Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 QKP9*dz
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 5r+0^UAO:J
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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 c~tSt.^WX
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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 6/-!oo
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分页支持类: "FXS;Jf
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java代码: vfbe=)}[
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package com.javaeye.common.util; asq/_`
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import java.util.List; G4{qWa/
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publicclass PaginationSupport { aW6+Up+G*
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publicfinalstaticint PAGESIZE = 30; z1FbW&V
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privateint pageSize = PAGESIZE; /SUV'J)
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privateList items; .3U[@ *b(
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privateint totalCount; &53#`WgJ
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privateint[] indexes = newint[0]; L~oFW'
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privateint startIndex = 0; 'iVo,m[yKU
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public PaginationSupport(List items, int }]~}DHYr
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totalCount){ 1 :Yt2]
setPageSize(PAGESIZE); 46zaxcY<!
setTotalCount(totalCount); -/-6Td1JY>
setItems(items); :xw3b)KS
setStartIndex(0); Vf?#W,5>=
} K7hf m%`N
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public PaginationSupport(List items, int HLe^|
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totalCount, int startIndex){ Ib2 @Wi
setPageSize(PAGESIZE); 9 <KtI7
setTotalCount(totalCount); \u]CD}/
setItems(items); W"kw>JEt
setStartIndex(startIndex); DVhTb
} &'7"i~pC
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public PaginationSupport(List items, int %;Z bQ9
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totalCount, int pageSize, int startIndex){ -L9R&r#_e
setPageSize(pageSize); p??/r
setTotalCount(totalCount); grQnV' q
setItems(items); ,GX~s5S8
setStartIndex(startIndex); eFSC^
} $a^isd4
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publicList getItems(){ Zva
return items; tin|,jA =
} *9vA+uN
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publicvoid setItems(List items){ naIv=
this.items = items; +oy&OKCa
} V+qJrZ,i
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publicint getPageSize(){ 5w3 ZUmjO
return pageSize; Q)S>VDLA
} -@L's{J{M
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publicvoid setPageSize(int pageSize){ ns#~}2"d
this.pageSize = pageSize; NaA+/:
} h.V]f S
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publicint getTotalCount(){ %X9b=%'+
return totalCount; A=%k/
} ]G0dS
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publicvoid setTotalCount(int totalCount){ U,<]J*b(@4
if(totalCount > 0){ 6<Z*Tvk{C
this.totalCount = totalCount; wn+j39y?ZY
int count = totalCount / W7L+8LU;
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pageSize; |mxNUo-
if(totalCount % pageSize > 0) .Z=Ce!
count++; 't(}Rq@
indexes = newint[count]; A XBkJ'jd
for(int i = 0; i < count; i++){
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indexes = pageSize * yI8m%g%
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} Hz?!BV0
}else{ H`m:X,6}
this.totalCount = 0; +z-[s6q2m
} 5vTv$2@
} 2{ o0@
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publicint[] getIndexes(){ <%z@
return indexes; 4:vTxNs&S
} RF_[?O)Q
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publicvoid setIndexes(int[] indexes){ x;]x_fz
this.indexes = indexes; <EMkD1e
} XGfzEld2"
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publicint getStartIndex(){ g nt45]@{
return startIndex; ]cIu|bRO
} }Y Q:6I
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publicvoid setStartIndex(int startIndex){ a3q\<"|
if(totalCount <= 0) x>%joKY[
this.startIndex = 0; nv"G;W
elseif(startIndex >= totalCount) 9\v.qo.
this.startIndex = indexes 4O!E|/`wO
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[indexes.length - 1]; ga-{!$b*
elseif(startIndex < 0) /D[dO6.
this.startIndex = 0; iZQ\
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else{ ibJl;sJ
this.startIndex = indexes W,3zL.qH"
'[nmFCG%m*
[startIndex / pageSize]; xO7Yt
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} JSgpb?(
} (/K5! qh
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publicint getNextIndex(){ "cMNdR1^,y
int nextIndex = getStartIndex() + s~J=<)T*6
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pageSize; R)+t]}
if(nextIndex >= totalCount) "jR]MZ
return getStartIndex(); KCUU#t|8V\
else rJQ=9qn\
return nextIndex; p0M=t-
} +8AvTSgX%
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publicint getPreviousIndex(){ DyfsTx
int previousIndex = getStartIndex() -
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/L&M,OUcr.
pageSize; MzzKJ;wbC6
if(previousIndex < 0) CISO<z0
return0; b9Y_!Qe
else ^ve14mbF#.
return previousIndex; sDC*J\X
} UTCzHh1
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} gnLn7?
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抽象业务类 y=a V=qD
java代码: c%f_.MiU
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/** a1c1k}
* Created on 2005-7-12 G[Tl%w
*/ *1A&'T2
package com.javaeye.common.business; gR Nv-^
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import java.io.Serializable; t6lE#<xZV;
import java.util.List; 27D!'S
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import org.hibernate.Criteria; 3[IJhR[
import org.hibernate.HibernateException; ?&X6:KJQ
import org.hibernate.Session; KE}H&1PjU
import org.hibernate.criterion.DetachedCriteria; |<qs
import org.hibernate.criterion.Projections; 0Scm?l3
import {1-V]h.<J
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org.springframework.orm.hibernate3.HibernateCallback; 9YN?
import 3x@<Z68S
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org.springframework.orm.hibernate3.support.HibernateDaoS /rc%O*R
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upport; 9X}I>
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import com.javaeye.common.util.PaginationSupport; ;_?MX/w|&
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public abstract class AbstractManager extends ZC0-wr\
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HibernateDaoSupport { 1B=>_3_
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privateboolean cacheQueries = false; Wp0
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privateString queryCacheRegion; SA"p\}"
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publicvoid setCacheQueries(boolean GW^,g@%C
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cacheQueries){ |N /G'>TS
this.cacheQueries = cacheQueries; v Gy8Qu>
} S$q=;"
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publicvoid setQueryCacheRegion(String p=Q0!!_r
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queryCacheRegion){ 0%Ll
this.queryCacheRegion = <UP
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queryCacheRegion; Uz7oL8
} friWW^
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publicvoid save(finalObject entity){ - YqYcer
getHibernateTemplate().save(entity); ]}="m2S3
} xM >W2
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publicvoid persist(finalObject entity){ * |.0Myjo
getHibernateTemplate().save(entity); "p&Y^]
} en S}A*Io
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publicvoid update(finalObject entity){ HAz By\M{
getHibernateTemplate().update(entity);
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} \W5O&G-C
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publicvoid delete(finalObject entity){ kl!wVLE
getHibernateTemplate().delete(entity); 5^<h}u9
} h0--B]f@
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publicObject load(finalClass entity, qU2~fNY
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finalSerializable id){ - O98pi
return getHibernateTemplate().load )~4II.`%^
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(entity, id); K5ZC:Ks
} x9/H/'
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publicObject get(finalClass entity, l&4,v
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finalSerializable id){ KH)D08
return getHibernateTemplate().get <?-YTY|
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(entity, id); [${
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} _It ,%<3
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publicList findAll(finalClass entity){ n55Pv3}C
return getHibernateTemplate().find("from 7{e{9QbJ4
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" + entity.getName()); D']ZlB'K
} 9TF f8'?d
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publicList findByNamedQuery(finalString Zfk*HV#\
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namedQuery){ bCref$|
return getHibernateTemplate 8^Hn"v
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().findByNamedQuery(namedQuery); 5MFxo63
} /9o!*K
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publicList findByNamedQuery(finalString query, a+hd(JX0~
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finalObject parameter){ <%xS{!'}
return getHibernateTemplate ;a-$D]Db
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().findByNamedQuery(query, parameter);
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} GN KF&M
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publicList findByNamedQuery(finalString query, v9Xp97J2
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finalObject[] parameters){ h~C.VJWl
return getHibernateTemplate *Z m^
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().findByNamedQuery(query, parameters); !"e5~7
} Vy_2 .
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publicList find(finalString query){ ;raN
return getHibernateTemplate().find *3T|M@Y
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(query); 7'
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} 1?
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publicList find(finalString query, finalObject upeU52@\
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parameter){ /r12h|
return getHibernateTemplate().find $T :un.TM
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(query, parameter); Cgz D$`~
} U^qt6$bK
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public PaginationSupport findPageByCriteria jE#O>3+.
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(final DetachedCriteria detachedCriteria){ Z3!f^vAi&
return findPageByCriteria _-5,zPR
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); iD= p\
} [o*7FEM|<
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public PaginationSupport findPageByCriteria "_2Ng<2
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(final DetachedCriteria detachedCriteria, finalint JsO
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startIndex){ 2< hAa9y
return findPageByCriteria H5D*|42
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(detachedCriteria, PaginationSupport.PAGESIZE, wO2_DyMm@
p">EHWc}D
startIndex); 4e;QiTj
} .'a&33J
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public PaginationSupport findPageByCriteria W
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(final DetachedCriteria detachedCriteria, finalint D/h/Y) Y
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pageSize, m~uOXb
finalint startIndex){ ?'"X"@r5
return(PaginationSupport) HNL42\Kz!
)/t?!T.[
getHibernateTemplate().execute(new HibernateCallback(){ ["}rk
publicObject doInHibernate "[:iXRu
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(Session session)throws HibernateException { ;\MW$/[JCy
Criteria criteria = Q]o C47(
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detachedCriteria.getExecutableCriteria(session); -[L!3jU
int totalCount = TY(bPq
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((Integer) criteria.setProjection(Projections.rowCount 5{$LsL
jjM{]
()).uniqueResult()).intValue(); 2Hum!p:1
criteria.setProjection upvS|KUil
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(null); `<[6YH_
List items = Y
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criteria.setFirstResult(startIndex).setMaxResults ;L&TxO>#J
7RDDdF E!
(pageSize).list(); $Ci0I+5w
PaginationSupport ps = L#)(H^[
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new PaginationSupport(items, totalCount, pageSize, #P#-xz
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startIndex); l^J75$7
return ps; 4.RG4Jq
} mJB2)^33a
}, true); |w}xl'>q
} {YUIMd!Y
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public List findAllByCriteria(final i
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DetachedCriteria detachedCriteria){ *)]"27^
return(List) getHibernateTemplate 9z?oB&5
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().execute(new HibernateCallback(){ P'MY[&|mM'
publicObject doInHibernate `MP|Ovns:H
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(Session session)throws HibernateException { kqG0%WtQ
Criteria criteria = f`>/
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detachedCriteria.getExecutableCriteria(session); 97!>%d[0
return criteria.list(); v6\F
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} `IINq{Zk
}, true); c.\O/N
} x( mE<UQN
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public int getCountByCriteria(final ;DnUQj
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DetachedCriteria detachedCriteria){ ^BZkHAp
Integer count = (Integer) a'\By?V]
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getHibernateTemplate().execute(new HibernateCallback(){ }_QKJw6/"
publicObject doInHibernate b{DiM098
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(Session session)throws HibernateException { b=a!j=-D
Criteria criteria = g=}v>[k E
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detachedCriteria.getExecutableCriteria(session); 6) \dBOz
return }2)DPP:ic
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criteria.setProjection(Projections.rowCount Hg}I]!B
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()).uniqueResult(); U3vEdw<lV
} 5H,G-
}, true); u%O-;>J
return count.intValue(); C-P06Q]
} TY;U2.Ud
} @E`?<|B}
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用户在web层构造查询条件detachedCriteria,和可选的 *.y' (tj[
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 *2u
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PaginationSupport的实例ps。 P#GD?FUc
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ps.getItems()得到已分页好的结果集 Pn TZ/|
ps.getIndexes()得到分页索引的数组 a
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ps.getTotalCount()得到总结果数 PB~_I=
ps.getStartIndex()当前分页索引 X<Za9
ps.getNextIndex()下一页索引 RagiV6c
ps.getPreviousIndex()上一页索引 ucg$Ed
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 H$!-f>Rxa
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 `ypL]$cW
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一下代码重构了。 <A~GW
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我把原本我的做法也提供出来供大家讨论吧: O.:I,D&]
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首先,为了实现分页查询,我封装了一个Page类: .Vx|'-u
java代码: rnvQ<671W
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/*Created on 2005-4-14*/ GAU!_M5 N
package org.flyware.util.page; ^tE_LL+ji|
G*\sdBW!k
/** d7~j^v)=^
* @author Joa _om[VKJd
* ('WY5Yps
*/ k}BDA|\s
publicclass Page { Kfjryo9
i| xt f
/** imply if the page has previous page */ rbh[j@s@
privateboolean hasPrePage; :ej_D}
*]!l%Uf%
/** imply if the page has next page */ ]31$KBC
privateboolean hasNextPage; :`zV
[A:D
4$i} Xk#3
/** the number of every page */ " dT>KQ
privateint everyPage; *aG"+c6|
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/** the total page number */ 7:kCb[ji"
privateint totalPage; P!>g7X
\1{_lynD
/** the number of current page */ v$JLDt_
privateint currentPage; ;Xh5oB\)W
cKpQr7]ur
/** the begin index of the records by the current \4@a
vrO%XvXW
query */ @WJf)
privateint beginIndex; 2$DSBQEx
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/** The default constructor */ Cn/q=
public Page(){ r"[L0Cbb
U
TS{H
} /gX%ABmS
`=v@i9cTZ
/** construct the page by everyPage >E~~7Yal
* @param everyPage hvL6zCi
* */ b8e*Pv/
public Page(int everyPage){ 8ur_/h7
this.everyPage = everyPage; _&=9 Ke
} BMF3XcH~G
,`+Bs&S 8
/** The whole constructor */
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public Page(boolean hasPrePage, boolean hasNextPage, >LCjtm\
)Jmw|B
#W.bZ]&WA
int everyPage, int totalPage, " _mmR
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int currentPage, int beginIndex){ 8@Q"YA3d+
this.hasPrePage = hasPrePage; 7~L|;^(
this.hasNextPage = hasNextPage; ,qYf#fU#7
this.everyPage = everyPage; VgUvD1v?}
this.totalPage = totalPage; &4[<F"W>47
this.currentPage = currentPage; B piEAwh
this.beginIndex = beginIndex; xvHOY:
} 5,Qy/t}K
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/** yM W'-\
* @return _%XbxP6rH
* Returns the beginIndex. +~@7"
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*/ _8Pmv$
publicint getBeginIndex(){ McO@p=M
return beginIndex; 9$8X>T^
} -<H ri5
_3*: y/M_
/** se}pdL}
* @param beginIndex 9$n+-GSK
* The beginIndex to set. V,`!rJ
*/ [9'|7fdU
publicvoid setBeginIndex(int beginIndex){ 6oPUYn-
this.beginIndex = beginIndex; +!D=SnBGs
} Zjw!In|vC
J{aQ1)
/** xn0s`I[
* @return +qE,<c}}
* Returns the currentPage. vQ?MM&6
*/ mrw]yu;2<n
publicint getCurrentPage(){ 7uWJ6Wk
return currentPage; oFX"F0rx
} z0EjIYI[N
_Ac/i r[,:
/** IptB.bYc
* @param currentPage GGYX!=]~
* The currentPage to set. ZJiuj!
*/ u?LW+o
publicvoid setCurrentPage(int currentPage){ yaCd4KP
this.currentPage = currentPage; |?4~T:
} =*@MQ
g6x/f<2x
/** TyxU6<>4J4
* @return OqAh4qa,$
* Returns the everyPage.
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*/ ,I9][_
publicint getEveryPage(){ G.A=hGw
return everyPage; nsM>% +o
} ]{q-Y<{"
c+)36/; X
/** E7d~#
* @param everyPage D;16}D
* The everyPage to set. {ziYd;Ys1
*/ (1saof*p%
publicvoid setEveryPage(int everyPage){ s0X/1Cq
this.everyPage = everyPage; LLXg
} :V5!C$QV
e{qp!N1!
/** , u8ZS|9
* @return T_5*iwI
* Returns the hasNextPage. u`L!za7fi
*/
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publicboolean getHasNextPage(){ 14@q $}sf
return hasNextPage; ArEH%e
} x`j$9XN5
6I5[^fv45G
/** 9}'l=b:Jms
* @param hasNextPage uJ)\P
* The hasNextPage to set. vMW-gk
*/ M;S-ESQ
publicvoid setHasNextPage(boolean hasNextPage){ ^Yf)lV&[
this.hasNextPage = hasNextPage; Ca`/ t8=
} ^Xt]wl*]+
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/** ?=|)n%
* @return FzsS~C$wH{
* Returns the hasPrePage. W~+!"^<n
*/ 6f5sIg
publicboolean getHasPrePage(){ +i q+
return hasPrePage; :`Zl\!]E`o
} >m;|I/2@
6"rFfdns
/** o<Rxt
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* @param hasPrePage )n3biQL_
* The hasPrePage to set. ~;O=
7
*/ .@/z-OgXg
publicvoid setHasPrePage(boolean hasPrePage){ ]mJAKycE%
this.hasPrePage = hasPrePage; no\}aTx
} #Ko+_Hm?4
m;tY(kO
/** 3Oig/KZ
* @return Returns the totalPage. NdED8 iRc
* V"Y
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*/ XR=c
8f
publicint getTotalPage(){ &oK/]lub
return totalPage; 7$d c?K
} 5)SZd)
zf!\wY"`
/** 3K'o&>}L
* @param totalPage (j"~]T!)1
* The totalPage to set. EuimZW\V
*/ BoiIr[ (
publicvoid setTotalPage(int totalPage){ ZZ.0'
this.totalPage = totalPage; .5Z@5g`
} 8Q)mmkI\=
yfw>y=/p
} Drq{)#7
lt(-,md
/Geks/
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 Er+3S@sfq,
i\R\bv[9
个PageUtil,负责对Page对象进行构造: Qc
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java代码: #?|1~HC
`GN5QLg#}0
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/*Created on 2005-4-14*/ h*X%:UbW
package org.flyware.util.page; yLa5tv/
DBh/V#* D
import org.apache.commons.logging.Log; &/#Tk>:
import org.apache.commons.logging.LogFactory; K}*p(1$u
^VYZ%
/** qxCL
* @author Joa Wes"t}[25
* RknSWuFKt
*/ 7/$Z7J!k
publicclass PageUtil { Sw9mrhzJfe
uXW.
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privatestaticfinal Log logger = LogFactory.getLog p){RSq
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(PageUtil.class); )^@V*$D
btz3f9
/** [&}<!:9'
* Use the origin page to create a new page Nm :lC%>X
* @param page ?@BaBU:o`F
* @param totalRecords hr"+0KeX
* @return ;? QAPTz
*/ 91Sb=9
publicstatic Page createPage(Page page, int szs3x-g
jl%eO.
totalRecords){ ?U[nYp}"v
return createPage(page.getEveryPage(), Y `p&*O
>-WOw
page.getCurrentPage(), totalRecords); %lW:8ckL
} +uXnFf d^
}(IDPaJ
/** _;RD-kv
* the basic page utils not including exception -^yc yZ
7027@M?A?
handler KvOI)"0(
* @param everyPage 0s[3:bZ\Ia
* @param currentPage ]* Ki7h|B
* @param totalRecords ~4gKAD
* @return page nM}`H'0
*/ I`>%2mP[C
publicstatic Page createPage(int everyPage, int 'UCx^-
eTHh
currentPage, int totalRecords){ {/!"}{G1e
everyPage = getEveryPage(everyPage); VQ}3r)ch
currentPage = getCurrentPage(currentPage); RxG./GY
int beginIndex = getBeginIndex(everyPage, $ !=:ES
!sWBj'[>
currentPage); ()JDjzQT
int totalPage = getTotalPage(everyPage, .Sw'Bo!Ee
l~c>jm8.
totalRecords); |^!@
boolean hasNextPage = hasNextPage(currentPage, xM,(|p(
nL~
b
totalPage); BVeNK=7m%
boolean hasPrePage = hasPrePage(currentPage); ixpG[8s
>?FCv7qN
returnnew Page(hasPrePage, hasNextPage, |:BYOxAYZ8
everyPage, totalPage, ?"u-@E[m
currentPage, =_3qUcOP
^Z+D7Q
beginIndex); ( "z;Q?(
} y5h[^K3
yBKlp08J
privatestaticint getEveryPage(int everyPage){ o)WSMV(&f
return everyPage == 0 ? 10 : everyPage; 7?#32B
Gr
} l))IO`s=_
x*)O<K
privatestaticint getCurrentPage(int currentPage){ [GM<Wt0
return currentPage == 0 ? 1 : currentPage; KHiJOeLc
} DJUtuex
MqH~L?~}|
privatestaticint getBeginIndex(int everyPage, int Z8UM0B=i
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currentPage){ 7C^ nk
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return(currentPage - 1) * everyPage; gvYs<,:
} [N)M]u
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privatestaticint getTotalPage(int everyPage, int 3J<,2
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totalRecords){ xM\ApN~W
int totalPage = 0; #w6CL
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if(totalRecords % everyPage == 0) @Iu-F4YT
totalPage = totalRecords / everyPage; 37Y]sJrs$
else v(~m!8!TI
totalPage = totalRecords / everyPage + 1 ; EVsZ:Ra^k
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return totalPage; ba13^;fm#
} Xg,BK0O
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privatestaticboolean hasPrePage(int currentPage){ 3LREue7Gr
return currentPage == 1 ? false : true; IIkJ"Qg.
} TZg7BLfy
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privatestaticboolean hasNextPage(int currentPage, @@jdF-Utj;
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int totalPage){ (6nw8vQ
return currentPage == totalPage || totalPage == L_,U*Jyo
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0 ? false : true; iY-dM(_:]
} AK
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} <=Qk^Y2k
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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。 -bwl~3ZTi
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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 i weP3u##
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做法如下: *M:Bhw
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 !T*izMX}
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的信息,和一个结果集List: J5k%
java代码: Ty=}A MMyE
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/*Created on 2005-6-13*/ C7{w I`~
package com.adt.bo; Fr~xN!
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import java.util.List; _bX)fnUu
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import org.flyware.util.page.Page; T1E{NgK
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/** Ev%\YI!MaY
* @author Joa )Ii=8etdv
*/ b}fH$.V@
publicclass Result { 4:.M*Dz
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private Page page; 5GKz@as8
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private List content; <*[(t;i
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/** @bZb#,n]
* The default constructor `)'YU^s
*/ N$?q Aek
public Result(){ {?8rvAjY
super(); M<SZ7^9<
} @c.pOX[]m,
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/** %:NI@59
* The constructor using fields j'Fni4;
* %n^]1R#
* @param page ~Y{K^:wN^
* @param content :0J;^@
*/ [Mx+t3M
public Result(Page page, List content){ R8HFyP
this.page = page; hQ9VcS6=gD
this.content = content; hGsYu )
} {J[0UZ6
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/** .k}h'nE
* @return Returns the content. =dPrG=A
*/ xu3qX"
publicList getContent(){ r'&VH]m
return content; )Ipa5i>t
} vV%w#ULxE~
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/** "bJW yUb
* @return Returns the page. YtFtU;{
*/ qTG/7tn
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public Page getPage(){ [j):2
return page; /)j:Y:5
} ikUG`F%W
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/** LqNsQu";
* @param content Wh,p$|vL
* The content to set. 8RB\P:6h
*/ wtK+\Qnb
public void setContent(List content){ yN9/'c~
this.content = content; 3>ytpXUEGx
} _qr?v=,-A
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/** 0`:0m/fsU
* @param page dj 4:r!5_
* The page to set. T< D&%)
*/ V3
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publicvoid setPage(Page page){ ;tlvf?0!
this.page = page; N^v"n*M0|
} 13kl\<6
} vkp_v1F%+
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2. 编写业务逻辑接口,并实现它(UserManager, JD9)Qelw^$
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UserManagerImpl) yhc}*BMZ
java代码: s+DOr$\
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/*Created on 2005-7-15*/ f}=>c|Do
package com.adt.service; 1
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import net.sf.hibernate.HibernateException; t^
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import org.flyware.util.page.Page; ? fW['%
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import com.adt.bo.Result; z9Z4MXl
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/** 2)hfYLi
* @author Joa ^p)#;$6b
*/ 'hR0JXy
publicinterface UserManager { [4w*<({*
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public Result listUser(Page page)throws :CLWmMC_
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HibernateException; >$,P )cB'
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} ,.Lwtp,n
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java代码: 3^[P
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/*Created on 2005-7-15*/ da<