Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 9Zmq7a
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 )D)4=LJ
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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 (uy\~Zb
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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 _
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分页支持类: Z6Z/Y()4Tl
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java代码: .<xD'54
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package com.javaeye.common.util; lDF7~N9J_
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import java.util.List; $9xp@8b\_
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publicclass PaginationSupport { Z}Q/u^Z
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publicfinalstaticint PAGESIZE = 30; WS?Y8~+{5
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privateint pageSize = PAGESIZE; ;Bw3@c
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privateList items; 9'(m"c_
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privateint totalCount; qn,fx6v4
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privateint[] indexes = newint[0]; :#{0yno)H
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privateint startIndex = 0; *J
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public PaginationSupport(List items, int _34%St!lg
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totalCount){ <^'IC9D]
setPageSize(PAGESIZE); AxF$7J(
setTotalCount(totalCount); oIMS >&
setItems(items); (H:A|Lw
setStartIndex(0); 52,'8`
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} 6D`.v@
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public PaginationSupport(List items, int
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totalCount, int startIndex){ OsVz[w N
setPageSize(PAGESIZE); 9C7HL;MF
setTotalCount(totalCount); (:%t
setItems(items); g[~J107%A
setStartIndex(startIndex); h0$ \JXk
} Nez '1
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public PaginationSupport(List items, int {yEL$8MC
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totalCount, int pageSize, int startIndex){ qV,x )y:V
setPageSize(pageSize); "(kiMog-
setTotalCount(totalCount); E9t8SclV
setItems(items); "Vp:Sq9y
setStartIndex(startIndex); [Ls%nz|
} /TIt-c
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publicList getItems(){ )7Qp9Fxo
return items; /11CC \
} &%k_BdlkQ
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publicvoid setItems(List items){ L `=*Pwcj
this.items = items; Tu,nX'q]m
} V`YmGo
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publicint getPageSize(){ hhI*2|i"L
return pageSize; 7s2*VKr
} 0tPwhJ
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publicvoid setPageSize(int pageSize){ JE*?O*&|Q
this.pageSize = pageSize; jHA(mU)b
} HqV4!o9'
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publicint getTotalCount(){ /q7$"wP
return totalCount; >?G!>kw
} ljz=u;O)
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publicvoid setTotalCount(int totalCount){ jZvIqR/
if(totalCount > 0){ se}$/Y}t
this.totalCount = totalCount; 6Bexwf<u
int count = totalCount / \yLFV9P}EL
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pageSize; &zVXd
if(totalCount % pageSize > 0) IlI5xkJ(
count++; Mii&doU
indexes = newint[count]; 9y} J|z
for(int i = 0; i < count; i++){ +JXn
indexes = pageSize * A_2lG!!
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} !|9k&o
}else{ 5Fq+^
this.totalCount = 0; jMX|1b
} P=y1qqC
} {!wd5C@
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publicint[] getIndexes(){ IF<T{/MA
return indexes; |%3>i"Y@AK
} 4$ah~E>,t
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publicvoid setIndexes(int[] indexes){ 62G%.'7
this.indexes = indexes; 7qWa>fX
} /#L4ec-'
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publicint getStartIndex(){ 9VIAOky-
return startIndex; 2Qc_TgWF
} qDfhR`1k
Z *v`kl
publicvoid setStartIndex(int startIndex){ }>3jHWxLc
if(totalCount <= 0) TQ[J,
this.startIndex = 0; _.EM])b
elseif(startIndex >= totalCount) C8}=fa3u
this.startIndex = indexes vNZ"x)?
e ]2GAJLI
[indexes.length - 1]; nf:wJ-;*
elseif(startIndex < 0) 2uF'\y
this.startIndex = 0; {W%XSE
else{ J @IKXhb7_
this.startIndex = indexes *xKy^f
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[startIndex / pageSize]; V{\1qg{
} T$;BZ=_
} fl4'dv
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publicint getNextIndex(){ Z]5xy_La
int nextIndex = getStartIndex() + %/!f^PIwX
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pageSize; ,Hp7`I>/
if(nextIndex >= totalCount) r CUs
return getStartIndex(); }We-sZ/w7r
else "tDB[?
return nextIndex; r $ YEq5
} )2u_[Jc=
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publicint getPreviousIndex(){ a\B?J
int previousIndex = getStartIndex() - (S6>^:;=~
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pageSize; _U,Hi?b"$}
if(previousIndex < 0) t+,2 p|B
return0; }b{7+ +
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else +]~}kvk:
return previousIndex; hxw6^EA
} gnf4H
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} wX!0KxR/Z
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抽象业务类 S]4!uv^y
java代码: N,F[x0&?
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/** lcfs
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* Created on 2005-7-12 uE..1N&*
*/ NZ+TTMv
package com.javaeye.common.business; zP|^@Homk
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import java.io.Serializable; \"Qa)1|
import java.util.List; uOh
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import org.hibernate.Criteria; `84,R!
import org.hibernate.HibernateException; V%`\x\Xat
import org.hibernate.Session; Ac}5,
import org.hibernate.criterion.DetachedCriteria; _d>{Hz2
import org.hibernate.criterion.Projections; wz Y{ii
import 1>umf~%Wa
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org.springframework.orm.hibernate3.HibernateCallback; vSCJ xSt#e
import xA0=C
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org.springframework.orm.hibernate3.support.HibernateDaoS C[><m2T
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upport; 3 k/X;:,.
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import com.javaeye.common.util.PaginationSupport; o Z%oP V:
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public abstract class AbstractManager extends MaF4lFmS
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HibernateDaoSupport { /HdjPxH
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privateboolean cacheQueries = false; 7IrH(~Fo
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privateString queryCacheRegion; bu=RU
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publicvoid setCacheQueries(boolean `1lGAKv
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cacheQueries){ +{%)}?F
this.cacheQueries = cacheQueries; R ^INl@(O
} #K/95!)
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publicvoid setQueryCacheRegion(String v"_E0
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queryCacheRegion){ ku#WQL
this.queryCacheRegion = M5N#xgR
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queryCacheRegion; h1$75E?,
} X]=8Oa
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publicvoid save(finalObject entity){ HI[Pf%${
getHibernateTemplate().save(entity); WfYG#!}x
} N%)q.'M
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publicvoid persist(finalObject entity){ `(E$-m-~jH
getHibernateTemplate().save(entity); bzECNi5^
} a&7uRR26
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publicvoid update(finalObject entity){ O0eM*~zI
getHibernateTemplate().update(entity); }:!X@C~
} drbim8!q~
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publicvoid delete(finalObject entity){ |3`8$-
getHibernateTemplate().delete(entity); |w5,%#AeO$
} {TDZDH
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publicObject load(finalClass entity, g|tclBx
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finalSerializable id){ !1Ht{cA0
return getHibernateTemplate().load wEQZ9?\
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(entity, id); 7"OJ,Mx%
} xl@~K^c]
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publicObject get(finalClass entity, dk 0} q6~
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finalSerializable id){ 'LR|DS[Ne
return getHibernateTemplate().get F
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(entity, id); ZX'3qW^D
} h05<1>?|
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publicList findAll(finalClass entity){ e`Co ='
return getHibernateTemplate().find("from Of}C.N8
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" + entity.getName()); 7R5+Q\W
} e$&n)>%
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publicList findByNamedQuery(finalString
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namedQuery){ 2rb@Md]dx
return getHibernateTemplate =q*c}8R_0
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().findByNamedQuery(namedQuery); by\Sq}
} DcE4r>8B
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publicList findByNamedQuery(finalString query, #aiI]'
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finalObject parameter){ 9_ZGb"(Lj
return getHibernateTemplate \ _?d?:#RD
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().findByNamedQuery(query, parameter); 5=R]1YI~$
} -aV(6i*n
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publicList findByNamedQuery(finalString query, $EzWUt
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finalObject[] parameters){ 9!.S9[[N
return getHibernateTemplate WpRM|"CF
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().findByNamedQuery(query, parameters); e0j4t-lL
} whm|"}x)u
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publicList find(finalString query){ mA@!t>=oMq
return getHibernateTemplate().find =ADOf_n}
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(query); cwzgIm+
} C>SOd]
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publicList find(finalString query, finalObject y>)c?9X
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parameter){ _]{LjJ!M
return getHibernateTemplate().find (H\ `/%Bp
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(query, parameter); $VhY"<
} &9"Y:),
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public PaginationSupport findPageByCriteria _ {6l}
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(final DetachedCriteria detachedCriteria){ wuW{2+)B
return findPageByCriteria 8H`L8:
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 5=%KK3
} iio-RT?!
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public PaginationSupport findPageByCriteria G6+6uWvl
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(final DetachedCriteria detachedCriteria, finalint $\|Q+ 7lQ
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startIndex){ ]2
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return findPageByCriteria X4Pm&ol
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(detachedCriteria, PaginationSupport.PAGESIZE, K\59vtga
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startIndex); DIJmISk
} )dh`aQ%N "
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public PaginationSupport findPageByCriteria L&~' SC
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(final DetachedCriteria detachedCriteria, finalint H6Bw3I[
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pageSize, 29m$S7[
finalint startIndex){ B|,d
return(PaginationSupport) 3s67)n
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getHibernateTemplate().execute(new HibernateCallback(){ "_&c[VptWi
publicObject doInHibernate +S`cUn7
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(Session session)throws HibernateException { .!Kqcz% A
Criteria criteria = M{)&SNI*C
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detachedCriteria.getExecutableCriteria(session); B2a#:E,6
int totalCount = /Ov1eQBNG
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((Integer) criteria.setProjection(Projections.rowCount L#J2J$=
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()).uniqueResult()).intValue(); #9F>21UU
criteria.setProjection E31YkD.A
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(null); El: @l%
List items = &Yc'X+'4
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criteria.setFirstResult(startIndex).setMaxResults 3^xq+{\)
+l.LwA
(pageSize).list(); cc:$$_'L
PaginationSupport ps = MvnQUZ
= ^Vp \
new PaginationSupport(items, totalCount, pageSize, 6(uZn=
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startIndex); 9qgs*]J
return ps; `@v;QLD"d<
} 4>a(!ht
}, true); "tK|/R+
} %>6ilGQ+
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public List findAllByCriteria(final 2eA.04F
ts}OE
DetachedCriteria detachedCriteria){ 6,MQT,F
return(List) getHibernateTemplate Yyr9Kj:
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().execute(new HibernateCallback(){ DdUw~n,
publicObject doInHibernate :Fu7T1
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(Session session)throws HibernateException { /&_q"y9
Criteria criteria = BG=
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detachedCriteria.getExecutableCriteria(session); E^br-{|{
return criteria.list(); ';My"/
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} +6
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}, true); TA2ETvz^
} ZS;V?]\(
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public int getCountByCriteria(final odC"#Rb
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DetachedCriteria detachedCriteria){ yU4mS;GX
Integer count = (Integer) } .Z`
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getHibernateTemplate().execute(new HibernateCallback(){ gIusp917
publicObject doInHibernate )0ydSz`B
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(Session session)throws HibernateException { k0#s{<I]E
Criteria criteria = VZ=:`)
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detachedCriteria.getExecutableCriteria(session); i/H;4#Bz
return gmgri
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criteria.setProjection(Projections.rowCount hITYBPqRO
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()).uniqueResult(); Y6Cm
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} gx',K1T
}, true); TI/RJF b
return count.intValue(); &vt)7[
} HGh
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} H{,1-&>|
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用户在web层构造查询条件detachedCriteria,和可选的 %7P]:G+Y\
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 Ui" {0%
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PaginationSupport的实例ps。 jZPGUoRLg
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ps.getItems()得到已分页好的结果集 1"75+Q>D
ps.getIndexes()得到分页索引的数组 WFFQxd|Z
ps.getTotalCount()得到总结果数 O-K*->5S
ps.getStartIndex()当前分页索引 qsbV)c
ps.getNextIndex()下一页索引 PREGQ0
ps.getPreviousIndex()上一页索引 dE_"|,:
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 r|DIf28MIq
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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 (=;'>*L(
+ xO3<u
一下代码重构了。 w0oTV;yh
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我把原本我的做法也提供出来供大家讨论吧: qHdUnW
, QWus"5H
首先,为了实现分页查询,我封装了一个Page类: W02z}"#
java代码: v<g=uEpN
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/*Created on 2005-4-14*/ ~%g,Uypi
package org.flyware.util.page; ,d38TN
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/** *jWh4F,
* @author Joa Z_xQ2uH$:
* n8=Dzv0
*/ 8IQ}%|lN
publicclass Page { +hr|$
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/** imply if the page has previous page */ Ky,upU
privateboolean hasPrePage; `PL}8ydZ
N>"L2E=z$|
/** imply if the page has next page */ Z_4%Oi
privateboolean hasNextPage; *AW v
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/** the number of every page */ {d;z3AB
privateint everyPage; saP%T~
}u3|w0~c)
/** the total page number */ fxoEK}TM
privateint totalPage; :i?6#_2IC
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/** the number of current page */ 5R~M@
privateint currentPage; 5$'[R;r
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/** the begin index of the records by the current `4'=&c9
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query */ R@z`
privateint beginIndex; 2p\xgAW?
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/** The default constructor */ f7\X3v2W}3
public Page(){ O!f37n-TB
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} l1'v`!
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/** construct the page by everyPage M.}J SDt
* @param everyPage kBcTXl
* */ ]bh%pn
public Page(int everyPage){ cl`Wl/Q#
this.everyPage = everyPage; >.`*KQdan
} vr4r,[B6y
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/** The whole constructor */ gggD "alDx
public Page(boolean hasPrePage, boolean hasNextPage, 2XeyNX
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d wG!]j>:_
int everyPage, int totalPage, YSt*uOZK
int currentPage, int beginIndex){ r|4D.O]
this.hasPrePage = hasPrePage; 'q$ Ym0nL
this.hasNextPage = hasNextPage; 5G\OINxy
this.everyPage = everyPage; MJ?t{=
this.totalPage = totalPage; vbeE}7 *2
this.currentPage = currentPage; jIe
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this.beginIndex = beginIndex; ~ E6e~
} y.D+M$f
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/** z=U+FHdh/-
* @return hIV]ZYbH
* Returns the beginIndex. 6JZ>&HA
*/ E9j<+Ik
publicint getBeginIndex(){ -_5Dk'R#`
return beginIndex; 8CUtY9.
} Gkem _Z
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/** "X2'k@s`
* @param beginIndex ]goJ- &
* The beginIndex to set. a<\n$E#q
*/ D|)_c1g
publicvoid setBeginIndex(int beginIndex){ lCp6UkE
this.beginIndex = beginIndex; C/Z#NP~ *
} ;BH.,{*@B
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/** :qbU@)p*
* @return $RY-yKmi
* Returns the currentPage. u_' -vZ_
*/ t*H2;|zn_
publicint getCurrentPage(){ ;6pB7N
return currentPage; ):>?N`{V
} k6ry"W3
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/** 7,p.M)t)
* @param currentPage /fb}]e]N
* The currentPage to set. mJ<`/p?:
*/ P:.jb!ZU
publicvoid setCurrentPage(int currentPage){ Ya\:C]
this.currentPage = currentPage; e_Hpai<b
} !`?i>k?Q E
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/** 5Z; 5?\g
* @return j]kgdAq>
* Returns the everyPage. Bc }o3oc
*/ [T =>QS@g
publicint getEveryPage(){ NN'pBUR
return everyPage; |\uj(|
} <dP\vLH_
i;C` .+
/** )4B`U(%M~
* @param everyPage zX*5yNd
* The everyPage to set. _`;KmD&5
*/ `dV2\^*A
publicvoid setEveryPage(int everyPage){ Ot-P
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this.everyPage = everyPage; OeASB}
} Oo;]j)z
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/** K\%\p$ZD
* @return j3-o}6
* Returns the hasNextPage. ed',\+.uB
*/ lG'D/#
publicboolean getHasNextPage(){ +`Q]p "G
return hasNextPage; V':A!
} 3GE;:;8B
vb>F)po1}
/** sS
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* @param hasNextPage d)!'5ZrM
* The hasNextPage to set. p1d%&e
*/ SJP3mq/^K
publicvoid setHasNextPage(boolean hasNextPage){ }hg=#*
this.hasNextPage = hasNextPage; myX&Z F_9
} Q >[>{N&\
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/** [XI:Yf
* @return P!f0&W
* Returns the hasPrePage. SzB<PP2
*/ 'J} ?'{.
publicboolean getHasPrePage(){ 0`7yPq*
return hasPrePage; AA^K/y
} 9;6)b0=$
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/** QnS^ G{
* @param hasPrePage ._tEDY/1m
* The hasPrePage to set. 5`fUR/|[
*/ .^9khKJ;
publicvoid setHasPrePage(boolean hasPrePage){ ),`jMd1`
this.hasPrePage = hasPrePage; ,yNuz@^
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} {0F/6GwUC
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/** f4.jWBF
* @return Returns the totalPage. q>'#; QA
* D6@ c|O{Q
*/ pJ8F+`*
publicint getTotalPage(){ v]on0Pi!
return totalPage; .-HM{6J
} };rp25i
_ s}aF
/** NbU4|Oi
* @param totalPage )=}qAVO8
* The totalPage to set. &aIFtlC
*/ }G{"Mp4
publicvoid setTotalPage(int totalPage){ Rq+7&%dy
this.totalPage = totalPage; BV@q@C
} w=_^n]`R
5TpvJ1G
} ,^e2ma|z
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 am? k
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个PageUtil,负责对Page对象进行构造: =PA?6Bm
java代码: t|oIzjKE/
jG&HPVr
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/*Created on 2005-4-14*/ i ?pd|J
package org.flyware.util.page; Dom]w.W5
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import org.apache.commons.logging.Log; 30WOH
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import org.apache.commons.logging.LogFactory; 9teP4H}m
0/]h"5H3
/** D`G; C
* @author Joa :I&y@@UG
* RYvdfj.ij
*/ DRRQ]eK0
publicclass PageUtil { 7{M&9| aK
q M_c-^F
privatestaticfinal Log logger = LogFactory.getLog Jf=V<
#]1jvB
(PageUtil.class); |)>+&
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/** Kh=\YN\E<
* Use the origin page to create a new page {06-h %qr
* @param page L
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* @param totalRecords c0e[vrP:
* @return +`"Tn`O
*/ |) ~-Wy
publicstatic Page createPage(Page page, int >G!=lLyR
HP*{1Q@5
totalRecords){ UZFs]z!,k
return createPage(page.getEveryPage(), AEj%8jh
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page.getCurrentPage(), totalRecords); :D3:`P>,c
}
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/** MkGQ
* the basic page utils not including exception q,7W,<-
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handler .'66]QW
* @param everyPage Tz6I7S-w
* @param currentPage dR=sdqS#J
* @param totalRecords 40
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* @return page _(m455HZ
*/ a3M I+
publicstatic Page createPage(int everyPage, int *iru>F8r:
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currentPage, int totalRecords){ r<(UN@T}
everyPage = getEveryPage(everyPage); (p#c p
currentPage = getCurrentPage(currentPage); &Hf%Va[B
int beginIndex = getBeginIndex(everyPage, $FT6c@&y
_\IA[-C+O
currentPage); $ Lfbt=f
int totalPage = getTotalPage(everyPage, !!ZGNZ_
?1r;6
totalRecords); 8*?H~q~
boolean hasNextPage = hasNextPage(currentPage, &X~8S/nPAw
Xsanc@w)^C
totalPage); &?p(UY7'"
boolean hasPrePage = hasPrePage(currentPage); b-VQn5W
Q~f]?a`
returnnew Page(hasPrePage, hasNextPage, @b 17jmq{
everyPage, totalPage, p)Q5fh0-
currentPage, )Z4iM;4]
$; _{|{Yj
beginIndex); r@i)Sluf
} 0#Us*:[6
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privatestaticint getEveryPage(int everyPage){ i4> M
return everyPage == 0 ? 10 : everyPage; DU,B
} WRbdv{1E
p"6[ S
privatestaticint getCurrentPage(int currentPage){ lBG=jOS
return currentPage == 0 ? 1 : currentPage; xa_ IdkV
} wO!>kc<
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privatestaticint getBeginIndex(int everyPage, int 6*$A/D
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currentPage){ ZB$yEW]]~
return(currentPage - 1) * everyPage; 6IK>v*<
} Z?[R;V1j
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privatestaticint getTotalPage(int everyPage, int
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totalRecords){ 1xkk5\3]
int totalPage = 0; 9+ve0P7$
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if(totalRecords % everyPage == 0) Z{%W!>0
totalPage = totalRecords / everyPage; kda*rl~c
else u#u/uS"
totalPage = totalRecords / everyPage + 1 ; IAb.Z+ig
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return totalPage; o:5mgf7
} p[|V7K'Z
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privatestaticboolean hasPrePage(int currentPage){ kAUL7_>6X
return currentPage == 1 ? false : true; .8'uIA{_2
} 32j#kJ W
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privatestaticboolean hasNextPage(int currentPage, 753gcY#i
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int totalPage){ 07(LLhk@d
return currentPage == totalPage || totalPage == {9P(U\]e]k
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0 ? false : true; uJ1oo| sn
} u@Ni *)p`
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} }(na)B{m
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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。 O]="ggq&
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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 &jnBDr
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做法如下: rnMi
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1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 D}ZPgt#
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的信息,和一个结果集List: BdvpG
java代码: y{P~!Yn|
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/*Created on 2005-6-13*/ !qH)ttW
package com.adt.bo; "K|':3n|
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import java.util.List; :$X dR:f}}
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import org.flyware.util.page.Page; W8]?dL}|
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/** 7<8'7<X
* @author Joa j\BtaC
*/ `X&