Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 i+jSXn"_
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 fT/;TK>z>
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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 _7]* 5Pxo
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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 2@1A,
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分页支持类: v%=G~kF}[
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java代码: qWtvo';3
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package com.javaeye.common.util; )fpZrpLXE
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import java.util.List; Cz
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publicclass PaginationSupport { yFshV\
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publicfinalstaticint PAGESIZE = 30; P$N\o @
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privateint pageSize = PAGESIZE; L=VJl[DL
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privateList items; Bh"o{-$p8`
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privateint totalCount; zm9>"(H
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privateint[] indexes = newint[0]; nv*q
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privateint startIndex = 0; vEvVT]g[V
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public PaginationSupport(List items, int |OUr=b
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totalCount){ QK%{\qu
setPageSize(PAGESIZE); OCa74)(
setTotalCount(totalCount); d11~mU\
setItems(items); 5K;jW
setStartIndex(0); ~0!s5
} 4E J
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public PaginationSupport(List items, int O2q`2L~
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totalCount, int startIndex){ cc*A/lD
setPageSize(PAGESIZE); %/CCh;N#
setTotalCount(totalCount); 't{~#0d=
setItems(items); 1xar
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setStartIndex(startIndex); >jME
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} ux& WN ,
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public PaginationSupport(List items, int weU'3nNN
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totalCount, int pageSize, int startIndex){ PR|F-/o
setPageSize(pageSize); fDNiU"
setTotalCount(totalCount); vtK Qv Q
setItems(items); `-"2(Gp
setStartIndex(startIndex); G}&B{Ir
} e]'ui<`
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publicList getItems(){ y-)|u:~h
return items; &{]zL
} #pErGz'{
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publicvoid setItems(List items){ Vi?[yu<F
this.items = items; )AEJ`xC
} G ?jKm_`L
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publicint getPageSize(){ M^AwOR7<
return pageSize; 3E$M{l
} %(MaH
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publicvoid setPageSize(int pageSize){ IC{\iwO/~c
this.pageSize = pageSize; U}~SY
} z8G1[ElY
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publicint getTotalCount(){ b
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return totalCount; |,cQJ
} Fo=Icvo
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publicvoid setTotalCount(int totalCount){ &q^\*<B.^
if(totalCount > 0){ @#hd8_)A.
this.totalCount = totalCount; 7IB<0
int count = totalCount / :3pJGMv(
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pageSize; {Iy<iV
if(totalCount % pageSize > 0) xeF0^p7Z
count++; c
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indexes = newint[count]; RSC^R}a5
for(int i = 0; i < count; i++){ <^c?M[j
indexes = pageSize * y[:\kI
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} fb3(9
}else{ 2a|9D\
this.totalCount = 0; As
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} 5ltEnvN
} dQT A^m
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publicint[] getIndexes(){ }^U7NZn<"
return indexes; b;G3&R]
} -c|dTZ8D)8
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publicvoid setIndexes(int[] indexes){ xl8=y
this.indexes = indexes; ]rGZ
} M3P\1
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publicint getStartIndex(){ 3tzb@T
return startIndex; .sI*\@w.
} VPW@y
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publicvoid setStartIndex(int startIndex){ GOrDDp
if(totalCount <= 0) tj$&89
this.startIndex = 0; -< D7
elseif(startIndex >= totalCount) yw2Mr+9I
this.startIndex = indexes $c"byQ[3S
9'nM$a
[indexes.length - 1]; wX5Yo{
elseif(startIndex < 0) 2[!#Xf
this.startIndex = 0; hEUS&`K
else{ J<hqF4z
this.startIndex = indexes :/UO3 c(
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[startIndex / pageSize]; }MQNzaXY^
} ere h!
} T'_#Dwmj*
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publicint getNextIndex(){ KYa}k0tVAp
int nextIndex = getStartIndex() + Q+@/.qJ
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pageSize; k{\wjaf)
if(nextIndex >= totalCount) DwSB(O#X
return getStartIndex(); Q^13KWvuV
else *Z}^T:3iw}
return nextIndex; %87D(h!.I4
} 1g_p`(
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publicint getPreviousIndex(){ )gF>nNE
int previousIndex = getStartIndex() - h,-2+}
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pageSize; YX*NjXL
if(previousIndex < 0) 2L!s'^m-
return0; Ao?y2 [sE
else QFekj@
return previousIndex; ox:m;-Ml?_
} pHKcKqB*13
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} 3DjlX*
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抽象业务类 )M3}6^s]
java代码: xXb7/.*qE
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/** L#h uTKX}
* Created on 2005-7-12 JG^fu*K
*/ $-^
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package com.javaeye.common.business; LV}Z[\?
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import java.io.Serializable; ;]gj:6M
import java.util.List; +az=EF
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import org.hibernate.Criteria; #*;G8yV
import org.hibernate.HibernateException; EBQ,Ypv
import org.hibernate.Session; aI. 5w9
import org.hibernate.criterion.DetachedCriteria; Z7]["
import org.hibernate.criterion.Projections; UP<B>Y1a
import \7V[G6'{
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org.springframework.orm.hibernate3.HibernateCallback; !LI
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import DP@F-Q4
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org.springframework.orm.hibernate3.support.HibernateDaoS N[=c|frho
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upport; itYTV?bd
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import com.javaeye.common.util.PaginationSupport; *ggai?
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public abstract class AbstractManager extends d\O*Ol*/v
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HibernateDaoSupport { .gQYN2#zb
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privateboolean cacheQueries = false; !l9i)6W
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privateString queryCacheRegion; D( \c?X"
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publicvoid setCacheQueries(boolean :<p3L!?8y
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cacheQueries){ R6cd;| fan
this.cacheQueries = cacheQueries; O[Yc-4
} F_I.=zQr
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publicvoid setQueryCacheRegion(String YMG~k3Yb
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queryCacheRegion){ 'Lu d=u{
this.queryCacheRegion = f|+aa6hN
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queryCacheRegion; S7v# `#
} MV.&GUez{
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publicvoid save(finalObject entity){ 4`Ib wg6"B
getHibernateTemplate().save(entity); o?
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} zhZ!!b^6<
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publicvoid persist(finalObject entity){ mYx6JU*`
getHibernateTemplate().save(entity); 0n/+X[%Ti
} [,yYr
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publicvoid update(finalObject entity){ Ir6(EIwx0
getHibernateTemplate().update(entity); 7lUnqX.
} w~AW(
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publicvoid delete(finalObject entity){ 'O^<i`8U]
getHibernateTemplate().delete(entity); *";O_ :C!
} k0bDEz.X
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publicObject load(finalClass entity, ThiM6Hb
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finalSerializable id){ 'T+v&M
return getHibernateTemplate().load f0@4>\g
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(entity, id); Oil~QAd,
} oiRrpS\T.
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publicObject get(finalClass entity, $!goM~pZ
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finalSerializable id){ [R0E4A?M
return getHibernateTemplate().get <4:%M
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(entity, id); K+<F,
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} i%GNmD
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publicList findAll(finalClass entity){ TCI)L}L|
return getHibernateTemplate().find("from 4N(iow4
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" + entity.getName()); T+j-MR}{\
} VQ7A"&hh
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publicList findByNamedQuery(finalString ^wlo;.8Y
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namedQuery){ K3^2;j1F Q
return getHibernateTemplate LEd@""h
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().findByNamedQuery(namedQuery); G-[.BWQ
} -Oplk*
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publicList findByNamedQuery(finalString query, ` InBhU>
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finalObject parameter){ MLvd6tIv,
return getHibernateTemplate kYZj^tR
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().findByNamedQuery(query, parameter); )}to7r7`
} 9P& \2/ {
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publicList findByNamedQuery(finalString query, !BDJU
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finalObject[] parameters){ PUEEfq!%
return getHibernateTemplate 4Z0Y8y8)
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().findByNamedQuery(query, parameters); 3Ct)5J
} 06NW2A%wv
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publicList find(finalString query){ PouWRGS_
return getHibernateTemplate().find 2gJkpf9JN
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(query); Y'O3RA5E
} B8 r#o=q1
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publicList find(finalString query, finalObject ]--"
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parameter){ !i8'gq'q
return getHibernateTemplate().find &?*H`5#?G
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(query, parameter); hQ}y(2A.XI
} TG6E^3a P
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public PaginationSupport findPageByCriteria RG6U~o1
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(final DetachedCriteria detachedCriteria){ E`#/m@:|-
return findPageByCriteria @n;$Edza/
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); &%;K_asV;
} ~\UAxB=
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public PaginationSupport findPageByCriteria Ap!Y 3C
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(final DetachedCriteria detachedCriteria, finalint do DpTwvh
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startIndex){ Yu:!l>
return findPageByCriteria s:*" b'
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(detachedCriteria, PaginationSupport.PAGESIZE, Lnc>O'<5P9
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startIndex); g|<$\}
} -"5r-q q*
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public PaginationSupport findPageByCriteria ^oDSU7j5,
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(final DetachedCriteria detachedCriteria, finalint zXGi
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pageSize,
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finalint startIndex){ b G/[mZpRT
return(PaginationSupport) K?6#jT6#
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getHibernateTemplate().execute(new HibernateCallback(){ )|B3TjHC
publicObject doInHibernate kqZ+e/o>O9
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(Session session)throws HibernateException { ZDr&Alp)o
Criteria criteria = K9c5HuGy
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detachedCriteria.getExecutableCriteria(session); }TG=ZVi
int totalCount = =j~Xrytn
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((Integer) criteria.setProjection(Projections.rowCount <nJ8%aY,
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()).uniqueResult()).intValue(); '7UIzk|
criteria.setProjection XX'mM v
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(null); \s_`ZEB
List items = G$E+qk
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criteria.setFirstResult(startIndex).setMaxResults hIFfvUl
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(pageSize).list(); ]SG(YrF
PaginationSupport ps = h`pXUnEZ
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new PaginationSupport(items, totalCount, pageSize, L~HL*~#d
q]wP^;\Jl
startIndex); GI)eq:K_U8
return ps; S\ ) ~9?
} "U*6?]f
}, true); ?btZdnQ))S
} #_'|
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public List findAllByCriteria(final aUbmEHFTV
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DetachedCriteria detachedCriteria){ 1Ts$kdO
return(List) getHibernateTemplate \kG;T=H
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().execute(new HibernateCallback(){ BL H~`N3U
publicObject doInHibernate wD5fm5r=
h5}:>yc
(Session session)throws HibernateException { 6HRr4NDcj
Criteria criteria = []hC*
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detachedCriteria.getExecutableCriteria(session); 9K4Jg]?
return criteria.list(); DGO\&^GT^
} fl o9iifZ
}, true); O9R[F
} xMHu:,ND
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public int getCountByCriteria(final /Gvd5
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DetachedCriteria detachedCriteria){ @Q%<~b[y
Integer count = (Integer) (!0fmL
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getHibernateTemplate().execute(new HibernateCallback(){ 8"C[sRhz
publicObject doInHibernate #pr{tL
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(Session session)throws HibernateException { -gVsOX0
Criteria criteria = OpFm:j3
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detachedCriteria.getExecutableCriteria(session); @h!nVf%fe
return /7hC
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criteria.setProjection(Projections.rowCount D\k'Eez
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()).uniqueResult(); S94S[j0D
} #T$yQ;eQ
}, true); W \XLf,_+
return count.intValue(); eWWfUNBSLX
} o((!3H{D
} y-lBaTE9
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用户在web层构造查询条件detachedCriteria,和可选的 vY!'@W
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 oP_}C[
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PaginationSupport的实例ps。 tPaNhm[-q7
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ps.getItems()得到已分页好的结果集 B;c2gu
ps.getIndexes()得到分页索引的数组 C^*3nd3
ps.getTotalCount()得到总结果数 k%%0"+y#a
ps.getStartIndex()当前分页索引 yhh\?qqy
ps.getNextIndex()下一页索引 z~Is
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ps.getPreviousIndex()上一页索引 |:,i
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 % 9} ?*U
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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 }fh<L CwTi
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一下代码重构了。 FgnPh%[u
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我把原本我的做法也提供出来供大家讨论吧: GGez!?E%
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首先,为了实现分页查询,我封装了一个Page类: &*#Obv
java代码: bDjm:G
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/*Created on 2005-4-14*/ 7~!F3WT{
package org.flyware.util.page; nd,2EX<bE
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/** .>
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* @author Joa GBYwS{4
* ):7mK03J
*/
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publicclass Page { \k.W
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/** imply if the page has previous page */ r mJ`^6V
privateboolean hasPrePage; NM+(ss'
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/** imply if the page has next page */ 3gs!ojG
privateboolean hasNextPage; #83pitcc
q!AcMd\
/** the number of every page */ p mUG`8SY
privateint everyPage; .O6(QI*
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/** the total page number */ Ni>!b6Z`[
privateint totalPage; w@x||K= Z
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/** the number of current page */ /wU4^8Hz
privateint currentPage; M`p[ Zq
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/** the begin index of the records by the current <op|yh3Jkk
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query */ qaG8:
privateint beginIndex; dy3fZ(=q^
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/** The default constructor */ _~bG[lX !
public Page(){ tL]T_]z
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} >E9 k5
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/** construct the page by everyPage }///k]_Sh
* @param everyPage ){4 !
* */ X+QoO=02LR
public Page(int everyPage){ %+@<T<>J<k
this.everyPage = everyPage; EIF"{,m
} 6cXZ3;a
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/** The whole constructor */ ',]^Qu`a
public Page(boolean hasPrePage, boolean hasNextPage, p4vX3?&1W
/ "@cv{
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int everyPage, int totalPage, }#2I/dn
int currentPage, int beginIndex){ 7V-uQ)*
this.hasPrePage = hasPrePage; i2E@5 v=|Y
this.hasNextPage = hasNextPage; |:pBk:
this.everyPage = everyPage; I ;F\'P)e
this.totalPage = totalPage; s[#_sR`y
this.currentPage = currentPage; P
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this.beginIndex = beginIndex; La$?/\Dv)
} BMb0Pu8
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/** *g"Xhk
* @return 4 {+47=n
* Returns the beginIndex. x:+]^?}r
*/ a xz-H`oq4
publicint getBeginIndex(){ BG/RNem
return beginIndex; 6iS7Hao"
} u1`JvfLrL
G
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/** auAwZi/
* @param beginIndex [D2<)
* The beginIndex to set. 2 }rYH;Mx
*/ :{%~L4$HI
publicvoid setBeginIndex(int beginIndex){ ('+C $
this.beginIndex = beginIndex; Q2"K!u]
} S3^(L
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/** H3+P;2{
* @return 465?,EpS
* Returns the currentPage. vF9fXY=
*/ V^< Zs//7
publicint getCurrentPage(){ pYh\l.@qf
return currentPage; yM*_"z!L
} Rbcu5.6
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/** ~:99
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* @param currentPage O@a7MzJ
* The currentPage to set. {bNVNG^
*/ }(!3)k7*
publicvoid setCurrentPage(int currentPage){ G%>M@nYUE
this.currentPage = currentPage; |xrnLdng0R
} \lF-]vz*
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/** ?8YbTn1f)
* @return ijmGk:L(
* Returns the everyPage. _|7bpt9
*/ wZt2%+$6m
publicint getEveryPage(){ \hP.Q;"MtO
return everyPage; 2FQTu*p&B
} >aT~G!y
JZ/T:Hsh4
/** *fI\|%K
* @param everyPage M/kBAxNIC|
* The everyPage to set. iUlSRfrC$#
*/ q^6l`JJ
publicvoid setEveryPage(int everyPage){ 8|tnhA]~
this.everyPage = everyPage; Esf\Bo"
} T=':$(t
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/** P>'29$1'
* @return lQpl8>
* Returns the hasNextPage. D&1(qi=x&
*/ ]xPy-j6C
publicboolean getHasNextPage(){ ^GNL:D%6d
return hasNextPage; Ks-$([_F
} zGa
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/** NG?g(
* @param hasNextPage t(UdV
* The hasNextPage to set. 04:QEC"9mj
*/ =d/$B!t{
publicvoid setHasNextPage(boolean hasNextPage){ P?Kg7m W
this.hasNextPage = hasNextPage; :(;ho.zz
} $Y8iT<nP
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/** ,%U\@*6=
* @return UL"
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* Returns the hasPrePage. !e}4>!L,(^
*/ o_&Qb^W
publicboolean getHasPrePage(){ |k]fY*z(
return hasPrePage; [<X ~m
} 3\K;y>NK
e8{!Kjiz
/** oE)xL%*
* @param hasPrePage 5:%`&B\
* The hasPrePage to set. XV1XzG# C
*/ ^(KDtc
publicvoid setHasPrePage(boolean hasPrePage){ t? Q
this.hasPrePage = hasPrePage; XoGOY|2`6
} = VMELk!z
zN/nKj: Q
/** bSa]={}L(
* @return Returns the totalPage. <t dsUh:?&
* ;WG%)^e
*/ Rg3g:TV9c
publicint getTotalPage(){ ynJ)6n7a
return totalPage; 9[h8Dy
} 6u xF<
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/** SD jJ?K
* @param totalPage ~|{_Go{
Q
* The totalPage to set. |{La@X
*/ `t+;[G>ZE
publicvoid setTotalPage(int totalPage){ FBa-gm<9
this.totalPage = totalPage; L$^)QxH7
} >J{e_C2ZS
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} rVwW%&
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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 ]PB95%
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个PageUtil,负责对Page对象进行构造: jWso'K
java代码: y0'WB`hNQ
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/*Created on 2005-4-14*/ !w/]V{9`X
package org.flyware.util.page; =69sWcC8
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CQ
import org.apache.commons.logging.Log; N!<X%Ym
import org.apache.commons.logging.LogFactory; 6\? 2=dNX
f;!L\$yKy
/** HBA|NV3.
* @author Joa sn+ kFvk}S
* n!U1cB{
*/ 6n
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publicclass PageUtil { w I[Hoi
V
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privatestaticfinal Log logger = LogFactory.getLog c_Iq!MH
~;uU{TT
(PageUtil.class); B^.:dn
}S{VR(i`J
/** lYU?j|n
* Use the origin page to create a new page df/7u}>9
* @param page zUWeOR'X
* @param totalRecords SPnW8
* @return %
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*/ >RrG&Wv59
publicstatic Page createPage(Page page, int gp+@+i>b+[
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totalRecords){ O7p=|F"
return createPage(page.getEveryPage(), oo1h"[
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page.getCurrentPage(), totalRecords); c/%GfB[w0
} n{=Ot^
";
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/** Th4}$)yrkN
* the basic page utils not including exception k<RaC=
`:d\L
H
handler A2.4#Qb'
* @param everyPage fsWPU]\)
* @param currentPage 4D6LP*
* @param totalRecords kJ)Z{hy
* @return page Ob]J!.
*/ CDT;AdRw7
publicstatic Page createPage(int everyPage, int #<es>~0!
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currentPage, int totalRecords){ oVd7ucnK
everyPage = getEveryPage(everyPage); iKv"200h(
currentPage = getCurrentPage(currentPage); I")mg~f
int beginIndex = getBeginIndex(everyPage, 0Kg?X
6Q_ZP#oAV
currentPage); o'? WWJK6w
int totalPage = getTotalPage(everyPage, )ib$*dmUP
Su<>UsdUC
totalRecords); VdGpreRPC
boolean hasNextPage = hasNextPage(currentPage, [4+I1UR`
#Vy:6O
totalPage); HT6$|j
boolean hasPrePage = hasPrePage(currentPage); p9&gKIO_m
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y
returnnew Page(hasPrePage, hasNextPage, HIda%D
everyPage, totalPage, ?>My&yB
currentPage, +mYK
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beginIndex); Kp19dp}'b
} #P
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privatestaticint getEveryPage(int everyPage){ bd2QQ1[1vh
return everyPage == 0 ? 10 : everyPage; !Oi':OQG
} 9}+X#ma.Nc
K1p. {
privatestaticint getCurrentPage(int currentPage){ :mt<]Oy3
return currentPage == 0 ? 1 : currentPage; i"mQ
} sAnb
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privatestaticint getBeginIndex(int everyPage, int UYzNaw4/x
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currentPage){ z}Um$'. =
return(currentPage - 1) * everyPage; A.(e=;0bu
} p[}~Z|(
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privatestaticint getTotalPage(int everyPage, int 8EU/}Ym
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totalRecords){ 5>hXqNjP2
int totalPage = 0; @QE&D+NS
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if(totalRecords % everyPage == 0) D58RHgY[
totalPage = totalRecords / everyPage; 6_K7!?YG7
else AB<%GzW0(
totalPage = totalRecords / everyPage + 1 ; NHe[,nIV
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return totalPage; Hxn#vAc
} !t?5U_on
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privatestaticboolean hasPrePage(int currentPage){ ~.z82m
return currentPage == 1 ? false : true; )"_&CYnd
} fr}.#~{5Y
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privatestaticboolean hasNextPage(int currentPage, 2s}G6'xE]P
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int totalPage){ h)s&Nqg1B
return currentPage == totalPage || totalPage == M^G9t*I
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0 ? false : true; <@c@`K
} g!Ui|]BI9
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} 0 c]]
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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。 uH#X:Vne
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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 y2 R\SL,
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做法如下: VO /b&%
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 g+Y &rz
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的信息,和一个结果集List: { T<[-"h
java代码: {U4{v=,!I
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/*Created on 2005-6-13*/ D`U,T&@
package com.adt.bo; qCq?`0&#
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import java.util.List; 9%riB/vkrF
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import org.flyware.util.page.Page; ,rOh*ebF
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/** uc LDl
* @author Joa \\{78WDA
*/ %BQ?DTtb7'
publicclass Result { W,:j>vg
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private Page page; Vddod
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private List content; sXYXBX[
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/** "]q0|ZdOwH
* The default constructor z? GtC{L9
*/ 'a$/ !~X
public Result(){ |)mUO:*
super(); M0hR]4T
} g!i45]6[Nw
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/** w^:@g~
* The constructor using fields 5i'KGL
* "2 D{X
* @param page h;mOfF
* @param content '-#gQxIpD
*/ *z]P|_:&G
public Result(Page page, List content){ @6-3D/=
this.page = page; S_s;foT
this.content = content;
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} X5= Ki
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/** X?] Mzcu
* @return Returns the content.
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*/ C;ME"4,(
publicList getContent(){ lq?N>~PG
return content; J ayax]u7J
} :u2tu60&MJ
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/** YVk
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* @return Returns the page. "9Br)3
*/ YB4|J44Y
public Page getPage(){ )&-n-m@E
return page; 3%u: c]-wF
} VeH%E.:
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/** '=d y
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* @param content P<9T.l
* The content to set. )=5*iWe
*/ }ee3'LUPX
public void setContent(List content){ j`_Z`eG
this.content = content; e.(RhajB
} ~8'HX*B]z
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/** ^5+7D1>W%
* @param page ANR611-a
* The page to set. ) P|/<>z
*/ V1A7hRjxvG
publicvoid setPage(Page page){ yK mHTjX=
this.page = page; 3Q,p,
} McN'J.Sxp
} Rli`]~!w
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2. 编写业务逻辑接口,并实现它(UserManager, }(WUZ^L
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UserManagerImpl) OQDx82E
java代码: #Zn+-Ih
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/*Created on 2005-7-15*/ uuy0fQQ8ti
package com.adt.service; Iapzh y2l
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import net.sf.hibernate.HibernateException; wHQYBYKcd
7K!n'dAi6
import org.flyware.util.page.Page; HBw0N?
/#}%c'
import com.adt.bo.Result; 7/\SN04l
/ $'M
/** ])WIw'L!
* @author Joa RC!T1o~L
*/ 6X$\:>
publicinterface UserManager { ?MiMwVR
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public Result listUser(Page page)throws 5jTA6s9z A
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