Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 z/p^C~|}
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 tWaGCxaE
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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 *mYGs )|
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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 F|oyrG
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分页支持类: k;SKQN
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java代码: B
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package com.javaeye.common.util; <QaUq`,
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import java.util.List; RjrQDh|((
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publicclass PaginationSupport { 4/ q
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publicfinalstaticint PAGESIZE = 30; ;'[?H0Jw'
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privateint pageSize = PAGESIZE; %t74*cX
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privateList items; fwUF5Y
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privateint totalCount; `/i/AZ{
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privateint[] indexes = newint[0]; 1L?W+zMO
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privateint startIndex = 0; vv5rA 6+
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public PaginationSupport(List items, int o,0
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totalCount){ '[_.mx|cd`
setPageSize(PAGESIZE); } ,Dk6w$
setTotalCount(totalCount); 9Gx`[{wI9<
setItems(items); y;P%=MP
setStartIndex(0); V;Ln|._/t
} [`bK {Dq2
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public PaginationSupport(List items, int Of9 gS-m
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totalCount, int startIndex){ D})12qB;u9
setPageSize(PAGESIZE); \SYeDy
setTotalCount(totalCount); .>-D{
setItems(items); 2Ib
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setStartIndex(startIndex); R -mn8N&
} ^i3!1cS
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public PaginationSupport(List items, int 4gmlK,a
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totalCount, int pageSize, int startIndex){ i;IhsKO0R
setPageSize(pageSize); Nm%#rZrN~Q
setTotalCount(totalCount); 66_=bd(9
setItems(items); |X6R2I
setStartIndex(startIndex); iorQ/(
} <KoOJMx(
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publicList getItems(){ ]Qp-$)N
return items; N+pCC
} "%_T7A ![
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publicvoid setItems(List items){ 2l:cP2fa
this.items = items; ^L.'At
} cveQ6
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publicint getPageSize(){ :}gEt?TUhs
return pageSize;
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} [ThAvQ_$
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publicvoid setPageSize(int pageSize){ S5UQ
this.pageSize = pageSize; GE !p
} W}%[i+
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publicint getTotalCount(){ C!6D /S
return totalCount; |=:hUp Jp
} 8;f5;7Mn
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publicvoid setTotalCount(int totalCount){ #v6<9>%
if(totalCount > 0){ u1.0-Y?
this.totalCount = totalCount; Y&DoA0/y
int count = totalCount / r{Mn{1:O
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pageSize; w2lO[o~x}
if(totalCount % pageSize > 0) (eHTXk*V`
count++; 6/"#pe^
indexes = newint[count]; `/B+
for(int i = 0; i < count; i++){ K<pZ*l
indexes = pageSize * }-9 c1&m
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i; VG50n<m9
} Q=#FvsF#z3
}else{ Z=a~0&G
this.totalCount = 0; g!cW`B'
} T&Z*=ShH
} `9\^.g)
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publicint[] getIndexes(){ m )r,
return indexes; j;-2)ZLm
} ]U}B~Y
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publicvoid setIndexes(int[] indexes){ Gj[5ew?@
this.indexes = indexes; k_gl$`A
} 79h'sp6;
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publicint getStartIndex(){ la^K|!|
return startIndex; MfdkvJ'
} nmyDGuzk
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publicvoid setStartIndex(int startIndex){ by,3A
if(totalCount <= 0) vRDs~'f
this.startIndex = 0; M(^ e)7a1
elseif(startIndex >= totalCount) \#F>R,
this.startIndex = indexes 5%@~"YCo
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[indexes.length - 1]; ,F "P/`i'
elseif(startIndex < 0) ni<\AF]`
this.startIndex = 0; 8u1?\SYnb
else{ nu2m5RYx
this.startIndex = indexes >q ,Z*s>?
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[startIndex / pageSize]; w")m]LV
} ? YluX
} ~b4kV)[ q
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publicint getNextIndex(){ N-45LS@
int nextIndex = getStartIndex() + "}oo`+]Cq
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pageSize; 7)FYAk$@
if(nextIndex >= totalCount) :dxKcg7
return getStartIndex(); 8;,|z%rS"
else X `F>kp1
return nextIndex; 1Cw$^jd
} Q"3gvIyc
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publicint getPreviousIndex(){ =CjWPZShV
int previousIndex = getStartIndex() - ~w.y9)",
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pageSize; |A+,M"F?
if(previousIndex < 0) J- 5kvQi8
return0; e-VGJxR
else wT-Kg=-q
return previousIndex; 0}'/3Q
} B^{~,'
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抽象业务类 ^SM5oK
java代码: u7 <VD
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/** BQs\!~Ux2
* Created on 2005-7-12 btbuE
*/ z<J2e^j
package com.javaeye.common.business; RS@G.|
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import java.io.Serializable; [*5hx_4%B
import java.util.List; qt4%=E;[
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import org.hibernate.Criteria; Mq#Hi9SKY
import org.hibernate.HibernateException; *<}R=X.
import org.hibernate.Session; 46B'Ec
import org.hibernate.criterion.DetachedCriteria; "_=t1UE
import org.hibernate.criterion.Projections; bXqTc2>=
import ,?+uQXfXR
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org.springframework.orm.hibernate3.HibernateCallback; $Yw~v36`t/
import 8>xd
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org.springframework.orm.hibernate3.support.HibernateDaoS Y@ vC!C
~aXJ5sY"f&
upport; ,kl``w|1M
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import com.javaeye.common.util.PaginationSupport; vJsg6oH
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public abstract class AbstractManager extends -M4VC^_
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HibernateDaoSupport { $if(n||
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privateboolean cacheQueries = false; y'z9Ya
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privateString queryCacheRegion; Jid_&\
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publicvoid setCacheQueries(boolean kv2 H3O
bw!*=<
cacheQueries){ `(6cRT`Wp
this.cacheQueries = cacheQueries; h8;H<Y;yQ
} VZ7E#z+nM#
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publicvoid setQueryCacheRegion(String }1Q>A 5e
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queryCacheRegion){ ;q#Pl!*5
this.queryCacheRegion = Q!I><u
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queryCacheRegion; $bN_0s0:'
} Xo6zeLHO
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publicvoid save(finalObject entity){ E?VOst&
getHibernateTemplate().save(entity); AKS. XW
} |:SIyXGbY
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publicvoid persist(finalObject entity){ o
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getHibernateTemplate().save(entity); FtDF}
} 2tQ?=V(Di
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publicvoid update(finalObject entity){ 8v=t-GJW
getHibernateTemplate().update(entity); E
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} ]Y$jc
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publicvoid delete(finalObject entity){ *Xn6yL9
getHibernateTemplate().delete(entity); H|'n|\{lt
} Y^XZ.R
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publicObject load(finalClass entity, e+?;Dc-SJ\
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finalSerializable id){ ):n'B` f}z
return getHibernateTemplate().load Dv4 H^
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(entity, id); Lzx/9PPYn
} 6QNZ/Ox:
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publicObject get(finalClass entity, Zm+GH^f'
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finalSerializable id){ o)'06FF\$
return getHibernateTemplate().get D4?cnwU
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(entity, id); <L2z| %`
} =dp`4N
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publicList findAll(finalClass entity){ } V"A;5j`
return getHibernateTemplate().find("from WE+Szg(4x
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" + entity.getName()); c @KNyBy2
} >GmO8dK
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publicList findByNamedQuery(finalString <y#@v G
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namedQuery){ g\*2w
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return getHibernateTemplate <<-BQ
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().findByNamedQuery(namedQuery); zKh <zj
} ViUx^e\
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publicList findByNamedQuery(finalString query, (@bq@0g
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finalObject parameter){ 4~hP25q
return getHibernateTemplate ={jj'X9
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().findByNamedQuery(query, parameter); cs4IO
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} }|j#C[
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publicList findByNamedQuery(finalString query, _*xY>?Aq
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finalObject[] parameters){ VmZDU(M
return getHibernateTemplate OD?y
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().findByNamedQuery(query, parameters); j#YVv c%
} V}JBv$+ko
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publicList find(finalString query){ Vw`%|x"Xz
return getHibernateTemplate().find th5UzpB4
*r|13|k
(query); #fXy4iL l
} >xXq:4l>}
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publicList find(finalString query, finalObject XMaw:Fgr
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parameter){ IU"8.(;o
return getHibernateTemplate().find ; NO#/
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(query, parameter); c]|Tg9AW
} ojVN-*5
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public PaginationSupport findPageByCriteria sGa "
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(final DetachedCriteria detachedCriteria){ yP34h*0B
return findPageByCriteria v7@*dg
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); d-gcXaA-8
} <t"fL
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public PaginationSupport findPageByCriteria @scSW5+
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(final DetachedCriteria detachedCriteria, finalint >VG*La'c
q}(f9
startIndex){ dE3M
return findPageByCriteria y4H/CH$%
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(detachedCriteria, PaginationSupport.PAGESIZE, ghk"XJ|
}$a*XY1
startIndex); r/QI-Cf&
} I}awembw g
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public PaginationSupport findPageByCriteria {RD9j1
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(final DetachedCriteria detachedCriteria, finalint dx.Jv/Mb
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pageSize, Ki /j\
finalint startIndex){ JQW7y!Z
return(PaginationSupport) D"{%[;J
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getHibernateTemplate().execute(new HibernateCallback(){ 9|K:\!7
publicObject doInHibernate 0Cyus
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(Session session)throws HibernateException { "DRiJ.|APs
Criteria criteria = B.);Ju
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detachedCriteria.getExecutableCriteria(session); +Edq4QYwR
int totalCount = w~n+hhMF
p#>,{
((Integer) criteria.setProjection(Projections.rowCount V! .I>
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()).uniqueResult()).intValue(); tNAmA
criteria.setProjection >B.KI}dE
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(null); sjHcq5#U!
List items = Q0L1!}w
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criteria.setFirstResult(startIndex).setMaxResults <4I`|D3@
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(pageSize).list(); UUvR>5@n
PaginationSupport ps = k7 Ne(4P
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new PaginationSupport(items, totalCount, pageSize, ^vI`#}?
w=~X 6[+3
startIndex); /5Yl, P
return ps; NkAu<>
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} ]v_u2f'
}, true); t;y@;?~
} >Hd!o"I
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public List findAllByCriteria(final NQN?CBFQ
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DetachedCriteria detachedCriteria){ 9zpOp-K6
return(List) getHibernateTemplate f2ck=3
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().execute(new HibernateCallback(){ 6-\M }xq?
publicObject doInHibernate 6dRvx;d
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(Session session)throws HibernateException { 1.nYT*
Criteria criteria = R!>SN0
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detachedCriteria.getExecutableCriteria(session); pO2XQYhrY
return criteria.list(); Zy>y7O(,
} M2A_T.F=H
}, true); sDkO!P
} TR:4$92:H
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public int getCountByCriteria(final i,l$1g-i
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DetachedCriteria detachedCriteria){ X$_z"t
Integer count = (Integer) Qn@[{%),4
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getHibernateTemplate().execute(new HibernateCallback(){ WH.3
publicObject doInHibernate MO|8A18B
)Zfb M|
(Session session)throws HibernateException { l^__oam
Criteria criteria = QL-E4]
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detachedCriteria.getExecutableCriteria(session); ^,Ft7 JAn
return :7s2M
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criteria.setProjection(Projections.rowCount cfHtUv
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()).uniqueResult(); )c.!3n/pb
} 2UTmQOm
}, true); -LlS9[r0
return count.intValue(); k
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} :79u2wSh
} ]'0}fuV
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用户在web层构造查询条件detachedCriteria,和可选的 *~zB {
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 w[u>*I
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PaginationSupport的实例ps。 )1!0'j99.
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ps.getItems()得到已分页好的结果集 4?c0rC<
ps.getIndexes()得到分页索引的数组 /LG}nY
ps.getTotalCount()得到总结果数 <4-g2.\
ps.getStartIndex()当前分页索引 >|1-o;UU
ps.getNextIndex()下一页索引 yxi* 4R
ps.getPreviousIndex()上一页索引 { ^R>H|~
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 N^'(`"J s
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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 Xj<xen(
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一下代码重构了。 JcC2Zn6
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我把原本我的做法也提供出来供大家讨论吧: :,.HJ[Vg&
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首先,为了实现分页查询,我封装了一个Page类: 3s#/d,+
java代码: {v2[x W
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/*Created on 2005-4-14*/ D_BdvWSxj
package org.flyware.util.page; {O4&HW%
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/** %kuUQ%W1
* @author Joa Pje1,B q
* jPs{Mr<
*/ 5
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publicclass Page { u0%bv\$m
af&P;#U
/** imply if the page has previous page */ EnEaUb?P
privateboolean hasPrePage; <=%G%V_s
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/** imply if the page has next page */ tYx>?~
privateboolean hasNextPage; )Dyyb1\)
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/** the number of every page */ f;bVzti+w
privateint everyPage; `_OB_F
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/** the total page number */ eRg;)[#0>$
privateint totalPage;
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Mz;KXP
/** the number of current page */ k>:\4uI|<\
privateint currentPage; &x/Z{ut
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/** the begin index of the records by the current soA] f
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query */ b6@0?_n
privateint beginIndex; 5L,q,kVS
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/** The default constructor */ (w
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public Page(){ ^j2z\yo
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} ogoEtKi
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/** construct the page by everyPage xj JoWB
* @param everyPage VI)hA
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* */ /$j,p E=
public Page(int everyPage){ z h%b<
this.everyPage = everyPage; fbkAu
} f2k~(@!h
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/** The whole constructor */ Zk5AZ R!|
public Page(boolean hasPrePage, boolean hasNextPage, 6dYa07
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@QDpw1;V'
int everyPage, int totalPage, tZ:fh p
int currentPage, int beginIndex){ z\Z+>A
this.hasPrePage = hasPrePage; 9+~1# |
this.hasNextPage = hasNextPage; =27Z Y Z
this.everyPage = everyPage; '
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this.totalPage = totalPage; (i-L:
this.currentPage = currentPage; Iv?1XI=
this.beginIndex = beginIndex; ix 5\Y
} ZpZoOdjslV
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/** sAjN<P
* @return 6ciA|J'MR
* Returns the beginIndex. LWV^'B_X-
*/ 8x9;3{R
publicint getBeginIndex(){ #y1M1O g
return beginIndex; Jjh=zxR>
} VgMuX3=
>n%ckL|rG
/** Kp6%=JjO
* @param beginIndex 3Q_)Xs
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* The beginIndex to set. )b,FE}YX
*/ E/_n}$Z
publicvoid setBeginIndex(int beginIndex){ 8*eVP*g
this.beginIndex = beginIndex; +>:[irf
} zvT8r(<n}
Srrzj-9^)K
/** .xtam 8@
* @return 0I*{CVTQj
* Returns the currentPage. Nb\B*=4AR
*/ 2 y&k
publicint getCurrentPage(){ f5'vjWJ30
return currentPage; :* J!
} +<WNAmh
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/** m21H68y
* @param currentPage 4cDe'9
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* The currentPage to set. b>nwX9Y/U
*/ +KIFLuL
publicvoid setCurrentPage(int currentPage){ ][>-r&V
this.currentPage = currentPage; L"(
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} ZJHaY09N
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/** cY.5z:7u~v
* @return 3GXmyo:o$
* Returns the everyPage. aF.fd2k
*/ }q:4Zh'l!
publicint getEveryPage(){ hdYd2
j
return everyPage; r^,"OM]
} #}[NleTVt
'w_Qs~6~{
/** P@U2Q%\
* @param everyPage l^rQo_alk
* The everyPage to set. D~ 7W
*/ FMC]KXSd
publicvoid setEveryPage(int everyPage){ j_SUR)5
this.everyPage = everyPage; ]m#*4
} ubl)$jZ:Q
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/** (Z Q?1Qxo
* @return RHmT$^=
* Returns the hasNextPage. LVJn2t^
*/ \
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publicboolean getHasNextPage(){ P3TM5
return hasNextPage; TmJXkR.5
} fj[Kbo 7!h
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/** ZN!<!"~
* @param hasNextPage {}BAQ9|q
* The hasNextPage to set. 3lN@1jlh
*/ l_P90zm39!
publicvoid setHasNextPage(boolean hasNextPage){ 0Q[;{}W}
this.hasNextPage = hasNextPage; }`]Et99Q5
} lDZ~
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/** BVS
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* @return >txeo17Ba\
* Returns the hasPrePage. 5e&;f
*/ %.;;itB
publicboolean getHasPrePage(){ ^t,haO4
return hasPrePage; V2$M`|E
} 2h1P!4W85
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/** "lL/OmG
* @param hasPrePage Raf-I+
* The hasPrePage to set. ~Sx\>wBlc
*/ 6ck%M#v
publicvoid setHasPrePage(boolean hasPrePage){ 6u{%jSA>D\
this.hasPrePage = hasPrePage; ]6,D9^{;
} 3]kN9n{
>C`#4e?}
/** bl#6B.*=
* @return Returns the totalPage. %Hu.FS5'
* #j"GS/y"
*/ 5i%\m
publicint getTotalPage(){ .d+zF,02Z
return totalPage; 6+:;Mb_S
} 593!;2/@
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/** rnBp2'EM
* @param totalPage 8(
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* The totalPage to set. T[2<_ nn=
*/ sk@aOv'*(
publicvoid setTotalPage(int totalPage){ d"thM
this.totalPage = totalPage; nY,LQ0r
} |Gr@Mi5
P[r$KGz
} TNF
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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 Pav
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个PageUtil,负责对Page对象进行构造: GZm=>!T
java代码: DH:9iX '
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/*Created on 2005-4-14*/ kH4m6p
package org.flyware.util.page; fr&p0)85>B
j_S3<wEJ
import org.apache.commons.logging.Log; lHE+o;-
import org.apache.commons.logging.LogFactory; i#PR
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/** (
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* @author Joa N]&hw&R{Q
* /buj(/q^#
*/ nPH\Lra
publicclass PageUtil { $9Gra#
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privatestaticfinal Log logger = LogFactory.getLog )M@^Z(W/a
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(PageUtil.class); L+0:'p=
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/** T#HF!GH]
* Use the origin page to create a new page ~w(A3I.
* @param page ed#>q;jX
* @param totalRecords ::@JL
* @return m/`L3@7Tt
*/ <"av /`;
publicstatic Page createPage(Page page, int &"Fz)}
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totalRecords){ ^Zlbs
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return createPage(page.getEveryPage(), ,<[x9 "3\
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page.getCurrentPage(), totalRecords); ${`q!
} D3y4e8+Z'
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/** `0-i>>
* the basic page utils not including exception ^[v>B@p*{
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handler m`jGBSlw_
* @param everyPage l I2UpfkBP
* @param currentPage `R*!GHro
* @param totalRecords jEK{47i v
* @return page id]}10
*/ :)Da^V
publicstatic Page createPage(int everyPage, int 4 &0MB>m
;}k_
currentPage, int totalRecords){ T;i+az{N:V
everyPage = getEveryPage(everyPage); ?XVox*6K&
currentPage = getCurrentPage(currentPage); m3|l-[!OA"
int beginIndex = getBeginIndex(everyPage, n% s$!R-\
~!_UDD
currentPage); 5"D\n B%
int totalPage = getTotalPage(everyPage, Ah
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f?"909&
totalRecords); fLV@~T|
boolean hasNextPage = hasNextPage(currentPage, ][~rk?YY
RI BB*
totalPage);
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boolean hasPrePage = hasPrePage(currentPage);
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returnnew Page(hasPrePage, hasNextPage, dCzS f4:
everyPage, totalPage, $C8s
currentPage, 6>h"Lsww
wL&[Vi_j{
beginIndex); bLUyZ3m!
} fg
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privatestaticint getEveryPage(int everyPage){ 7s;*vd>
return everyPage == 0 ? 10 : everyPage; $-gRD|oY
} VC^QCuSq
tz2$j@!=
privatestaticint getCurrentPage(int currentPage){ /q^_
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return currentPage == 0 ? 1 : currentPage; `U{#;
} w^S]HzMd
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privatestaticint getBeginIndex(int everyPage, int I2?g'tz
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currentPage){ Bhe0z|&
return(currentPage - 1) * everyPage; Y7`Dx'x
} _Fjax
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privatestaticint getTotalPage(int everyPage, int M2nZ,I=l
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totalRecords){ x^
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int totalPage = 0; lsVg'k/Z!
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if(totalRecords % everyPage == 0) U"K%ip:Wd
totalPage = totalRecords / everyPage; +b{tk=Q:
else &9xcP.3
totalPage = totalRecords / everyPage + 1 ; [8[`V)b
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return totalPage; 83Fmu/(
} d^`n/"Ice
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privatestaticboolean hasPrePage(int currentPage){ QW&@>i
return currentPage == 1 ? false : true; {;hRFQ^b
} N ^H
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privatestaticboolean hasNextPage(int currentPage, Ft8ii|-
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int totalPage){ @T{I;8S
return currentPage == totalPage || totalPage == 2X=*;r"{J
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0 ? false : true; 'zQp64]F
} Y>K3.*.
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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。 <2PO3w?Z
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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 ra{HlB{
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做法如下: =UFmN"
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 QkY;O<Y_
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的信息,和一个结果集List: !:|D[1m
java代码: Fh ^Ax3P(
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/*Created on 2005-6-13*/ vrXNa8,L
package com.adt.bo; d~O)mJ
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