Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 UzHhU*nW
p:
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 F
) ~pw
QnLgP7Ft
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 Z*"t]L
TiEJyd`P
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 jAHn`Bxz
&-Er n/[
。 eG>Fn6G<g
IVODR
分页支持类: Cs=i9.-A
=C1Qo#QQ%
java代码: ([o:_5/8I
]=<@G.[=
vg1s5Yqk
package com.javaeye.common.util; _!1c.[\T
y+R$pzX
import java.util.List; 3edK$B51;
Vzm7xl [
publicclass PaginationSupport { ZaindX{.1
G)|HFcE
publicfinalstaticint PAGESIZE = 30; jF85bb$
5z]KkPQ
privateint pageSize = PAGESIZE; |noTIAI
$:Zxb
privateList items; lfd{O7 L0b
Z i&X ,K~
privateint totalCount; 3PeJPw
|]b/5s;>
privateint[] indexes = newint[0]; 8so}^2hTlT
481u1
privateint startIndex = 0; 9 NSYrIQ"
j'cCX[i
public PaginationSupport(List items, int \9Zfu4WR
7O :Gi*MA
totalCount){ (7!(e
,
setPageSize(PAGESIZE); vG:,oB}
setTotalCount(totalCount); v3#47F)
setItems(items); 5*Iz3vTq
setStartIndex(0); vB4qJ{f
} hmk5
1
:Xr3 3
public PaginationSupport(List items, int vtjG&0GSK
,kuOaaV7K
totalCount, int startIndex){ (XWs4R.mkb
setPageSize(PAGESIZE); (I
g
*iJ%2
setTotalCount(totalCount); 1&nrZG9
setItems(items); * OFT)S
setStartIndex(startIndex); o62gLO]z@
} wj~8KHan
f2f$aZ
public PaginationSupport(List items, int ^E*C~;^S
)A;<'{t #L
totalCount, int pageSize, int startIndex){ f89<o#bm7h
setPageSize(pageSize); 36UWoo
setTotalCount(totalCount); Yb/^Qk59
setItems(items); ^>uGbhBp
setStartIndex(startIndex); ^T>.04";x
} ?id^v 7d
]TN}`]
publicList getItems(){ Q&{5.}L
return items; {'C74s
} 'iK*#b8l
JDlIf
publicvoid setItems(List items){ `rLMMYD=
this.items = items; e#{L~3
} 0C_Qp% Z
V^5 t~)#46
publicint getPageSize(){ $%t
return pageSize; ]UTP~2N
} /m:}rD
2N#L'v@g=+
publicvoid setPageSize(int pageSize){ T3 Fh7S /
this.pageSize = pageSize; qpCi61lTDJ
} aS2
Y6
_:
x$"i
publicint getTotalCount(){ e&nw&9vo
return totalCount; ),|bP`V
} #xB%v
GV/FK{v5
publicvoid setTotalCount(int totalCount){ RzRLrfV
if(totalCount > 0){ ' 'N@ <|
this.totalCount = totalCount; j+seJg<_
int count = totalCount / )qe o`4+y
;rbn/6
pageSize; @,.H)\a4
if(totalCount % pageSize > 0) dno*Usx5d0
count++; ,B><la87
indexes = newint[count]; Ho|n\7$
for(int i = 0; i < count; i++){ uqH;1T;s
indexes = pageSize * un=)k;oh
o,I642R~
i; L}+!<Ug
} j>zVC;Sj*
}else{ S/aPYrk>6
this.totalCount = 0; l.!
~t1i
} Oylw,*%
} %yVZ|d*Q
= %m/
publicint[] getIndexes(){ T@.CwV
return indexes; u@Lu.t!],
} @hv]
[(<
-Zh+5;8g
publicvoid setIndexes(int[] indexes){ Qfi5fp=f
this.indexes = indexes; 5+J/Qm8{bb
} A`Nb"N$H13
6(=:j"w0
publicint getStartIndex(){ usip>y
return startIndex; va.wdk g
} dewu@
# L R[6l
publicvoid setStartIndex(int startIndex){ oR }
if(totalCount <= 0) 2}AV_]]
this.startIndex = 0; XDF",N)
elseif(startIndex >= totalCount) M?o`tWLhF
this.startIndex = indexes =O<BMq{d
vPi+8)
[indexes.length - 1]; }PJ:9<G
y
elseif(startIndex < 0) "%Ak[04'
this.startIndex = 0; %JZIg!
else{ 1C{~!=6#
this.startIndex = indexes ~+Y;jAdU
.O(UK4Mb
[startIndex / pageSize]; K!X8KPo
} o2L/8q.
} DzEixE-
}m?L/Y'}
publicint getNextIndex(){ &nYmVwi?"Q
int nextIndex = getStartIndex() + )mU)7@!
?/~1z*XUW
pageSize; 4^5s\f B
if(nextIndex >= totalCount) {+MMqJCa
return getStartIndex(); A`KTm(
else y? g7sLDc
return nextIndex; li[g =A,
} u/AN|
y
2iu;7/
publicint getPreviousIndex(){ <fxYTd<#D[
int previousIndex = getStartIndex() - ^]kDYhe*Y
+^.(3Aw
pageSize; 0M"E6z)9
if(previousIndex < 0) IlVi1`]w
return0; 6S(3tvUr
else %K%z<R8
return previousIndex; c-,/qn/
} LQe<mZ<
T-MLW=Vu
} Yr!3mU-Uvt
p0/I}n4<5n
4%pvw;r
AjpQb~\
抽象业务类 1g@kHq
java代码: lUrchLoDt
3yQ(,k #
t|//oEY
/** ~b+>o
* Created on 2005-7-12 _%x|,vo`(
*/ {5*5tCIt
package com.javaeye.common.business; n\QG-?%Pi
5ZPl`[He
import java.io.Serializable; )wC>Hq[mhW
import java.util.List; Y9C] -zEv
zr,jaR;
import org.hibernate.Criteria; n V<YwqK
import org.hibernate.HibernateException; 61]6N;kJ;
import org.hibernate.Session; Wrlmo'31
import org.hibernate.criterion.DetachedCriteria; jooh`| `P
import org.hibernate.criterion.Projections; X,p&S^
import 4):\,>%pK
Uc&0>_Z
org.springframework.orm.hibernate3.HibernateCallback; 49CMRO,T
import sx9N8T3n
q>Y_I<;'g
org.springframework.orm.hibernate3.support.HibernateDaoS ?#W>^Za=
OS3J,f}<=
upport; OIN]u{S
I++!F,pB
import com.javaeye.common.util.PaginationSupport; u3q!te
|YH1q1l
public abstract class AbstractManager extends tW,<Pe
2$jY_{B+x
HibernateDaoSupport { ZnQnv@{8l
<1"6`24
privateboolean cacheQueries = false; dM
QnN[d6
4m~\S)ad
privateString queryCacheRegion;
9TeDLp
7Kn=[2J5k'
publicvoid setCacheQueries(boolean iVFnt!
E*kS{2NAq
cacheQueries){ ]xuq2MU,l
this.cacheQueries = cacheQueries; 9Y7 tI3
} -V9Cx_]y
).-FuL4Y
publicvoid setQueryCacheRegion(String fx*Swv%r
7JujU.&{6
queryCacheRegion){ XVY^m}pMe
this.queryCacheRegion = ': HV9]k
;$86.2S>B
queryCacheRegion; 9AS,-5;XQ
} ,7eN m>$
j@9A!5<CCk
publicvoid save(finalObject entity){ }!2|*Y
getHibernateTemplate().save(entity); L,R9jMx?_
} LG;xZQx'
==$Ox6.
publicvoid persist(finalObject entity){ FC(m)S2
getHibernateTemplate().save(entity); RVD=CX
} &4]%&mX)-
fz:F*zT1
publicvoid update(finalObject entity){ P afmHXx
getHibernateTemplate().update(entity); wTOB'
} \"n&|_SZ\
^E5Xpza
publicvoid delete(finalObject entity){ 0\.y0
K8
getHibernateTemplate().delete(entity); WC`<N4g|
} ;v.l<AOE
$?0<rvGJ
publicObject load(finalClass entity, 0^hz 1\g
?Hq`*I?b9
finalSerializable id){ '*K/K],S]
return getHibernateTemplate().load ,5<-\"{]
[3j]r{0I
(entity, id); y1P ?A]v
} ~jJu*s$?
gp;(M~we
publicObject get(finalClass entity, wjY3:S~
<;=X7l+
finalSerializable id){ X\M0Q%8
return getHibernateTemplate().get #B54p@.}
!DLIIKO78
(entity, id); n`CmbM@@
} D`Fl*Wc4H
$.v5G>-)3
publicList findAll(finalClass entity){ GK:*|jV
return getHibernateTemplate().find("from &bTadd%0
{<&x9<f9
" + entity.getName()); T?Gi;ld7
} 9erTb?@S
jMg Ni@
publicList findByNamedQuery(finalString O75ioO0
-Ndd6O[ a5
namedQuery){ 6=FF*"-6E
return getHibernateTemplate c_%vD~6W-
b>G!K)MS3
().findByNamedQuery(namedQuery); `$Q
$l
} sA:0b5_a
o:m:9dn
publicList findByNamedQuery(finalString query, Lk`0z
b5KX` r
finalObject parameter){ GT`:3L
return getHibernateTemplate }KJ/WyYW
Hz28L$
().findByNamedQuery(query, parameter); u2o6EU`
} :*Sl\:_X)
%WdAI,
publicList findByNamedQuery(finalString query, vfmKY iLp
E+csK*A7
finalObject[] parameters){ D{\hPv
return getHibernateTemplate jR*1%.Ng
R$wo{{KX
().findByNamedQuery(query, parameters); s!uewS.
} t hTY('m
izOtt^#DZt
publicList find(finalString query){ h2K1|PUKl[
return getHibernateTemplate().find gy,B+~p
u:<%!?
(query); 0lY.z$V
} iw<+rh*C
J$@3,=L6V
publicList find(finalString query, finalObject iwrS>Sm
q>f1V3
parameter){ Q;Xb-\\
return getHibernateTemplate().find vxY7/ _]
Y[@$1{YS
(query, parameter); m8#+w0p)
} mam|aRzd
R8?Xz5
public PaginationSupport findPageByCriteria Ez+.tbEA,
XoL9:s(m~
(final DetachedCriteria detachedCriteria){ e qj^
return findPageByCriteria D<C ZhYJ
/mF%uI>:
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 8.F]&D0p8
} ' !ZFK}
HS>Z6|uLY
public PaginationSupport findPageByCriteria ^0c:ro
mQ:lj$Gf
(final DetachedCriteria detachedCriteria, finalint j8_WEjG
t@.M;b8
startIndex){ ?3k;Yg/
return findPageByCriteria QzCu$ [
`gSqwN<x%
(detachedCriteria, PaginationSupport.PAGESIZE, zHeqV
Z<;am
startIndex); CZuV{Oh}?
} vrLI`3n]
gfR B
public PaginationSupport findPageByCriteria WfL5.&
5W(G~m?jC6
(final DetachedCriteria detachedCriteria, finalint #iJ+}EW
_
"~> # ;x{
pageSize, XN'x`%!*3#
finalint startIndex){ 2a3i]e5Kt
return(PaginationSupport) UW88JA0
$
nx&(V
getHibernateTemplate().execute(new HibernateCallback(){ VMe~aUd
publicObject doInHibernate ;n?H/(6X8>
|Rf4^vN
(Session session)throws HibernateException { &J,MJ{w6"
Criteria criteria = eZJrV}V
YP5V~-O/
detachedCriteria.getExecutableCriteria(session); Rbm"Qz
int totalCount = [yJcM
[p\
.q"`)PT
((Integer) criteria.setProjection(Projections.rowCount 5~5d%C^3k
t6W$t
()).uniqueResult()).intValue(); g!,>.
criteria.setProjection h}nceH0s3d
mhv{6v
(null); CuR.a
List items = 9|jk=`4UK
Z^zUb
criteria.setFirstResult(startIndex).setMaxResults Lp`q[Z*
n3SCiSr
(pageSize).list(); %ZDo;l+<F6
PaginationSupport ps = H<92tP4M
>j%HVRW
new PaginationSupport(items, totalCount, pageSize, 2WE_NEpJI
KU|dw^Y k
startIndex); }'U"HHv
return ps; w)2X0ev"
} Yg3Vj=
}, true); / q*n*j
} UC"<5z
lcu
xlg 6cO
public List findAllByCriteria(final eZ'J,;
s,!+wHv_8
DetachedCriteria detachedCriteria){ NifzZEX
return(List) getHibernateTemplate z<YOA
-Jr6aai3+
().execute(new HibernateCallback(){ {9S=:
publicObject doInHibernate ~G+o;N,V
vN=e1\
(Session session)throws HibernateException { wxYB-Wh<
Criteria criteria = yj13>"n h
?`#)JG,A7
detachedCriteria.getExecutableCriteria(session); 6`Zx\bPDm
return criteria.list(); kmXpj3
} EZlcpCS
}, true); G}<%%U D
} 3GqvL_
e@}zp
public int getCountByCriteria(final } Wx#"6
!#wd~: H
DetachedCriteria detachedCriteria){ =B-a]?lM
Integer count = (Integer) zGjf7VV2a
3\j{*f$J
getHibernateTemplate().execute(new HibernateCallback(){ B! $a Y
publicObject doInHibernate 8VxjC1v+
r\-Mj\$-
(Session session)throws HibernateException {
>G(M&
Criteria criteria = J\VG/)E
lv\C(^mGq
detachedCriteria.getExecutableCriteria(session); nK=-SQ
return t6V@00M@
+ o^b ,!
criteria.setProjection(Projections.rowCount yU`"]6(@[
g).k+
()).uniqueResult(); MLf,5f;e
} f4eLnY
}, true); gBBS}HF
return count.intValue(); cyu)YxT
} hYOUuC
} sz4)xJgF(
b~uz\%'3
5:ca6H
tai
?|Y/&/;%I
'Pyeb`AXE9
用户在web层构造查询条件detachedCriteria,和可选的 X-[_g!pV
U,q
]
startIndex,调用业务bean的相应findByCriteria方法,返回一个 0k Ezi
I`"B<=zi
PaginationSupport的实例ps。 l;_zXN
vd+yU9
ps.getItems()得到已分页好的结果集 ?+EN.P[;3
ps.getIndexes()得到分页索引的数组 eTVI.B@p
ps.getTotalCount()得到总结果数 G4DuqN~2m
ps.getStartIndex()当前分页索引 M8j%bmd(,
ps.getNextIndex()下一页索引 $$QbcnOf$
ps.getPreviousIndex()上一页索引 2\
3}y(
(NPDgR/
Pt<lHfd
5R6@A?vr
ETQ.A< v
H3<
`
DY]\@<ez
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Gc6`]7 s
Id-?her>B
,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 V0y Q
t<'-?B2g
一下代码重构了。 ^@V$'Bk
&d/v/Y
我把原本我的做法也提供出来供大家讨论吧: _h;#\ )%~
jn[%@zD }
首先,为了实现分页查询,我封装了一个Page类: O{WJi;l
java代码: uEp
v l
/Hxz@=LC1
v"x{oD$R
/*Created on 2005-4-14*/ ;533;(d*o
package org.flyware.util.page; #IH7WaN
;yh}$)^9
/** @#sBom+K`
* @author Joa |4RuT
.-o
* ai/VbV'|
*/ zQsu~8PX
publicclass Page { Mx&
P^#B3
GS1Vcav<
/** imply if the page has previous page */ WPbWG$Li
privateboolean hasPrePage; nFE0y3GD8
Sw!/IPO
/** imply if the page has next page */ aBL+i-
privateboolean hasNextPage; bqBgq
;-Bi~XD
/** the number of every page */ 9D
2B8t"a
privateint everyPage; %\xwu(|kN
yj]\%3o<Z7
/** the total page number */ c o}o$}
privateint totalPage; M+Rxt.~6
NUiNn 7C
/** the number of current page */ N[G<&f9
privateint currentPage; n|,kL!++.
cZnB 2T?
/** the begin index of the records by the current xxnMvL;
$O|J8; "v
query */ P(N$U^pj
privateint beginIndex; F,B, D^WD
'k2Z$+
/*B^@G |]'
/** The default constructor */ P<@Yux#
public Page(){ Mk-C'
**jD&h7$s-
} K%TlB KV
Yjo$^q
/** construct the page by everyPage y~jKytq^@
* @param everyPage 4BSSJ@z
* */ nx<q]Juv\
public Page(int everyPage){ gB\
a
this.everyPage = everyPage; 0>jo+b\D$
} K<`"Sr
|Tz/9t
/** The whole constructor */ FBfyW-
7
public Page(boolean hasPrePage, boolean hasNextPage, (+g!~MP
v 6{qKpU#
UnjUA!v
int everyPage, int totalPage, ti`R
int currentPage, int beginIndex){ (^h47kY
this.hasPrePage = hasPrePage; y@!kp*0
this.hasNextPage = hasNextPage; 0q_Ol]<V
this.everyPage = everyPage; zw=as9z1-
this.totalPage = totalPage; muSQFIvt
this.currentPage = currentPage; R!7emc0T
this.beginIndex = beginIndex; wA`A+Z2*?
} Dim,HPx]d
"Q*Z?6[Z
/** hM*T{|y
* @return ]#hT!VOd
* Returns the beginIndex. GnbXS>
*/ l\l\T<wa,
publicint getBeginIndex(){ *GsrG*OM*D
return beginIndex; XK:KWqW
} 2fc8w3
22?9KZ`Z=
/** #+Lo&%p#3
* @param beginIndex h#bpog
* The beginIndex to set. 1a{~B#
*/ [MM11K
publicvoid setBeginIndex(int beginIndex){ h~$Q\WCm#
this.beginIndex = beginIndex; @vf{_g<
} 7Kx3G{5ja
yc,Qz.+g
/** )i; y4S
* @return =dbLA ,z9
* Returns the currentPage. 9\W~5J<7
*/ r\+AeCyb"p
publicint getCurrentPage(){ "HR
&Rf k
return currentPage; 8;3T65KY
} IXp P.d
L4SvE^2+
/** :SSlUl4sU$
* @param currentPage ZiDmx-X
* The currentPage to set. Rs;,_
*/ ?Mp)F2'
publicvoid setCurrentPage(int currentPage){ Q!>8E4Z
this.currentPage = currentPage; S<+_yB?
} (JC -4X_
dL"$YU9z
/** n
}lav
* @return vO" $Xw
* Returns the everyPage. {m}B=u
*/ ih1s`CjG
publicint getEveryPage(){ 7I4G:-V:^
return everyPage; hIa@JEIt
} ,2?"W8,
DSix(bs9
/** M3 8,SH<
* @param everyPage n15c1=gs
* The everyPage to set. zx{\SU
*/ Qwx}e\=
publicvoid setEveryPage(int everyPage){ hD\C[C,
this.everyPage = everyPage; Cm}ZeQ
} Jg|3Wjq5
}}~^!
/**
K)GC&%_$O
* @return 2q# t/oN3T
* Returns the hasNextPage. Q>}I@eyJ
*/ ~I/7{B|yX
publicboolean getHasNextPage(){ Bd m<<<
return hasNextPage; n[WXIE<
} J8a4.prqI
Z.m.Uyz{7
/** D8W:mAGEu
* @param hasNextPage I_xJ[ALdm
* The hasNextPage to set. w`1qx;/!
*/ BU:s&+LYUv
publicvoid setHasNextPage(boolean hasNextPage){ 451C2 %y
this.hasNextPage = hasNextPage; L~V
63K
} 2!dIW5I
UR-e'Z&]
/** u
` 9Eh;
* @return D4[5}NYU
* Returns the hasPrePage. I}Q3B3Byg
*/ Fg4eIE-/M
publicboolean getHasPrePage(){ wr*A%:
return hasPrePage; >C_! }~
} (m3p28Q?
[sz#*IJ
/** : M0LAN
* @param hasPrePage wlKpHd*
* The hasPrePage to set. @tjC{?5Y
*/ \{?v|%n=/i
publicvoid setHasPrePage(boolean hasPrePage){ ~"EkX
this.hasPrePage = hasPrePage; oG@P M+{
} ZH:#~Zyj
21 cB_"
/** z!Jce}mx
* @return Returns the totalPage. 3SQ
5C'E
* )X\3bPDJR
*/ h.'h L
publicint getTotalPage(){ xKsn);].`
return totalPage; X?rJO~5
} 9>@_};l
lW&glU(
/** p fAp2"
* @param totalPage TaM,9MAu
* The totalPage to set. ]RnX'yw^
*/ 2%vwC]A
publicvoid setTotalPage(int totalPage){ X+iA"B
this.totalPage = totalPage; f$V']dOj1q
} pS%,wjb&P
)Y?Hf2']
} Xg!Mc<wA[
>YoK?e6
;5y4v
"cJ5Fd:*
Vzbl*Zmx
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 FG#E?G
5+%BZ
个PageUtil,负责对Page对象进行构造: zCvR/
java代码: :Fj4YP"
'U}i<^,c
E
C 7 f
/*Created on 2005-4-14*/ o}WbW }&
package org.flyware.util.page; 3L>V-RPi M
aeUm,'Y$
import org.apache.commons.logging.Log; JpS:}yyJ>N
import org.apache.commons.logging.LogFactory; Pn 7oQA\
d:sUh
/** NqqLRgMOR'
* @author Joa z8z U3?
* wm2Q(l*HH
*/ (nda!^f_s
publicclass PageUtil { jIdhmd* $z
,PN>,hFL
privatestaticfinal Log logger = LogFactory.getLog ={maCYlE.
DU1,i&(
(PageUtil.class); !JYDg
[U3z*m>e;
/** qd{|"(9B
* Use the origin page to create a new page y
I mriCT
* @param page sMO3eNLn
* @param totalRecords \UB<'~z6!
* @return XyhOd$)
*/ B)^]V<l(w
publicstatic Page createPage(Page page, int $ a5K
U7x}p^B9\N
totalRecords){ G2L7_?/m
return createPage(page.getEveryPage(), miN(a; Q2P
i@B5B2
page.getCurrentPage(), totalRecords); a+]=3o
} ITbl%q
}P}l4k1W
/** p3x(:=
* the basic page utils not including exception ?6j@EJ<2q
$g|g}>Sc
handler 1YnDho;~
* @param everyPage IHagRldG
* @param currentPage W=)}=^N0
* @param totalRecords m5d;lrk@&/
* @return page ~=c^Oo:
*/ 9pjk3a
publicstatic Page createPage(int everyPage, int @RaMO#
wp*;F#: G
currentPage, int totalRecords){ GB[W'QGiq
everyPage = getEveryPage(everyPage); 0W=IuPDU
currentPage = getCurrentPage(currentPage); c yN_Sg
int beginIndex = getBeginIndex(everyPage, 5jjJQ'
>)S
a#w;
currentPage); Vl9\&EL
int totalPage = getTotalPage(everyPage, PVtQ&m$y
.+[[m$J
totalRecords); ]m}>/2oSs
boolean hasNextPage = hasNextPage(currentPage, f4w|
>Xb]n_`
totalPage); 1uy+'2[Z-D
boolean hasPrePage = hasPrePage(currentPage); <<;j=Yy({`
[9+M/O|Vs
returnnew Page(hasPrePage, hasNextPage, 4L5Wa~5\
everyPage, totalPage, 6 'wP?=
currentPage, m&ZdtB|
r2&{R!Fj`
beginIndex); 3{$cb"5
} `pcjOM8u
6(ja5)sn*
privatestaticint getEveryPage(int everyPage){ hR{Fn L
return everyPage == 0 ? 10 : everyPage; }:hdAZ+z
} u-k*[!JU
R6AZIN:
privatestaticint getCurrentPage(int currentPage){ d0N7aacY
return currentPage == 0 ? 1 : currentPage; sk],_ l<
} C2`END;
eN jC.w9
privatestaticint getBeginIndex(int everyPage, int 9CL&tpqv
f
,%ajIs"Gi
currentPage){ '-v~HwC+/T
return(currentPage - 1) * everyPage; #4"\\
} Bq$bxuhV
t~bjD V^`
privatestaticint getTotalPage(int everyPage, int \{~x<<qFd
m*I5 \
totalRecords){ a{u)~:/G
int totalPage = 0; beIEy(rA
].1R~7b
if(totalRecords % everyPage == 0) ^|gN?:fA}
totalPage = totalRecords / everyPage; =CqLZ$10
else da2BQ;
totalPage = totalRecords / everyPage + 1 ; !A<?nz
Uv
g\jdR_/
return totalPage; >eU;lru2Q
} XVI+Y
'vCFT(C-
privatestaticboolean hasPrePage(int currentPage){ p6ZKyi
return currentPage == 1 ? false : true; .Wa6?r<g
} h"<rW7z
*np%67=jO
privatestaticboolean hasNextPage(int currentPage, 12rr:(#%s
@w|~:>/g
int totalPage){ w\\
return currentPage == totalPage || totalPage == 8taaBM`:
OY@/18D<>
0 ? false : true; f:HRrKf9
} ;xj^*b
02=eE|Y@
Zo&U3b{Dy
} Cjwg1?^RZ
g4~{#P^i
:/1WJG:!
IXC: Q
g/T`4"p[H
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。 +i
K.+B
,':?3| $c
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 5$9j&&R
rgOB0[
做法如下: 2p'qp/
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 <K2 )v~
EnfSVG8kB8
的信息,和一个结果集List: 2P]r J
java代码: fw-LZ][
Pw+cpM8<
7DT9\BT
/*Created on 2005-6-13*/ 3 i>uKU1
package com.adt.bo; LdRLKE<'e
="XxS|Mq3
import java.util.List; Q+#, VuM
*DU86JL`
import org.flyware.util.page.Page; O*c+TiTb
G`TO[p]q
/** L]9*^al
* @author Joa ! WQEv_G@
*/ /oh[Nu1D
publicclass Result { hL&z"_`
M(5l Su
private Page page; =o9
%)
g.z/%LpK
private List content; i5:fn@&
"|&SC0*
/** %"{SGp
* The default constructor
1vQ*Br
*/ ZfIQ Fh>
public Result(){ g9
g
&]
super(); j1>1vD-`T
} Wny{qj)=
?HU(0Vgn'
/** ?n[+0a:8E
* The constructor using fields UXe @c@3
* %/~Sq?f-9@
* @param page &Tl3\T0D
* @param content Xi$uK-AHpj
*/ z+Y0Zh";/#
public Result(Page page, List content){ +AXui|mn
this.page = page; ]BX|G`CCc
this.content = content; I)n%aT fo8
} QL
@0+@.&Z
/** 3M/kfy
* @return Returns the content. $S3C_..
*/ z,$^|'pP
publicList getContent(){ ofRe4
*\j
return content; UDGVq S!,E
} 5Vf#(r f
na>UFw7>*
/** 02?y%
* @return Returns the page. Sh=z
*/ n{=vP`V_
public Page getPage(){ ~#OnA1)
return page; <Y<%=`
} ".~,(*
b$%W<D
/** l2z@t3{
* @param content ig jr=e
* The content to set. Pv/$;R%
*/ Qp]V~s(
public void setContent(List content){ arRbq!mO
this.content = content; ZC@Pfba[`
} <D!"<&N