Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ;^K4kK&f
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 LYv$U;*+
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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 A=5A8B1
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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 \:/:S"-
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分页支持类: s28rj6q
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java代码: 3:;2Av2(X.
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package com.javaeye.common.util; ATb[/=hP<R
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import java.util.List; UvtSNP&/2d
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publicclass PaginationSupport { 8"\g?/
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publicfinalstaticint PAGESIZE = 30; Xt!%W
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privateint pageSize = PAGESIZE; UF)4K3X
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privateList items; KF#,Q
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privateint totalCount; y~cDWD<h
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privateint[] indexes = newint[0];
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privateint startIndex = 0; ]ctlK'.
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public PaginationSupport(List items, int ?1z." &
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totalCount){ !\0UEC
setPageSize(PAGESIZE); nM)q;9-ni
setTotalCount(totalCount); _FET$$>z N
setItems(items); ;c-J)Ky
setStartIndex(0); Q@in?};
} 1Ue;hu'q:
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public PaginationSupport(List items, int R0n#FL^E
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totalCount, int startIndex){ %z(nZ%,Z
setPageSize(PAGESIZE); -}B&>w,5
setTotalCount(totalCount); k8}*b&+{vz
setItems(items); g)<t=+a
setStartIndex(startIndex); Lwg@*:`d
} !XvQm*1
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public PaginationSupport(List items, int pL{h1^O}
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totalCount, int pageSize, int startIndex){ PN!NB.
setPageSize(pageSize); lJfn3
setTotalCount(totalCount); 8}&O7zO?
setItems(items); MMMuT^X
setStartIndex(startIndex); <3wfY
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} f\ wP}c'
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publicList getItems(){ ^b{w\HZ
return items; Wn(pz)+Y
} Q.q'pJ-
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publicvoid setItems(List items){ ?3Ytn+Py
this.items = items; =+T$1
} Qz+hS\yx
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publicint getPageSize(){ s/,wyxKd
return pageSize; kAF[K,GG
} e%(,)WlTaU
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publicvoid setPageSize(int pageSize){ 3J2j5N:g
this.pageSize = pageSize; a)+;<GZ~
} J!$q"0G'WT
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publicint getTotalCount(){ 5$,dpLbL
return totalCount; R89;<,Ie
} r*|#*"K"a
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publicvoid setTotalCount(int totalCount){ ?I6us X9$
if(totalCount > 0){ nV|H5i;N7
this.totalCount = totalCount; e B`7C"Z
int count = totalCount / K[%)_KW
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pageSize; ;T Af[[P
if(totalCount % pageSize > 0) HQ8oOn
count++; nQ/R,+6h
indexes = newint[count]; %<|w:z$vp
for(int i = 0; i < count; i++){ $"d< F3k
indexes = pageSize * 2L#$WuM~^
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i; < sJ
} zCvt"!}RRa
}else{ Tl.dr
this.totalCount = 0; _H:mBk,,
} zj ;'0Zu
} Y <'T;@
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publicint[] getIndexes(){ 2]Nc@wX`p
return indexes; CS;bm`8a
} NuLyu=.?
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publicvoid setIndexes(int[] indexes){ j4v.8;
this.indexes = indexes; *C~O[:6D
} }uJH!@j
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publicint getStartIndex(){ RT2%)5s
return startIndex; /bE=]nM
} }H[v!l@
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publicvoid setStartIndex(int startIndex){ b~khb!]
if(totalCount <= 0) IXp (Aeb
this.startIndex = 0; qVOlUH
elseif(startIndex >= totalCount) _raj
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this.startIndex = indexes `K.2&6xc
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[indexes.length - 1]; lx8@;9fLy
elseif(startIndex < 0) UenB4
this.startIndex = 0; xn49[T
else{ 3cuVyf<v
this.startIndex = indexes q[l!kC+Eh
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[startIndex / pageSize]; zJnF#G
} 0v%ZKvSID
} $"z|^ze
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publicint getNextIndex(){ Ax*=kZmH|
int nextIndex = getStartIndex() + -!OFt}
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pageSize; N? r{Y$x
if(nextIndex >= totalCount) f;<qGM.#|
return getStartIndex(); 4{?Djnh
else Y#9dVUS
return nextIndex; EV}c,*);y
} K
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publicint getPreviousIndex(){ o`hVI*D
int previousIndex = getStartIndex() - iElE-g@Ws
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pageSize; ?lg
if(previousIndex < 0) `Pa)H
return0; cNi)[2o7
else M_wqb'=
return previousIndex; {H
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} '+6H= Qn
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} _^+z2m+~N
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抽象业务类 M_-LI4>
java代码: vs3px1Xe#
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/** 6%/@b`vZ
* Created on 2005-7-12 OR4ZjogzY
*/ Q{ hXP*5
package com.javaeye.common.business; 1bW[RK;GE
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import java.io.Serializable; N# o" W
import java.util.List; DA)mkp
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import org.hibernate.Criteria; &/K:zWk3mx
import org.hibernate.HibernateException; 7X\azL
import org.hibernate.Session; !&f(Xs
import org.hibernate.criterion.DetachedCriteria; vYT%e:8)q
import org.hibernate.criterion.Projections; Nqih LUv
import E'|@hL-jn
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org.springframework.orm.hibernate3.HibernateCallback; .G"UM>.}d
import GtQ$`~r
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org.springframework.orm.hibernate3.support.HibernateDaoS JI{|8)S
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upport; 0/".2(\}T
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import com.javaeye.common.util.PaginationSupport; +}IOTw"O`
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public abstract class AbstractManager extends 5r;M61
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HibernateDaoSupport { k)VoDxMKK
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privateboolean cacheQueries = false; ich\`j[i
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privateString queryCacheRegion; K OZHz`1!
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publicvoid setCacheQueries(boolean W'f{u&<
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cacheQueries){ Z:Hk'|q}I
this.cacheQueries = cacheQueries; A"wor\(
} YQU#aOl
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publicvoid setQueryCacheRegion(String d,r%LjNI
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queryCacheRegion){ Q+d9D1b
this.queryCacheRegion = pNY+ E5
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queryCacheRegion; d|UK=B^x
} Za+26#g
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publicvoid save(finalObject entity){ ZJL[#}*
getHibernateTemplate().save(entity); `(j}2X'[
} Hu"?wZj
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publicvoid persist(finalObject entity){ _7?LINF9
getHibernateTemplate().save(entity); /UGH7srx
} Pb05>J3N
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publicvoid update(finalObject entity){ `mU'{
getHibernateTemplate().update(entity); #!,tId
} * A B
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publicvoid delete(finalObject entity){ uj@rv&
getHibernateTemplate().delete(entity); ,z6&k
} ({/@=e x*
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publicObject load(finalClass entity, YG<7Zv
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finalSerializable id){ >_ji`/d{
return getHibernateTemplate().load Y{]RhRR
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(entity, id); ^P&)2m:s
} Z!Y ^iN
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publicObject get(finalClass entity, Xne{:!btw
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finalSerializable id){ @/6cEiC+r\
return getHibernateTemplate().get Go>_4)jy
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(entity, id); !b<c*J?f
} !o.l:Mr
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publicList findAll(finalClass entity){ vO#4$,
return getHibernateTemplate().find("from !MNo
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" + entity.getName()); gie}k)&M
} H]a; <V9[
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publicList findByNamedQuery(finalString ZJz6{cY
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namedQuery){ [ Fid
return getHibernateTemplate o,a3J:j]
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().findByNamedQuery(namedQuery); tA?P$5?-*
} +(d\`{A
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publicList findByNamedQuery(finalString query, Q>y2C8rnJ/
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finalObject parameter){ [([?+Ouy
return getHibernateTemplate y>zPsc,
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().findByNamedQuery(query, parameter); %;0Llxf"
} /JPyADi
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publicList findByNamedQuery(finalString query, .@{W6
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finalObject[] parameters){ zItf>j7|Z
return getHibernateTemplate !2oe;q2X[G
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().findByNamedQuery(query, parameters); x|/zn<\^
} ?A7&SdJaO
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publicList find(finalString query){ `PI,tmv!
return getHibernateTemplate().find WZ}c)r*R
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(query); M%H<F3
} uZ mi
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publicList find(finalString query, finalObject Q8.SD p
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parameter){ 6AgevyVG
return getHibernateTemplate().find BwO^F^Pr?k
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(query, parameter); vluA46c
} XYD}OddO
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public PaginationSupport findPageByCriteria V6'"J
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(final DetachedCriteria detachedCriteria){ y~_wr}.CS
return findPageByCriteria 2T!pFcc
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 09y%FzV
} 7VkT(xnm
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public PaginationSupport findPageByCriteria :|J'HCth
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(final DetachedCriteria detachedCriteria, finalint :AYp{"{
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startIndex){ =\7o@ 38
return findPageByCriteria -~Kw~RX<(
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(detachedCriteria, PaginationSupport.PAGESIZE, l;$HGoJ
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startIndex); QjMH1S
} !%n3_tZC
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public PaginationSupport findPageByCriteria [>xwwm
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(final DetachedCriteria detachedCriteria, finalint 3 A2X1V"
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pageSize, X
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finalint startIndex){ Y85M$]e,
return(PaginationSupport) _+%RbJ~H
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getHibernateTemplate().execute(new HibernateCallback(){
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publicObject doInHibernate E[bJ5o**#
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(Session session)throws HibernateException { .]`L R@qf
Criteria criteria = 7a.$tT
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detachedCriteria.getExecutableCriteria(session); !kZ9Ox9^
int totalCount = 1wpT"5B
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((Integer) criteria.setProjection(Projections.rowCount ?qwTOi
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()).uniqueResult()).intValue(); mZsftby}
criteria.setProjection /Y("Q#Ueq
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(null); [r%WVf.#d
List items = qQC<oR
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criteria.setFirstResult(startIndex).setMaxResults ]fz0E:x
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(pageSize).list(); 86!"b
PaginationSupport ps = 7(B|NYq
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new PaginationSupport(items, totalCount, pageSize, p$^}g:
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startIndex); +grIw#j
return ps; FHWzwi*u}
} T4n.C~
}, true); !$r4 lu
} $PA=7`\MP/
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public List findAllByCriteria(final U^<\'`
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DetachedCriteria detachedCriteria){ =qH9<,p`H
return(List) getHibernateTemplate |5|^[v
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().execute(new HibernateCallback(){ !HyPe"`oL
publicObject doInHibernate 6@kKr
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(Session session)throws HibernateException { pE(\q+1<
Criteria criteria = ^b=] =w
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detachedCriteria.getExecutableCriteria(session); 0MDdcjqw
return criteria.list(); Kr $R "
} )%'Lm
}, true); ~qe9U 0
} wWs<{ T
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public int getCountByCriteria(final Erz{{kf]1V
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DetachedCriteria detachedCriteria){ 3In`
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Integer count = (Integer) O<nJbsl_w
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getHibernateTemplate().execute(new HibernateCallback(){ 5qo^SiB.
publicObject doInHibernate [wB-e~
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(Session session)throws HibernateException { $#ks`$vM
Criteria criteria = +tFm DDx=
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detachedCriteria.getExecutableCriteria(session); ;!U`GN,tH
return z^=.05jB
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criteria.setProjection(Projections.rowCount qGG
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()).uniqueResult(); It,m %5
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} JJJlgr]#
}, true); g;)xf?A9q
return count.intValue(); @7xb/&N
} IxC/X5Mp^q
} (,$ H!qKy
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用户在web层构造查询条件detachedCriteria,和可选的 m)4s4P57y
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 5Gm,lNQ Av
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PaginationSupport的实例ps。 z#*M}RR
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ps.getItems()得到已分页好的结果集 QW :-q(s
ps.getIndexes()得到分页索引的数组 SpbOvY=>
ps.getTotalCount()得到总结果数 N\b%+vR
ps.getStartIndex()当前分页索引 [AE-~+m)^
ps.getNextIndex()下一页索引 ypEcjVPD
ps.getPreviousIndex()上一页索引 ^luAX
}*
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 9Mo(3M
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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 t{t*.{w
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}
一下代码重构了。 NikY0=i
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我把原本我的做法也提供出来供大家讨论吧: %Y8#I3jVJ
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首先,为了实现分页查询,我封装了一个Page类: UP=0>jjbn:
java代码: @2Xw17[f35
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/*Created on 2005-4-14*/ -E~pCN(E
package org.flyware.util.page; ~6!{\un
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/** P6w!r>?6N
* @author Joa wic"a
Y<m
* ]0P-?O:
*/ ,^,KWi9
publicclass Page { tU7,nE>p
A2 r1%}{
/** imply if the page has previous page */ )@)wcf!b
privateboolean hasPrePage; @f442@_4
f h05*]r
/** imply if the page has next page */ IT&
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privateboolean hasNextPage; n1K"VjZk
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/** the number of every page */ ?H8w/{J
privateint everyPage; Dg~r%F
gaBt;@?:Q
/** the total page number */ -;=0dfC(
privateint totalPage; b0PqP<{ t
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/** the number of current page */ "R@N}q<*v2
privateint currentPage; #W[/N|~wx
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/** the begin index of the records by the current f ?:
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fis**f0
query */ 2= FGZa*.
privateint beginIndex; fk-zT
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/** The default constructor */ =N,9#o6^
public Page(){ mKY}+21!Q
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} Arh0m. w
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/** construct the page by everyPage ]S+NH[g+
* @param everyPage HJ[@;F|aU
* */ Y6L_
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public Page(int everyPage){ |&Gm.[IX;q
this.everyPage = everyPage; xI?%.Z;*+
} x5\C MWW
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/** The whole constructor */ fR<_ 4L
public Page(boolean hasPrePage, boolean hasNextPage, >?K@zsv}
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int everyPage, int totalPage, z
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int currentPage, int beginIndex){ +O
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this.hasPrePage = hasPrePage; yHL 2!
this.hasNextPage = hasNextPage; E5 "%-fAJ
this.everyPage = everyPage; b:Oa4vBa
this.totalPage = totalPage; 8'J"+TsOW
this.currentPage = currentPage; ;w";s$
this.beginIndex = beginIndex; [#S[=%
} fT1/@
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/** ]5W|^%
* @return +[C(hhk("
* Returns the beginIndex. T+p?VngF
*/ 1,,kU
publicint getBeginIndex(){ #7/;d=
return beginIndex; @]ydWd
} Z
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/** dLl/V3C6t
* @param beginIndex -Z)j"J
* The beginIndex to set. q_PxmPE@3v
*/ ?m5@ 635
publicvoid setBeginIndex(int beginIndex){ 2(V;OWY(@
this.beginIndex = beginIndex; e1a8>>bcI
} kGm-jh
*'D(
j#&
/** UMsJg7~
* @return *aF#on{
* Returns the currentPage. Dizc#!IGU
*/ >t_5(K4
publicint getCurrentPage(){ ?K]Cs&E4
return currentPage; 'J(rIH3U
} $<R\|_6J
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/** $g? ]9}p
* @param currentPage :D(4HXHK%
* The currentPage to set. !p$z8~
*/ \q9wo*A
publicvoid setCurrentPage(int currentPage){ Y'tPD#|r
this.currentPage = currentPage; {&Kck>C'
} E`68Z/%
Ce 3{KGBw
/** j G8W|\8
* @return ()K,~
* Returns the everyPage. 1#LXy%^tO
*/ ._2#89V
publicint getEveryPage(){ )EQWc0iKG
return everyPage; S8-3Nv'
} <1i:Z*l.
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/** yH}(0
* @param everyPage t){})nZ/4
* The everyPage to set. 49S*f
*/ GG0l\!2)
publicvoid setEveryPage(int everyPage){ 0X6|pC~
this.everyPage = everyPage; v%gkQa
} 9z>I&vcX
:&*Y
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/** >2Z0XEe
* @return Mrpz (})
* Returns the hasNextPage. N<&"_jzm
*/ g}(yq:D
publicboolean getHasNextPage(){ V`*N2ztSL
return hasNextPage; AAbI+L0m{
} (`C#Tq
HLMcOuj
/** 5P=3.Mk
* @param hasNextPage OU2.d7
* The hasNextPage to set. Wp7lDx
*/ 2>%|PQ
publicvoid setHasNextPage(boolean hasNextPage){ kw,eTB<;R
this.hasNextPage = hasNextPage; VRe7Q0
} FDfLPCQm
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/** SrlTwcD
* @return &>Zm gz
* Returns the hasPrePage. KO*# ^+g
*/ KZ8Hp=s
publicboolean getHasPrePage(){ 3<Qe'd
^
return hasPrePage; 6T*MKu
} ^y"
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/** uY 6]rt_#a
* @param hasPrePage [4p~iGC
* The hasPrePage to set. b)+nNqY|
*/ pxf(C<y6_
publicvoid setHasPrePage(boolean hasPrePage){ S87E$k
this.hasPrePage = hasPrePage; DxuT23.
(
} HW|5'opF
l(&3s:Ud
/** clhmpu
* @return Returns the totalPage. JATW'HWC|I
* dJvT2s.t[
*/ m
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publicint getTotalPage(){ jh7-Fl`
return totalPage; I8ZBs0sfF{
} zG
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/** Ax"]+pb
* @param totalPage @4)NxdOE
* The totalPage to set. Ez()W,6]g
*/ ]iI2
publicvoid setTotalPage(int totalPage){ f\p#3IwwH
this.totalPage = totalPage; /\7E&n:)2
} IKaa=r~
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} xxnvz
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mVaWbR@HS
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 <b
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个PageUtil,负责对Page对象进行构造: B3AWJ1o
java代码: /RG>n
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y$Nqw9
/*Created on 2005-4-14*/ }Gvu!a#R
package org.flyware.util.page; rXh*nC
r`dQ<U,
import org.apache.commons.logging.Log; U#
+$ N3%
import org.apache.commons.logging.LogFactory; - uk}Fou
u;
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/** gWK[%.Jnw
* @author Joa 8]@$7hy8
* G'#f*) f
*/ 7\0}te
publicclass PageUtil { ?hC,49
{>v5~G
privatestaticfinal Log logger = LogFactory.getLog gT-"=AsxZQ
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(PageUtil.class); NIo!WOi
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/** 0jJ:WPR
* Use the origin page to create a new page `erKHZ]S
* @param page C@o8C%o
* @param totalRecords #Sc9&DfX
* @return o=]\Jy
*/ ( IXUT6|
publicstatic Page createPage(Page page, int VY#nSF`
?zk#}Ex1
totalRecords){ A<szY92&5
return createPage(page.getEveryPage(), 0s$;3qE
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page.getCurrentPage(), totalRecords); TSKT6_IJw
} dug^o c1
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/** 7 /6Zp?
* the basic page utils not including exception zG*
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handler jk\z-hd
* @param everyPage 0h-'TJg*sk
* @param currentPage Fp&tJ]=B.
* @param totalRecords UdOO+Z_K%
* @return page >vPv4e7&3
*/ Ee3-oHa
publicstatic Page createPage(int everyPage, int ,{C
hHnJ%#
# 4&t09
currentPage, int totalRecords){ 14pyHMOR
everyPage = getEveryPage(everyPage); vojXo|c
currentPage = getCurrentPage(currentPage); e"(SlR
int beginIndex = getBeginIndex(everyPage, c5em*qCw$
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FX
currentPage); H~NK:qRzK
int totalPage = getTotalPage(everyPage, @ogj -ol&
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totalRecords); hLICu[LC?
boolean hasNextPage = hasNextPage(currentPage, 0FcG;i+
cj\?vX\V
totalPage); JHXtKgFX
boolean hasPrePage = hasPrePage(currentPage); Gk']Ma2J}
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returnnew Page(hasPrePage, hasNextPage, B#;6z%WK
everyPage, totalPage, &[z<p
currentPage, WYN0,rv1:+
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beginIndex); j Gp&P
} 8n,/hY>w
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privatestaticint getEveryPage(int everyPage){ KvH t`
return everyPage == 0 ? 10 : everyPage; -pHUC't
} 3}}8ukq
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privatestaticint getCurrentPage(int currentPage){ w9w=2 *
return currentPage == 0 ? 1 : currentPage; Sq SiuO.D
} ` 7P%muY.
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privatestaticint getBeginIndex(int everyPage, int >{)\GK0i7
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currentPage){ qi*Dd[OG
return(currentPage - 1) * everyPage; TD sjNFe3
} [XhG7Ly
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privatestaticint getTotalPage(int everyPage, int "Q`Le{
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totalRecords){ {.])'~[U
int totalPage = 0; =o:1Rc7J
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if(totalRecords % everyPage == 0) 2YQ;Kh"S
totalPage = totalRecords / everyPage; /Un\P
else - -\eYVh[
totalPage = totalRecords / everyPage + 1 ; qjsEyro$-
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return totalPage; -asjBSo*D
} skYHPwJdW
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privatestaticboolean hasPrePage(int currentPage){ VXnWY8\
return currentPage == 1 ? false : true; !CdF,pd/)m
} NY6;\ 7!n
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privatestaticboolean hasNextPage(int currentPage, ?3%r:g4
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int totalPage){ Px3I+VP
return currentPage == totalPage || totalPage == *P/DDRq(2
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0 ? false : true; 3Rhoul[S
} +NJIi@
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} mT/^F{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。 HB,?}S#TP
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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 D_?dy4\
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做法如下: rd;E /:`5
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 *'*,mfk[
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的信息,和一个结果集List: H.;2o(vD
java代码: 9^&B.6! 6
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/*Created on 2005-6-13*/ jNI9 .45y
package com.adt.bo; j/jFS]iC
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import java.util.List; d)3jkHYEjj
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import org.flyware.util.page.Page; ->*~e~T
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/** v cUGBGX_&
* @author Joa =
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*/ +,g!xv4Q
publicclass Result { o@hj.)u
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private Page page; 6HPuCP
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private List content; * H~=dPC
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/** HRyhq;C
* The default constructor "sIww
*/ wwet90_g
public Result(){ gi>W&6
super(); 0e07pF/!
} IEd?-L
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/** P+y XC^ ,
* The constructor using fields \mTi@T!&
* }]M'f:%b
* @param page \=P(?!v
* @param content V(XZ7<& {
*/ F2MC)
public Result(Page page, List content){ 4\ |/S@.
this.page = page; z7z9lDS
this.content = content; ,@fx[5{
} j;qV+Rq]t
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/** ESk:$`P
* @return Returns the content. $E!f@L
*/ PJ=| g7I
publicList getContent(){ r,3\32[?
return content; R)4,f~@"
} >Q'*~S@v3
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/** ;>/yY]F7
* @return Returns the page. :0ltq><?
*/ ll[&O4.F
public Page getPage(){ cq 5^7.
return page; yJ`{\7Uqg
} y>:U&P^
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/** CbXSJDs
* @param content [c -|`d^
* The content to set. ?bu=QV@
*/ p5py3k
public void setContent(List content){ )*R';/zaI
this.content = content; MIyT9",Pl
} ,6#%+u}f
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/** .LDp.#d9r1
* @param page LitdO>%#2
* The page to set. k
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*/ .XkD2~;
publicvoid setPage(Page page){ %pH|2VB#
this.page = page; O,-NzGs
} miTff[hsMa
} I;1)a4Xc4R
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^7*7^<
2. 编写业务逻辑接口,并实现它(UserManager, MslgQmlM
Q, "8Ty
UserManagerImpl) pr1bsrMuL
java代码: )pe17T1|
LE)$_i8gX
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/*Created on 2005-7-15*/ QN?EI:
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package com.adt.service; j:>0XP
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import net.sf.hibernate.HibernateException; 3Agyp89}Q
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