Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 k?2k'2dy
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 I4&::y^C
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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 !qX_I db\
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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 i86>]
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分页支持类: V*W;OiE_3
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java代码: H@ t'~ZO
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package com.javaeye.common.util; }<dRj
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import java.util.List; |Pg@M
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publicclass PaginationSupport { 6 ~>FYX
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publicfinalstaticint PAGESIZE = 30; kYLM&&h
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privateint pageSize = PAGESIZE; 9;veuX#(
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privateList items; wQRZ"ri,
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privateint totalCount; >Jp:O
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privateint[] indexes = newint[0]; 8jyG"%WO
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privateint startIndex = 0; QR>gt;
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public PaginationSupport(List items, int
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totalCount){ 6C-z=s)P&
setPageSize(PAGESIZE); Ox@sI:CT
setTotalCount(totalCount); 1bH;!J
setItems(items); JJ%ePgWT
setStartIndex(0); X$yN_7|+
} !H ~<
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public PaginationSupport(List items, int &8z[`JW,T
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totalCount, int startIndex){ / 4lvP
setPageSize(PAGESIZE); gH G
setTotalCount(totalCount); NOp609\^
setItems(items); ,u/aT5\_
setStartIndex(startIndex); xKFn.qFr
} 7PkJ-JBA
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public PaginationSupport(List items, int yR4|S2D3xn
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totalCount, int pageSize, int startIndex){ lv]hTH 4T
setPageSize(pageSize); Op_RzZP`
setTotalCount(totalCount); ^.>jGI%rB
setItems(items); (7 r<''
setStartIndex(startIndex); &-mX ,
} IV)<5'v
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publicList getItems(){ lIProF0
return items; Jej` ;I
} _vZ"4L+Iw+
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publicvoid setItems(List items){ >$ e9igwe
this.items = items; C?2'+K
} 'z$Q rFW
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publicint getPageSize(){ bP^Je&nS*
return pageSize; ,13Lq-
} R%'^ gFk8
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publicvoid setPageSize(int pageSize){ A$w4PVS
this.pageSize = pageSize; 3}/&w\$
} Yc'kvj)_M
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publicint getTotalCount(){ 8)4P Ll
return totalCount; o";Z$tAJkC
} zF`c8Tsx])
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publicvoid setTotalCount(int totalCount){ rp0ZvEX
if(totalCount > 0){ d`F&aC
this.totalCount = totalCount; 4!LCR}K
int count = totalCount / 7R\oj8[
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pageSize; IEzaK
if(totalCount % pageSize > 0) AU$Uxwz4
count++; _~T!9
indexes = newint[count]; 1u6^z
for(int i = 0; i < count; i++){ =|YxDas
indexes = pageSize * D`VM6/iQR
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i; PZ*pQ=`
} %Jrt4sg[j-
}else{ Mv6-|O
this.totalCount = 0; dS<C@(
} $t6e2=7
} iySRY^
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publicint[] getIndexes(){ YxP@!U9dE,
return indexes; <NuUW9+
} `YIf_a{
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publicvoid setIndexes(int[] indexes){ 48*Do}l]
this.indexes = indexes; u6bXv(
} Yx>"bv
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publicint getStartIndex(){ afb+GA!
return startIndex; Q
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} a$Cdhx!
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publicvoid setStartIndex(int startIndex){ q@xBJ[IM
if(totalCount <= 0) HdPoO;
this.startIndex = 0; 0JJS2oY/
elseif(startIndex >= totalCount) 1Q.\s_2
this.startIndex = indexes XGkkB
cwL1/DGDB
[indexes.length - 1]; !ki.t
elseif(startIndex < 0) %C=]1Q=T)
this.startIndex = 0; |e2be1LD
else{ [NTtz
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this.startIndex = indexes :P(K2q3
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[startIndex / pageSize]; 4`8<
} r!{LLc}>
} hc'-Dh
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publicint getNextIndex(){ 1M}&Z H
int nextIndex = getStartIndex() + Y>&Ew*Y
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pageSize; (1NA
if(nextIndex >= totalCount) _X'"w|0
return getStartIndex(); PfZ+PqS
else ?:L:EW8
return nextIndex; hjQ~uqbg
} I*`* Q$
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publicint getPreviousIndex(){ dH^ <t,v
int previousIndex = getStartIndex() - V.{H9n]IO
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pageSize; xQ'2BAEa
if(previousIndex < 0) \l@,B +)
return0; xu'yVt9RC
else $]rj73p^tH
return previousIndex; s$a09x
} iIP8`!
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} 6}KZp~s
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抽象业务类 uSR~@Lj ~
java代码: NoJ`6MB
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/** Q(\4]i< S
* Created on 2005-7-12 IEcf
*/ edK|NOOZ
package com.javaeye.common.business; e~"fn*"
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import java.io.Serializable; H/"lAXfb
import java.util.List; v%RP0%%{s
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import org.hibernate.Criteria; kn/Ao}J74z
import org.hibernate.HibernateException; YXI'gn2b#
import org.hibernate.Session; l3IWoa&sh
import org.hibernate.criterion.DetachedCriteria; Y!T
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import org.hibernate.criterion.Projections; }YHX-e<Yx]
import lbuAE%
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org.springframework.orm.hibernate3.HibernateCallback; DK
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import E.U_W
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org.springframework.orm.hibernate3.support.HibernateDaoS Tr#V*.x
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upport; 3ux0Jr2yT
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import com.javaeye.common.util.PaginationSupport; .YZgOJi
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public abstract class AbstractManager extends R+7oRXsu
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HibernateDaoSupport { 2 6>ZW4Z
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privateboolean cacheQueries = false; ''kS*3
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privateString queryCacheRegion; o^V(U~m]
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publicvoid setCacheQueries(boolean "hQ_sgz[Z
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cacheQueries){ f
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this.cacheQueries = cacheQueries; JXj8Br?Z@
} <u=4*:QE
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publicvoid setQueryCacheRegion(String >pr=|$zk=
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queryCacheRegion){ X~xd/M=9^
this.queryCacheRegion = Jx=hJ-FY
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queryCacheRegion; X7g3
} L-9~uM3@\
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publicvoid save(finalObject entity){ E.iSWAJ(w
getHibernateTemplate().save(entity); 2>l,no39t+
} ZoB{x*IH
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publicvoid persist(finalObject entity){ NzW`B^p
getHibernateTemplate().save(entity); NxLXm,
} :(_+7N[KA
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publicvoid update(finalObject entity){ 4Ua>Yw0
getHibernateTemplate().update(entity); 1lpwZ"
} ehA;i.n
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publicvoid delete(finalObject entity){ y8\S}E0
getHibernateTemplate().delete(entity); @EoZI~
} )aX2jSp
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publicObject load(finalClass entity, k'PQ}
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finalSerializable id){ Zx$ol;Yd
return getHibernateTemplate().load W#Qmv^StZ
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(entity, id); 5p
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} 4&cL[Ny
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publicObject get(finalClass entity, ;2m<CSv!D
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finalSerializable id){
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return getHibernateTemplate().get Mzd[fR5a8
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(entity, id); 4R8G&8b
} zW8*E E+,
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publicList findAll(finalClass entity){ v0 Ir#B,[H
return getHibernateTemplate().find("from ]p!Gt,rYq
dr<<! q /
" + entity.getName()); i7LJ&g/)
} cUO<.
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publicList findByNamedQuery(finalString hwqbi "o
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namedQuery){ -ti{6:H8
return getHibernateTemplate .6~`Ubr}E
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().findByNamedQuery(namedQuery); 1w"8~Z:UXV
} g`>og^7g
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publicList findByNamedQuery(finalString query, vEG'HOP
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finalObject parameter){ bOI3^T
return getHibernateTemplate J/A[45OD
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().findByNamedQuery(query, parameter); jn.C|9/mj
} @d&/?^dp6
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publicList findByNamedQuery(finalString query, z* <y5
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finalObject[] parameters){ Yif*"oO
return getHibernateTemplate :h,`8 Di
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().findByNamedQuery(query, parameters); ]Zf6Yw .Y
} mNYl@+:psj
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publicList find(finalString query){ \x>65;
return getHibernateTemplate().find QjPj[c
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(query); u? fTL2~
} #?B%Ja%
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publicList find(finalString query, finalObject u
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parameter){ (.3'=n|kE
return getHibernateTemplate().find 3^=+gsc
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(query, parameter); l?*r5[O>n
} nIfCF,6,
9PUes3"v
public PaginationSupport findPageByCriteria :!zC"d9@
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(final DetachedCriteria detachedCriteria){ m?[5J)eR
return findPageByCriteria z{]?h cY
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 5f:DN\ ]
} XUV!C7
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public PaginationSupport findPageByCriteria uENdI2EY8y
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(final DetachedCriteria detachedCriteria, finalint =22ALlxk
R \s!*)
startIndex){ nF)uTk
return findPageByCriteria [XlB<P=|>
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(detachedCriteria, PaginationSupport.PAGESIZE, 0F;,O3Q
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startIndex); #:ns64|
} G"y.Z2$
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public PaginationSupport findPageByCriteria Dmdy=&G
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(final DetachedCriteria detachedCriteria, finalint f*xpE`&
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pageSize, kVDe6},D7
finalint startIndex){ %|XE#hw
return(PaginationSupport) Rn+4DcR
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getHibernateTemplate().execute(new HibernateCallback(){ ~=y3Gd
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publicObject doInHibernate !#? kWAU
}lZ>
(Session session)throws HibernateException { 8rbG*6
Criteria criteria = ;Pb8YvG1$
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detachedCriteria.getExecutableCriteria(session); {b!7
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int totalCount = qS8B##x+=
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((Integer) criteria.setProjection(Projections.rowCount 8)0L2KL'
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()).uniqueResult()).intValue(); +'03>!V
criteria.setProjection K6pR8z*?
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(null); :wgfW .w
List items = -g`IH-B
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criteria.setFirstResult(startIndex).setMaxResults v@u<Ww;=@
O%1/r*
(pageSize).list(); mgkyC5)d
PaginationSupport ps = pvXcLR)L+3
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new PaginationSupport(items, totalCount, pageSize, }C(5 -7
3#.\
startIndex); M1u{A^d.Z
return ps; W."f8ow
} -)w]a{F
}, true); d34Y'r
} @Z\~
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public List findAllByCriteria(final H}b\`N[nr
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DetachedCriteria detachedCriteria){ IjZ@U%g@;
return(List) getHibernateTemplate !Ua&0s%
t<b 3K-
().execute(new HibernateCallback(){ ?~2Bi^W5
publicObject doInHibernate !0fI"3P@r
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(Session session)throws HibernateException { h[=nx^
Criteria criteria = 6f]r Q9
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detachedCriteria.getExecutableCriteria(session); FrZ]=:
return criteria.list(); p#H]\P'
} v$$]Gv(
}, true); m@oUvxcd
} ; Zq/eiB
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public int getCountByCriteria(final 5()Fvae{k
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DetachedCriteria detachedCriteria){ MEU[%hty_
Integer count = (Integer) J_ V,XO
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getHibernateTemplate().execute(new HibernateCallback(){ +Z+ExS<#z
publicObject doInHibernate Fh`-(,e?5
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(Session session)throws HibernateException { ')nnWlK
Criteria criteria = ^Rmoz1d
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detachedCriteria.getExecutableCriteria(session); 4 iH&:Al
return |NEd@
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criteria.setProjection(Projections.rowCount 6GKT yN
J E)J<9gf
()).uniqueResult(); u7muaSy
} `-D$Fsl
}, true); }aZrou3E
return count.intValue(); sb'p-Mj
} _pSIJ3O
} FDq{M?6i
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用户在web层构造查询条件detachedCriteria,和可选的 qeMv
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 p\+6"28{_~
pF='jj51
PaginationSupport的实例ps。 @"8~Y|L93
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ps.getItems()得到已分页好的结果集 t F/nah
ps.getIndexes()得到分页索引的数组 .&(8(C
ps.getTotalCount()得到总结果数 4e/cqN6
ps.getStartIndex()当前分页索引 sV'v*
1|
ps.getNextIndex()下一页索引 |#cAsf_{
ps.getPreviousIndex()上一页索引 9cOx@c+/
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 qvTKfIl{
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 6!RikEAh
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一下代码重构了。 ,cS0
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我把原本我的做法也提供出来供大家讨论吧: &(0N.=R
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首先,为了实现分页查询,我封装了一个Page类: _3U|2(E
java代码: l4Y1(
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/*Created on 2005-4-14*/ 2H>aC
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package org.flyware.util.page; H%~Q?4
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/** U6a zhi&,
* @author Joa !5E9sk{)
* *2#FRA#q
*/ P#F_>GB
publicclass Page { q]+)c2M
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/** imply if the page has previous page */ S[.5n]
privateboolean hasPrePage; TnxU/)
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/** imply if the page has next page */ .h!9wGi`
privateboolean hasNextPage; r?afv.@L2
^#7viZ*
/** the number of every page */ uOb2npPj
privateint everyPage; )BB%4=u@~.
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/** the total page number */ 4[xA-
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privateint totalPage; EaCZx
cb4b,Ri
/** the number of current page */ @92gb$xT
privateint currentPage; uc\.oG;~q
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/** the begin index of the records by the current s79q5
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query */ Q~h6J*
privateint beginIndex; QglYU
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/** The default constructor */ XX:q|?6_ 4
public Page(){ V-:`+&S{^
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} Gzj3Ka
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/** construct the page by everyPage Jtpa@!M
* @param everyPage \ bC}&Iz6
* */ RAdvIIQp:
public Page(int everyPage){ T[m ~6
this.everyPage = everyPage; Q{8qm<0g
} SUo^c1)G
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/** The whole constructor */ GtG&yeB
public Page(boolean hasPrePage, boolean hasNextPage,
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v=j>^FZ
G u6[{u
int everyPage, int totalPage, o;*]1
int currentPage, int beginIndex){ %OuX`w=
this.hasPrePage = hasPrePage; )2#vhMpdN
this.hasNextPage = hasNextPage; nxD'r
this.everyPage = everyPage; tb:
this.totalPage = totalPage; _,t&C7Yf;
this.currentPage = currentPage; BjwMb&a;
this.beginIndex = beginIndex; v)%[
} /5jKX 5r
exsQmbj* %
/** vs+We*8H
* @return 8~}s 3j4
* Returns the beginIndex. 9y;y7i{>?
*/ xp~YIeSg
publicint getBeginIndex(){ 8IpxOA#jQ
return beginIndex; HKM~BL
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} +tPx0>p;
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/** OA!R5sOz"
* @param beginIndex vP-3j
* The beginIndex to set. VPdwSW[eM
*/ @pTD{OW?
publicvoid setBeginIndex(int beginIndex){ SHytyd
this.beginIndex = beginIndex; Q
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} U2VV[e)Z!
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/** _w\Y{(k
* @return q"P5,:W
* Returns the currentPage. _s2m-jm7
*/ {(_B
publicint getCurrentPage(){ H\ {E%7^h-
return currentPage; ~:2&/MOP?
} C{DlcZ<
9e0C3+)CY
/** .@fK;/OuC
* @param currentPage Nvi Fq
* The currentPage to set. _E3U.mV
*/ <>SR 4
publicvoid setCurrentPage(int currentPage){ Zlr{L]c
this.currentPage = currentPage; Sb'N];
} U LV)0SB
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/** \I'f3
* @return +SAk:3.#CV
* Returns the everyPage. ~*jsB=XM/
*/ @gH(/pFX
publicint getEveryPage(){ >6*(}L9
return everyPage; Y>xi|TWN
} nXv 7OEpTx
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/** lv=yz\
* @param everyPage e 4 p*51ra
* The everyPage to set. I/oIcQS!k
*/ ~8XX3+]z:X
publicvoid setEveryPage(int everyPage){ hN Z4v/
this.everyPage = everyPage; vsu@PuqH
} x%_qJ]o
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/** 9Q,Msl4n
* @return ^fFtI?.6jI
* Returns the hasNextPage. R)sp
*/ 3Ne9%"
publicboolean getHasNextPage(){ V"w`!
return hasNextPage; -iY9GN89c
} aQ32p4C
- 3C* P
/** muL>g_H
* @param hasNextPage LvSP #$f
* The hasNextPage to set. EC^Ev|PB\u
*/ b24NL'jm
publicvoid setHasNextPage(boolean hasNextPage){ .jvSAV5B
this.hasNextPage = hasNextPage; 3'?h;`v\Lo
} om XBnzT
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/** 6T R8D\
* @return 83{x"G3>
* Returns the hasPrePage. 'LJ %.DJ
*/ qf_hb
publicboolean getHasPrePage(){ +io;K]C
return hasPrePage;
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} V}vl2o
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/** &&]"Y!r -
* @param hasPrePage :5TXA
* The hasPrePage to set. "[%;B0J
*/
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publicvoid setHasPrePage(boolean hasPrePage){ Kj~>&WU
this.hasPrePage = hasPrePage; *,O
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} @4G.(zW
}}kS~
w-#
/** a)I=U[
* @return Returns the totalPage. `ENlV9
* 7V9%)%=h|
*/ nu\
publicint getTotalPage(){ o|rGy5
return totalPage; O\|C,Epm
} XV74Fl
s[0prm5.
/** G ;PbTsW
* @param totalPage I}*]m%'-Y
* The totalPage to set. Ma`
*/ aHBByH
publicvoid setTotalPage(int totalPage){ }V1DyLg:
this.totalPage = totalPage; >XD02A[
} 3EbnZb
[(D}%+2
} NZfo`iHAN
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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 U6/m_`nc
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个PageUtil,负责对Page对象进行构造: jw`&Np2Q
java代码: pl
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/*Created on 2005-4-14*/ A^T~@AO
package org.flyware.util.page; SX_kr^#
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import org.apache.commons.logging.Log; +t7c&td\
import org.apache.commons.logging.LogFactory; n.Ur-ot
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/** D{,[\^c
* @author Joa *@\?}cX
* XPc9z}/(e
*/ Z4wrXss~
publicclass PageUtil { p%1xj2 ?nN
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privatestaticfinal Log logger = LogFactory.getLog F8|5_214'
1+16i=BF)
(PageUtil.class); 6T{o3wc;
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/** )rs|=M=Xk
* Use the origin page to create a new page dVj'
* @param page ;JPbBwm
* @param totalRecords Vz7w{HY
* @return =`7#^7Q9
*/ J{GFb
publicstatic Page createPage(Page page, int Ovl?j&8
)$gsU@H -
totalRecords){ +(I`@5
return createPage(page.getEveryPage(), giPhW>
D]G'R5H
page.getCurrentPage(), totalRecords); DWm;&RPJ
} Pv{,aV\I}
Z?.p%*>`T=
/** *6sJ*lh
* the basic page utils not including exception ch)Ps2i
Qq;m"M /
handler :oon}_MdRd
* @param everyPage M0;t%*1
* @param currentPage q/rHHuY}
* @param totalRecords # o;CmB
* @return page 8ACYuN\
*/ HdY3DdC%q
publicstatic Page createPage(int everyPage, int !SO$k%b}!
j &0fC!k
currentPage, int totalRecords){ 9d,]_l.sB
everyPage = getEveryPage(everyPage); m>Z\
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currentPage = getCurrentPage(currentPage); Ul$X%
int beginIndex = getBeginIndex(everyPage, =}%#$
pb/{ss+
currentPage); LAK-!!0X
int totalPage = getTotalPage(everyPage, @??c<]9F
}0Kqy;
totalRecords); },n,P&M\`
boolean hasNextPage = hasNextPage(currentPage, ard3yNQt
'n>3`1E,
totalPage); "dLMBY~
boolean hasPrePage = hasPrePage(currentPage); lkSz7dr@
(8@hF#N1
returnnew Page(hasPrePage, hasNextPage, :ET3&J
L
everyPage, totalPage, MoKXl?B<
currentPage, Oc"'ay(g
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beginIndex); [o[v"e\w
} <mo^Y k3
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privatestaticint getEveryPage(int everyPage){ >jrz;r
return everyPage == 0 ? 10 : everyPage; Vhbj.eX.)
} 11@2 ;vw
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privatestaticint getCurrentPage(int currentPage){ $D,
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return currentPage == 0 ? 1 : currentPage; FkxhEat8
} TReM8Vd
Z_^Kl76D
privatestaticint getBeginIndex(int everyPage, int Mc$v~|i6
\MFWK#W
currentPage){ ,Zcx3C:#
return(currentPage - 1) * everyPage; tXG4A$(2&
} ~Q$c!=
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privatestaticint getTotalPage(int everyPage, int :AqnWy
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totalRecords){ .X<"pd*@e
int totalPage = 0; 1n"+~N^\
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if(totalRecords % everyPage == 0) "13
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totalPage = totalRecords / everyPage; s:jL/%+COZ
else ;FgEE%
totalPage = totalRecords / everyPage + 1 ; [Tb3z:UUvf
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return totalPage; N5w]2xz!
} )q]j?Z.
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privatestaticboolean hasPrePage(int currentPage){ G|PIH#
return currentPage == 1 ? false : true; J,^pt Ql
} K3r>nGLBo
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privatestaticboolean hasNextPage(int currentPage, H:{(CY?t
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int totalPage){ G$x["
return currentPage == totalPage || totalPage == 4}_w4@(
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0 ? false : true; xU\:Vid+A
} 1O3<%T#LOZ
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} AZ]SRz9mKY
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 Jm J,~_
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 /hEGk~
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做法如下: H;7H6fyZ
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 c"sw@<HG
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的信息,和一个结果集List: Dgq[g_+l
java代码: -_4jJxh=OB
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/*Created on 2005-6-13*/ Y'a(J 7
package com.adt.bo; O*n%2Mam
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import java.util.List; X8l1xD
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i
import org.flyware.util.page.Page; f?<M3P
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/** CL}I:/zRB
* @author Joa n$![b_)*
*/ DwrCysIK
publicclass Result { ?e_}X3{
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private Page page; WlLZtgq
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private List content; 36Z`.E>~L
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/** AO 7qs:+
* The default constructor cSs/XJZ
*/ 0!'M#'m
public Result(){ 7/OOq=z
super(); 3]]6z K^i
} UUEDCtF)
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/** 6exlb:
* The constructor using fields -K'84 bZ
* p*&LEjaVM4
* @param page :ktX7p~
* @param content !/(}meZj
*/ TtjSLkF
public Result(Page page, List content){ eWk2YP!
this.page = page; zt?w n*_
this.content = content; o-CJdOS
} j83Y'VJJC
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/** A`/7>'k/q[
* @return Returns the content. \w_[tPz}
*/ >E,L"&_j
publicList getContent(){ BHE =Zo
return content; np>!lF:
} _C8LK.M#j
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/** J&Qy