Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Y^94iOk%T
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 HX /GLnY/X
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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 8XS{6<
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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 c5wkzY h
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分页支持类: H.l,%x&K
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java代码: Hl3XqR
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package com.javaeye.common.util; lEYT{
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import java.util.List; Tk v
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publicclass PaginationSupport { Y#SmZ*zok
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publicfinalstaticint PAGESIZE = 30; _;J9q}X
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privateint pageSize = PAGESIZE; e??{&[
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privateList items; T956L'.+G
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privateint totalCount; ~0^,L3M
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privateint[] indexes = newint[0]; 'j"N2NJ
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privateint startIndex = 0; -o!,,XYj .
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public PaginationSupport(List items, int 5#9Wd9LP
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totalCount){ y~A7pzBZ=
setPageSize(PAGESIZE); NKUI! [
setTotalCount(totalCount); R&=GB\`:a
setItems(items); o4[2`mT
setStartIndex(0); _!^FW%
} SJ[@fUxO)
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public PaginationSupport(List items, int F;X q:e8
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totalCount, int startIndex){ ^<
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setPageSize(PAGESIZE); gJGBD9wC
setTotalCount(totalCount); vs0H^L
setItems(items); 2-E71-J
setStartIndex(startIndex); <9@]|
} x&fCe{5
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public PaginationSupport(List items, int {5tEsv
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totalCount, int pageSize, int startIndex){ XX[Wwt
setPageSize(pageSize); ^$Io;*N4
setTotalCount(totalCount); '
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setItems(items); JdYF&~
setStartIndex(startIndex); _TN$c
} yzNX2u1
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publicList getItems(){ 8`~3MsE"
return items; .9fluAG
} 4p.{G%h
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publicvoid setItems(List items){ l`%}
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this.items = items; 6dy4{i
} VaIP
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publicint getPageSize(){ dDn4nwH
return pageSize; LLHOWD C(2
} ,0~
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publicvoid setPageSize(int pageSize){ j p]geV54
this.pageSize = pageSize; rLVc<595
} K ':pU1
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publicint getTotalCount(){ ZznWs+
return totalCount; D&m"~wI
} 9la~3L_g
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publicvoid setTotalCount(int totalCount){ 2_\|>g|
if(totalCount > 0){ fvM3.P
this.totalCount = totalCount; Odtck9L
int count = totalCount / aw"%B-N\
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pageSize; ?HyioLO
if(totalCount % pageSize > 0) r8?Lr-;
count++; q<uLBaL_]r
indexes = newint[count]; (*Q|;
for(int i = 0; i < count; i++){ FH21m wV
indexes = pageSize * (g:W|hS
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i; 1WN93SQ=
} a&VJYAB
}else{ K$GXXE`
this.totalCount = 0; 3&Rqz9 W
} +5mkMZ
} Qu\l$/
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publicint[] getIndexes(){ h1o+7
return indexes; =F[,-B~
} O~0
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publicvoid setIndexes(int[] indexes){ L/LNX{|
this.indexes = indexes; ^!Jm/-
} 9cj-v}5j
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publicint getStartIndex(){ BVp.A]
return startIndex; EC#10.
} Bcon4
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publicvoid setStartIndex(int startIndex){ /k"P4\P`+Q
if(totalCount <= 0) 94@!.11
this.startIndex = 0; 3*JybMo"
elseif(startIndex >= totalCount) |YFlJ2w
this.startIndex = indexes l'\b(3JF
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[indexes.length - 1]; Z5-'|h$|
elseif(startIndex < 0) ,sl.:C 4
this.startIndex = 0; F[Sat;Sll
else{ /U]5#'i
this.startIndex = indexes e'&{KD,-T
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[startIndex / pageSize]; >@uYleD(
} 0pOha(,~
} )^sfEYoA
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publicint getNextIndex(){ ?3N86Qj
int nextIndex = getStartIndex() + 7HFO-r118
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pageSize; ?0Zw ^a
if(nextIndex >= totalCount) ^]gl#&"D
return getStartIndex(); tH(#nx8
else rnE'gH(V'
return nextIndex; {Aw3Itef
} mJ7kOQ-.$
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publicint getPreviousIndex(){ 6si-IJ
int previousIndex = getStartIndex() - C\D4C]/8
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pageSize; 0in6z
if(previousIndex < 0) /]&1 XT?
return0; DlI|~
else N> Y3[G+
return previousIndex; Y;>'~V#R
} _Tz!~z
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} ,#loVLy
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抽象业务类 Rim}DfO/
java代码: &tIm
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/** dX=^>9hN/
* Created on 2005-7-12 *TkABUL
*/ JnDR(s4(E
package com.javaeye.common.business; <n{9pZ5.
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import java.io.Serializable; a\MJbBXv
import java.util.List; f9$q.a*
9HP--Z=
import org.hibernate.Criteria; -(EqBr@_
import org.hibernate.HibernateException; m/AN*`V
import org.hibernate.Session; e|P60cd /
import org.hibernate.criterion.DetachedCriteria; M> <
import org.hibernate.criterion.Projections; VbYapPu4b!
import Jo@9f(hq
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org.springframework.orm.hibernate3.HibernateCallback; ;o\wSHc
import .^23qCs
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org.springframework.orm.hibernate3.support.HibernateDaoS pif gt
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upport; DI\sq8J^
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import com.javaeye.common.util.PaginationSupport; `*a,8M%
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public abstract class AbstractManager extends "`k[4C
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HibernateDaoSupport { >/*\xg&J
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privateboolean cacheQueries = false; ~xCy(dL^}
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privateString queryCacheRegion; H;6V
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publicvoid setCacheQueries(boolean |*b8-a8<
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cacheQueries){ OX"`VE
this.cacheQueries = cacheQueries; n!p&.Mt
} Jj!T7f*-GX
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publicvoid setQueryCacheRegion(String wa C%o%fD
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queryCacheRegion){ >nxtQ
this.queryCacheRegion = ktCh*R[`
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queryCacheRegion; 7>nA;F
8_
} #L"h>,b
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publicvoid save(finalObject entity){ 7;XdTx
getHibernateTemplate().save(entity); y!#1A?|k
} ~LVa#
`{ /tx!
publicvoid persist(finalObject entity){ p"T4;QBxQ
getHibernateTemplate().save(entity); DeUDZL%/
} ((y+FJH
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publicvoid update(finalObject entity){ V{n pK(
getHibernateTemplate().update(entity); ?$
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} NM4 n
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publicvoid delete(finalObject entity){ Zy'bX* s|
getHibernateTemplate().delete(entity); ~&pk</Dl
} GcKJpI\sB
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publicObject load(finalClass entity, *}?^)z7w
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finalSerializable id){ csC3Wm{v
return getHibernateTemplate().load Z5+0?X0i
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(entity, id); fROhn}<**[
} |$D^LY
1}(g=S
publicObject get(finalClass entity, HJ2]xe09
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finalSerializable id){ FOZqN K
return getHibernateTemplate().get p\(%bO
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(entity, id); M4QMD;Ez
} C}Khh`8@5.
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publicList findAll(finalClass entity){ htaB!Q?V
return getHibernateTemplate().find("from k,r\^1h
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" + entity.getName()); P6X 4m(t
} .G^.kg ,
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publicList findByNamedQuery(finalString '?-GZ0oM
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namedQuery){ U $+rlw}
return getHibernateTemplate !_]WUQvV?
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().findByNamedQuery(namedQuery); mFvw s
} H}:apRb
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publicList findByNamedQuery(finalString query, [p]Ayo$~
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finalObject parameter){ %3q@\:s
return getHibernateTemplate 5SDHZ?h
j"c"sF\q
().findByNamedQuery(query, parameter); 2qN6{+]
} U'@_fg
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publicList findByNamedQuery(finalString query, m86w{b$8
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finalObject[] parameters){ zRB1V99k
return getHibernateTemplate 8Uc#>Ae'_
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().findByNamedQuery(query, parameters); ;'nu9FU*O
} H*l8,*M}
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publicList find(finalString query){ w;X-i.%`
return getHibernateTemplate().find 75{QBlf<
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(query); ,cpPXcz ?,
} -FJ5N}R
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publicList find(finalString query, finalObject \5J/?
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parameter){ #A?U_32z/2
return getHibernateTemplate().find w2Pkw'a{
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(query, parameter); _pW\F(+8
} G:f]z;Xdp
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public PaginationSupport findPageByCriteria l^fz
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(final DetachedCriteria detachedCriteria){ K47W7zR
return findPageByCriteria 7ej"q
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); wz;IKdk[
} *y7^4I-J
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public PaginationSupport findPageByCriteria M" %w9)@
entO"~*EX
(final DetachedCriteria detachedCriteria, finalint _aq3G9C_
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startIndex){ ^O4.$4t|
return findPageByCriteria 4R@3jGXb8q
KI#),~nS
(detachedCriteria, PaginationSupport.PAGESIZE, 6wfCC, 2
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startIndex); u9QvcD^'z
} #~ UG9@a
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public PaginationSupport findPageByCriteria DTPYCG&%
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(final DetachedCriteria detachedCriteria, finalint 79=w]y
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pageSize, ,J~kwJ$L
finalint startIndex){ 1]m]b4]
return(PaginationSupport) WTZP}p1
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getHibernateTemplate().execute(new HibernateCallback(){ ~~]L!P
publicObject doInHibernate %Gv8]Yb
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(Session session)throws HibernateException { {w1sv=$+
Criteria criteria = CUaI 66
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detachedCriteria.getExecutableCriteria(session);
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int totalCount = `c ^2
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((Integer) criteria.setProjection(Projections.rowCount '/J}T -,Z
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()).uniqueResult()).intValue(); Szsq|T
criteria.setProjection +x\b- '
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(null); 5\A[ra
List items = bO^#RVH
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criteria.setFirstResult(startIndex).setMaxResults m$Lq#R={Z
}PTYNidlR
(pageSize).list(); 51u8.%{4
PaginationSupport ps = K1AI:$H
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new PaginationSupport(items, totalCount, pageSize, FY|.eY_7 {
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startIndex); DDsU6RyN
return ps; Py3Xvudv
} yZE"t[q#O
}, true); Y9F!HM-`
} uW3`gwwlU
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public List findAllByCriteria(final q90eB6G0g
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DetachedCriteria detachedCriteria){ P,^`|\#7
return(List) getHibernateTemplate M.iR5Uh
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().execute(new HibernateCallback(){ %"Q{|}
publicObject doInHibernate 9=p^E# d
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(Session session)throws HibernateException { _h",,"p#o
Criteria criteria = fOs"\Y4
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detachedCriteria.getExecutableCriteria(session); Bvj-LT=)
return criteria.list(); n>T1KC%
} n8n(<
}, true); @.T(\Dq^
} @AYO )Y8
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public int getCountByCriteria(final {h5 S=b
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DetachedCriteria detachedCriteria){ b1Bu5%bt,:
Integer count = (Integer) JDrh-6Zgj
}<6xZy
getHibernateTemplate().execute(new HibernateCallback(){ !g{9]"Z1T
publicObject doInHibernate 4)./d2/E
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(Session session)throws HibernateException { 7714}%Z
Criteria criteria = lL_M=td8W
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detachedCriteria.getExecutableCriteria(session); ""Nu["|E
return 8q*MhH>6I
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criteria.setProjection(Projections.rowCount *<?or"P
SEsc"l8
()).uniqueResult(); <;}jf*A
} oxT..=-
}, true); yDh(4w-~gk
return count.intValue(); +rse,b&U(
} ma@3BiM
} foY=?mbL
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用户在web层构造查询条件detachedCriteria,和可选的
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 J!r,ktO^U?
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PaginationSupport的实例ps。 F^&
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ps.getItems()得到已分页好的结果集 U(#)[S,
ps.getIndexes()得到分页索引的数组 #>~<rcE(
ps.getTotalCount()得到总结果数 X :2%U
ps.getStartIndex()当前分页索引 BZAeg">3
ps.getNextIndex()下一页索引 ($a ?zJr
ps.getPreviousIndex()上一页索引 :EOx>Pf_9)
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Wr3j8"f/
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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 O^fg~g X
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一下代码重构了。 gq9D#B
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我把原本我的做法也提供出来供大家讨论吧: QoZ7l]^
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首先,为了实现分页查询,我封装了一个Page类: [e1kfw
java代码: dD6I @N)X
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/*Created on 2005-4-14*/ sj;8[Xy's
package org.flyware.util.page; R#j-Z#/"
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/** 3L2@C%
* @author Joa K:}~8 P>^
* ?f1PQ
*/ Qd~M;L O"i
publicclass Page { cSdkhRAn
!3~VoNh,
/** imply if the page has previous page */ &P8 Run
privateboolean hasPrePage; s|3@\9\
@NBWNgBv
/** imply if the page has next page */ "=~P&Mi_
privateboolean hasNextPage; jO'+r'2B9
f"XFf@!
/** the number of every page */ uQy5t:!
privateint everyPage; ^B9rt\,q
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/** the total page number */ V>#iR>w_4,
privateint totalPage; 8?qEv,W
SB5[PDL_q
/** the number of current page */ V\axOz!
privateint currentPage; 8+^?<FKa
/m,0H)w1
/** the begin index of the records by the current Qxds]5WB/
@\gTi;u/x
query */ S@suPkQ<>
privateint beginIndex; J"w!Q\_
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/** The default constructor */ XQEGMaZ
public Page(){ JL~QE-pvD
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*$TF
} uM0!,~&9|
<}pwFl8C)
/** construct the page by everyPage O[RmQ8ll
* @param everyPage eqbxf#H!
* */ ld1t1'I'
public Page(int everyPage){ 9kPwUAw
this.everyPage = everyPage; myH:bc>6
} =J.)xDx*
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/** The whole constructor */ )Q 8T`Tly
public Page(boolean hasPrePage, boolean hasNextPage, {]ZZ]
?{#P.2
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int everyPage, int totalPage, W38My j!
int currentPage, int beginIndex){ 8VvoPlo
this.hasPrePage = hasPrePage; ]B>Y
+
this.hasNextPage = hasNextPage; <!:,(V>F(C
this.everyPage = everyPage; zypZ3g{vz
this.totalPage = totalPage; e,Xvt5
this.currentPage = currentPage; p7(xk6W
this.beginIndex = beginIndex; HzB&+c?Z
} |0(Z)s,
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/** 3+m#v8h1
* @return Kp"mV=RG2T
* Returns the beginIndex. ,_`\c7@
*/ JnCY O^Qj
publicint getBeginIndex(){ eif<aG5
return beginIndex; IoNZ'g?d
} 'DF3|A],
f(DGC2R
<
/** 1rC8]M.N
* @param beginIndex Rs)tf|`/
* The beginIndex to set. D@qq=M
*/ xk86?2b{)
publicvoid setBeginIndex(int beginIndex){ %Zx/XMs}e
this.beginIndex = beginIndex; #e&j]Q$Eh
} [7]p\'j
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/** tjOfekU
* @return po"M$4`9
* Returns the currentPage. ezlp~z"_k
*/ (|ga#%iI
publicint getCurrentPage(){ .D^k0V
return currentPage; /{7x|ay]
} Opmb
$${ebt
/** BmUEo$w
* @param currentPage 3Q[]lFJ}F
* The currentPage to set. ix^:qw;
*/ {exF"ap
publicvoid setCurrentPage(int currentPage){ hr@KWE`
this.currentPage = currentPage; G#duZNBdc
} D8h?s
9|jIrS%/~
/** =DE5Wq19
* @return |kV,B_qz
* Returns the everyPage. %S>lPt
*/ w[PW-m^`
publicint getEveryPage(){ Xa<siA{
return everyPage; \R&`bAd k
} @[zPN[z.
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/** ]lQhIf6)k
* @param everyPage S?hM
* The everyPage to set. XPUH\I=
*/ L4.yrA-]C%
publicvoid setEveryPage(int everyPage){ Yl8tjq}iC
this.everyPage = everyPage; ; {I{X}b
} tDEpR
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/** a+\Gz
* @return J;m[1Mae&
* Returns the hasNextPage. "793R^Tz
*/ 6g akopZO
publicboolean getHasNextPage(){ /;HytFP
return hasNextPage; DKIDLf
} gADt%K2#Z
{!^HG+
/** .h~)|"uzW
* @param hasNextPage Yz-b~D/=}
* The hasNextPage to set. XZp(Po:H
*/ EW2e k^
publicvoid setHasNextPage(boolean hasNextPage){ ;1{S"UY
this.hasNextPage = hasNextPage; ?H*_:?=6
} E6)FYz7x
#J2856bzS
/** &e,xN;
* @return +/Y)s5@<
* Returns the hasPrePage. webT
*/ #"i}wS
publicboolean getHasPrePage(){ 1`aFL5[0$
return hasPrePage; MlRgdVX
} qViky=/-
+#&2*nY
/** ;=h^"et
* @param hasPrePage %K ]u"
* The hasPrePage to set. u{6*}6@fi
*/ <PV @JJ"
publicvoid setHasPrePage(boolean hasPrePage){ LgUaX
this.hasPrePage = hasPrePage; krz@1[w-j
} 7;|6g8=
l[\[)X3$
/** T w"^I*B
* @return Returns the totalPage. 7!MW`L/`
* /tt
*/ 1L l@
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publicint getTotalPage(){
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return totalPage; >DbG$V<v'
} Nu9mK
H%faRUonz
/** &lGp
/m:
* @param totalPage (5G^"Srw
* The totalPage to set. |L`w4;
*/ .4-;
publicvoid setTotalPage(int totalPage){ -u{k
this.totalPage = totalPage; =gfLl1wY[
} =BX<;vU
M}%0=VCY7
} kTC6fNj[
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YToRG7X#
MWhFNfS8=
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 bR;H@Fdg?
C@Wm+E~;8
个PageUtil,负责对Page对象进行构造: Y%wF;I1x
java代码: urog.Q
vQIoj31
TR:D
/*Created on 2005-4-14*/ :&TOQ<vM
package org.flyware.util.page; i[jAAr$
u4.-AY {
import org.apache.commons.logging.Log; #j; &g1
import org.apache.commons.logging.LogFactory; t3bDi/m
fNB*o={r|
/** (mz a&WF7
* @author Joa -JUv'fk
* OwDjUKeN
*/ b5H[~8mf
publicclass PageUtil { n|^-qy'w
5(DCq(\P*
privatestaticfinal Log logger = LogFactory.getLog n}?kQOg0/
M)3h 4yQ
(PageUtil.class); v3aiX
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/** X\YeO>C
* Use the origin page to create a new page ]bS\*q0Zf(
* @param page ][qZOIk@
* @param totalRecords 7dU X(D,?
* @return uYO?Rb&}
*/ oA42?I ^
publicstatic Page createPage(Page page, int :Eob"WH
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totalRecords){ ][0HJG{{g
return createPage(page.getEveryPage(), S9xC> |<
orL7y&w(v:
page.getCurrentPage(), totalRecords); }*0%wP
} 3btciR!N]
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/** 4NbC V)Dm
* the basic page utils not including exception &f!!UZMt)
b\;QR?16R
handler /=-E`%R}!
* @param everyPage 4I2ppz
* @param currentPage P3N
f<
* @param totalRecords ~}TVM%0RTq
* @return page 5a_K|(~3I
*/
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publicstatic Page createPage(int everyPage, int [%3{mAd
,',fO?Qv'
currentPage, int totalRecords){ |NM.-@1
everyPage = getEveryPage(everyPage); z{AfR2L
currentPage = getCurrentPage(currentPage); 2>s:wABb /
int beginIndex = getBeginIndex(everyPage, c.d*DM}W
s[Njk@y,
currentPage); v'Lckw@G4
int totalPage = getTotalPage(everyPage, _u.l|yR
)|2g#hH5
totalRecords); R':a,6O
boolean hasNextPage = hasNextPage(currentPage, NEK;'"~
H,zRmK6A%
totalPage); m~X:KwK4
boolean hasPrePage = hasPrePage(currentPage); ,9q5jOnk
Q@l3XNH|c
returnnew Page(hasPrePage, hasNextPage, 7(wY4T
everyPage, totalPage, |n* I}w^
currentPage, 4J_18.JHP
R#Ss_y
beginIndex); ;.m"y-
} 9/Q5(P
y'Wz*}8pr
privatestaticint getEveryPage(int everyPage){ <tFq6|
return everyPage == 0 ? 10 : everyPage; qzV:N8+,`
} n {^D_S
9I.="b=J)
privatestaticint getCurrentPage(int currentPage){ L+d_+:w
return currentPage == 0 ? 1 : currentPage; 6``!DMDt/P
} MbjH\XRB
\}G/F!
privatestaticint getBeginIndex(int everyPage, int z^=9%tLJ
T;.#=h
currentPage){ 8Gs{Zfp!D
return(currentPage - 1) * everyPage; .PxtcC.K
} C2bN<K
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privatestaticint getTotalPage(int everyPage, int _H@S(!
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totalRecords){ *`mwm:4
int totalPage = 0; i wK,XnIR
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if(totalRecords % everyPage == 0) Q<Utwk?nL
totalPage = totalRecords / everyPage; ,9
else }6ec2I%`o
totalPage = totalRecords / everyPage + 1 ; Q>= :$I
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return totalPage; u9sffX5x[J
} :C>slxY
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privatestaticboolean hasPrePage(int currentPage){ w_4`Wsn
return currentPage == 1 ? false : true; o{nBtxZ"
} XeJx/'9o{
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privatestaticboolean hasNextPage(int currentPage, M0 =K#/
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int totalPage){ 53@*GXzE
return currentPage == totalPage || totalPage == ~B|K]&/]
c?j /H$
0 ? false : true; E*j)gj9
} kf.w:X"i
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} r1JKTuuo
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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。 ~Wf&$p<|
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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 vRYfB{~
DXsp 2
做法如下: xW!2[.O5H
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Mb"i}Yt{
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的信息,和一个结果集List: ,J!G-?:@n
java代码: nV@k}IJg:?
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/*Created on 2005-6-13*/ n2Q ~fx<6%
package com.adt.bo; oGu-:X=`9
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import java.util.List;
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import org.flyware.util.page.Page; wG ua"@IE
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/** [daUtKz
* @author Joa Y1h8O%?
*/ ^M0e 0
publicclass Result { jO &sS?
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private Page page; %scSp&X
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private List content; >TK:&V
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/** ]+@ @{?0
* The default constructor r#M0X^4A
*/ k)U9%Pr
public Result(){ dUegHBw_`R
super(); 0<d9al|J
} C2OBgM+
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/** He @d~9M
* The constructor using fields ve|ig]$5g<
* GTgG0Ifeh
* @param page Kx==vq%39
* @param content 5 YjqN
*/ '
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public Result(Page page, List content){ VJviX[V?4
this.page = page; 6b`3AAGU"
this.content = content; *m)+|v}
} %xv }
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/** !6.}{6b
* @return Returns the content. S<fSoU+RJ
*/
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publicList getContent(){ moz*=a
return content; %{"v^4
} '&v.h#<
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/** 2E7vuFH4c
* @return Returns the page. .Y`;{)
*/ W5a7HkM
public Page getPage(){ 1j4tR#L
return page; XM?>#^nC?u
} [9N>*dKB
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/** e"g=A=S
* @param content uUmkk
* The content to set. 0o-.m
*/ *n]f) Jc
public void setContent(List content){ Y8l
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this.content = content; }(MI}o}
} g+v.rmX
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/** =o_Ua^mr
* @param page bn*SLWWQ.3
* The page to set. L<dJWxf?D
*/ - 2DvKW$
publicvoid setPage(Page page){ `|rF^~6(dR
this.page = page; o*5iHa(Qm
} r3OR7f[
} fGtYvl O-5
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