Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 {hZZU8*
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 zSDiJ$Xk
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 G4=%<+
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 \A keC 6[D
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分页支持类: 3P I{LU
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java代码: k<8:
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package com.javaeye.common.util; wyvs#T
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import java.util.List; J=zh+oLCV
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publicclass PaginationSupport { YNk?1#k?i
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publicfinalstaticint PAGESIZE = 30; is#?O5:2
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privateint pageSize = PAGESIZE; wU?2aXY
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privateList items; cz&FOP+!
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privateint totalCount; *8X: fq
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privateint[] indexes = newint[0]; 4`!(M]u=
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privateint startIndex = 0; gd/W8*NFR
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public PaginationSupport(List items, int t6s#19g
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totalCount){ =(.HO:#
setPageSize(PAGESIZE); v3.JG]zLpP
setTotalCount(totalCount); -zG/@.
setItems(items); {@B<$g
setStartIndex(0); #}e)*(
} Gi ZyC
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public PaginationSupport(List items, int WAkKbqJV
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totalCount, int startIndex){ q31swP
setPageSize(PAGESIZE); :2K0/@<x
setTotalCount(totalCount); sh E>gTe
setItems(items); o D:?fs]
setStartIndex(startIndex);
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} >`8i=ZpCOS
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public PaginationSupport(List items, int <Cn-MOoM
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totalCount, int pageSize, int startIndex){ v7xc01x
setPageSize(pageSize); #RZW)Br
setTotalCount(totalCount); krI<'m;a
setItems(items); I:bi8D6
setStartIndex(startIndex); F|%[s|s
} $WrDZU 2z
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publicList getItems(){ 6\/C]![%
return items; V= !!;KR0
} $(.[b][S
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publicvoid setItems(List items){ rFdq \BSi
this.items = items; MXSPD#gN
} 1+.(N:) +
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publicint getPageSize(){ *d?,i-Q.+
return pageSize; UR:cBr
} W?5^cEF
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publicvoid setPageSize(int pageSize){ Mm+_>
this.pageSize = pageSize; IF$f^$
} O: :X$O7
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publicint getTotalCount(){ AEe*A+
return totalCount; aXhgzI5]
} 1^b-J0
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publicvoid setTotalCount(int totalCount){ 9JJ(KY
if(totalCount > 0){ 3?.3Z!H/
this.totalCount = totalCount; ~4`LOROC
int count = totalCount / XGbtmmQG
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pageSize; q}U^H
if(totalCount % pageSize > 0) gle_~es'K
count++; q1.w8$
indexes = newint[count]; {^1D|y
for(int i = 0; i < count; i++){ D42Bm&JocO
indexes = pageSize * cAC]%~orx
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i; wtu WzHrF
} Q]uxZ;}aF
}else{ ,mx>)}l95
this.totalCount = 0; [x
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} am]$`7R5d
} >MauuL,.j
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publicint[] getIndexes(){ '+hiCX-_
return indexes; `$ql>k-6C
} XkDjA#nx`
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publicvoid setIndexes(int[] indexes){ 1
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this.indexes = indexes; r n"'tvhm
} !iN=py
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publicint getStartIndex(){ +[<|TT
return startIndex;
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} dq+VW}[EO
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publicvoid setStartIndex(int startIndex){ Y6~/H
if(totalCount <= 0) D1}Bn2BM$
this.startIndex = 0; <5%x3e"7u
elseif(startIndex >= totalCount) 66NJ&ac
this.startIndex = indexes bS=aFl#
rvgArFf}]
[indexes.length - 1]; oKLL~X>!U
elseif(startIndex < 0)
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this.startIndex = 0; ?W:YS82
else{ /GCI`hx>"
this.startIndex = indexes hK5BOq!y
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[startIndex / pageSize]; P~HzNC
} klmRU@D
} u/-ul
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publicint getNextIndex(){ q1Gc0{+)
int nextIndex = getStartIndex() + =+HMPV6yg7
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pageSize; scZdDbL6+
if(nextIndex >= totalCount) iOXxxP%#
return getStartIndex(); 1AiqB Rs
else yxP(|
return nextIndex; kcGs2Y_*&
} hfw$820y[
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publicint getPreviousIndex(){ ye!}hm=w
int previousIndex = getStartIndex() - : $4
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pageSize; /Z`("X?_Kf
if(previousIndex < 0) EX zA(igS
return0; tl5}#uJ
else fl%X>\i/7
return previousIndex; 4&]Sb}
} Zt;3HY=y
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} $<'i+kK
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抽象业务类 a
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java代码: TrA&yXXL
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/** 3Ov? kWFO
* Created on 2005-7-12 YhQ;>Ko
*/ od\-o:bS
package com.javaeye.common.business; qI (<5Wxl
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import java.io.Serializable; 'VVEd[
import java.util.List; 2L?jp:$;X
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import org.hibernate.Criteria;
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import org.hibernate.HibernateException; m][i-|@M
import org.hibernate.Session; fviq}.
import org.hibernate.criterion.DetachedCriteria; ;.dyuKlI
import org.hibernate.criterion.Projections; 9&]g2iT P
import vSyR%
j
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org.springframework.orm.hibernate3.HibernateCallback; ]dvNUD
import 1dsMmD[O
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org.springframework.orm.hibernate3.support.HibernateDaoS J9buf}C[
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upport; 0 Z{;sW
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import com.javaeye.common.util.PaginationSupport; qpjG_G5/
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public abstract class AbstractManager extends
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HibernateDaoSupport { uu5L9.i9
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privateboolean cacheQueries = false; 0 rge]w.X
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privateString queryCacheRegion; Uxll<z,
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publicvoid setCacheQueries(boolean {`KRr:w
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cacheQueries){ V1h&{D\"
this.cacheQueries = cacheQueries; PP1?UT=]
} SAQ|1I#"/
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publicvoid setQueryCacheRegion(String SO!|wag$
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queryCacheRegion){ Y<vHL<G
this.queryCacheRegion = \7\7i-Vo
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queryCacheRegion; V{D~e0i/v
} )0\"8}!
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publicvoid save(finalObject entity){ 1Uy'TEk
getHibernateTemplate().save(entity); *i`t4N
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} Zb? u'Vm=u
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publicvoid persist(finalObject entity){ p#QR^|7"
getHibernateTemplate().save(entity); |mS-<e8LY4
} Kn#CIFbBN
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publicvoid update(finalObject entity){ WL#E%6p[
getHibernateTemplate().update(entity); 9-`P\/
} vB<2f*U
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publicvoid delete(finalObject entity){ -u nK;
getHibernateTemplate().delete(entity); =^5,ua6
} ~'.SmXZs
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publicObject load(finalClass entity, C"
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finalSerializable id){ 0e,U&B<W
return getHibernateTemplate().load 3!*qB-d
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(entity, id); RF|r@/S
} UzKB "Q
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publicObject get(finalClass entity, +YFA Zv7`
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finalSerializable id){ ]*&`J4i
return getHibernateTemplate().get ObzFh?W
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(entity, id); ^U.t5jj
} b+tm[@|,v
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publicList findAll(finalClass entity){ gK_#R]
return getHibernateTemplate().find("from k )=Gyv<
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" + entity.getName()); =#.qe=
} m2j]wUh"
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publicList findByNamedQuery(finalString `#c36
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namedQuery){ KfkU_0R+~v
return getHibernateTemplate 3cSP1=$*
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().findByNamedQuery(namedQuery); /$=<RUE
} DWXHx
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publicList findByNamedQuery(finalString query, ZQI;b0C
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finalObject parameter){ }c@duf-l
return getHibernateTemplate bqcwZ6r<
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().findByNamedQuery(query, parameter); y.,li<
}
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publicList findByNamedQuery(finalString query, +8Q5[lh2]j
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finalObject[] parameters){ iVZX
return getHibernateTemplate w%uM=YmuT
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().findByNamedQuery(query, parameters); | h%0)_
} ]r@CmwC
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publicList find(finalString query){
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return getHibernateTemplate().find #p7_\+&5s
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(query); Rwe!xY^d8
} ]\6*2E{1m
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publicList find(finalString query, finalObject xv9G%
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parameter){ }_,={<g
return getHibernateTemplate().find HzZ.q2Zz%
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(query, parameter); txFcV
} B]wfDUG
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public PaginationSupport findPageByCriteria ur JR[$p
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(final DetachedCriteria detachedCriteria){ "VI2--%v3
return findPageByCriteria ,ek0)z.
;
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); -}KW"#9c
} ~=/.ZUQNX
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public PaginationSupport findPageByCriteria +1>\o|RF
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(final DetachedCriteria detachedCriteria, finalint P%y$e0
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startIndex){ 6(-c$d`C.0
return findPageByCriteria C sx
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(detachedCriteria, PaginationSupport.PAGESIZE, tr$d?
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startIndex); @i=_y+|d_
} [5wU0~>'
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public PaginationSupport findPageByCriteria XBN,{
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(final DetachedCriteria detachedCriteria, finalint A"Sp7M[J
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pageSize, j38>5DM6L
finalint startIndex){ f (ug3(j
return(PaginationSupport) ~5
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getHibernateTemplate().execute(new HibernateCallback(){ ?7Skk
publicObject doInHibernate YnW,6U['{g
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(Session session)throws HibernateException { 0uhIJc'2
Criteria criteria = VCc57Bo
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detachedCriteria.getExecutableCriteria(session); v.{I^=
int totalCount = v\Edf;(
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((Integer) criteria.setProjection(Projections.rowCount EQ2HQz]
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()).uniqueResult()).intValue(); $X]Z-RCK3
criteria.setProjection ],w+4;+
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(null); V<0J j
List items = -< }#ImTN
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criteria.setFirstResult(startIndex).setMaxResults A}z1~Z+
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(pageSize).list(); Rv@(
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PaginationSupport ps = Fu"@)xw/-q
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new PaginationSupport(items, totalCount, pageSize, [*v-i%U}
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startIndex); ~)%DiGW&
return ps; Qm2(Z8Gh
} 'Z`fZ5q
}, true); &T[BS;
} A^@,Ha
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public List findAllByCriteria(final mBWhC<kKs
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DetachedCriteria detachedCriteria){ <n)R?P(or
return(List) getHibernateTemplate .Af H>)E
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().execute(new HibernateCallback(){ jW0aIS2O
publicObject doInHibernate 4!0nM|~
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(Session session)throws HibernateException { 2~q(?wY
Criteria criteria = 0/0rWqg
/
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detachedCriteria.getExecutableCriteria(session); +d/^0^(D\5
return criteria.list(); v m)'CC
} uc-Go
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}, true); u(P;) E"1
} OCYC
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public int getCountByCriteria(final TCS^nBEE
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DetachedCriteria detachedCriteria){ 5"8R|NU:\0
Integer count = (Integer) N6*v!M+
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getHibernateTemplate().execute(new HibernateCallback(){ ?ne!LDlE|
publicObject doInHibernate c0W4<(
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(Session session)throws HibernateException { 8GFA}_(^R
Criteria criteria = mB]Y;R<
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detachedCriteria.getExecutableCriteria(session); 'c|Y*2@
return
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criteria.setProjection(Projections.rowCount _I}rQfPJ
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()).uniqueResult(); sT"h)I)]*
} Pw_[{ LL
}, true); /]*#+;;%
return count.intValue(); MX#MDA-4
} :i_kA'dl&
} %*wOJx
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用户在web层构造查询条件detachedCriteria,和可选的 $k&}{c8P
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 X[
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PaginationSupport的实例ps。 `X7ns?
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ps.getItems()得到已分页好的结果集 Ghgo"-,#
ps.getIndexes()得到分页索引的数组 (~>L \]!
ps.getTotalCount()得到总结果数 `kP
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ps.getStartIndex()当前分页索引 GL_a`.=@
ps.getNextIndex()下一页索引 #j{!&4M
ps.getPreviousIndex()上一页索引 ZP&"[_
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 6_wf $(im
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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 syYg, G[
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一下代码重构了。 <M1XG7_I
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我把原本我的做法也提供出来供大家讨论吧: nJ|8#U7
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首先,为了实现分页查询,我封装了一个Page类: d/G P.d
java代码: lq$1CI
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/*Created on 2005-4-14*/ kQ$Q}3f
package org.flyware.util.page; nzTzc5
w
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/** j:0VtJo~
* @author Joa &DFe+y~PR
* >,` /
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*/ W9?Yzl
publicclass Page { ,XW6W&vR;
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/** imply if the page has previous page */ ih?_ fW
privateboolean hasPrePage; ~u&3Ki*x
1V?}";T
/** imply if the page has next page */ <GShm~XD2
privateboolean hasNextPage; 8=7u,t
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/** the number of every page */ <}%>a@
privateint everyPage; JBa=R^k
'
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/** the total page number */ QzIK580%t
privateint totalPage; w?.0r6j
.b vB8VOrW
/** the number of current page */ Xt/T0.I
privateint currentPage; d'Z|+lq:
'=x
/** the begin index of the records by the current v|jBRKU99
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query */ ]?^m;~MQZ
privateint beginIndex; Tn/
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{
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/** The default constructor */ W)V"QrFK
public Page(){ jh`&c{#*)M
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} J']1^"_'
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/** construct the page by everyPage IZ3w.:A
* @param everyPage }Fyf?TZ$T
* */ g`gH]W
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public Page(int everyPage){ +"T?.,
this.everyPage = everyPage; zp"sM
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} ]m(Uv8/6
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/** The whole constructor */ T\b
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public Page(boolean hasPrePage, boolean hasNextPage, eqs.zL
}9>W41
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int everyPage, int totalPage, Q9X_aB0
int currentPage, int beginIndex){ `>'E4z]-_
this.hasPrePage = hasPrePage; //>f#8Ho
this.hasNextPage = hasNextPage; RMmDcvM"k
this.everyPage = everyPage; c5<M=$
this.totalPage = totalPage; hI;tB6
this.currentPage = currentPage; ?^2(|t9KU
this.beginIndex = beginIndex; vl2!2X
} UbJ_'>hK 6
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/** :^1 Xfc"
* @return {G/4#r
2>
* Returns the beginIndex. 6N :fq
*/ ]U! ?{~
publicint getBeginIndex(){ Cz+>S3v M
return beginIndex; 2ME3= C
} U=QV^I Qm
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/** V3xC"maA@
* @param beginIndex ( m\PcF
* The beginIndex to set. n4Ry)O[.
*/ O]~ cv^
publicvoid setBeginIndex(int beginIndex){ uYhm
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this.beginIndex = beginIndex; pz6fL=Xd
} TV#pUQ3K
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/** zdzTJiY2[Z
* @return ),mKEpf
* Returns the currentPage. 9h<];
*/ BYyR-m
publicint getCurrentPage(){ sikG}p0mx<
return currentPage; /d&zE|!
} "b8<C>wY
[:
/** "Up3W%]SB
* @param currentPage T+9#P4
* The currentPage to set. y-)|u:~h
*/ d0"Hu^]
publicvoid setCurrentPage(int currentPage){ b\Y<1EV^[
this.currentPage = currentPage; y9{KBM%h
} Q.>@w<[!L
BRPvBs?Q,{
/** (y[+s?;WyB
* @return Fc M
* Returns the everyPage. S4aN7.'Q
*/ fr#Y<=Jo
publicint getEveryPage(){ zp:kdN7!^
return everyPage; 5f(yF
} P
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/** 'X d_8.
* @param everyPage ;!q _+P
* The everyPage to set. SMY,bU'a
*/ zRd^Uks
publicvoid setEveryPage(int everyPage){ 5I`j'j
this.everyPage = everyPage; y[:\kI
} ?&
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wmAZ {
/** [APwHIS
* @return [KR|m,QWp
* Returns the hasNextPage. {4J:t_<nKO
*/ {VtmQU?cJ
publicboolean getHasNextPage(){ _y*@Hj
return hasNextPage; {AUhF}O
}
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/** &*}`uJt
* @param hasNextPage meey5}
* The hasNextPage to set. bnHQvCO3$
*/ }Q&zYC]d
publicvoid setHasNextPage(boolean hasNextPage){ 7DZxrVw
this.hasNextPage = hasNextPage; }%Mj`Bh
} 3D32'KO_"
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/** E[q:65xl
* @return TgMa!Vz
* Returns the hasPrePage. Wi7!J[ B
*/ $/*19e~
publicboolean getHasPrePage(){ 9Rl-Jz8g
return hasPrePage; ^/@Z4(E
}
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/** [PG#5.jwQ
* @param hasPrePage DwSB(O#X
* The hasPrePage to set. 2E5n07,
*/ j11FEE<W
publicvoid setHasPrePage(boolean hasPrePage){ BNi6I\wa
this.hasPrePage = hasPrePage; X!H[/b:1O
} 8xf]zM"Q
h0**[LDH
/** z`g4 <
* @return Returns the totalPage. ox:m;-Ml?_
* g
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*/ 3oD?e
publicint getTotalPage(){ %!P^se
return totalPage; RJ}%pA4I
} <&w(%<;
ul(pp+%S
/** Q9T/@FX
* @param totalPage wFbw3>'a9
* The totalPage to set. <S[]VXy
*/ up _Qv#`Q
publicvoid setTotalPage(int totalPage){ 9 +1}8"~
this.totalPage = totalPage; lZ,w#sqbY
} .+3~
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} Rtywi}VV2
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 D9yAq'k$
idzc4jR6BT
个PageUtil,负责对Page对象进行构造: hqDnmzG
java代码: 2xxw8_~C
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/*Created on 2005-4-14*/ z:1"d
R
package org.flyware.util.page; 1S{AGgls5
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T
import org.apache.commons.logging.Log; bVxbQ$
import org.apache.commons.logging.LogFactory; `8 Ann~Z|k
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/** X_HU?Q_N
* @author Joa Cfr2~w
* 99GK6}~TGm
*/ MV.&GUez{
publicclass PageUtil { f]4j7K!e]
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privatestaticfinal Log logger = LogFactory.getLog
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(PageUtil.class); 50`=[l`V
d~abWBgC`
/** )z\ 73|w
* Use the origin page to create a new page j&-<e7O=
* @param page pgw_F
* @param totalRecords 'O^<i`8U]
* @return GIM'H;XG
*/ +\x}1bNS%j
publicstatic Page createPage(Page page, int 7`J= PG$A
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totalRecords){ {i"th(J$
return createPage(page.getEveryPage(), [;Y*f,UG_-
*{!E`),FX
page.getCurrentPage(), totalRecords); !d
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} RI2/hrW
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/**
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* the basic page utils not including exception s 9n_s=w
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handler fq?MnWc
* @param everyPage G`r/ te sW
* @param currentPage dZkj|Ua~
* @param totalRecords @bIZ0tr4
* @return page :h8-y&;
*/ Yn5a4
publicstatic Page createPage(int everyPage, int ja&S^B^@
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currentPage, int totalRecords){ |>/m{L[
everyPage = getEveryPage(everyPage); #BW:*$>}
currentPage = getCurrentPage(currentPage); =rN_8&
int beginIndex = getBeginIndex(everyPage, tjJi|
|.?$:D&6
currentPage); =X3Rk)2r
int totalPage = getTotalPage(everyPage, }u+cS[#-
x31Jl{x8\?
totalRecords); 06NW2A%wv
boolean hasNextPage = hasNextPage(currentPage, l.uW>AoLh
JN-W`2
totalPage); =`g@6S
boolean hasPrePage = hasPrePage(currentPage); ]$)U~)T
iW
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returnnew Page(hasPrePage, hasNextPage, JIXZI\Fk
everyPage, totalPage, Ey&gZ$|&
currentPage, hQ}y(2A.XI
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beginIndex); A5^tus/y
} ~=t K17i
IoCi(N;
privatestaticint getEveryPage(int everyPage){ MI,kKi
return everyPage == 0 ? 10 : everyPage; e=Q{CsP
} ^Is#_Z|
3M"eAK([
privatestaticint getCurrentPage(int currentPage){ P"a9+ti+'
return currentPage == 0 ? 1 : currentPage; >JHQA1mX
} s:*" b'
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privatestaticint getBeginIndex(int everyPage, int 6Ao{Aej|
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currentPage){ uF\ ;m.
return(currentPage - 1) * everyPage; -DWnDku8=
} ;uaZp.<um&
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privatestaticint getTotalPage(int everyPage, int K?6#jT6#
"$ U!1
totalRecords){ HME`7 dw?
int totalPage = 0; C!^[d
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LTf;
if(totalRecords % everyPage == 0) Y(R .e7]
totalPage = totalRecords / everyPage; S3sxK:
else :|N(:W>=$Y
totalPage = totalRecords / everyPage + 1 ; >?(}F':
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return totalPage; \s_`ZEB
} b$N&sZ
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privatestaticboolean hasPrePage(int currentPage){ $kxP{0u
return currentPage == 1 ? false : true; o,_R;'\E[a
} _e$T'*q
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privatestaticboolean hasNextPage(int currentPage,
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int totalPage){ Iz9b5
return currentPage == totalPage || totalPage == :NXM.@jJ="
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0 ? false : true; (}MN16!
} {J]x81}*;
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} x"{WLZ
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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。 XG01g3
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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 ?+?`Jso(
@<C<rB8R
做法如下: P:fcbfH+
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ~'#,*kA:6
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的信息,和一个结果集List: s> JWNP
java代码: <L+y
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/*Created on 2005-6-13*/ % jSB9
package com.adt.bo; Wph@LRB]
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import java.util.List; ZHimS7
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import org.flyware.util.page.Page; r0,XR
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/** 9_xJT^10
* @author Joa l9#@4Os
*/ bL0>ul"
publicclass Result { Zk>#T:{h
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private Page page; $HP<C>^Z8
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private List content; 4x"9Wr=}
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/** xL$7bw5fY
* The default constructor "g:1br?X,9
*/ rObg:(z&\
public Result(){ AI#.G7'O
super(); !z2 KQ
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} q}cm"lO$
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/** %![3?|8~
* The constructor using fields bDjm:G
* 'J_`CS
* @param page ZK5
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* @param content >,a$)z
*/ v4vIcHDs
public Result(Page page, List content){ DC(u,iW%6
this.page = page; >G}g=zy@
this.content = content; "ifv1KZ#
} @7`=0;g
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/** 9w dl1QS
* @return Returns the content. 1<;G
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*/ .O6(QI*
publicList getContent(){ <