Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 f;{K+\T
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 s:/Wz39SY3
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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 $j(laD#AR
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 m#Y[EPF=|
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分页支持类: c3aBPig\D
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java代码: y8.3tp
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package com.javaeye.common.util; "=Xky,k
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import java.util.List; mb GL)NI
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publicclass PaginationSupport { FlyRcj
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publicfinalstaticint PAGESIZE = 30; # A#,]XP
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privateint pageSize = PAGESIZE; rnSrkn"j{
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privateList items; ]^>RBegJBO
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privateint totalCount; E51'TT9
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privateint[] indexes = newint[0]; N2uTWT>
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privateint startIndex = 0; k*ZYT6Z?
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public PaginationSupport(List items, int kN g{
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totalCount){ AMe_D
setPageSize(PAGESIZE); jJ7 "9
setTotalCount(totalCount); SdXAL
setItems(items); 0c
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setStartIndex(0); c~)H" n
} 3gQ2wP*K
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public PaginationSupport(List items, int =`EVg>+^
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totalCount, int startIndex){ }$oZZKS
setPageSize(PAGESIZE); \R.Fmeko
setTotalCount(totalCount); ,<O|#`?"@G
setItems(items); CyKupJ.Fq
setStartIndex(startIndex); z{(c-7*
} M?v`C>j
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public PaginationSupport(List items, int s*tzU.E(
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totalCount, int pageSize, int startIndex){ g0k{b
setPageSize(pageSize); rd ]dDG
setTotalCount(totalCount); 2#_i_j
setItems(items); 7Um3myXU
setStartIndex(startIndex); T]lVwj
} +![\7
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publicList getItems(){ 7J|eL
yj
return items; 3e?a$~9
} \Lz4ZZjSY
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publicvoid setItems(List items){ a=r^?q'/
this.items = items; ]]6
} \~#$o34V
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publicint getPageSize(){ &eFv~9
return pageSize; *n*po.Xr
} {SwvUWOf"
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publicvoid setPageSize(int pageSize){ V\/5H~L
this.pageSize = pageSize; yIf>8ed]#
} Ey]P
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publicint getTotalCount(){ 9$ =o({
return totalCount; -!-1X7v|Fp
} 8C4v
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publicvoid setTotalCount(int totalCount){ UEH+E&BCC
if(totalCount > 0){ ^~DClZ
this.totalCount = totalCount; X+'B*K$
int count = totalCount / /9<62F@zJ"
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pageSize; Ixr#zt$T-G
if(totalCount % pageSize > 0) icXeB_&cS
count++; gVN&?`k*?
indexes = newint[count]; 9._Osbp3P
for(int i = 0; i < count; i++){ WoDQg64
indexes = pageSize * ^ Iy'<J
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i; &-(p~[|
} 9 UcSQ"D
}else{ #TD0)C/
this.totalCount = 0; Pi'[d7o
} Sz0CP1WB
} (I ~r~5^
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publicint[] getIndexes(){ Wu
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return indexes; ='vkd=`Si
} P7y.:%DGD0
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publicvoid setIndexes(int[] indexes){ i1-wzI
this.indexes = indexes; 11BfJvs:
} (nt=
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publicint getStartIndex(){ mVEHVz $
return startIndex; b:YyzOqEu
} dH+oV`
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publicvoid setStartIndex(int startIndex){ t'DYT"3
if(totalCount <= 0) rRd8W}B
this.startIndex = 0; "Rq)%o$Z
elseif(startIndex >= totalCount)
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this.startIndex = indexes mqKr+
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[indexes.length - 1]; Q+=D#x
elseif(startIndex < 0) -: 8[
this.startIndex = 0; gs9VCaIa
else{ @1tv/W
this.startIndex = indexes }8?1)l
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[startIndex / pageSize]; dx[kG
} Cl'3I%$8K
} )+v'@]r
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publicint getNextIndex(){ G&v. cF#Y'
int nextIndex = getStartIndex() + VQ'DNv| 9
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pageSize; 707-iLkt.1
if(nextIndex >= totalCount) |c3Yh,Sv
return getStartIndex(); jLgx(bMn
else e2*Fe9:
return nextIndex; Bw8&Amxx:
} '(&,i/O
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publicint getPreviousIndex(){ g@B,0JRh
int previousIndex = getStartIndex() - oK{H
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pageSize; ui4*vjd
if(previousIndex < 0) OVf%m~%&s
return0; (d$ksf_[%f
else Kk<MS$Ov
return previousIndex; 4xnM7t\
} 4Q5c'
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} Hpq?I-g<^
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抽象业务类 \<4Hp_2?
java代码: fk
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/** 7(1UXtT
* Created on 2005-7-12 Th\t6K~
*/ b.sRB1
package com.javaeye.common.business; bsgr g
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import java.io.Serializable; i0e aBG]I
import java.util.List; 0F|DD8tHR
Q2 @Ugt$
import org.hibernate.Criteria; Nw|m"VLb
import org.hibernate.HibernateException; u @eKh3!
import org.hibernate.Session; {5N!udLDr5
import org.hibernate.criterion.DetachedCriteria; Ss
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import org.hibernate.criterion.Projections; 2$%E:J+2:$
import @N,I}_ 9-
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({
org.springframework.orm.hibernate3.HibernateCallback; Fu6~8uDV{{
import CxW-lU3G`
7d"gRM;
org.springframework.orm.hibernate3.support.HibernateDaoS >djTJ>dl_u
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upport; ;^Y]nsd
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import com.javaeye.common.util.PaginationSupport; N>'|fNx]
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public abstract class AbstractManager extends o,;Hb4Eu
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HibernateDaoSupport { (XJ0?;js=
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privateboolean cacheQueries = false; *g;4?_f
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privateString queryCacheRegion; ~[d |:]
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publicvoid setCacheQueries(boolean yk7 l{F
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cacheQueries){ XP'7+/A
this.cacheQueries = cacheQueries; |.c|\e z/
} ("$ ,FRTQ:
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publicvoid setQueryCacheRegion(String iQnIk|8
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queryCacheRegion){ U*7Yi-"/*
this.queryCacheRegion = K
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queryCacheRegion; HLml:B[F(
} 69>N xr~k
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publicvoid save(finalObject entity){ 8wQ|Ep\
getHibernateTemplate().save(entity); ,@]rvI6x
} E8QY6 gKF
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publicvoid persist(finalObject entity){ Rh.CnCbM
getHibernateTemplate().save(entity); 5,n{-V
} m:A1wL4c6
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publicvoid update(finalObject entity){ y8QJ=v* B
getHibernateTemplate().update(entity); n'-?CMH`
} =TzmhX5
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publicvoid delete(finalObject entity){ I||4.YT
getHibernateTemplate().delete(entity); =
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} t@1bu$y
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publicObject load(finalClass entity, {~RS$ |
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finalSerializable id){ _~_E(rTn
return getHibernateTemplate().load `[*n UdG
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(entity, id); fqcFfz6?x
} ]sf1+3
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publicObject get(finalClass entity, 3.^Tm+ C
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finalSerializable id){ +~~&FO2
return getHibernateTemplate().get m2o)/:
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(entity, id); u^!c:RfE?
} ZC\&n4~7
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publicList findAll(finalClass entity){ n6f
return getHibernateTemplate().find("from 5sc`L
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" + entity.getName()); n,E=eNc
} |VPJaiC~
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publicList findByNamedQuery(finalString Mx<?c
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namedQuery){ \&S-lsLY
return getHibernateTemplate
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().findByNamedQuery(namedQuery); =gjq@N]lAW
} S)h0@;q
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publicList findByNamedQuery(finalString query, jbU=D:|
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finalObject parameter){ (pFPuV
return getHibernateTemplate ."#M
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().findByNamedQuery(query, parameter); Fu%%:3_
} j.FW*iX1C
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publicList findByNamedQuery(finalString query, a9=pZ1QAG
:{ }]$+|)\
finalObject[] parameters){ S|pMX87R
return getHibernateTemplate \~:Uj~
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().findByNamedQuery(query, parameters); ;GgW&*|
} =QiVcw,G#
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publicList find(finalString query){ +?!x;qS^
return getHibernateTemplate().find m<DiYxK
y
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(query); WjrUns
} CfWtCA
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publicList find(finalString query, finalObject mimJ_=]DC
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parameter){ tL;!!vg#V
return getHibernateTemplate().find LXm5f;
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(query, parameter); w!=Fi
} p? dXs^ c
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public PaginationSupport findPageByCriteria TC=djC4$/
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(final DetachedCriteria detachedCriteria){ h5:>o
return findPageByCriteria m\}8N
u
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); yz CQ
} jBTXs5q
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public PaginationSupport findPageByCriteria FHu
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(final DetachedCriteria detachedCriteria, finalint 7HpfHqJ7
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startIndex){ ?ep'R&NV
return findPageByCriteria Zy>iaG9}
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(detachedCriteria, PaginationSupport.PAGESIZE, g@va@*|~d
q Z,7q
startIndex); I.M@we/bR}
} x*EzX4$x
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public PaginationSupport findPageByCriteria _m
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(final DetachedCriteria detachedCriteria, finalint 7^fpbrj
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pageSize, wQ 7G_kVp
finalint startIndex){ fY|Bc<,V9)
return(PaginationSupport) r@2{>j8
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getHibernateTemplate().execute(new HibernateCallback(){ Hyw T
publicObject doInHibernate =
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(Session session)throws HibernateException { N34.Bt
Criteria criteria = |r]f2Mrm
urlwn*!^s
detachedCriteria.getExecutableCriteria(session); ]kN<N0;\d
int totalCount = \WDL?(G<
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((Integer) criteria.setProjection(Projections.rowCount /-#1ys#F=
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()).uniqueResult()).intValue(); ^l UV^%f
criteria.setProjection $#cZJ@;]
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(null); X" hoDg
List items = sG/mmZHYzr
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criteria.setFirstResult(startIndex).setMaxResults U5 `h
GAZTCkB"
(pageSize).list(); [3yzVcr~4
PaginationSupport ps = 4k
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new PaginationSupport(items, totalCount, pageSize, :QndeUw
GTj=R$%09
startIndex); o]&w"3vOP0
return ps; P%#EH2J
} +h64idM{U
}, true); 6,ZfC<)
} M~0A-*N
}@6/sg
public List findAllByCriteria(final 2(-J9y|
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DetachedCriteria detachedCriteria){ z/JoUje
return(List) getHibernateTemplate KuU]enC3
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().execute(new HibernateCallback(){ @R5jUPUVV
publicObject doInHibernate fpjy[$8
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(Session session)throws HibernateException { ]x8_f6;D
Criteria criteria = P87!+pB(
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detachedCriteria.getExecutableCriteria(session); F{:ZHCm
return criteria.list(); 0XrB+nt
} Ub0hISA
}, true); !)jw o=l}J
} W+A-<Rh\
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public int getCountByCriteria(final F{#m~4O
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DetachedCriteria detachedCriteria){ U4DQ+g(A
Integer count = (Integer) 0W asE1t|
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getHibernateTemplate().execute(new HibernateCallback(){ egBjr?
publicObject doInHibernate y_^w|
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(Session session)throws HibernateException { HF9\SVR
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Criteria criteria = vybQ}dscn
R W=<EF&
detachedCriteria.getExecutableCriteria(session);
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return Sv*@ 3x
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criteria.setProjection(Projections.rowCount }Pm>mQZ},
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()).uniqueResult(); y8Q96zi
} =h?Q.vad
}, true); .Z,3:3,]
return count.intValue(); 5yvaY
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} FmfPi
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} pK)*{fC$`
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用户在web层构造查询条件detachedCriteria,和可选的 '~dE0ohWb
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 w#?@ulr]d
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PaginationSupport的实例ps。 TY|5O!
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ps.getItems()得到已分页好的结果集 x+kP,v
ps.getIndexes()得到分页索引的数组 -ff|Xxar{
ps.getTotalCount()得到总结果数 -{Lc?=
ps.getStartIndex()当前分页索引 F1V[8I.0
ps.getNextIndex()下一页索引 ?)B"\#`t
ps.getPreviousIndex()上一页索引 +]n.uA-`[a
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ryz
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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 5:jbd:o
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一下代码重构了。 5rAI[r
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我把原本我的做法也提供出来供大家讨论吧: :!omog
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首先,为了实现分页查询,我封装了一个Page类: jTNfGu0x
java代码: xy@1E;
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/*Created on 2005-4-14*/ eqt+EiH
package org.flyware.util.page; e*O-LI2O
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/** \]y4e^FZZ
* @author Joa uV]4C^k;`[
* ,hj5.;M
*/ a:C'N4K
publicclass Page { >*xa\ve
}*!7
Vrep
/** imply if the page has previous page */ Tct[0B
privateboolean hasPrePage; u$%>/cv
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/** imply if the page has next page */ `aFy2x`3
privateboolean hasNextPage; RP]hW{:U
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/** the number of every page */ KtWG2
privateint everyPage; ]w _,0q
lYlU8l5>
/** the total page number */ stnyJ9
privateint totalPage; lO/<xSjNd
By=/DVm)=
/** the number of current page */ qyP|`Pm4
privateint currentPage; :kycIM]s
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/** the begin index of the records by the current ZeD""vJRY
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query */ (fgX!G[W
privateint beginIndex; O_*(:Z
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/** The default constructor */ mU1lEx$
public Page(){ Lc>9[!+#
;!<WL@C~
} Wt +,6Cq
aq[ ;[$w
/** construct the page by everyPage r`]&{0}23
* @param everyPage K
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* */ 0G/VbS
public Page(int everyPage){ _(J 7^rN
this.everyPage = everyPage; {mPaloA
} }?,Gn]]
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/** The whole constructor */ ?^i$} .%W
public Page(boolean hasPrePage, boolean hasNextPage, wj>mk
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int everyPage, int totalPage, 6KiI3%y?0
int currentPage, int beginIndex){ j(|G) F
this.hasPrePage = hasPrePage; 9Vx2VjK2'
this.hasNextPage = hasNextPage; IVYWda0m
this.everyPage = everyPage; QDlEby m
this.totalPage = totalPage; !FweXFl
this.currentPage = currentPage; ]KGLJ~hm>
this.beginIndex = beginIndex; Wjt1NfS&
} }$W4aG*[
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/** ?45 kN=%*s
* @return x^aqnKoJ%\
* Returns the beginIndex. uX{n#i,~L
*/ N> RabD
publicint getBeginIndex(){ DSY:aD!
return beginIndex; U^4
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} nu,#y"WQ
qO=_i d
/** #5GIO
* @param beginIndex (: IUg
* The beginIndex to set. aG7QLCL
*/ %iWup:
publicvoid setBeginIndex(int beginIndex){ -UaUFJa8K&
this.beginIndex = beginIndex; )SZt If
} -|mWi
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/** 'iO?M'0gE#
* @return &~P5[[Q
* Returns the currentPage. }LS:f,1oGp
*/
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publicint getCurrentPage(){ ko2Kz
k
return currentPage; Ghgx8 ]e
} I]P'wav~O
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/** JicAz1P1W
* @param currentPage hXi^{ntw,
* The currentPage to set. p<>%9180!F
*/ ;crQ7}k
publicvoid setCurrentPage(int currentPage){ ;bVC7D~~4w
this.currentPage = currentPage; ig:/60Z
} f3e#.jan
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/** 8YC\Bw
* @return >ir'v5
* Returns the everyPage. M:|Z3p K
*/ hoI?,[@F
publicint getEveryPage(){ $X_JUzb
return everyPage; @-bX[}.
} _^Lv8a3(O
][-N<
/**
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* @param everyPage vCT5do"C&
* The everyPage to set. fk)ts,p?
*/ edhNQWn
publicvoid setEveryPage(int everyPage){ `e]L.P_e?
this.everyPage = everyPage; v4!zB9d
} g\&[;v
i
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/** }l&Uh&B`
* @return Vh^fbv`?
* Returns the hasNextPage. Vu '/o[nF>
*/ pv&:N,p
publicboolean getHasNextPage(){ 3o%,8l,
return hasNextPage; 1g6AzUXg
} 9;s:Bo
an^"_#8DA@
/** `m?%{ \
* @param hasNextPage U>6MT@\
* The hasNextPage to set. tVd\ r"0k
*/ D8N}*4S
publicvoid setHasNextPage(boolean hasNextPage){ 5Z}]d@
this.hasNextPage = hasNextPage; SCE5|3j
} n'=-bj`
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/** Qj~m;F!
* @return mdvooJ
* Returns the hasPrePage. LziEF-_
*/ ;T~]|#T\6
publicboolean getHasPrePage(){ <jF]SN
return hasPrePage; cc7*O
}
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/** 0ZPwEP
* @param hasPrePage EZaWEW
* The hasPrePage to set. 8
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*/ sfi.zuG
publicvoid setHasPrePage(boolean hasPrePage){ IRNL(9H
this.hasPrePage = hasPrePage; |WH'aGG
} QlJ
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/** PHl{pE*
* @return Returns the totalPage. &=H{ 36i@
* w*<XPBi
*/ ?>5[~rMn
publicint getTotalPage(){ !/+ZKx("9
return totalPage; o9ZHa
} B1 T:c4:N
84^'^nd
/** cjt<&b*
* @param totalPage \"B?'Ep;
* The totalPage to set. 7l> |G,[c
*/ D].!u{##
publicvoid setTotalPage(int totalPage){ T:q_1W?h]
this.totalPage = totalPage; *LpEH,J
} >_P7 k5Y^
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} CI"7* z_
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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 SLp &_S@4
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个PageUtil,负责对Page对象进行构造: m7wD#?lm
java代码: CY#|VE M
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/*Created on 2005-4-14*/ S[,!
package org.flyware.util.page; ^;jJVYx-PP
^T@ (`H4@
import org.apache.commons.logging.Log; bh|M]*Pq
import org.apache.commons.logging.LogFactory; s. I%[kada
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/** Pe6}y
* @author Joa k8H@0p
* X.hU23w
*/ 2g~qVT,
publicclass PageUtil { W1'F)5(?7
uKc x$
privatestaticfinal Log logger = LogFactory.getLog IvGQ7
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"s!!\/^9C
(PageUtil.class); 52?zBl`|
1=(jpy
/** *I6z;.#
* Use the origin page to create a new page |57u ;
* @param page 1Q\P]
-
* @param totalRecords :8b{|}aYV
* @return d%_=r." Y
*/ 6 "fYSn>
publicstatic Page createPage(Page page, int Q ^X
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totalRecords){ ly"Jl8/<
return createPage(page.getEveryPage(), lM1~K
cb!mV5M-g
page.getCurrentPage(), totalRecords); TI4#A E
} ,5oe8\uz
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/** {$D[l
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* the basic page utils not including exception Cbu/7z
!>QS746S@
handler fB^h2
* @param everyPage xIu#
* @param currentPage Py*( %
* @param totalRecords M)S(:Il6Xx
* @return page x|4m*>Ke
*/ 0_'(w;!wq:
publicstatic Page createPage(int everyPage, int
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MU6|>{
currentPage, int totalRecords){ X`i'U7%I
everyPage = getEveryPage(everyPage); vD<6BQR
currentPage = getCurrentPage(currentPage); "fK`F/
int beginIndex = getBeginIndex(everyPage, YXCltME
np2oXg%
currentPage); fkf69,+"]
int totalPage = getTotalPage(everyPage, n@5Sp2p
D4,kGU@
totalRecords); Qn=3b:S-
boolean hasNextPage = hasNextPage(currentPage, gc(Gc vdB\
AGaM
&x=
totalPage); Gk_%WY*
boolean hasPrePage = hasPrePage(currentPage); Z]?Tx2|7
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returnnew Page(hasPrePage, hasNextPage, .Zo%6[X
everyPage, totalPage, \:]
currentPage, tGt/=~n9
iMG)zPj
beginIndex); %smQ`u|
} l{b<rUh5W
.OhpItn
privatestaticint getEveryPage(int everyPage){ m 2c>RCq
return everyPage == 0 ? 10 : everyPage; >,c$e' h
} - 7MR2)U
wEju`0#;
privatestaticint getCurrentPage(int currentPage){ O-m=<Fk>
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return currentPage == 0 ? 1 : currentPage; =&+]>g{T
} 337y,;
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privatestaticint getBeginIndex(int everyPage, int =5:L#` .
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currentPage){ \s_lB~"P!3
return(currentPage - 1) * everyPage; rJLn=|uR
} 3V=(P.A Tm
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privatestaticint getTotalPage(int everyPage, int /$NDH]a
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totalRecords){ A8,9^cQ]
int totalPage = 0; V11(EZJ/j
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if(totalRecords % everyPage == 0) 1.S7MSpTV
totalPage = totalRecords / everyPage; W,sU5sjA
else ^gw htnI
totalPage = totalRecords / everyPage + 1 ; R7)\wP*l5
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return totalPage; UI:YzR
} SZUhZIz&
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privatestaticboolean hasPrePage(int currentPage){ 5>9KW7^L
return currentPage == 1 ? false : true; i4<&zj})
} -,xCUG<g
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privatestaticboolean hasNextPage(int currentPage, mL5 Nu+#
j
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int totalPage){ (PVK|Q55y
return currentPage == totalPage || totalPage ==
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}"}
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0 ? false : true; So?.V4aD_
} 3=[#(p:
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} +Dvdv<+
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 TFZvZi$u&
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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 hKkUsY=R
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做法如下: 48}L!m @
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 cb36 ~{
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的信息,和一个结果集List: K&L9Ue
java代码: ! z!lQ~
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/*Created on 2005-6-13*/ z-9@K<`H
package com.adt.bo; *[
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import java.util.List; ? PIq/[tk
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import org.flyware.util.page.Page; \o|5/N
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/** L#
* @author Joa 3o).8b_3g
*/ Vgh;w-a
publicclass Result { Z)JJ-V!
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private Page page; ~Onj|w7
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private List content; "o| f
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/** |6qxRWT"
* The default constructor I
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*/ o0yyP,?yh
public Result(){ v~l_6V}
super(); `zRE $O
} cImOZx
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/** <5Ye')+
* The constructor using fields os:/-A_m
* ] ^f7s36
* @param page W^o*^v
* @param content trl:\m
*/ [Ej#NHs
public Result(Page page, List content){ m7dpr$J
this.page = page; |3Fo4K%+
this.content = content; Mz?xvP?z
} fG *1A\t]
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/** "PFczoRZ
* @return Returns the content. s!lLdR[g
*/ %NyV2W=~X
publicList getContent(){ 3CKd[=-Z
return content; @Feusprs
} I "8:IF
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/** -d j9(~?^
* @return Returns the page.
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*/ DGs=.U-=e
public Page getPage(){ {S9't;%]
return page; +%O_xqq
} P^lzl:|
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/** .o27uB.
* @param content '}nH\?(
* The content to set. j{U#g8
*/ ;~A-32;Y4
public void setContent(List content){ Fwu:x.(
this.content = content; iRbTH}4i
} Lip(r3
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/** pCB^\M%*
* @param page >A]U.C
* The page to set.
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*/ 3`Ug]<m
publicvoid setPage(Page page){ Y)Os]<N1
this.page = page; h20<X;
} }\iH ~T6
} !=)R+g6b
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2. 编写业务逻辑接口,并实现它(UserManager, A^m]DSFOO
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UserManagerImpl) UQ7E7yY#
java代码: FnZMW, P
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/*Created on 2005-7-15*/ g9T9TQ-O
package com.adt.service; C >@T+xOZ
ak SUk)}e
import net.sf.hibernate.HibernateException; sI/]pgt2
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import org.flyware.util.page.Page; _`oP*g =
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import com.adt.bo.Result; &N