Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 !JzM<hyg3
U2
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 & V^Z
H)}>&Z4
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 x5YW6R.<t
$[T^S
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 ' 7+x,TszI
gPh;
。 *9y)B|P^
#wK { G)J
分页支持类: vP`Sz}FU
a$yAF4HR<
java代码: aTuD|s
9u ^PM
~m8".Z"
package com.javaeye.common.util; rCGXHbj%
$~!%Px)
import java.util.List; R2vT\ 6xv
BCYTlxC'
publicclass PaginationSupport { %i{Z@
U<gMgA
publicfinalstaticint PAGESIZE = 30; @)1>ba
4='Xhm
privateint pageSize = PAGESIZE; t'|A0r$
1PpZ*YK3z
privateList items; B>rz<bPT
;{EIx*<d
privateint totalCount; B(7oHj.i2
Xyy;BO:
privateint[] indexes = newint[0]; Y<-h#_
Ok2KTsVl
privateint startIndex = 0; < aJl
i
bc=,$
public PaginationSupport(List items, int g = ~Y\$&
r*HbglB
totalCount){ `-fWNHs
setPageSize(PAGESIZE); :+NZW9_
setTotalCount(totalCount); V
6I77z
setItems(items); 5xC4lT/U
setStartIndex(0); )12.W=p
} |0ATH`{
:dq.@:+<R
public PaginationSupport(List items, int VK*Dm:G0
\~m\pf?
totalCount, int startIndex){ Q,R>dkS
setPageSize(PAGESIZE); <|Srbs+
setTotalCount(totalCount); Gu+9R>
setItems(items); 2(LF @xb
setStartIndex(startIndex); x1H1[0w,i
} x1]J
K8#MQR2@
public PaginationSupport(List items, int k%uR!cL
[As9&]Bv5
totalCount, int pageSize, int startIndex){ F-AU'o
*
setPageSize(pageSize); scX'>\w&c
setTotalCount(totalCount); #lAC:>s3U
setItems(items); uN>JX/-
setStartIndex(startIndex); cq]JD6937
} & "i4og<
F
t/yPv
publicList getItems(){ XSk*w'xO
return items; 2[|52+zhc
} =mR~\R(
I
z]_2lx2e
publicvoid setItems(List items){ 5~D(jHY;
this.items = items; ebno:)
} '8%jA$o\g
<*JFY%y"
publicint getPageSize(){ /pY-how%!
return pageSize; GDF/0-/Z
} aeZ$Wu>]W
pwvzs`[;
publicvoid setPageSize(int pageSize){ eHHY.^|
this.pageSize = pageSize; (#kKL??W
} 0JFS%Yjw[
"s-3226kj
publicint getTotalCount(){ y0vJ@ %`
return totalCount; H9;0$Y(e-
} ;~D$rT
yFoPCA86y
publicvoid setTotalCount(int totalCount){ $%BI8_
if(totalCount > 0){ L0l'4RRm\
this.totalCount = totalCount; Ft
E5H
int count = totalCount / Zd5Jz+f
'tTUro1~
pageSize; R2Es~T
if(totalCount % pageSize > 0) -pmb-#`M
count++; Gj_7wP$
indexes = newint[count]; ^H"o=K8=
for(int i = 0; i < count; i++){ &F-
\t5X=i
indexes = pageSize * |I[/Fl:
. ;rE4B
i; o6tPQ (Vi
} d1P|v(
`S9
}else{ Qb%o%z?hee
this.totalCount = 0; (+yH
} 3rVfBz
} (E;+E\E
Ez8k.]q u
publicint[] getIndexes(){ *+OS;R1<
return indexes; |`ya+/ff+
} ?(Se$iTZ
OZc4 -5
publicvoid setIndexes(int[] indexes){ za%gD
this.indexes = indexes; 8)lrQvZ
} apOXcZ
xKR\w!+Z'
publicint getStartIndex(){ 44NMof8N
return startIndex; Gv[s86AP,
} 1=Z!ZY}}e
_aeIK
publicvoid setStartIndex(int startIndex){ r<$o [,W
if(totalCount <= 0) _01wRsm%2
this.startIndex = 0; Rh}}8 sv
elseif(startIndex >= totalCount) #x qiGK
this.startIndex = indexes 5U-SIG*
=t^jlb
[indexes.length - 1]; #M%K82"
elseif(startIndex < 0) G9^xv
this.startIndex = 0; bwM?DY
else{ 6hMKAk
this.startIndex = indexes 3eg6 CdT
F\, vIS
[startIndex / pageSize]; Sn
S$5o
} Jz}`-fU`
} TjDtNE
ua"2nVxK_K
publicint getNextIndex(){ ;4U"y8PVTh
int nextIndex = getStartIndex() + d~AL4~}
&|j0GP&
pageSize; U
shIQh
if(nextIndex >= totalCount) C1'y6{,@
return getStartIndex(); ,PmUl=
else n$`+03 a
return nextIndex; `m#-J;la
} @I}VD\pF
re_nb)4g
publicint getPreviousIndex(){ {nXygg
J
int previousIndex = getStartIndex() - =[8K#PZ$w
m~
5"q%;
pageSize; $[}EV(#y
if(previousIndex < 0) O2\(:tvw
return0; 67hfv e
else 5RvE ),
return previousIndex; :_y!p
} 'da
'WZG
q8&l%-d`
} a_+?#m
$'I&u
=w}JAEE|(i
Cdib{y<ji
抽象业务类 +}N'Xa/Jt
java代码: O>pv/Ns
Db<#gH
E(j#R"
/** 9sT5l"?g
* Created on 2005-7-12 }dop]{RG
*/ BO#tn{(#
package com.javaeye.common.business; 5e$1KN`
oWL_Hh%-f`
import java.io.Serializable; 2?GMKd)
import java.util.List; &}[P{53sr
('SId@
import org.hibernate.Criteria; h#"$W;(
import org.hibernate.HibernateException; *s*Y uY%y
import org.hibernate.Session; ?9a%g\`?:
import org.hibernate.criterion.DetachedCriteria; MNWI%*0LO
import org.hibernate.criterion.Projections; {='Bd6_=
import z,4mg6gt
cd1G.10
org.springframework.orm.hibernate3.HibernateCallback; hK{H7Ey*
import Nw'03Jzx_
7Vsp<s9bj
org.springframework.orm.hibernate3.support.HibernateDaoS =K18| Q0m
GM0Q@`d
upport; !*}UP|8
nq]6S$3
6
import com.javaeye.common.util.PaginationSupport; >4jE[$p]"
X8Q'*
public abstract class AbstractManager extends *$ g!/,
N
o6!gZ1
HibernateDaoSupport { M&j|5UH%.
YND }P9 h
privateboolean cacheQueries = false; Zt!A!Afu
NC%hsg^0/
privateString queryCacheRegion; ^sD
M>OHp
WJOoDS!i
publicvoid setCacheQueries(boolean h<U?WtWT-p
Q2VF+g,
cacheQueries){ b&+zAt.
this.cacheQueries = cacheQueries; );h(D!D,
} >MHlrSH2
ZpVkgX4
publicvoid setQueryCacheRegion(String `y3'v]
\;)g<TwL
queryCacheRegion){ w'2FYe{wj
this.queryCacheRegion = N s +g9+<A
L'e^D|
queryCacheRegion; {siOa%;*
} z#GZb
cRVL1ne
publicvoid save(finalObject entity){ $V(]z`b&
getHibernateTemplate().save(entity); 2bNOn%!
} x,,y}_YX
4GRD- f[
publicvoid persist(finalObject entity){ Dcvul4Q
getHibernateTemplate().save(entity); \b"rf697,
} 'w+]kt-
zl@^[km{
publicvoid update(finalObject entity){ eBrNhE-[G]
getHibernateTemplate().update(entity); etr-\Cp
} >ou=}/<
~?F,kmO}?
publicvoid delete(finalObject entity){ #{8IFA
getHibernateTemplate().delete(entity); by@KdQow
} `I5^zi8
/ I`TN5~
publicObject load(finalClass entity, a;HAuy`M x
fwFJe(.
finalSerializable id){ 2tq2
return getHibernateTemplate().load zuvPV{
X
%#x4wi
(entity, id);
OUv<a`0
} k&dXK
1INX#qTZ
publicObject get(finalClass entity, PJ.\)oP
+F;2FD$
finalSerializable id){ <7^|@L
6
return getHibernateTemplate().get $Ll9ak}
A[Mke
(entity, id); Pd91<L
} z#tIa
iq; |
i!
publicList findAll(finalClass entity){ 75# 8P?i
return getHibernateTemplate().find("from g&$=Y7G
tIuM9D{P
" + entity.getName()); *2/Jg'de
} axC|,8~tq
Z=JKBoAY
publicList findByNamedQuery(finalString 1sqE/-v1_^
mU/o%|h
namedQuery){ >fBPVu\PA
return getHibernateTemplate OIblBQ!
Lw>B:3e
().findByNamedQuery(namedQuery); [6!k:-t+
} }t)+eSUA
Fw<"]*iu
publicList findByNamedQuery(finalString query, P<]U
.WF"vUp
finalObject parameter){ kKyU?/aj
return getHibernateTemplate b"I#\;Ym
2 2v"?*
().findByNamedQuery(query, parameter); V! Wy[u
} h.\I
tK{)
Tv ``\<
publicList findByNamedQuery(finalString query, hi8q?4jE
c!Hz'W
finalObject[] parameters){ Bz]tKJ
return getHibernateTemplate )4g_S?l=
^j<v~GTx+
().findByNamedQuery(query, parameters); ,->ihxf
} {T4_Xn -I
/@9Q:'P
publicList find(finalString query){ pv]@}+<Dt
return getHibernateTemplate().find g NI1W@)
t ed:]
(query); ytcLx77`:
} kF|$oBQ
J
n.7W5v
publicList find(finalString query, finalObject `^)`J
4$Ai!a
parameter){ B{Cm`f8E
return getHibernateTemplate().find R$:-~<O
@@Q4{o
(query, parameter); zIc6L3w$
} DsdM:u*s
fQoAdw
public PaginationSupport findPageByCriteria b^W&-Hh
IL@yGuO,
(final DetachedCriteria detachedCriteria){ !:+U-mb*
return findPageByCriteria tV++QC7@L
k\OZ'dS
(detachedCriteria, PaginationSupport.PAGESIZE, 0); xg p)G!
} 4&*lpl*N
~>:JwTy
public PaginationSupport findPageByCriteria o]?
yyP
v^C\
GDH
(final DetachedCriteria detachedCriteria, finalint 3p#UEH3
LK h=jB^bT
startIndex){ wkt4vE87
return findPageByCriteria
qCI&H7u@
[MeivrJ+
(detachedCriteria, PaginationSupport.PAGESIZE, t#(NfzN
st w@@GQ
startIndex); 0}i
9`p
} lU1SN/'zx
e@hPb$7
public PaginationSupport findPageByCriteria :DH@zR
1]}\h]*
(final DetachedCriteria detachedCriteria, finalint !&U75FpN}:
<$nPGz)}
pageSize, Q=Q+*oog
finalint startIndex){ d!I%AlV
return(PaginationSupport) `q}D#0
LW=qX%o{
getHibernateTemplate().execute(new HibernateCallback(){ =9&2udV1
publicObject doInHibernate JQ+Mg&&Q
48p3m)5
(Session session)throws HibernateException { KDN#CU
Criteria criteria = L4iWR/&
whI4@#
detachedCriteria.getExecutableCriteria(session); R&uPoY,f
int totalCount = I(6%'s2
cC8$ oCR?
((Integer) criteria.setProjection(Projections.rowCount ihkZs3}
Gb^63.}
()).uniqueResult()).intValue(); i3 js'?7E
criteria.setProjection ZRhk2DA#FF
)=)N9C Ry
(null); &^ERaPynd
List items = B}
qRz
(CQ! &Z8
criteria.setFirstResult(startIndex).setMaxResults m]DP{-s4
{JWixbA
(pageSize).list(); T)tr"<F5NP
PaginationSupport ps = [)`*k#.=
yK{P%oh)
new PaginationSupport(items, totalCount, pageSize, RlfI]uCDM
n[/D>Pi
startIndex); W@}@5,}f>
return ps; )F9IzR-&m
} Qe~C}j%
}, true); 51}C`j|V3{
} 1=]#=)+
yc0
1\o
public List findAllByCriteria(final z{R
Mb
TrDTay
DetachedCriteria detachedCriteria){ IiKU=^~w
return(List) getHibernateTemplate B)k/]vz)*D
!5 S#
().execute(new HibernateCallback(){ DvWBvs,
publicObject doInHibernate _~Lu%
|TJ gH<I
(Session session)throws HibernateException { [?z;'O}y
Criteria criteria = ['(qeS@5O
E.#JCO|(1
detachedCriteria.getExecutableCriteria(session); 1mV
'
~W
return criteria.list(); X'd\b}Bm
} NiG&Lw*8
}, true); pTAm}
} ;zqxDl_
K*~xy bA
public int getCountByCriteria(final 8\il~IFyi
:MDFTw~ |
DetachedCriteria detachedCriteria){ d/NjY[` 5+
Integer count = (Integer) 4gZ R!J
E2hML
getHibernateTemplate().execute(new HibernateCallback(){ Q8TR@0d
publicObject doInHibernate .t^1e
qPu?rU{2
(Session session)throws HibernateException { ; <- f
Criteria criteria = 3meZ]u
P'}EZ'
detachedCriteria.getExecutableCriteria(session); JNU9RxR
return u}'m7|)8
yJx,4be
criteria.setProjection(Projections.rowCount %5ov!nm7
} %3;j5 ;6
()).uniqueResult(); 9'X "a
} x+sSmW
}, true); C
B;j[.
return count.intValue(); KjA7x
} w^~s4Q_>>
} ,*$Y[UT
J?p|Vy|9
({4?RtYm
s]vsD77&
&~"N/o
j;Z
hI y
用户在web层构造查询条件detachedCriteria,和可选的 n~,6!S
h\C1:0x{
startIndex,调用业务bean的相应findByCriteria方法,返回一个 MO]zf3f!
e{:
-N
PaginationSupport的实例ps。 |r*y63\T
~HctXe' x
ps.getItems()得到已分页好的结果集 8pmWw?
ps.getIndexes()得到分页索引的数组 7x*L 1>[`'
ps.getTotalCount()得到总结果数 98}l`J=i
ps.getStartIndex()当前分页索引 ~LH).\V
ps.getNextIndex()下一页索引 @&h_+|:-
ps.getPreviousIndex()上一页索引 Q{hK+z`D
} BP.t$_
r*7J#M /
SM}&
@cJ
H2_6m5[&,
j"0TAYmXwu
TIV|7nKL
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 N,)rrBD
F0xm%?
,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 `=TJw,q
S{cK~sZj
一下代码重构了。 'pAq;2AA
ud(w0eX
我把原本我的做法也提供出来供大家讨论吧: Ze`ms96j{
Kt#X'!9/<
首先,为了实现分页查询,我封装了一个Page类: -z/>W+k
java代码: .v) A|{:2
$nthMx$
QswFISch
/*Created on 2005-4-14*/ O sIvW'$\
package org.flyware.util.page; gA+@p'XnR
5X`m.lhUc
/** GQkI7C
* @author Joa -eoXaP{[
* -|A`+1-R+
*/ q*4=sf,>
publicclass Page { z7g=L@
=?gB@vS
/** imply if the page has previous page */ OB5`a,5dI
privateboolean hasPrePage; >hmBV7nR
ify}xv
/** imply if the page has next page */ -mK;f$X
privateboolean hasNextPage; EG[Rda
g
O ;oM?|
/** the number of every page */ LL^WeD_Y
privateint everyPage; .a`(?pPr,
aqzIMOAf
/** the total page number */ RwptFO
privateint totalPage; j LG
Q^v"
a$ FO5%o
/** the number of current page */ K_sHZ
privateint currentPage; yJAz#~PO/
/KH,11)yc
/** the begin index of the records by the current kls
6Dk#
'9d]
B^)F
query */ 8C>\!lW"
privateint beginIndex; HTU?hbG(
ev;R; 0<
\_J;i[
/** The default constructor */ a8laPN
public Page(){ 1z$K54Mj
;XXB^,
} 1iTI8h&[@
lo:{T_ay
/** construct the page by everyPage B78e*nNS#2
* @param everyPage RO+N>Wkt
* */ MYVgi{
public Page(int everyPage){ w[X/|O
this.everyPage = everyPage; Q&A^(z}
} W2F *+M
nkn4VA?"
/** The whole constructor */ <UC_QPA\
public Page(boolean hasPrePage, boolean hasNextPage, 9#X"m,SB
Oq3]ZUVa
osdl dS
int everyPage, int totalPage, 5:sk&0:@U
int currentPage, int beginIndex){ 2=/,9ka~
this.hasPrePage = hasPrePage; T>2_ r6;
this.hasNextPage = hasNextPage; kMP3PS
this.everyPage = everyPage; 7uW=f kxT
this.totalPage = totalPage; o1zKns?
this.currentPage = currentPage; lrL:v~g
this.beginIndex = beginIndex; >j$y@"+
} vQ",rP%
;*}tbh3;.
/** /_l$h_{DH
* @return }a?( }{z-
* Returns the beginIndex. 6(0ME$
*/ N0_@=uE
publicint getBeginIndex(){ #l?E2
U4WL
return beginIndex; f\U(7)2
} |.EC>D/
l1I\khS
/** _(%;O:i
* @param beginIndex {GP#/5$=
* The beginIndex to set. > t~2
*/ T1[B*RwC
publicvoid setBeginIndex(int beginIndex){ ~,O&A B
this.beginIndex = beginIndex; dlJc~|
} ,?/AIL]_
fIwG9cR
/**
uoi~JF
* @return =Hf`yH\#
* Returns the currentPage. RoYwZX~
*/ -4!S?rHwd+
publicint getCurrentPage(){ q)rxv7Iu\
return currentPage; 8RaRXnJ
} vMv?
fE"
Or<OmxJg
/** ZXH{9hxd
* @param currentPage
Xn=
* The currentPage to set. 4RyQ^vL
*/ =s/UF _JN
publicvoid setCurrentPage(int currentPage){ ?w5>Z/V
this.currentPage = currentPage; y1Op Z
} _?rL7oTv
94Q?)0W$
/** *w5xC5*
* @return tLSM]Q
* Returns the everyPage. :TkR]bhm
*/ y^[?F>wB
publicint getEveryPage(){ D7|qFx;]g
return everyPage; 2qpUUo f
} M T]2n{e
4D=^24f`0
/** A w"Y_S8.
* @param everyPage *c>B,
* The everyPage to set. zr@HYl
*/ <:ptNGR
publicvoid setEveryPage(int everyPage){ R?5v//[
this.everyPage = everyPage; Cc&SHG*R
} Gc*p%2c
|{V@t1`
/** 7&w$@zs87
* @return %Fp1c K
* Returns the hasNextPage. , .]1N:
*/ J7FzOwd1h
publicboolean getHasNextPage(){ f=paa/k0
return hasNextPage; |* v w(
} @ebSM#F?
uq\[^
/** Mem1X rBH
* @param hasNextPage e]zd6{g[m
* The hasNextPage to set. ~ya@ YP]';
*/ EK2mJCC|
publicvoid setHasNextPage(boolean hasNextPage){ Aq;WQyZ2
this.hasNextPage = hasNextPage; 'y%*W:O
} jeWI<ms
{n 4W3
/** ^E]y >Y
* @return ;/ASl<t,
* Returns the hasPrePage. OOZxs?pR
*/ s_#6^_
publicboolean getHasPrePage(){ a?1Ml>R6P
return hasPrePage; 'bn$"A"{o
} m<I>NYfE
<_3OiU=w
/** [ XBVES8
* @param hasPrePage WY$c^av<
* The hasPrePage to set. vocWV/
*/ i{biQ|,.sL
publicvoid setHasPrePage(boolean hasPrePage){ ?5j}&Y3
this.hasPrePage = hasPrePage; QE4TvnhK
} )QAS 7w#k
FwwOp"[~t
/** |m F=X*
* @return Returns the totalPage. $SfYO!n7Q
* /pQUu(~h_
*/ ,d@FO|G#pt
publicint getTotalPage(){ VI k]`)#
return totalPage; Rj!9pwvT
} w)Z-, J
$0&<Jx
/** 9a$ 7$4m
* @param totalPage 0JU+v:J[=
* The totalPage to set. JmF:8Q3H
*/ C Xh>'K
publicvoid setTotalPage(int totalPage){ X?++I4\
this.totalPage = totalPage; 6Sz|3ms
} g=e~YM85
X}ft7;Jpy
} D9%t67s
)QW
p[bV
l?O%yf`s
g_;4@jwTP"
1T0s
UIY
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 q);@iiJ-
cCv@fks
个PageUtil,负责对Page对象进行构造: "R^0eNv$
java代码: _g%,/y 9y
_<u>?
Qt
Kb~i9x&
/*Created on 2005-4-14*/ #k|f%!-Vo
package org.flyware.util.page; irF+(&q]jh
5%]O'h
import org.apache.commons.logging.Log;
[7Liken
import org.apache.commons.logging.LogFactory; \{.c0
?fX`z(Z
/** qnJs,"sn
* @author Joa ,qwVDYJ
* kE854Ej
*/ @*=eqO
publicclass PageUtil { (05a9
gB])@O%/
privatestaticfinal Log logger = LogFactory.getLog qo7jrY5G
#Q/xQ`+|.
(PageUtil.class); R c
7Cx-yv
/** t/J|<Ooj?
* Use the origin page to create a new page +2,EK
* @param page t#2szr+
* @param totalRecords \kP1 Jr
* @return G;AJBs>Y}
*/ ;N^4R$Q.
publicstatic Page createPage(Page page, int ^?S lM
thSXri?kl
totalRecords){ YP73
return createPage(page.getEveryPage(), Ww
=ksggpB
ZY*_x)h+#7
page.getCurrentPage(), totalRecords); ]SUW"5L-
} AZva
[/U5M>#n
/** (p(-E
* the basic page utils not including exception FL[w\&fp
"c*#ZP
handler 0}9
* @param everyPage #Yx
/ubg6
* @param currentPage c/}-pZn<
* @param totalRecords [<.dOe7|
* @return page 8gJg7RxL
*/ z-m:l;
publicstatic Page createPage(int everyPage, int <;hy-Q()D
}*c[}VLN
currentPage, int totalRecords){ ne# %Gr
everyPage = getEveryPage(everyPage); 8gW$\
currentPage = getCurrentPage(currentPage); JfzfxfM
int beginIndex = getBeginIndex(everyPage, $KPf[JvQ
%<\tN^rP
currentPage); Id{Ix(O
int totalPage = getTotalPage(everyPage, ~;@\9oPpz%
yAQ)/u[|
totalRecords); G$t:#2
boolean hasNextPage = hasNextPage(currentPage, >S@><[C
Q&vU|y
totalPage); 6\RZ[gA?
boolean hasPrePage = hasPrePage(currentPage); w_*$wVl
&{S@v9~IT
returnnew Page(hasPrePage, hasNextPage, b
q8nV
everyPage, totalPage, pt%Y1<9Eh?
currentPage, o"g<Vz
6c*QBzNL
beginIndex); N3ccn
} $.O(K4S
`gdk,L]
privatestaticint getEveryPage(int everyPage){ v,c;dlg_
return everyPage == 0 ? 10 : everyPage; }i52MI1-XP
} *R8P brN
R:U!HE8j
privatestaticint getCurrentPage(int currentPage){ U/jCM?~
return currentPage == 0 ? 1 : currentPage; JnS@}m
} ]Uul~T
(S8hr,%n
privatestaticint getBeginIndex(int everyPage, int {i)FDdDGD
^t P|8k
currentPage){ })C}'!+]
return(currentPage - 1) * everyPage; =~'y' K]
} }8Nr.gY
@+Anp4%;Y
privatestaticint getTotalPage(int everyPage, int @!B%ynrG
ad`7[fI
totalRecords){ j9|1G-CM
int totalPage = 0; Oe&gTXo
b"eG8
if(totalRecords % everyPage == 0) }T"&4Rvs2R
totalPage = totalRecords / everyPage; d[sY]_ dj
else H'jo3d~+
totalPage = totalRecords / everyPage + 1 ; yK w.69.
^"+Vx9H"{
return totalPage; B1o*phM
g
} (#rhD}
m5lTf
privatestaticboolean hasPrePage(int currentPage){ w5q'M
return currentPage == 1 ? false : true; [ N0"mE<
} gZ6tbp,X
P=.T|l1
privatestaticboolean hasNextPage(int currentPage, M!
uE#|
M8|kmF\B
int totalPage){ 14yzGhA
return currentPage == totalPage || totalPage == ]EEac
Xd'B0kQaT
0 ? false : true; F<(?N!C?@
} 4x_#
1 -
iM~qSRb#mJ
#./8inbG
} xn}HB
J:0`*7
#X*=oG
@Wd1+Yky
TJs ~}&L
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。 S=3 H.D!f
r-5xo.J'
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 F`57;)F
S{zl<>+
做法如下: `,Y/!(:;
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 /\5u-o)
fi'\{!!3m^
的信息,和一个结果集List: 2Y%E.){
java代码: HQ^:5XH
>/y+;<MZ
td|O #R
/*Created on 2005-6-13*/ 1p(9hVA
package com.adt.bo; ,pa=OF
3'[
g2JR
import java.util.List; TFtD>q X
VevDW }4q*
import org.flyware.util.page.Page; :6W* ;<o
77;|PKE /
/** o*xft6U
* @author Joa n4
J*04K
*/ (BY5omlh
publicclass Result { z_ L><}H
Ia-nA|LBxI
private Page page; g
I4Rku
#)( D_*
private List content; ]/od p/jm
hmJa1fw=
/** nH|7XY9"
* The default constructor 2w>yW]
*/ W.TdhJW9
public Result(){ $J]o\~Z J
super(); =Y-mc#{8
}
|:5[`
$Zf]1?|xa
/** o7v,:e:
* The constructor using fields ,\D*=5
* Pa
*/&WeB
* @param page ^MUvd
* @param content ^-26K|{3
*/ a
VIh|v
public Result(Page page, List content){ 4!DXj0^
this.page = page; g5~wdhpb
this.content = content; <{1=4PA
} _:VIlg
U
td(4Fw||1y
/** y/!jC]!+c
* @return Returns the content. ZGQz@H5
*/ L'<.#(|
publicList getContent(){ +cC$4t0$^A
return content; \Culf'iX
} b1-'q^M
&v<Am%!N
/** utBKl'`
* @return Returns the page. @Jr@
fF}
*/ B"2#}HM
public Page getPage(){ a_o99lP
return page; ljJR7<
} YQ7tZl;:t
&E`=pe/e
/** Qi\"b
* @param content e6uVUzP4
* The content to set. >2dF^cDE-3
*/ L<_zQ
public void setContent(List content){ ;@V1*7y
this.content = content; R]"3^k*
} dn:/8~B"X
{V5eHn9/Q'
/** _A,mY6*
* @param page n$y@a?al
* The page to set.
A!^gF~ 5
*/ -9^A,vX
publicvoid setPage(Page page){ C,nU.0
this.page = page; P%Tffsl
} wvlM(
} CC.ri3+.
4-Cca
IHvrx:7
G~KYFNHr
%M
u$0~ct"
2. 编写业务逻辑接口,并实现它(UserManager, Z$:iq
W;!)Sj4<T!
UserManagerImpl) 0=V
-{
java代码: zb& 3{,
K5EU?J&
G2!J`}
/*Created on 2005-7-15*/ :XeRc"m<
package com.adt.service; U['|t<^uf
iuS*Vw
import net.sf.hibernate.HibernateException; I"bz6t\~|
}<qT[m
import org.flyware.util.page.Page; s|d"2w6t
#D|n6[Y'.t
import com.adt.bo.Result; i;mA|
>
,;<Bz|X
/** =9L1Z \f
* @author Joa %)p?&_
*/ D2MWrX
publicinterface UserManager { tl+ 9SBl
x f<wM]&
public Result listUser(Page page)throws yNOoAnGT W
MyaJhA6c
HibernateException; Qkb=KS%z
YG
J)_y
} u?I 2|}#
-)Of\4kx
a<CACWsN.T
_BHEK
<#~n5W{l
java代码: ]oxi~TwY^
-~v1@
'mO>hD`V
/*Created on 2005-7-15*/ /MZ^;XG
package com.adt.service.impl; -T{G8@V0I
*=(vIm[KL
import java.util.List; 3oBR
X}B]0z>
import net.sf.hibernate.HibernateException; z4{:X Da
B/Z-Cpz]
import org.flyware.util.page.Page; D-4{9[
import org.flyware.util.page.PageUtil; 'b:e8m
S pk8u4
import com.adt.bo.Result; xq<X:\O
import com.adt.dao.UserDAO; cV:Ak~PKl
import com.adt.exception.ObjectNotFoundException; |&U{
z?
import com.adt.service.UserManager; 2B"&WKk
frT<9$QUL
/** &gsBbQ+qA
* @author Joa p> g[: ~
*/ v W4n>h}]
publicclass UserManagerImpl implements UserManager { AL;4-(KH
%uDH_J|^
private UserDAO userDAO; "NtY[sT{V
R*DQLBWc
/** 7>
8L%(7
* @param userDAO The userDAO to set. _BZ6Ws$C2
*/ XeX`h_
publicvoid setUserDAO(UserDAO userDAO){ q![`3m-d.
this.userDAO = userDAO; |dhKeg_
} `k`P;(:
2]=`^rC*
/* (non-Javadoc) VhN 6
oI
* @see com.adt.service.UserManager#listUser gUY~
l= c
J?C:@Q
(org.flyware.util.page.Page) *USG
p<iH
*/ &yG5w4<
public Result listUser(Page page)throws -tfUkGdx;l
-ARks_\
HibernateException, ObjectNotFoundException { G`RQl@W>)(
int totalRecords = userDAO.getUserCount(); "3/&<0k
if(totalRecords == 0) qHnX)
throw new ObjectNotFoundException us+z8Mz
|Wr$5r
("userNotExist"); 0+e
page = PageUtil.createPage(page, totalRecords); 2'u%
List users = userDAO.getUserByPage(page); O L 9(~p
returnnew Result(page, users); 1!NrndJ I
} in6*3C4
9{
#5~WP
} 7}vI/?r
F^81?Fi.
K&eT*JW>
qA"BoSw 4
51Vqbtj^
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 )qe
rA
{@6:kkd
询,接下来编写UserDAO的代码: eph2&)D}Ep
3. UserDAO 和 UserDAOImpl: x#gZC1$Y
java代码: sUU[QP-
FbRGfHL[
L9-Jwy2(>
/*Created on 2005-7-15*/
HQ]mDo
package com.adt.dao; |<'6rJ[i>
BoxtP<C"
import java.util.List; ~6IY4']m*
OTl9MwW
import org.flyware.util.page.Page; NfnPXsad
2vh }:A_
import net.sf.hibernate.HibernateException; )K$YL='kX
z%#-2&i
/** +(PUiiP'"v
* @author Joa M\-[C!h,
*/ eL~3CAV{
publicinterface UserDAO extends BaseDAO { (Ldvx_
e ^oGiL~
publicList getUserByName(String name)throws E- [Eg
mP Hto-=fB
HibernateException; ;!G#Y
Oe
'&e8;X
publicint getUserCount()throws HibernateException; OGIv".~s4
CAC%lp
publicList getUserByPage(Page page)throws 1Iy1xiP
WMC\J(@.
HibernateException; H(gY=
TY'c'u,
} Hqs!L`oW)
Ar[|M2|
U[02$gd0l
}X?#"JFX?
wN58uV '
java代码: fgeh;cD
1G7l+6w5~^
[^s;Ggi9
/*Created on 2005-7-15*/ ?_d6;
package com.adt.dao.impl; T- _))
l
_%<U
import java.util.List; ]J'TebP=L5
8toOdh
import org.flyware.util.page.Page; z=) m6\
/'aqQ
K<
import net.sf.hibernate.HibernateException; "+T`{$Z=C
import net.sf.hibernate.Query; }oA>0Nw$K
v@tEHRadz
import com.adt.dao.UserDAO; !u@P\8M}
)~)l^0X
/** )ds]fvMW]N
* @author Joa Yj1|]i5b
*/ Vy
I\Jmr
public class UserDAOImpl extends BaseDAOHibernateImpl JPAjOcmU/
`
PQQU~^
implements UserDAO { "WuUMt
\c4jGJ
/* (non-Javadoc) wpuK?fP
* @see com.adt.dao.UserDAO#getUserByName 3 a.!9R>
\?
)S{
(java.lang.String) c0'ryS_Z9
*/ D<d,9 S,)
publicList getUserByName(String name)throws 8 5X}CCQ
lUB?eQuN_
HibernateException { &`@YdZtd"
String querySentence = "FROM user in class D\&S {
84.L1|k
com.adt.po.User WHERE user.name=:name"; Mq)]2>"v
Query query = getSession().createQuery (87| :{
RW+u5Y
(querySentence); I51]+gEN
query.setParameter("name", name); $uDgBZA\
return query.list(); Qgj# k
} myR{}G
H" `'d
/* (non-Javadoc) 'k[qx}
* @see com.adt.dao.UserDAO#getUserCount() ,\iHgsZ
*/ 0 (wu
publicint getUserCount()throws HibernateException { (Fon!_$:
int count = 0; KCyV |,+n
String querySentence = "SELECT count(*) FROM sdZ$3oE.
i,r:R
g~
user in class com.adt.po.User"; 17Cb{Q
Query query = getSession().createQuery uAeo&|&
u6Gqg(7hw
(querySentence); FHQ`T\fC$@
count = ((Integer)query.iterate().next 88v8lt;R
p"p~Bx
()).intValue(); v,ZYh w
return count; H5x7)1Ir|
} +FqD.= 8
xj;:B( i
/* (non-Javadoc) $ ubU"
* @see com.adt.dao.UserDAO#getUserByPage @@H_3!B%4v
0fXMY-$I
(org.flyware.util.page.Page) G-T^1?
*/ \L(cFjLIl
publicList getUserByPage(Page page)throws Dhn7N8(LF!
:,0(aB
HibernateException { 6P{^j
String querySentence = "FROM user in class kP%hgZ
-_ I)5*N
com.adt.po.User"; -{cmi,oy
Query query = getSession().createQuery i7.8H*z'
PK2;Ywk`
(querySentence); 5U~KYy^v
query.setFirstResult(page.getBeginIndex()) ;nBf
.setMaxResults(page.getEveryPage()); =%7drBo D
return query.list(); +<1 |apS1
} Qjfgxy]
8D )nM|
} H:c5
q0O^x
Z&n[6aV'F
T o["o!(;z
5)%ahmY
*2X~NJCt
至此,一个完整的分页程序完成。前台的只需要调用 @-)?uYw:r
*lSu=dk+
userManager.listUser(page)即可得到一个Page对象和结果集对象 0A)0Zw
src9EeiV
的综合体,而传入的参数page对象则可以由前台传入,如果用 ;-Yvi,sS+
l/G+Xj4M
webwork,甚至可以直接在配置文件中指定。 s=n4'`y1
MV" n{1B
下面给出一个webwork调用示例: +06{5-,
java代码: uB
I/3aQ
72sqt5C]
eyMn! a
/*Created on 2005-6-17*/ j9h/`Bn
package com.adt.action.user; /q IQE&V-
PeIx41. +s
import java.util.List; 0V~zZ/e
S oeoUI]m
import org.apache.commons.logging.Log; uBRlvNJ
import org.apache.commons.logging.LogFactory; 7
XxZF43
import org.flyware.util.page.Page; VP#KoX85
F=Bdgg9s
import com.adt.bo.Result; z}MxMx
c4h
import com.adt.service.UserService; O6G\0o
import com.opensymphony.xwork.Action; Lm4`O%
\}jA1oy
/** %/Wk+r9uu
* @author Joa ,&UKsrs_
*/ :PT{>r[
publicclass ListUser implementsAction{ AmF[#)90P
r%=-maPL[
privatestaticfinal Log logger = LogFactory.getLog _^BA;S@
V$ H(a`!
(ListUser.class); w7@`:W
SI!A?34
private UserService userService; 9`*ST(0/
<<0sv9qw1
private Page page; n2K1X!E$
h+W$\T)
privateList users; G`FYEmD
~lo43$)^
/* X84T F~2Y
* (non-Javadoc) 2=_$&oT**
* >%tG[jb
* @see com.opensymphony.xwork.Action#execute() }:2##<"\t
*/ =de'Yy:\-
publicString execute()throwsException{ zGtJ@HbB
Result result = userService.listUser(page); hW#^H5?
page = result.getPage(); u!K1K3T6k
users = result.getContent(); e`n ZiM>
return SUCCESS; /JS_gr@DK
} u#Ig!7iUu
OyO]; Yk
/** T`E0_ZU;
* @return Returns the page. 4k225~GQ:C
*/ w^0hVrws=,
public Page getPage(){ M{L- V
return page; n<C]
6H
} |,$&jSe
n[Q(q[ULV
/** /wLBmh1"
* @return Returns the users. ]Kt@F0U<o
*/ {5B j*m5
publicList getUsers(){ 6.)ug7aF
return users; 2K9X (th1
}
JQQ[jl;
pWxk^qhe/
/** #+ch
* @param page xq((]5P y
* The page to set. ^.6yzlY
*/ fQ5v?(
publicvoid setPage(Page page){ JN/=x2n.
this.page = page; q@wD@_
} 1b3 a(^^E
9E ^!i
/** Z{B
e
* @param users I,hw0e
* The users to set. 3Z";a
*/ d}Pfj=W
publicvoid setUsers(List users){ ;0Z-
this.users = users; 7GO9z<m)
} vi}16V84l
%4nf(|8n
/** +KbkdYZ
* @param userService kU/MvoV
* The userService to set. ]`)5 Qe4
*/ n}UJ-\$
publicvoid setUserService(UserService userService){ lMFo)4&P
this.userService = userService; qGA|.I9,
} ^UKAD'_#%O
} NfClR HpVc
Z;G*wM"
',R%Q0Q
i F+:j8
b
R>0[w$
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, >T]9.`xhK
iHhdoY[]
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 Tv"T+!Z
)pl5nu#<
么只需要: :f[ w
java代码: Rj";?.R*e
cjL)M=pIS
pL,XHR@Iv
<?xml version="1.0"?> =H)]HxEEM
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork trDw|WA
w8X5kk
1.0//EN" "http://www.opensymphony.com/xwork/xwork- Sesdhuy.@
y^ skE{
1.0.dtd"> zd5=W"Y;]
F2
B(PGa7
<xwork> }@HgF M"
e$s&B!qJ
<package name="user" extends="webwork- ^"7-`<J
w=XIpWl
interceptors"> }ex4dhx2M
"9P @bA
<!-- The default interceptor stack name DyqqY$ vH(
fof}I:vO
--> fYPu%MN7
<default-interceptor-ref [RKk-8I
9.(|ri
name="myDefaultWebStack"/> l1T`[2
?Ojv<L-f.:
<action name="listUser" 8a*&,W
d_we?DZ|
class="com.adt.action.user.ListUser"> JL
G!;sov
<param HsTY* ^V
[q%`q`EG
name="page.everyPage">10</param> Lx>[`QT
<result t#(=$
]0T*#U/P
name="success">/user/user_list.jsp</result> Ee MKo
</action> a0)w/A&
o*A, 6y
</package> +JYb)rn$^
Zq&'a_
</xwork> lha;|
$yi:0t8t
0?ab'vYcp
odca?
*Zg=cI@)(
:q3w;B~
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 uxn+.fA
H0&wn#);6R
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 mlc8q s
1c QF(j_
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 y@v)kN)Y9\
w tGS"L
t0fgG/f'
\mLEwNhRY
]v}W9{sY
我写的一个用于分页的类,用了泛型了,hoho o:v_I{
##''d||u
java代码: s@$0!8sxm
q !9;JrX
Lk]|;F-2i
package com.intokr.util; @{RhO|UR
+a*Ic8*
import java.util.List; JAKs [@:
o|d:rp!^
/** 7]Qxt%7/>
* 用于分页的类<br> &8f/ 6dq
* 可以用于传递查询的结果也可以用于传送查询的参数<br> 2He R1m<
* W=EcbH9/.)
* @version 0.01 C3^3<
* @author cheng HaL'/V~
*/ Y?1T
XsvF
public class Paginator<E> { bBML +0a
privateint count = 0; // 总记录数 lIEZ=CEmY
privateint p = 1; // 页编号 $X;OK
privateint num = 20; // 每页的记录数 >{(c\oMD
privateList<E> results = null; // 结果 [mwqCW&
3}g>/F~
/** ^W=hs9a+F
* 结果总数 n~
$S
*/ tk-)N+M.
publicint getCount(){ 0TV16--
return count; 5l@}1n
} p q?# X0
a!6r&<s=E
publicvoid setCount(int count){ indbg
d
this.count = count; FZU1WBNL%t
} e`][zx
w(_:+-rqQ<
/** -">Tvi4
* 本结果所在的页码,从1开始 c"knzB vy
* o$->|k
* @return Returns the pageNo. c]VK%zl
*/ B!`.,3
publicint getP(){ WxD$k3U
return p; D`Vb3aNB=L
} >cjxu9Vr1K
SkipPEhA
/** ^"4?Q
* if(p<=0) p=1 ;W+1 H !
* hC{2LLu;n
* @param p HW_2!t_R
*/ uCW}q.@4
publicvoid setP(int p){ ~ cu+QR)
if(p <= 0) h$~$a;2cR
p = 1; H.n|zGQTB
this.p = p; 4
}_}3.
} N{RHbSa(
c\P}ZQ
/** *WzPxQ_
* 每页记录数量 LM"b%
*/ GQ.akA_(
publicint getNum(){ 26zif
return num; +&X>ul
} xXV15%&
}
-hH2
/** kz#x6NXj
* if(num<1) num=1 yYk?K<ou
*/ 3\<(!yY8
publicvoid setNum(int num){ Um/ g&k
if(num < 1) (|6!pQ7
num = 1; rY6bc\?`x
this.num = num; |SJ%Myy
} iu+H+_
uWXxK"J.
/** blbzh';0}
* 获得总页数 L(`q3>iC4.
*/ HwMe^e;
publicint getPageNum(){ +x:VIi
return(count - 1) / num + 1; M@.?l=1X
} ok&v+A
oFGgr2Re
/** OJcI0(G
* 获得本页的开始编号,为 (p-1)*num+1 rPW9lG
*/ OHF:E44k
publicint getStart(){ {\!@k\__
return(p - 1) * num + 1; #>$w9}gFi
} 97!VH>MX
W9SEYkg
/** 6ozBU^n
* @return Returns the results. ~]K<Vh`
*/ N;,N6&veK/
publicList<E> getResults(){ yF&?gPh&
return results; eY$Q}BcW
} g5&,l
W.b?~
public void setResults(List<E> results){ bzMs\rj\
this.results = results; q/tC/V%@(
} }xzbg
$0E_4#kwB
public String toString(){ +@oo8io
StringBuilder buff = new StringBuilder b{JxTT}03
VrRBwvp-K
(); ;,_c1x/F
buff.append("{"); Uw_z9ZL
buff.append("count:").append(count); 9=^4p=1J
buff.append(",p:").append(p); |a Ht6F
buff.append(",nump:").append(num); =gr3a,2
buff.append(",results:").append kIUb`b>B
QVrMrm+vRv
(results); ODqWXw#
buff.append("}"); ut^^,w{o>
return buff.toString(); xSHeP`P^X
} 80ms7 B
ep"54o5=d
} 7_#i,|]58
E
:Y
*;
ddD $ 4+