Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 m'M5O@?
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 8#[2]1X^8
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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 6}~k4;'}A
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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 5 Pf)&iG
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分页支持类: 5F!i%{XQvm
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java代码: }2S)CL=
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package com.javaeye.common.util; p+0gE5
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import java.util.List; Jp|eKZ
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publicclass PaginationSupport { E)wf'x
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publicfinalstaticint PAGESIZE = 30; e,d}4 jy
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privateint pageSize = PAGESIZE; :yTr:FoF
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privateList items; %gWQ}QF
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privateint totalCount; <~aKwSF[wW
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privateint[] indexes = newint[0]; 1 ^30]2'_
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privateint startIndex = 0; s3 fQGbU
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public PaginationSupport(List items, int N1$PW~)Y
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totalCount){ Zrj#4E1
setPageSize(PAGESIZE); *!E~4z=
setTotalCount(totalCount); %m
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setItems(items); bdfs'udt9
setStartIndex(0); 0g HV(L?
} CD5% iFy
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public PaginationSupport(List items, int \En"=)A
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totalCount, int startIndex){ [rW];H8:~
setPageSize(PAGESIZE); x-W~&`UU
setTotalCount(totalCount); j"fx|6l)
setItems(items); Lf%=vd
setStartIndex(startIndex); dp&G([
} HXC\``E
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public PaginationSupport(List items, int TY5R=jh=
*e<}hmDr
totalCount, int pageSize, int startIndex){ Uq`6VpZ
setPageSize(pageSize); _+Sf+ta
setTotalCount(totalCount); o^Lq8u;i*
setItems(items); )y i~p
setStartIndex(startIndex); LbYIRX
} G!wb|-4<$
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publicList getItems(){ `)4v Q+A>
return items; lrL:G[rt
} Dr[;\/|#
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publicvoid setItems(List items){ 5#s],h
this.items = items; Ab>Kf r#
} ]mz '(t
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publicint getPageSize(){ /y|ZAN
return pageSize; 2`j{n\/
} A{M7
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publicvoid setPageSize(int pageSize){ :U=3*f.{
this.pageSize = pageSize; )WW*X6[k
} R
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publicint getTotalCount(){ <mj/P|P@
return totalCount; lpS v
} U OGjil{.
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publicvoid setTotalCount(int totalCount){ vLBuE
if(totalCount > 0){
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this.totalCount = totalCount; ;#S]mso1
int count = totalCount / /xcXd+k]
t;/uRN*.
pageSize; <m\<yZ2aa
if(totalCount % pageSize > 0) mBb3Ta
count++; nRu %0Op
indexes = newint[count]; ~WORC\kCW
for(int i = 0; i < count; i++){ AzSu_
indexes = pageSize * IG{Me
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i; G-|c%g!ejf
} *uf)t,%
}else{ 4;3Vc%
this.totalCount = 0; GB<.kOGQ[
} { Ie~MW
} S'W,AkT
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publicint[] getIndexes(){ aXG|IN5 *m
return indexes; HV-;?5
} "Da-e\yA
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publicvoid setIndexes(int[] indexes){ Pk;yn;
this.indexes = indexes; 7U1M;@y
} J/E''*
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publicint getStartIndex(){ pL}
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return startIndex; g|->W]q@;
} 8y
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publicvoid setStartIndex(int startIndex){ 9S[.ESI{>
if(totalCount <= 0) a5saN5)H
this.startIndex = 0; {dh,sbl
elseif(startIndex >= totalCount) H&%oHyK
this.startIndex = indexes TwVkI<e0s?
e`H>}O/ai
[indexes.length - 1]; O[eU{;P
elseif(startIndex < 0) X}i2 qv
this.startIndex = 0; US3)+6
else{ 9I2&Vx=DSt
this.startIndex = indexes 0#Pa;(
],[<^=|
[startIndex / pageSize]; SZLugyZ2Y
} m@+QC$6S
} @: =vK?8L
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publicint getNextIndex(){ 27+faR
int nextIndex = getStartIndex() + 7l/lY-zO
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pageSize; kksffzG
if(nextIndex >= totalCount) Ejr'Yzl3_
return getStartIndex(); /kK!xe
else q~5zv4NX
return nextIndex; | 4}Y:d
} %4F\#" A
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publicint getPreviousIndex(){ hmOGteAf-
int previousIndex = getStartIndex() - J Eo;Fx]
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pageSize; 4 qY
if(previousIndex < 0) !G\gqkSL
return0; zLJmHb{(
else 00f'G2n
return previousIndex; .5!`wwVi
} ]s^+/8d=
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} (ER9.k2
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抽象业务类 @_$$'XA7
java代码: IHi[3xf<
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/** X$1YvYsID
* Created on 2005-7-12 J?X{NARt
*/ fe`_0lxj
package com.javaeye.common.business; _[rQt8zn
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import java.io.Serializable; j$XaO%y)
import java.util.List; v=hn# U
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import org.hibernate.Criteria; _h \L6.
import org.hibernate.HibernateException; [kqtkgK$j2
import org.hibernate.Session; [q3zs_nz
import org.hibernate.criterion.DetachedCriteria; $RRX-
import org.hibernate.criterion.Projections; }N(gP_?n
import RPf <-J:t
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org.springframework.orm.hibernate3.HibernateCallback; Qc?W;Q+
import yvzH}$!]
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org.springframework.orm.hibernate3.support.HibernateDaoS ^VG].6
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upport; EmrkaV-?k
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import com.javaeye.common.util.PaginationSupport; W^xO/xu1/
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public abstract class AbstractManager extends 7}~w9jK"F
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HibernateDaoSupport { ::#[lw
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privateboolean cacheQueries = false; .;Gx.}ITG6
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privateString queryCacheRegion; 0asP,)i
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publicvoid setCacheQueries(boolean 3(t,x
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cacheQueries){ jVN06,3z
this.cacheQueries = cacheQueries; NQ[X=a8N
} ty#6%
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publicvoid setQueryCacheRegion(String YZ8[h`z
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queryCacheRegion){ BgUp~zdo
this.queryCacheRegion = z_R^C%0k
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queryCacheRegion; [:gg3Qzx
} *P7/ry^<F
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publicvoid save(finalObject entity){ $H)!h^7^9
getHibernateTemplate().save(entity); )$i,e`T
} +"BJjxG
N *$GP3]
publicvoid persist(finalObject entity){ .uS`RS8JM
getHibernateTemplate().save(entity); uI?Z_
} sU*?H`U3d
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publicvoid update(finalObject entity){ 4TPdq&';C:
getHibernateTemplate().update(entity); Op]*wwI*h
} m>P\}A^N
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publicvoid delete(finalObject entity){ uHZ4
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getHibernateTemplate().delete(entity); 6.KEe^[-
} ]
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publicObject load(finalClass entity, P/1YN
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finalSerializable id){ B'(zhjV
return getHibernateTemplate().load hI*v)c
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(entity, id); ;Bz|hB{
} R?:Q=7K
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publicObject get(finalClass entity, (2>q
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finalSerializable id){ ~!PWJ~U
return getHibernateTemplate().get ,'`yh|}G\
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(entity, id); B?-w<":!
} F$
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publicList findAll(finalClass entity){ k]r4b`x`
return getHibernateTemplate().find("from .0xk},
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" + entity.getName()); `4xQ#K.-
} e<1Ewml(]
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publicList findByNamedQuery(finalString GeY!f/yQ<
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namedQuery){ PcT]
return getHibernateTemplate `f&::>5tD
a*X{hU9P
().findByNamedQuery(namedQuery); =0EKrG
} O9By5j 4
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publicList findByNamedQuery(finalString query, SZr c-f_
^ }5KM87
finalObject parameter){ [s]$&
return getHibernateTemplate :fL7"\
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().findByNamedQuery(query, parameter); 1irSI,j%z
} ]nRf%Vi8g
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publicList findByNamedQuery(finalString query, 5,^DT15a4P
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finalObject[] parameters){ A_U=`M=-
return getHibernateTemplate 59j`Z^e
{p/Yz#
().findByNamedQuery(query, parameters); ><"|>(y
} D-C]0Jf3
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publicList find(finalString query){ )b]wpEFl
return getHibernateTemplate().find =,N"% }
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(query); sBI/`dGZV
} \7qj hA@
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publicList find(finalString query, finalObject +3zQ"lLD^
*@#Gc%mGu
parameter){ N]iarYc
return getHibernateTemplate().find ETU-6qFtO
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(query, parameter); !=,zy
} ] WYub1
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public PaginationSupport findPageByCriteria t~K[`=G\ex
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(final DetachedCriteria detachedCriteria){ 'do2n/
return findPageByCriteria Uq'W<.v5
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 3zKeN:w
} 6U8esPs,
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public PaginationSupport findPageByCriteria k -R"e
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(final DetachedCriteria detachedCriteria, finalint 1U/9=b
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startIndex){ "wZvr}xk
return findPageByCriteria rWNe&gFM
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(detachedCriteria, PaginationSupport.PAGESIZE, )O+Zbn
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startIndex); ZoJqJWsd
} %$ o[,13=
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public PaginationSupport findPageByCriteria )_j(NX-C:
7z3tDE[#
(final DetachedCriteria detachedCriteria, finalint fCY??su*
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pageSize, 3p HI+a
finalint startIndex){ WO%pX+PoH
return(PaginationSupport) d\3 %5Y
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getHibernateTemplate().execute(new HibernateCallback(){ 2Uf/'
publicObject doInHibernate G/3T0d+-
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(Session session)throws HibernateException { zTMLE~w
Criteria criteria = &Lzd*}7
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detachedCriteria.getExecutableCriteria(session); =BR+J9
int totalCount = ,!^c`_Q\>@
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((Integer) criteria.setProjection(Projections.rowCount i qxMTH#!
1|G\&T
()).uniqueResult()).intValue(); nJv=kk1|o
criteria.setProjection T<Y*();Zo
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(null); Sw>>]UjU
List items = rt*>)GI]b
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criteria.setFirstResult(startIndex).setMaxResults b1'849i'y=
+UziO#D
(pageSize).list(); _0^>^he
PaginationSupport ps = `q^qe> '
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new PaginationSupport(items, totalCount, pageSize, k&5T-\ q
)n9,?F#l
startIndex); K^"l.V#J
return ps; (
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} kFkI[WKyZ
}, true); havmhS)O
} G{X7;j e
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public List findAllByCriteria(final eF7I5k4
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DetachedCriteria detachedCriteria){ 5/U{b5
return(List) getHibernateTemplate [8Z#HjhQ
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().execute(new HibernateCallback(){ ^K J#dT
publicObject doInHibernate +C7W2!I[G2
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(Session session)throws HibernateException { sb_/FE5e
Criteria criteria = cg]Gt1SU
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detachedCriteria.getExecutableCriteria(session); ydY(*]
return criteria.list(); rrgOp5aV"
} fXnewPr=#
}, true); ps` j>vX*
} :,qvqh][
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public int getCountByCriteria(final 4|cRYZj5
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DetachedCriteria detachedCriteria){ FaWc:GsfB
Integer count = (Integer) znWB.H
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getHibernateTemplate().execute(new HibernateCallback(){ PvW4%A@0
publicObject doInHibernate +CSv@ />3
)+,h}XqlX
(Session session)throws HibernateException { $f+I#uJ
Criteria criteria = +zDRed_]=_
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detachedCriteria.getExecutableCriteria(session); DS@Yto
return RTg\c[=w
"|&3z/AUh
criteria.setProjection(Projections.rowCount oXk6,b"
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Tx
()).uniqueResult(); v/~&n
} 8[AU`F8W
}, true); An?#B4:
return count.intValue(); S"^'ksL\
} jd5kkX8=
} sieC7raO
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hRB?NM
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用户在web层构造查询条件detachedCriteria,和可选的 f9y+-GhaD
9 2D~trn
startIndex,调用业务bean的相应findByCriteria方法,返回一个 jbT{K|d-
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PaginationSupport的实例ps。 $7Z-Nn38
6#jql
ps.getItems()得到已分页好的结果集 %B1TN#KoT
ps.getIndexes()得到分页索引的数组 mv,a>Cvs[
ps.getTotalCount()得到总结果数 T <k;^iqR
ps.getStartIndex()当前分页索引 D-i, C~W
ps.getNextIndex()下一页索引 6'uCwAQU
ps.getPreviousIndex()上一页索引 aYc<C$:NC"
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Q3bU"f
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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 (OwGp3g
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一下代码重构了。 1!U:M8T|
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我把原本我的做法也提供出来供大家讨论吧: b9T6JS j
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首先,为了实现分页查询,我封装了一个Page类: {w"Cr0F,
java代码: }$uwAevP{y
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/*Created on 2005-4-14*/ Vom,^`}
package org.flyware.util.page; VhMVoW
#
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/** \3K7)o^
* @author Joa GA[bo)"
* c3#eL
*/ H{9P=l
publicclass Page { [wQJVYv
Z1$U[Tsd
/** imply if the page has previous page */ 8D? $@!-
privateboolean hasPrePage; ~FXq%-J
7\nXJ381
/** imply if the page has next page */ S&[9Vb
privateboolean hasNextPage; glROT@
ij3W8i9'
/** the number of every page */ 8*B+@`
privateint everyPage; |tLD^`bt
3q@JhB
/** the total page number */ (ToD
u@p
privateint totalPage; ]WcN6|b+
w0H#M)c
/** the number of current page */ :1bDkoK
privateint currentPage; (@^ySiU
H;tE=
/** the begin index of the records by the current (w(k*b/
AkO);4A;Jd
query */ :Zob"*T
privateint beginIndex; 6<5:m:KE
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/** The default constructor */ G7-k ,P^
public Page(){ ,BGUIu6
PVljb=8F
} 8)"lCIf
W| 0))5a
/** construct the page by everyPage 2cGiE{
* @param everyPage bNm]h.
* */ >O~V#1 H
public Page(int everyPage){ Y2dml!QM
this.everyPage = everyPage; <|82)hO
} ,jw`9a
*O[/-
p&7
/** The whole constructor */ Zvfy%k
public Page(boolean hasPrePage, boolean hasNextPage, O%F*i2I:+k
ouFKqRs;
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int everyPage, int totalPage, R4k+.hR
int currentPage, int beginIndex){ [)0^*A2
this.hasPrePage = hasPrePage; 2@ZRz%(Oa&
this.hasNextPage = hasNextPage; 4Xt`L"f
this.everyPage = everyPage; q.@% H}
this.totalPage = totalPage; oj'YDQ^uj
this.currentPage = currentPage; O?A%
this.beginIndex = beginIndex; ^si[L52BZ
} !V/7q'&t=
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/** w5/6+@}
* @return s6_i>
* Returns the beginIndex. b9-3
*/ Y}Y~?kE>M|
publicint getBeginIndex(){ L?&&4%%
return beginIndex; S}]B |Q
} Bx$?*y&f!v
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/** mV4gw'.;7
* @param beginIndex YH^@8
* The beginIndex to set. KQw>6)
*/ S0r+Y0J]<
publicvoid setBeginIndex(int beginIndex){ g:G5'pZf
this.beginIndex = beginIndex; +bJ~S:[
} #,XZ @u+
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/** (FgX9SV]p9
* @return MpJ<. |h
* Returns the currentPage. q6>}
*/ }? c%L8\
publicint getCurrentPage(){ =]pEvj9o
return currentPage; =9^}>u
} QF*cdc<
e#3RT8u#
/** Acd@BL*
* @param currentPage )ZrB-(u~k
* The currentPage to set. p
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*/ fy|I3
publicvoid setCurrentPage(int currentPage){ m@w469&<(q
this.currentPage = currentPage; C|3cQ{
} DVKb`KJ"
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/** T,vh=UF%]
* @return Q|S>C%4?
* Returns the everyPage. BS?$eai@:9
*/ bz~aj}"`
publicint getEveryPage(){ [/ertB
return everyPage; y}|E)
} IXm[c@5l
$%
gz ,{
/** . n)R@&9
* @param everyPage ue'dI
* The everyPage to set. Z'}%Mkm`i}
*/ ozl!vf# kv
publicvoid setEveryPage(int everyPage){ +o"CMI
this.everyPage = everyPage; R(cg`8
} .c__T{<)[
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/** S'NLj(
* @return p0]\QM l1
* Returns the hasNextPage. :)tsz;
*/ V
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publicboolean getHasNextPage(){ |GsMLY:0
return hasNextPage; Wv;,@xTZ
} ?.lo[X<,*
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/** zpeCT3Q5O
* @param hasNextPage d~h;|Bl[
* The hasNextPage to set. u=vBjaN2_w
*/ gG}H5uN
publicvoid setHasNextPage(boolean hasNextPage){ M7 kWJ
this.hasNextPage = hasNextPage; a)Pr&9I
} ;Bzx}7A
*rHz/& ,
/** _9p79S<+
* @return d"Wuu1tEY
* Returns the hasPrePage. NuUiW*|`7
*/ z1^fG)
publicboolean getHasPrePage(){ Cg`lQYU
return hasPrePage; 7l~^KsX
} *,*O.#<6
- _6`0
/** .9,x_\|G*
* @param hasPrePage "bWx<
* The hasPrePage to set. lQvgq
*/ T:H~Y+qnt
publicvoid setHasPrePage(boolean hasPrePage){ 9&`";dg
this.hasPrePage = hasPrePage; >7~*j4g
} j|N<6GSke
a l6y=;\jZ
/** [C<K~
* @return Returns the totalPage. ~UNha/nt
* l(}L-:@A
*/ $8AW
publicint getTotalPage(){ $|3zsi2
return totalPage; 84WcaH
} 6-)WXJ@V
-"i$^Q`
/** rXE0jTf:a
* @param totalPage [6_.Y*}N
* The totalPage to set. "19#{yX4
*/ *FZav2]-
publicvoid setTotalPage(int totalPage){ 4#]g852
this.totalPage = totalPage; M6^
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} d,Oagx
\@N~{72:k
} g7*Uuh#
A*81}P_
~1twGG_;
}HmkTk
P3Lsfi.
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 CV\y60n
vTK8t:JQ~
个PageUtil,负责对Page对象进行构造: vf+z0df
java代码: Hs:zfvD
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A|:+c*7]
/*Created on 2005-4-14*/ vq+CW?*"
package org.flyware.util.page; o9]32l
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import org.apache.commons.logging.Log; r `n|fD.
import org.apache.commons.logging.LogFactory; {#4a}:3
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/** XBkaum4j
* @author Joa [6JDS;MIN
* 7
@}`1>97
*/ q9j~|GE|
publicclass PageUtil { Dykh|"
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privatestaticfinal Log logger = LogFactory.getLog _5~|z$GW
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~
(PageUtil.class); j%-Ems*H
pUF JQ*
/** '-Cx-=
* Use the origin page to create a new page &ZkJ,-
* @param page lX"m|W
* @param totalRecords 2y!aXk\#C
* @return &B[*L+-E
*/ HQ"
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publicstatic Page createPage(Page page, int }zsIp,
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totalRecords){ .!Z5A9^
return createPage(page.getEveryPage(), FA)ot)]
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page.getCurrentPage(), totalRecords); h9<PP2.(
} R%\3[
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/** Q<;EQb#
* the basic page utils not including exception 'PY;
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handler e7{6<[k3+$
* @param everyPage 3C%|src
* @param currentPage |9]-_a
* @param totalRecords qK#"uU8B
* @return page RH _b
*/ eF.nNu
publicstatic Page createPage(int everyPage, int 9"+MZ$
:f39)g5>
currentPage, int totalRecords){ )V[j~uOU)]
everyPage = getEveryPage(everyPage); )$9wKk\F
currentPage = getCurrentPage(currentPage); +pYwc0~
int beginIndex = getBeginIndex(everyPage, 0=6mb]VUi=
,\P|%yv
currentPage); "U4c'iW
int totalPage = getTotalPage(everyPage, eaDZ^Z
Er
MZ-;'w&Z
totalRecords); #-G@ p
boolean hasNextPage = hasNextPage(currentPage, Ot`%5<E^
y] D\i5Xv
totalPage); &&P9T/Zks
boolean hasPrePage = hasPrePage(currentPage); zNrn|(Y%Y
Q5Nbu90
returnnew Page(hasPrePage, hasNextPage, bO/r1W
everyPage, totalPage, (:`4*xK
currentPage,
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nA("
cD[,
beginIndex); yx-"&K=`
} :LNZC,-f}5
Is3Y>oX
privatestaticint getEveryPage(int everyPage){ cyB+(jLHDs
return everyPage == 0 ? 10 : everyPage; JkT!X
} 85Yi2+8f4
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privatestaticint getCurrentPage(int currentPage){ .*njgAq7
return currentPage == 0 ? 1 : currentPage; `Kf@<=
} ^"
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privatestaticint getBeginIndex(int everyPage, int z8}QXXa
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currentPage){ 9v*y&V9/
return(currentPage - 1) * everyPage; <5pNFj}0;X
} *v K~t|z
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privatestaticint getTotalPage(int everyPage, int 5Wa)_@qI)`
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totalRecords){ \M@IKE
int totalPage = 0; 2SD
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if(totalRecords % everyPage == 0) (n?f016*%d
totalPage = totalRecords / everyPage; _zM?"16I}
else HP[B%
totalPage = totalRecords / everyPage + 1 ; {-m e;ayk
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return totalPage; %gFIu.c
} l6w\E=K
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privatestaticboolean hasPrePage(int currentPage){ P(7el
return currentPage == 1 ? false : true; Qfy_@w]
} Ji!i}UjD7!
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privatestaticboolean hasNextPage(int currentPage, i>h3UIx\
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int totalPage){ gTTKjlI[
return currentPage == totalPage || totalPage == :'ZR!w
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0 ? false : true; R+uZi~
} 3T]cDVQ_
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} 5 cQ]vb
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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。 k}<H
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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 ~?b1x+soV
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做法如下: ",gVo\^
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Z9 ws{8@_
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的信息,和一个结果集List: YiuV\al
java代码: b~>@x{
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/*Created on 2005-6-13*/ 2Q@na@s
package com.adt.bo; iExKi1knx
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import java.util.List; ['\R4H!x
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import org.flyware.util.page.Page; +0ukLc@
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/** Pz2Q]}(w
* @author Joa ~gZ1*8 s`
*/ ]JGq{I>%+6
publicclass Result { v ,h"u
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private Page page; dPpQCxf
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private List content; Hc\@{17
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/** 1:T"jsWw
* The default constructor |*zgX]-+;
*/ BWYv.&