<&T
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[startIndex / pageSize]; (#z6w#CU(
} 8=0I4\
} $2}%3{<j
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publicint getNextIndex(){ &=:3/;c
int nextIndex = getStartIndex() + ZYt <O
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pageSize; Xi\c>eALO
if(nextIndex >= totalCount) =WZ@{z9J
return getStartIndex(); ?FR-aXx
else +.|RH
return nextIndex; S9%,{y
} pDvznpQ
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publicint getPreviousIndex(){ pW>{7pXn
int previousIndex = getStartIndex() - PQh s^D
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pageSize; 0plX"NU
if(previousIndex < 0) F>X<=YO0
return0; pe3;pRh'
else ),xD5~_=q
return previousIndex; &" J;
} wg\p&avvb
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} SN\c2^#
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抽象业务类 A%^7D.j
java代码: }owl7G3
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/** )Z['=+s%
* Created on 2005-7-12 _G25$%/LU
*/ E7aG&K
package com.javaeye.common.business; n"Bc2}{
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import java.io.Serializable; apfr>L3
import java.util.List; iXvrZofE
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import org.hibernate.Criteria; _)~VKA]""
import org.hibernate.HibernateException; ?~yJ7~3TS<
import org.hibernate.Session; 5wl;fL~e
import org.hibernate.criterion.DetachedCriteria; #5'&
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import org.hibernate.criterion.Projections; ``6-
import Nv6"c<(L=
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org.springframework.orm.hibernate3.HibernateCallback; D&~%w!
import Vry_X2
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org.springframework.orm.hibernate3.support.HibernateDaoS 6h %rt]g
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upport; 6CW5ay_,
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import com.javaeye.common.util.PaginationSupport; ~oT*@
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public abstract class AbstractManager extends KNj~7aTp
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HibernateDaoSupport { J1~E*t^
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privateboolean cacheQueries = false; #Q*V9kvU/H
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privateString queryCacheRegion; BpYxH#4
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publicvoid setCacheQueries(boolean tAI
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cacheQueries){ 4i^WE;|s
this.cacheQueries = cacheQueries; K{"hf:k
} W-/V5=?
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publicvoid setQueryCacheRegion(String `<M>"~W
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queryCacheRegion){ _:p-\Oo.
this.queryCacheRegion = J.M&Vj:
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queryCacheRegion; uLPBl~Y
} 5/7(>ivn
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publicvoid save(finalObject entity){ 0(:SEiz6s
getHibernateTemplate().save(entity); FOMJRq
} vZ.<OD4
< *;GJ{
publicvoid persist(finalObject entity){ jvL!pEC!
getHibernateTemplate().save(entity); 9n;6zVV%`
} 5$cjCjY
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publicvoid update(finalObject entity){
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getHibernateTemplate().update(entity); 57gt"f
} 5s`r&2 w
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publicvoid delete(finalObject entity){ h,]VWG
getHibernateTemplate().delete(entity);
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} ;e/F( J
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publicObject load(finalClass entity, }*xjO/Ey
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finalSerializable id){ ?# _{h
return getHibernateTemplate().load pi/0~ke4"
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(entity, id); ()O&O+R|)
} \]5I atli
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publicObject get(finalClass entity, ctLNzJes%
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finalSerializable id){ [Z#Sj=z
return getHibernateTemplate().get 5\#I4\
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(entity, id); ov;^ev,(
} +jF2{"
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publicList findAll(finalClass entity){ 2.b,8wT/
return getHibernateTemplate().find("from PoPR34]^J
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" + entity.getName()); GQ7uxdqWBQ
} ~?HK,`0h>
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publicList findByNamedQuery(finalString gD4vV'|
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namedQuery){ 3Ke6lV)uq
return getHibernateTemplate m|{^T/kIbQ
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().findByNamedQuery(namedQuery); GJrmK
} L+<h5>6
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publicList findByNamedQuery(finalString query, {5<fvMO!6
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finalObject parameter){ bp=r]nO
return getHibernateTemplate 4R\jZ@D
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().findByNamedQuery(query, parameter); %]DA4W
} =&$z
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publicList findByNamedQuery(finalString query, Abt<23$h
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finalObject[] parameters){ sVw:d_ E
return getHibernateTemplate !3Pmjip
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().findByNamedQuery(query, parameters); s_VcC_A
} 9*ZlNZ
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publicList find(finalString query){ E1OrL.A6
return getHibernateTemplate().find mY4pvpZw8
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(query); #O\as~-
} rlY0UA,
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publicList find(finalString query, finalObject UgS`{&b36
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parameter){ 86Q3d%;-yo
return getHibernateTemplate().find 2J&~b 8 :
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(query, parameter); kex V~Q
} e7xBi!I)~
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public PaginationSupport findPageByCriteria ~ a`[p\
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(final DetachedCriteria detachedCriteria){ _r{H)}9
return findPageByCriteria <a @7's
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); .G!xcQ`?
} 6Uk+a=Ar
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public PaginationSupport findPageByCriteria 5 k3m"*
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(final DetachedCriteria detachedCriteria, finalint J~]@#=,v
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startIndex){ ^?+[yvq
return findPageByCriteria P{6$".kIY
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(detachedCriteria, PaginationSupport.PAGESIZE, '!7>*<
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startIndex); goIvm:?
} ~. vridH
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public PaginationSupport findPageByCriteria (!5Ta7X
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(final DetachedCriteria detachedCriteria, finalint aM;SE9/U
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pageSize, %0C [v7\
finalint startIndex){ .F 6US<]
return(PaginationSupport) },l
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getHibernateTemplate().execute(new HibernateCallback(){ <lf692.3
publicObject doInHibernate $e7%>*?m
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(Session session)throws HibernateException { .s*N1
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Criteria criteria = F8?2+w@P
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detachedCriteria.getExecutableCriteria(session); g&xj(SMj-$
int totalCount = @9HRGxJ=}
:
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((Integer) criteria.setProjection(Projections.rowCount fc*>ky.v
1 #,4P1"
()).uniqueResult()).intValue(); rx gSQ+G_
criteria.setProjection $lf/Mg_H
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(null); .))jR:{3
List items = 3&^hf^yg
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criteria.setFirstResult(startIndex).setMaxResults Jq&Hz$L|
-eF-r=FR
(pageSize).list(); {kk%_q
PaginationSupport ps = >S7t
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new PaginationSupport(items, totalCount, pageSize, h8`On/Ur_8
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startIndex); K'Ywv@
return ps; 2j%=o?me^p
} wBXa;.
}, true); M\m:H3[
} `CS\"|z
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public List findAllByCriteria(final Ur
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DetachedCriteria detachedCriteria){ H_RfIX)X
return(List) getHibernateTemplate iN
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().execute(new HibernateCallback(){ I2$DlEke
publicObject doInHibernate \
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(Session session)throws HibernateException { vYV!8o.I
Criteria criteria = BrE#.g Jq
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detachedCriteria.getExecutableCriteria(session); o(SPT?ao~
return criteria.list(); ih0a#PB8
} >k\pSV[
}, true); @\ y{q;
} O]PM L`
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public int getCountByCriteria(final &6vaLx
w/*G!o-<
DetachedCriteria detachedCriteria){ !YAX.e
Integer count = (Integer) 7?whxi Qs
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getHibernateTemplate().execute(new HibernateCallback(){ Q0R05*
publicObject doInHibernate =l43RawAmu
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(Session session)throws HibernateException { A,_O=hA2I
Criteria criteria = ) 1AAL0F\B
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detachedCriteria.getExecutableCriteria(session); tC'E#2
return BwWSztJ+B
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criteria.setProjection(Projections.rowCount ej-A=avd
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()).uniqueResult(); +;~o R_p
} kku<0<(N
}, true); JI.=y5I
return count.intValue(); _s5^\~ao
} Gf"TI:xa
} i"a3POV>
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用户在web层构造查询条件detachedCriteria,和可选的 X+]>pA
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 S3Y.+. 0U
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a
PaginationSupport的实例ps。 e El)wZ,A
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ps.getItems()得到已分页好的结果集 zE/l
ps.getIndexes()得到分页索引的数组 wvq4 P
ps.getTotalCount()得到总结果数 +Xs E
ps.getStartIndex()当前分页索引 Z|E9}Il]
ps.getNextIndex()下一页索引 p Run5 )7
ps.getPreviousIndex()上一页索引 Qa_V
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Hnt*,C.0
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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 T>asH
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一下代码重构了。 '{2]:
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我把原本我的做法也提供出来供大家讨论吧: G"?7 Z&+
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首先,为了实现分页查询,我封装了一个Page类: d/9YtG%q
java代码: m&gd<rt/
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/*Created on 2005-4-14*/ 1M&Lb.J6
package org.flyware.util.page; >Y08/OAI.2
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/** <ZSXOh,'
* @author Joa _+By=B.'
* P#hRqETw
*/ h]s6)tII
publicclass Page { XA!a^@<H
3l?|+sU>O
/** imply if the page has previous page */ lV^#[%
privateboolean hasPrePage; ndLEIqOY
,RR{Y-
/** imply if the page has next page */ A6=Z2i0w>X
privateboolean hasNextPage; &"%Ws{Qn]
7=Muq]j2
/** the number of every page */ our
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privateint everyPage; yDqwz[v b
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/** the total page number */ 8s6[-F5
privateint totalPage; q?7''xk7
xZ {6!=4!
/** the number of current page */ 0E26J@jcZ7
privateint currentPage; ="$w8iRU
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/** the begin index of the records by the current ~k&b
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query */ zU!{_Ao9
privateint beginIndex; J`5+Zngr
ura&9~
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/** The default constructor */ 0;TiNrzg
public Page(){ x 4v:67_^
&)k=ccm
} 4JK6<Pk
nCi
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/** construct the page by everyPage W5Z-s.o
* @param everyPage :<P4=P P
* */ GPHb-
public Page(int everyPage){ Ll=G+cw6P
this.everyPage = everyPage; W~mo*EJ'^
} f)_<Ih\/7_
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/** The whole constructor */ @LI;q
public Page(boolean hasPrePage, boolean hasNextPage, L!xFhVA<
Q (f0S
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int everyPage, int totalPage, _5 SvZ;4
int currentPage, int beginIndex){ j:cu;6|
this.hasPrePage = hasPrePage; t/t6o&
this.hasNextPage = hasNextPage; #|E#Rkw!
this.everyPage = everyPage; 6ZIPe~`
this.totalPage = totalPage; 01@WU1IN
this.currentPage = currentPage; p?$N[-W 6-
this.beginIndex = beginIndex; D
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} Nmx\qJUR(
`
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/** (m2%7f.I
* @return 1SjVj9{:
* Returns the beginIndex. q,ie)`
*/ <2]h$53y!
publicint getBeginIndex(){ CCG5:xS
return beginIndex; c{Z
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} 0\!Bh^++1
i{EQjZ
/** ]@9W19=P!P
* @param beginIndex A]m*~Vj]
* The beginIndex to set. Cl3vp_
*/ aiX&`
publicvoid setBeginIndex(int beginIndex){ c<_1o!68
this.beginIndex = beginIndex; CfW#Wk:8J
} _XZK2Q[
q}Po)IUT`5
/** Kv*
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* @return #6c,_!
* Returns the currentPage. SHYekX
*/ g"n>v
c7
publicint getCurrentPage(){ TFb7P/g
return currentPage; EC$F|T0f
} {Yxvb**
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/** je$H}D
* @param currentPage ~Zsj@d
* The currentPage to set. e-`9-U%6
*/ /{buFX2"}
publicvoid setCurrentPage(int currentPage){ yI8O#
this.currentPage = currentPage; TkTGYh
} fASklcQ
!KXcg9e
/** kq=Htbv7
* @return t'Yd+FK
* Returns the everyPage. H$ nzyooh
*/ f
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publicint getEveryPage(){ @{qcu\sZ
return everyPage; H%n/;DW
} j6^.Q/{^
^kK")+K
/** pWzYC@_W
* @param everyPage a`yCPnB(
* The everyPage to set. 4;~xRg;u&*
*/ ww
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publicvoid setEveryPage(int everyPage){ DOtz
this.everyPage = everyPage; H$?MPA-c
} W:<2" &7
,+BFpN'
/** *8qRdI9
* @return #vK99S2
* Returns the hasNextPage. EIzTbW{p
*/ e?(4lD)d
publicboolean getHasNextPage(){ O~8jz
return hasNextPage; Wp
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} Z5rL.a&
^'N!k{x
/** pD P*
3
* @param hasNextPage 6$PQ$
* The hasNextPage to set. =^M Q 4
*/ b/.EA'/
publicvoid setHasNextPage(boolean hasNextPage){ =Cf@!wZ^
this.hasNextPage = hasNextPage;
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} Wx/PD=Sf&
*9KT@"v
/** &:d`Pik6
* @return zLr:zf l
* Returns the hasPrePage. ~yN>9f U
*/ eYRd#w
publicboolean getHasPrePage(){ Zu#^a|PE*
return hasPrePage; /!&eP3^
} G@rh/b<$
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/** M&Q&be84
* @param hasPrePage tWZ8(E$
* The hasPrePage to set. D'g@B.fXd
*/ ?jO<<@*2S
publicvoid setHasPrePage(boolean hasPrePage){ c;b<z|}z
this.hasPrePage = hasPrePage; :[?7,/w
} D@w&[IF
/FTP8XHwL)
/** (Ms #)E
* @return Returns the totalPage. ?aaYka]
* ]S(nA!]
*/ MYJDfI
publicint getTotalPage(){ KxmB$x5-=8
return totalPage; \RVfgfe
} "OP$n-*@%
uG.`
/** @B+8' b$9
* @param totalPage y\6C9%.
* The totalPage to set. G?s;L NR
*/ MkZoHzg}c
publicvoid setTotalPage(int totalPage){ Xa}y.qH
this.totalPage = totalPage; h _c11#
} j*VYUM@y1\
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} Ey&A\
gvjy'Rm
>0N$R|B&
L!5="s[}
F ww S[3
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 hNcEBSQ
l0!`>Xx[b
个PageUtil,负责对Page对象进行构造: !9C]Fs*`?
java代码: B&3@b
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tPJU,e)
/*Created on 2005-4-14*/ w&^Dbme
package org.flyware.util.page; U&+lw=
FGMYpapc~
import org.apache.commons.logging.Log;
#s=\
import org.apache.commons.logging.LogFactory; wXeJjE%j:3
j}%C;;MPH
/** c@O7,y:`I
* @author Joa g{?{N
* !q+
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*/ ~:="o/wo
publicclass PageUtil { >tkU+$;-
>Co@K^'
privatestaticfinal Log logger = LogFactory.getLog rt! lc-g%/
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(PageUtil.class); K]U8y$^
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/** ,-1taS
* Use the origin page to create a new page }WNgKw
* @param page ]waCYrG<sY
* @param totalRecords <ot%>\C
* @return w\a9A#v,
*/ @:u2{>Yl
publicstatic Page createPage(Page page, int 5)K?:7
=-uk7uZM
totalRecords){ 7:)$oH
return createPage(page.getEveryPage(), {bp~_`O
@rW%*?$7
page.getCurrentPage(), totalRecords); w`Z@|A
} HX:^:pF}
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/** V/DdV}n!
* the basic page utils not including exception `ucr;P
`{@?O%UB
handler TSd;L
u%hr
* @param everyPage !B*d,_9c
* @param currentPage :B_ itl0{e
* @param totalRecords 'l'[U
* @return page (Bfy
*/ 9fb"R"(M
publicstatic Page createPage(int everyPage, int ~F]If \b
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currentPage, int totalRecords){ ld23^r
everyPage = getEveryPage(everyPage); dLu3C-.(
currentPage = getCurrentPage(currentPage); 6EX8,4c\
int beginIndex = getBeginIndex(everyPage, |)R{(AK-
DO=zxdTI!
currentPage); -}<W|r
int totalPage = getTotalPage(everyPage, cW, 6MAQo
R$40cW3`
totalRecords); aSNTm8SYX
boolean hasNextPage = hasNextPage(currentPage, |(1z ?Spbe
N|WR^MQD
totalPage); Y]1b39O
boolean hasPrePage = hasPrePage(currentPage); @MGc_"b
g~=#8nJ
returnnew Page(hasPrePage, hasNextPage, I'RhA\`
everyPage, totalPage, @Nt$B'+S&
currentPage, R*psL&N
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beginIndex); `_&7-;)i*\
} O!\\m0\e
J\kv}v
privatestaticint getEveryPage(int everyPage){ "(#]H;!W
return everyPage == 0 ? 10 : everyPage; v.I>B3bEg
} lo!_;`v=U
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privatestaticint getCurrentPage(int currentPage){ gnSb)!i>z
return currentPage == 0 ? 1 : currentPage; {p(.ckze+
}
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privatestaticint getBeginIndex(int everyPage, int [2cG 7A
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currentPage){ b]U%|bp
return(currentPage - 1) * everyPage; t.oP]_mI
} q6v%HF-q4
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privatestaticint getTotalPage(int everyPage, int PYz^9Ud 6g
ra k@oW]
totalRecords){ qS|t7*
int totalPage = 0; sIh,@b
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if(totalRecords % everyPage == 0) hK&/A+*
totalPage = totalRecords / everyPage; /A;!g5Y
else IGd]!
totalPage = totalRecords / everyPage + 1 ; _(s|@UT#
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return totalPage; L?e N(L
} %<w)#eV?
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privatestaticboolean hasPrePage(int currentPage){ `PR)7}/<
return currentPage == 1 ? false : true; vHPp$lql
} p M:lg
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privatestaticboolean hasNextPage(int currentPage, E=Z.v
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int totalPage){ SXA_P{j&a
return currentPage == totalPage || totalPage == ;'r} D!8w/
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0 ? false : true; QvH=<$
} Zg/ra1n
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} d&QB?yLd
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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 @e_ bG@
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做法如下: |BGQ|7DyG
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 <m#ov G6
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的信息,和一个结果集List: B#_<?
java代码: Vs)Pg\B?
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/*Created on 2005-6-13*/ {]/}3t
package com.adt.bo; J?~El&
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import java.util.List; l* =\0
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import org.flyware.util.page.Page; C$~2FTx
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/** -#
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* @author Joa V(|@6ww
*/ ^-9g_5
publicclass Result { |Fk>NX
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private Page page; Ccld;c&+
ndn)}Z!0h
private List content; _h2axXFhT
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/** @Q;%hb
* The default constructor @-9I<)Z/2
*/ "|yuP1;L
public Result(){ 0HA`
super(); eot]VO:
} g?.ls{H
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/** "#d>3M_
* The constructor using fields -s5j^U{h|
* [eebIJs
* @param page [%M=nJ{8
* @param content Wm{Lg0Nr
*/ :nZVP_d+
public Result(Page page, List content){ )_eEM1
this.page = page; x$o?ckyH
this.content = content; 2 5DXJb^:
} iYi3x_A`
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/** 7{%_6b"
* @return Returns the content. );o2eV
*/ ~)XyrKw
publicList getContent(){ u]K&H&AxT
return content; 4NaL#3
} 7JvBzD42
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/** kcg{z8cd'r
* @return Returns the page. uHj"nd13
*/ OT[&a6