Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 3wa<,^kqy
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 YjIED,eRv
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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 ==e#CSJq
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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 wk@(CKQzI,
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分页支持类: Ei?9M^w
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java代码: )kY_"= d
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package com.javaeye.common.util; 4MF}FS2)
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import java.util.List; n[MIa]dK
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publicclass PaginationSupport { VATXsD
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publicfinalstaticint PAGESIZE = 30; abJ@>7V
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privateint pageSize = PAGESIZE; "e7$q&R
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privateList items; h2/1S{/n]
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privateint totalCount; L9unhx
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privateint[] indexes = newint[0]; K^cWj_a"
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privateint startIndex = 0; hO<w]jV,
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public PaginationSupport(List items, int |>/&EElD
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totalCount){ s?Qb{
setPageSize(PAGESIZE); c[d'1=Qiy
setTotalCount(totalCount); sWZtbW;)
setItems(items); nGJIjo_I
setStartIndex(0); :86luLFm
} l"pz
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public PaginationSupport(List items, int >s 8:1l
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totalCount, int startIndex){ T.m)c%]^/
setPageSize(PAGESIZE); I;11j
setTotalCount(totalCount); D -+)M8bt
setItems(items); O"s`-OM;n
setStartIndex(startIndex); ^* /v,+01f
} 3W0E6H"
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public PaginationSupport(List items, int 3RH#e1Y
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totalCount, int pageSize, int startIndex){ v[yTk[zd0
setPageSize(pageSize); hZ\W ?r
setTotalCount(totalCount); U0bEB
setItems(items); E[Ws} n.
setStartIndex(startIndex); fF-\TW
} M?4r 5R
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publicList getItems(){ bmq XP
return items; 5t5S{aCDr
} v`ZusHJ1d
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publicvoid setItems(List items){ s3E~X
this.items = items; m)]fJ_
} /&!d
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publicint getPageSize(){ +@7x45;D
return pageSize; &F*QYz[
} 1PTu3o&3
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publicvoid setPageSize(int pageSize){ xdBZ^Q
this.pageSize = pageSize; QVRokI`BF
} Gv+Tg/
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publicint getTotalCount(){ (#l_YI
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return totalCount; T#_n-b>
} DGfQo5#
, ZP3F+XKb
publicvoid setTotalCount(int totalCount){ >\oJ&gdc
if(totalCount > 0){ I&NpN~AU
this.totalCount = totalCount; !%\To(r[
int count = totalCount / \gzwsT2&
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pageSize; -S3+
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if(totalCount % pageSize > 0) ${?ex nb$
count++; Dx# @D#
indexes = newint[count]; *=0r>]
for(int i = 0; i < count; i++){ [oN> :
indexes = pageSize * I7z]%Z
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} [dF=1E>W_J
}else{ w{O3P"N2
this.totalCount = 0; lnC Wu@{
} |tJ%:`DGw
} #`L}.
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publicint[] getIndexes(){ g*c\'~f;
return indexes; /uz5V/i0
} ?N?pe}
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publicvoid setIndexes(int[] indexes){ %iS]+Sa.K
this.indexes = indexes; (*WZsfk>/<
} wukos5
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publicint getStartIndex(){ _5S$mc8K0
return startIndex; JTB~nd>
} q.b4m 'J
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publicvoid setStartIndex(int startIndex){ g!Yh=kA'N
if(totalCount <= 0) u,,WD
this.startIndex = 0; Hi"
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elseif(startIndex >= totalCount) l}-`E@w
this.startIndex = indexes /Vd#q)b%T
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[indexes.length - 1]; ,p`bWm
elseif(startIndex < 0) R}6la.mQ
this.startIndex = 0; v4##(~Tu
else{ n_&)VF#n(
this.startIndex = indexes %s :
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[startIndex / pageSize]; NEou2y+}
} qVe6RpS
} 4NR5?s
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publicint getNextIndex(){ 2&K|~~
int nextIndex = getStartIndex() + Wk6&TrWlY
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pageSize; :h^UC~[h 3
if(nextIndex >= totalCount) Ci9wF(<k
return getStartIndex(); |{IU<o
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else u2O^3rG-
return nextIndex; `b`52b\6S
} c%/&@vs7
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publicint getPreviousIndex(){ & O\!!1%
int previousIndex = getStartIndex() - `"mK\M
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pageSize; yx;R#8;b.
if(previousIndex < 0) UkbQ'P+oS
return0; R/cq00g
else Jd2Y)
return previousIndex; 'yRv~BA
} mf_'|
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} I%C:d#p
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抽象业务类 PH%gX`N
java代码: WM
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/** cE>/iZc
* Created on 2005-7-12 }e=GvWGa
*/ Pc4cSw#5
package com.javaeye.common.business; 1gej$G@
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import java.io.Serializable; xQ
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import java.util.List; t\d;}@bl
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import org.hibernate.Criteria; c
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import org.hibernate.HibernateException; 5d{Ggg{s
import org.hibernate.Session; pcTXTy 28
import org.hibernate.criterion.DetachedCriteria; k#NMD4(%O
import org.hibernate.criterion.Projections; cD@lorj
import Y8'_5?+ 0
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org.springframework.orm.hibernate3.HibernateCallback; g@f/OsR76
import N%E2BJ?
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org.springframework.orm.hibernate3.support.HibernateDaoS QO1Gq9
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upport; '^3pF2lIw
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import com.javaeye.common.util.PaginationSupport; Jd6Q 9~z#
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public abstract class AbstractManager extends 5<?$/H|7T
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HibernateDaoSupport { BW=6gZ_
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privateboolean cacheQueries = false; 1Klu]J%
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privateString queryCacheRegion; L>GYj6D9
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publicvoid setCacheQueries(boolean H1i4_T
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cacheQueries){ }U1shG[
this.cacheQueries = cacheQueries; Qh%vh;|^
} q[A3$y(
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publicvoid setQueryCacheRegion(String e;r-}U
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queryCacheRegion){ ui0(#2'h%
this.queryCacheRegion = @5GP;3T
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queryCacheRegion; %t.IxMY
} 6.=1k
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publicvoid save(finalObject entity){ ?|yJ#j1=
getHibernateTemplate().save(entity); I3b-uEHev
} g~u!,Zc
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publicvoid persist(finalObject entity){ |q)Q<%VS'
getHibernateTemplate().save(entity); iqP0=(^m
} xl=|]8w
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publicvoid update(finalObject entity){ 90D.G_45
getHibernateTemplate().update(entity); X]%4QIeS
} }gaKO 5
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publicvoid delete(finalObject entity){ U<byR!qLie
getHibernateTemplate().delete(entity); Ggjb86v\
} |.nWy"L
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publicObject load(finalClass entity, vjS7nR"T
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finalSerializable id){ tvCTC ey
return getHibernateTemplate().load 8#-}3~l[
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(entity, id); WLFzLW=PD
} XaSl6CH
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publicObject get(finalClass entity, vbJMgdHFR
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finalSerializable id){ @},k\Is
return getHibernateTemplate().get L6qA=b~iz
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(entity, id); s#49pDN
} X~!?t}
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publicList findAll(finalClass entity){ |8ZAE%/d
return getHibernateTemplate().find("from =5F49
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" + entity.getName()); P~>nlm82]
} EJY:C9W
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publicList findByNamedQuery(finalString y+h=x4t
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namedQuery){ EatDT*!
return getHibernateTemplate aW5~z^I
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().findByNamedQuery(namedQuery); Pw1H)<X
} kp"cHJNx
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publicList findByNamedQuery(finalString query, 0Z(b/fdS
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finalObject parameter){ VQ`O;n6/`
return getHibernateTemplate _~"3
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().findByNamedQuery(query, parameter); JOk`emle
} "5bk82."
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publicList findByNamedQuery(finalString query, {'[1I_3
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finalObject[] parameters){ 9rz "@LM
return getHibernateTemplate a[De
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().findByNamedQuery(query, parameters); E ..[F<5
} TA5M4r6
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publicList find(finalString query){ I}x*AM 7+
return getHibernateTemplate().find B$j,: ^
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(query); c:5BQr
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} ]T`qPIf;yJ
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publicList find(finalString query, finalObject #^Y-*vf2
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parameter){ qB`P7!VN^]
return getHibernateTemplate().find i"@?eq#h
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(query, parameter); !h\3cs`QU
} ;?9~^,l
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public PaginationSupport findPageByCriteria @hv]
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(final DetachedCriteria detachedCriteria){ Qfi5fp=f
return findPageByCriteria lQjq6Fl2
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); LV0{~g(!%
} ufOaD7
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public PaginationSupport findPageByCriteria `P~RG.HO
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(final DetachedCriteria detachedCriteria, finalint U_?RN)>j
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startIndex){ V{r@D!}
return findPageByCriteria A{vG@Pwc:
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(detachedCriteria, PaginationSupport.PAGESIZE, xM,3F jF
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startIndex); =&'j;j
} WUWQcJj
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public PaginationSupport findPageByCriteria }e$);A|
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(final DetachedCriteria detachedCriteria, finalint '*:YC
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pageSize, d8>D=Ve
finalint startIndex){ rv%Xvs B
return(PaginationSupport) &!=3Fbn
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getHibernateTemplate().execute(new HibernateCallback(){ RzkJS9)m
publicObject doInHibernate |^{IHF\
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(Session session)throws HibernateException { JkmL'Zk>:
Criteria criteria = 6Jm4?ex
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detachedCriteria.getExecutableCriteria(session); y? g7sLDc
int totalCount = E^!%m8--
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((Integer) criteria.setProjection(Projections.rowCount M;OYh
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()).uniqueResult()).intValue(); ^]kDYhe*Y
criteria.setProjection +^.(3Aw
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(null); IlVi1`]w
List items = 6S(3tvUr
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criteria.setFirstResult(startIndex).setMaxResults c-,/qn/
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(pageSize).list(); ]=/f`
PaginationSupport ps = Yr!3mU-Uvt
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new PaginationSupport(items, totalCount, pageSize, %$08*bAtB7
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startIndex); P*}Oi7Z
return ps; 1/z1~:Il
}
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}, true); YG% Zw
} 0y(d|;':
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public List findAllByCriteria(final `]Xbw^Y'x
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DetachedCriteria detachedCriteria){ ,70|I{,Km
return(List) getHibernateTemplate .R1)i-^
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().execute(new HibernateCallback(){ 5VI'hxU4Qg
publicObject doInHibernate s=q}XIWK
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(Session session)throws HibernateException { -Fb/GZt|
Criteria criteria = y ^YrGz.
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detachedCriteria.getExecutableCriteria(session); tY7u\Y;^
return criteria.list(); 49CMRO,T
} =(o$1v/k
}, true); (C!fIRY
} kAqk~.
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public int getCountByCriteria(final ,}NG@JID
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DetachedCriteria detachedCriteria){ =zsXa=<
Integer count = (Integer) Ws=J)2q
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getHibernateTemplate().execute(new HibernateCallback(){ P~~RK&+i
publicObject doInHibernate |(w x6H:
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(Session session)throws HibernateException { P)T:6K
Criteria criteria = Dv$xP)./
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detachedCriteria.getExecutableCriteria(session); JL<}9K
return CxO)d7c
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criteria.setProjection(Projections.rowCount .AKx8=f
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()).uniqueResult(); <4Ak$E%"
} *d@}'De{8
}, true); 5ewQjwW0
return count.intValue(); Ouj5NL
} ;$86.2S>B
} 9AS,-5;XQ
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用户在web层构造查询条件detachedCriteria,和可选的 FC(m)S2
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 &4]%&mX)-
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PaginationSupport的实例ps。 P afmHXx
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ps.getItems()得到已分页好的结果集 \"n&|_SZ\
ps.getIndexes()得到分页索引的数组 ^E5Xpza
ps.getTotalCount()得到总结果数 k%hif8y
ps.getStartIndex()当前分页索引 /H\ZCIu/7
ps.getNextIndex()下一页索引 o'W &gkb9
ps.getPreviousIndex()上一页索引 @#sQ7eMoy
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 olh|.9Kdj}
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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 4H{L>e
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一下代码重构了。 @T1-0!TM')
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我把原本我的做法也提供出来供大家讨论吧: u'}DG#@ -
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首先,为了实现分页查询,我封装了一个Page类: iHTxD1D+H
java代码: eqXW|,zUm
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/*Created on 2005-4-14*/ @UD6qA
package org.flyware.util.page; ~bgFU
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/** E-l>z%
* @author Joa 9erTb?@S
* HAP9XC(F]
*/ O75ioO0
publicclass Page { D*heYh
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/** imply if the page has previous page */ 7HFw*;
privateboolean hasPrePage; ,OG sx
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/** imply if the page has next page */ nAg|m,gA
privateboolean hasNextPage; ZcIwyh(`
m/CA
/** the number of every page */ d[jxU/.p;
privateint everyPage; 5'.j+{"
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/** the total page number */ _8t{4C
privateint totalPage; .,-t}5(VSq
p-MQI }
/** the number of current page */ <^OGJ}G
privateint currentPage; n&k1'KL&
|7%M:7Q
/** the begin index of the records by the current jR*1%.Ng
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query */ KK/~W
privateint beginIndex; _epi[zf@
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/** The default constructor */ 9^>nZ6
public Page(){ `nn;E%n
'd'*4 )]k
} ga0W;Vq&X
kx*=1AfU+Y
/** construct the page by everyPage vxY7/ _]
* @param everyPage Y[@$1{YS
* */ m8#+w0p)
public Page(int everyPage){ nQb{/ TqC'
this.everyPage = everyPage; DCFYpkR%
} `UGHk*DL)
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/** The whole constructor */ %E,s*=j
public Page(boolean hasPrePage, boolean hasNextPage, @/yef3
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int everyPage, int totalPage, m'@NF--#Oq
int currentPage, int beginIndex){
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this.hasPrePage = hasPrePage; PG+ICg
this.hasNextPage = hasNextPage; gtqgf<mS
this.everyPage = everyPage; ig)rK<@*[
this.totalPage = totalPage; -"#;U`.oh7
this.currentPage = currentPage; _.yBX\tf[
this.beginIndex = beginIndex; u 6$fF=
} >@`D@_v
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/** `pOiv&>
* @return rt^<=|Z
* Returns the beginIndex. !ku5P+y$
*/ [r<lAS{ .
publicint getBeginIndex(){ ldO6W7G|h
return beginIndex; vrLI`3n]
} 1s"6
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/** ok iI:
* @param beginIndex {?$-p%CF`8
* The beginIndex to set. Vd1.g{yPV
*/ ?1JS*LQ$
publicvoid setBeginIndex(int beginIndex){ DgGGrV`
this.beginIndex = beginIndex; OxZw;yD
} &Vd,{JU
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/** \J.PrE'(}
* @return y?zNxk/p
* Returns the currentPage. :?O+EE
*/ 2aNCcZw0
publicint getCurrentPage(){ 37Q9goMov
return currentPage; Z4b<$t[u
} #"jEc*&=
0 V}knR.l
/** 'x$>h)t]
* @param currentPage >T'^&l(:
* The currentPage to set. VK5|w:
*/ 9|jk=`4UK
publicvoid setCurrentPage(int currentPage){ Z^zUb
this.currentPage = currentPage; 9~J
} 3){ /u$iH.
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/** )#%k/4(Y
* @return /{gCf
* Returns the everyPage. /4}{SE
*/ 07:CcT
publicint getEveryPage(){ %3M1zZY
return everyPage; H.3+5po
} A'^y+42jY
&!x!j,nT
/** tF}Vs}
* @param everyPage no~hYyW2
* The everyPage to set. 5|. _K(M
*/ f5.rzrU
publicvoid setEveryPage(int everyPage){ 60c cQ7=
this.everyPage = everyPage; #T &z`
} @doo2qqIe]
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/** 6nRXRO
* @return j-e/nZR@
* Returns the hasNextPage. |j3mI\ANF
*/ :FcYjw
publicboolean getHasNextPage(){ |]kcgLqj
return hasNextPage; n&DRh.@
} >AX&PMb`
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/** bKRz=$P?
* @param hasNextPage } Wx#"6
* The hasNextPage to set. !#wd~: H
*/ x%Ivd
publicvoid setHasNextPage(boolean hasNextPage){ BU
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this.hasNextPage = hasNextPage; o&g-0!"
} ~"6/OJA
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/** 'mx_]b^O
* @return U{6i5;F#H
* Returns the hasPrePage. aZ"9)RJe
*/ 1iyd{r7|
publicboolean getHasPrePage(){ F0
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return hasPrePage; d}#G~O+y3v
} @62QDlt;
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/** Wyh
* @param hasPrePage -b'93_ZTu:
* The hasPrePage to set. >U?HXu/TJr
*/ P4@<`Eb
publicvoid setHasPrePage(boolean hasPrePage){ hYOUuC
this.hasPrePage = hasPrePage; tu{y
} b~uz\%'3
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/** m/vwM"
* @return Returns the totalPage. wju2xM
* $n>|9(K8
*/ ?|Y/&/;%I
publicint getTotalPage(){ f7NK0kuA
return totalPage; =23JE'^=
} M`^;h: DN^
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/** j<[+vrj
* @param totalPage 4|i.b?"
* The totalPage to set. 0`y;[qAG[
*/ yf5X=f.%@
publicvoid setTotalPage(int totalPage){ ?fF{M%i-%
this.totalPage = totalPage; 0tV" X
} H]>b<Cs
z@5t7e)!R
} (9R;a np
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8
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 9;,_Qq
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个PageUtil,负责对Page对象进行构造: #SWL$Vm>
java代码: (KQAKEhD!
wbg_%h:
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/*Created on 2005-4-14*/ 5T]GyftFV
package org.flyware.util.page; aDr46TB`J
P){F2&!P
import org.apache.commons.logging.Log; ;;4xpg
import org.apache.commons.logging.LogFactory; u`GzYG-L
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/** -UgD
* @author Joa 5<1,`Bq@
* =+@Ip Xj
*/ 5\1C@d
publicclass PageUtil { B1\@ n$
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privatestaticfinal Log logger = LogFactory.getLog ai/VbV'|
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(PageUtil.class); XHq8p[F
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/** pMJK?- )
* Use the origin page to create a new page OG}auM4
* @param page cQj{[Wt4
* @param totalRecords G}.t!"
* @return <3]Qrjl
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*/ &j2fh!\4
publicstatic Page createPage(Page page, int z>_jC+
P8#;a
totalRecords){ GUUVE@Z
return createPage(page.getEveryPage(), :m|%=@]`
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page.getCurrentPage(), totalRecords); \gd.Bl
} _Se~bkw?v
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/** 'W0?XaEk-
* the basic page utils not including exception 9r@T"$V#c
P(N$U^pj
handler F,B, D^WD
* @param everyPage S(;3gQ77
* @param currentPage `9%Q2Al
* @param totalRecords Mq7d*Bgb
* @return page [;5?=X,LD
*/ e[D'0L
publicstatic Page createPage(int everyPage, int C+/D!ZH%P
O{"
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currentPage, int totalRecords){ ((BuBu>
everyPage = getEveryPage(everyPage); wr\d5j
currentPage = getCurrentPage(currentPage); Z$h39hm?c
int beginIndex = getBeginIndex(everyPage, &^-quzlZ
K>H_q@-?f
currentPage); X2#;1 ku
int totalPage = getTotalPage(everyPage, /mST<{(_G\
4%5H<:V7
totalRecords); n
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boolean hasNextPage = hasNextPage(currentPage, XO |U4#ya
r{~K8!=oU]
totalPage); "WKE%f
boolean hasPrePage = hasPrePage(currentPage); 0q%=Vs~@g
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returnnew Page(hasPrePage, hasNextPage, EFl[u+
1tx
everyPage, totalPage, /?b<}am
currentPage, =d_@k[8<0
$ohg?B;
beginIndex); VN=S&iBa/
} WZ"g:Khw
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privatestaticint getEveryPage(int everyPage){ IyE9G:fY
return everyPage == 0 ? 10 : everyPage; $;<h<#_n;
} ; *G[3kk
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privatestaticint getCurrentPage(int currentPage){ -B\`O*Q
return currentPage == 0 ? 1 : currentPage; :z=/z!5:j
} 4i'2~w{/
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privatestaticint getBeginIndex(int everyPage, int ye U4,Ko
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currentPage){ +M9=KVr
return(currentPage - 1) * everyPage; Z+"%MkX0
} Q"]C"?
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privatestaticint getTotalPage(int everyPage, int 5utMZ>%w_#
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totalRecords){ &Vi"m!Bf
int totalPage = 0; KZV$rJ%G
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if(totalRecords % everyPage == 0) l7 D/]&
totalPage = totalRecords / everyPage; ?9q{b\=l
else z41
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totalPage = totalRecords / everyPage + 1 ; 'Mjbvh4
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return totalPage; YW"?Fy
} 1 sCF
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privatestaticboolean hasPrePage(int currentPage){ !ViHC}:
return currentPage == 1 ? false : true; g5TXs^g
} RB'12^[
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privatestaticboolean hasNextPage(int currentPage, fU~>A-P
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int totalPage){ Ch
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return currentPage == totalPage || totalPage == (mHFyEG
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0 ? false : true; <wTkPErUG
} qv3L@"Ub
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} 6<A\U/
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{
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/B!"\0G/,
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。 \~nUk7.
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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 wP/rR D6
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做法如下: ,K7C2PV6
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 yoV"?W>!
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的信息,和一个结果集List: hmkcWr`
java代码: <2y~7h:
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/*Created on 2005-6-13*/ V&KH{j/P
package com.adt.bo; M:?eK
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import java.util.List; |6\ ?"#
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import org.flyware.util.page.Page; Yl1@gw7
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/** >T~{_|N
* @author Joa l;Zc[6
*/
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publicclass Result { 4E3HYZ
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private Page page; :KX/GN!n
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private List content; 2ok>z$Y
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/** #f/-i u=L
* The default constructor aqs']
*/ Q8Usyc'3
public Result(){ F>A-+]X3o
super(); IG +nrTY0
} }SpMHR`
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/** iCk34C7
* The constructor using fields biGaP#"0
* GLc+`,.
* @param page L6$,<}l
* @param content 1Sz5&jz
*/ >!? f6
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public Result(Page page, List content){ P9`i6H'~
this.page = page; ~`tc|Zu
this.content = content; k1-?2kf"{
} ?\hXJih
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/** hPFIf>%}
* @return Returns the content. w/G5I )G
*/ s'\"%~nF<
publicList getContent(){ F$F5N1<
return content; ~>}BDsM
} AH=6xtS-
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/** XfbkK )d
* @return Returns the page. `!m+g0
*/ ['-ln)96.
public Page getPage(){ `34[w=Zm
return page; W,Dr2$V
} oL}FD !}
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/** "P<~bw5
* @param content &B3\;|\
* The content to set. [+GQ3Z\
*/ >wcsJ{I
public void setContent(List content){ k~=-o>}C
this.content = content; |BYD] vK
} E?Q=#+}U
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/** b@,=;Y)O
* @param page ,b{G(sF
* The page to set. -]'Sy$,A
*/ Mm.!$uR
publicvoid setPage(Page page){ "{{xH*ij'
this.page = page;
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} FLy|+4D_%4
} e1&c_"TOih
5-u=ZB%p
,st4K;-
$#Ji=JX
l@#X]3h!
2. 编写业务逻辑接口,并实现它(UserManager, NJl|/(]v
:^iR&`2~
UserManagerImpl) sOJ"~p
java代码: -QS_bQG%
2~]c`/M3
e`}|*^-
/*Created on 2005-7-15*/ 3Q`'C7Pi
package com.adt.service; >Ckb9A
$ HUCp9
import net.sf.hibernate.HibernateException; 3'&]v6|
Nt/*VYUn
import org.flyware.util.page.Page; HM[BFF[;/
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import com.adt.bo.Result; O~aS&g/sf
&