Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Je1d|1!3
_M&TT]a
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 z8Q!~NN-K
*qd:f!Q3
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 <'a~ Y3B"o
k$w~JO!s
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 EKwQ$?I
I0Pw~Jj{
。 lkn|>U[
0bg"Q4
分页支持类: 94u{k1d x
.+9hm|
java代码: *@2Bh4
_ E;T"SC
Zv u6/#
package com.javaeye.common.util; Z/#_Swv
w,LtQhQ
import java.util.List; CLR1CGnn7
O
VV@
publicclass PaginationSupport { m[9.'@ye
06&J!,p
:
publicfinalstaticint PAGESIZE = 30; :C~Ar]
Ott6y
privateint pageSize = PAGESIZE; 5)k8(kH
uN|A}/hr]
privateList items; `g)}jo`W
[XfR`@
privateint totalCount; /{i~CGc;"
f%Q{}fC{*
privateint[] indexes = newint[0]; Xz+%Ym
*o6}>;
privateint startIndex = 0; bx0.(Nv/X
AjC:E+g
public PaginationSupport(List items, int :t}\%%EbmE
b\k]Jx
totalCount){ h)KHc/S
setPageSize(PAGESIZE); jEc_!Q
setTotalCount(totalCount); YG "Ta|@5
setItems(items); 51#*8u+L
setStartIndex(0); $
V^gFes
} p@m0Oi,=
z:Ml;y
public PaginationSupport(List items, int qpjY &3SI
1Ms[$$b$
totalCount, int startIndex){ /k#-OXP~
setPageSize(PAGESIZE); g 9_ zkGc7
setTotalCount(totalCount); ~wvt:E,fC
setItems(items); Rn1oD3w
setStartIndex(startIndex); .Ro/ioq
} LD$5KaOW
b+rxin".
public PaginationSupport(List items, int ,T/Gv;wa2
D -}>28
totalCount, int pageSize, int startIndex){ zTz}H*U
setPageSize(pageSize); `c`VIq?
setTotalCount(totalCount); 0Y.z
setItems(items); Kl1v^3\{
setStartIndex(startIndex); 7+O)AU{
} @CMI$}!{V
=~#mF<z5
publicList getItems(){ j{@O%fv=
return items; ( xs'D4
} pGbfdX
i! .]U@{k
publicvoid setItems(List items){ DeO-@4+qKd
this.items = items; FXQWT9Kk~_
} ke4E1T-1n
LCF}Y{
publicint getPageSize(){ th?+TNb^
return pageSize; {15j'Qwm
} vgfC{]v<W]
^_7|b[Bt
publicvoid setPageSize(int pageSize){ oV|O`n
this.pageSize = pageSize; ({f}Z-%
}
!`69.v
X+hHE kJ
publicint getTotalCount(){ Z%t_1t
return totalCount; 6FUW^dt
} w:&""'E
2M
%j-yG"
publicvoid setTotalCount(int totalCount){ W5*ldXXk
if(totalCount > 0){ /x VHd
this.totalCount = totalCount; @CprC]X
int count = totalCount / yx-{PjX
Y.^L^ "%dF
pageSize; p|>*M\LE#
if(totalCount % pageSize > 0) +8Xjk\Hi
count++; I!x.bp~V!
indexes = newint[count]; Y:^hd809
for(int i = 0; i < count; i++){ Hon2;-:]{]
indexes = pageSize * |'^s3i&w
%iyc1]w{
i; 1\}vU
} FO!Td
}else{ A*JOp8\)
this.totalCount = 0; /{T&l*'
} iaGA9l<b
} j=WxtMS
K-qWT7<
publicint[] getIndexes(){ u]^s2v
return indexes; 0PzSp ]
} |v&)O)Jg
Jo? LPR
\6
publicvoid setIndexes(int[] indexes){ VB |?S|<
this.indexes = indexes; %hB-$nE
} l.Q
~7m`p3W@
publicint getStartIndex(){ XlppA3JON|
return startIndex; m#"_x{oa
} "?"
:
-&+:7t
publicvoid setStartIndex(int startIndex){ Cbbdq%ySI
if(totalCount <= 0) ddn
IKkOp
this.startIndex = 0; u
Ie^Me
elseif(startIndex >= totalCount) 7?.uAiM'zT
this.startIndex = indexes x :SjdT
-(vHy/Hz.
[indexes.length - 1]; )nUdU
= m
elseif(startIndex < 0) _c5@)I~
this.startIndex = 0; [2:d@=%.
else{ ZO+RE7f*?c
this.startIndex = indexes SN6 QX!3
g2OnLEF]s
[startIndex / pageSize]; pPReo)
} ]_KWN$pd
} vYgJu-Sl
/[R=-s ;
publicint getNextIndex(){ * #yF`_p
int nextIndex = getStartIndex() + K\xz|Gq
V@'Xj .ze
pageSize; l@`k:?
if(nextIndex >= totalCount) xP8/1wd.
return getStartIndex(); 0h-NT\m
else gtKih
return nextIndex; D*l(p5[
} j.M]F/j
l)r\SE1
publicint getPreviousIndex(){ y-pdAkDh
int previousIndex = getStartIndex() - :zW? O#aL-
Z$z-Hx@%
pageSize; [* xdILj
if(previousIndex < 0) 7F`\Gz_2
return0; qlhc"}5x }
else S|tD8A
return previousIndex; Z%~}*F}7X
} ^B"LT>.[
}T_"Vg q
} W ?x~"-*
fh#:j[R4e
yQJ0",w3o.
V_i&@<J
抽象业务类 `E~"T0RX
java代码: Y3@+aA
~/^fdGr
!(*&P
/** m"L^tSD~
* Created on 2005-7-12 [REH*_
*/ B:>:$LIL
package com.javaeye.common.business; QPuc{NcB>
O>E}Lu;|
import java.io.Serializable; {-)^?Zb
@
import java.util.List; Csyh
'v
6;E3|st1X
import org.hibernate.Criteria; ,Uh^e]pC
import org.hibernate.HibernateException; +9/K|SB{$
import org.hibernate.Session; gs<~)&x
import org.hibernate.criterion.DetachedCriteria; uh\G6s!4/
import org.hibernate.criterion.Projections; p39$V[*g(
import =Ti!9_~
ru:"c^W:[
org.springframework.orm.hibernate3.HibernateCallback; 1
-Z&/3T]
import 6{I7=.V
p3_
Qx
org.springframework.orm.hibernate3.support.HibernateDaoS 6+=_p$crMx
k7uX!}
upport; k;qS1[a
CG uuadNI
import com.javaeye.common.util.PaginationSupport; L IKuK#
rL<N:@HL
public abstract class AbstractManager extends [kJ;Uxncz~
5$i(f8*
HibernateDaoSupport { A":=-$)
hq"nRH
privateboolean cacheQueries = false; =LGM[Z3$s
LYAGpcG
privateString queryCacheRegion; (YJ2-
X~
Dx\~#$S!=
publicvoid setCacheQueries(boolean 5H'Iul<Os
@l3&vt2=J
cacheQueries){ =pzTB-G
this.cacheQueries = cacheQueries; xJ#O|7N
} ]G&[P8hzB
u/k'
ry=
publicvoid setQueryCacheRegion(String Ud"_[JtGM
?Kmz urG
queryCacheRegion){ S#CaJ}M
this.queryCacheRegion = Gy+c/gK
;+DMv5A "
queryCacheRegion; k
%{q
q v
} ;=0-B&+v
}2Ge??!
publicvoid save(finalObject entity){ K}q5,P(
getHibernateTemplate().save(entity); ^0"fPG`
} uih8ZmRt
uJ|,-"~F
publicvoid persist(finalObject entity){ 0^L:`[W+
getHibernateTemplate().save(entity); TN Z-0
}
"X=^MGV
p Dg!Cs
publicvoid update(finalObject entity){ 1z; !)pG.
getHibernateTemplate().update(entity); 5T"h7^}e
} O*2{V]Y
@
c.Izm+9k
publicvoid delete(finalObject entity){ d:Z|It
getHibernateTemplate().delete(entity); 6wOj,}2Mn
} q-1vtbn
Dd
OK&
publicObject load(finalClass entity, ]c\`EHN
@6[aLF]F
finalSerializable id){ ! qtj1.w
return getHibernateTemplate().load A\"4[PXpQ
@CPkP
(entity, id); u3cg&lEgT
} V[8!ymi0
gjJ:s,Fg
publicObject get(finalClass entity, wd,6/5=lh
>0 := <RW
finalSerializable id){ cri-u E?
return getHibernateTemplate().get rWL&-AZQl
.i7"qq.M
(entity, id); X#W6;?Z\
} OK@yMGz1I
v&])D/a
publicList findAll(finalClass entity){ kT^`j^Jr
return getHibernateTemplate().find("from [8b{Ybaz
ASS<XNP
" + entity.getName()); Pr/q?qZY
} HT_nxe`E
W
Emh
publicList findByNamedQuery(finalString >)`*:_{
h-03]M#8=
namedQuery){ h?QGJ^#8
return getHibernateTemplate t,5AoK/NL9
BgsU:eKe
().findByNamedQuery(namedQuery); w~AO;X*Ke"
} o3'Za'N.
4E$6&,\
publicList findByNamedQuery(finalString query, qz-lQ
9]S;%:64
finalObject parameter){ ^Y"|2 :
return getHibernateTemplate BE!WCDg,
oJc v D
().findByNamedQuery(query, parameter); 9 KU3)%U
} %8KbVjn
y<ZT~e
publicList findByNamedQuery(finalString query, SQdK`]4
'V4B{n7h
finalObject[] parameters){ T#YJ5Xw
return getHibernateTemplate YB9)v5Nz(
|v"&Y
().findByNamedQuery(query, parameters); .A7ON1lc^C
} T\TKgO=)
NE?tfj
publicList find(finalString query){ 5BM rn0
return getHibernateTemplate().find \`?4PQ
Yx"~_xA/u
(query); 5Noy~;
} ^B'N\[
WHR6/H
publicList find(finalString query, finalObject .#Lu/w' -M
X> V`)
parameter){ 6P`!yBAu
return getHibernateTemplate().find Uclta
`_.(qg
(query, parameter); 6$5SS#
} bx3kd+J7
b59NMGn
public PaginationSupport findPageByCriteria SuJ4)f;'0
Y#oY'S .;y
(final DetachedCriteria detachedCriteria){ 3W@ta1
return findPageByCriteria =BgQSs/^c
,Y27uey{wa
(detachedCriteria, PaginationSupport.PAGESIZE, 0); $+w -r#,
} Y'x+!&H
I~>Ye<g#
public PaginationSupport findPageByCriteria IUwMIHq&sW
h~.z[
(final DetachedCriteria detachedCriteria, finalint dJ=z'?|%g
hR~~k~84
startIndex){ $McbVn)~f
return findPageByCriteria 2PEA<{u
@l@erCw@
(detachedCriteria, PaginationSupport.PAGESIZE, w7Vl,pN,
-e_L2<7
startIndex); !WQ S.&
} ??? ;H
Kd').w
public PaginationSupport findPageByCriteria YjwC8#$
e'5sT#T9 l
(final DetachedCriteria detachedCriteria, finalint W4S! rU
nB#XQ8Nzx^
pageSize, {Nny.@P)H
finalint startIndex){ S2"H E`
return(PaginationSupport) U<.,"`=l
7eQc14
getHibernateTemplate().execute(new HibernateCallback(){ W3 2]#M=
publicObject doInHibernate NekPl/4
^#&:-4/
(Session session)throws HibernateException { #'oGtFCd`
Criteria criteria = 9*j$U$:'
0m&W: c
detachedCriteria.getExecutableCriteria(session); (2p<I)t
int totalCount = z3Q#Wmv2
%H8s_O
((Integer) criteria.setProjection(Projections.rowCount }(Dt,F`
PuGc{kt
()).uniqueResult()).intValue(); {K42PmQL
criteria.setProjection +:#UU;W
pn-`QB:{h
(null); >}6V=r3[+
List items = >m4Q*a4M
YuKg|<WO
criteria.setFirstResult(startIndex).setMaxResults [X\~J &kD
S_dM{.!Z(,
(pageSize).list(); wJu,N(U
PaginationSupport ps = KkD&|&!Q7u
9 Aq\1QC
new PaginationSupport(items, totalCount, pageSize, j55;E
E!
F*j0o
+B5
startIndex); w4(g]9^Q
return ps; H&E3RU>`
} .<kbYo:MV
}, true); fH*1.0f]6
} }>< v7
jltW@co2sV
public List findAllByCriteria(final L@>$
Aw
p^THoF'~T
DetachedCriteria detachedCriteria){ dxK3462
return(List) getHibernateTemplate 5><KTya?=
8q_"aa,`
().execute(new HibernateCallback(){ )H|cri~D
publicObject doInHibernate t?;\'
9HBRWh6
(Session session)throws HibernateException { s?~lMm' !
Criteria criteria = r0(* ]K:.
{?hpW+1,#
detachedCriteria.getExecutableCriteria(session); $s"{C"4q
return criteria.list(); AOscewQ
} x#c%+
}, true); ;?.w!|6
} s>c0K@ADO
\^]*T'>b
public int getCountByCriteria(final ?{rpzrc!*
q!4eVg*
DetachedCriteria detachedCriteria){ AtYqD<hl:
Integer count = (Integer) Q7 @oAeNd
S\R5SRE
getHibernateTemplate().execute(new HibernateCallback(){ +
[~)a4#
publicObject doInHibernate fe8}2#<o
2 pmqP-pKd
(Session session)throws HibernateException { "xV0$%
Criteria criteria = Y4Y~ep
Nn='9s9F?}
detachedCriteria.getExecutableCriteria(session); nR`)kORc
return >vKOG@I
#bwGDF
criteria.setProjection(Projections.rowCount #$ooV1E
gnN"6r1
()).uniqueResult(); rBUWzpE"
} z=yE- I{
}, true); i)th] 1K%
return count.intValue(); am+w<NJ(us
} P^[y~I#{
} _bn
"c@s
9>9,
0S2/,[-u+
K7c[bhi_w
j06qr\Es
vo>i36
用户在web层构造查询条件detachedCriteria,和可选的 XJe}^k
2KtK.2; 7
startIndex,调用业务bean的相应findByCriteria方法,返回一个 TXo`P_SE
kJK*wq]U6
PaginationSupport的实例ps。 Wn-'iD+9<
kwUy^"O
ps.getItems()得到已分页好的结果集 w0^}c8%WR
ps.getIndexes()得到分页索引的数组 L L?
.E
ps.getTotalCount()得到总结果数 )=pa*
ps.getStartIndex()当前分页索引 zvK'j"Wq=
ps.getNextIndex()下一页索引 D`R~d;U~
ps.getPreviousIndex()上一页索引 SFR<T
;cfPS
<S3s==Cg
&a.A8v)
7j8lhrM}^
53WCF[
__Zex5Y#-
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 aM+Am,n`@
B
*%ey?
,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 0Ua&_D"
PUmgcMt
一下代码重构了。 FxmHy{JG
V{UY_
e8W
我把原本我的做法也提供出来供大家讨论吧: >R}G
U^8S@#1Q
首先,为了实现分页查询,我封装了一个Page类: M $f6.j
java代码: `j8pgnY>5~
\,ne7G21j
0*E_D
/*Created on 2005-4-14*/ Q^bYx (r5w
package org.flyware.util.page; J`[gE`d
83J63Xa
/** 28qlp>U
* @author Joa ![9$ru
* -&l%CR,U
*/ {gh<SZsE
publicclass Page { +kN,OK~
Zc'^iDAY
/** imply if the page has previous page */ ,b4oV
privateboolean hasPrePage; uS5G(} [
25 cJA4
/** imply if the page has next page */ (hEg&@
privateboolean hasNextPage; _y&XFdp
\q\"=
/** the number of every page */ 0S96x}]J B
privateint everyPage; q%LjOPE
V
Xdf4%/Op
/** the total page number */ hn~btu9h
privateint totalPage; #p
;O3E@
#\
uB!;Q
/** the number of current page */ UA|\D]xe
privateint currentPage; ^a<kp69qS
U\(71=
/** the begin index of the records by the current +NbiUCMX
`hdN 6PgK
query */ /24}>oAH
privateint beginIndex; >#)%/Ti}DU
EJ(36h
T%Bz >K
/** The default constructor */ .yDGw Lry
public Page(){ /b\c<'3NY
1nw\?r2
} (%OZ `?`
nRvaCAt^
/** construct the page by everyPage yj=OR|v
* @param everyPage \d*ts(/a*
* */ \~g,;>%7Y
public Page(int everyPage){ 'iTY?
this.everyPage = everyPage; c8Q}m(bhWI
} Xmi~fie
XOLE=zdSp
/** The whole constructor */ KY}H-
public Page(boolean hasPrePage, boolean hasNextPage, ltlo$`PR
hw.>HT|.N
bYoBJ
#UX
int everyPage, int totalPage, 8
/%{xB^
int currentPage, int beginIndex){ :d pwr9)
this.hasPrePage = hasPrePage; !FD d5CS
this.hasNextPage = hasNextPage; I,<?Kv
this.everyPage = everyPage; =Z{jc
this.totalPage = totalPage; ?J,,RK.
this.currentPage = currentPage; @meT8S9t
this.beginIndex = beginIndex; 2W2T
} TMo DN%{
{o 2 qY|S
/** `a!9_%|8
* @return Rj4C-X4=
* Returns the beginIndex. MB7*AA;
*/ -Lu&bVt<>
publicint getBeginIndex(){ R}cNhZC
return beginIndex; ec`re+1r
} jRd$Vt
#lg R"%
/** $wi4cHh
* @param beginIndex -cijLlz%+
* The beginIndex to set. zhm 0J-g
*/ C JER&"em7
publicvoid setBeginIndex(int beginIndex){ a+cDH
this.beginIndex = beginIndex; lx=tOfj8
} ]%y>l j?Y
46pR!k
/** 7~F~ 'V
* @return xQ7U$QF|]
* Returns the currentPage. "l9aBBiu
*/ 1.+6x4%rV
publicint getCurrentPage(){ gnjhy1o
return currentPage;
)UM^#<-
} |35OA/O?X
s'oNW
/** tv.<pP9-C
* @param currentPage S1I.l">P
* The currentPage to set. k=[s%O6H
*/ 92t.@!m`
publicvoid setCurrentPage(int currentPage){ -fl6M-CYX
this.currentPage = currentPage; ,oh;(|=
} r uGeN
}{VOy PG
/** Z.u1Dz
* @return jS~Pdz
* Returns the everyPage. jeJgDAUv
*/ `d$@1
publicint getEveryPage(){ Ei):\,Nv
return everyPage; FOk;=+
} @aZ Tx/
P!E2.K,
/** /1v9U|j
* @param everyPage KMz!4N
* The everyPage to set. )S(Ly.
*/ XC)9aC@s
publicvoid setEveryPage(int everyPage){ *;]}`r
this.everyPage = everyPage; }ePl&-9T
} *=2W:,$
~bxev/$d
/** 4|E^
#C
* @return giX[2`^NG
* Returns the hasNextPage. xsn=Ji2 F
*/ )?UoF&c/
publicboolean getHasNextPage(){ Jp_#pV*}:
return hasNextPage; r+8D|stS
} j&oRj6;Ha+
#}FUa u$
/** V(F9=r<X
* @param hasNextPage _OTVQo Ap
* The hasNextPage to set. Bskp&NV':
*/ .WqqP
publicvoid setHasNextPage(boolean hasNextPage){ Lr D@QBT
this.hasNextPage = hasNextPage; j}eb
_K+I
} DkEv1]6JI_
T1$E][@Iv
/** p>;@]!YWQ
* @return G:":CX"O(
* Returns the hasPrePage. 5EcVW|(
*/ UGI<V!
publicboolean getHasPrePage(){ w CB*v<*
return hasPrePage; v={{$=/t
} KDq="=q
o~IAZU39
/** nYjrEy)Q
* @param hasPrePage e))L&s
* The hasPrePage to set. 3@Mh* \;\b
*/ X!ruQem /
publicvoid setHasPrePage(boolean hasPrePage){ jRg
gj`o
this.hasPrePage = hasPrePage; 3WJk04r
} #mw!_]
@m9pb+=v
/** q\?s<l63
* @return Returns the totalPage. > 0MP[
* Z|uvrFa
*/ ovTL'j!
publicint getTotalPage(){ p>`rTaeZg
return totalPage; Iz09O:ER
} 1xW!j!A;
B/1j4/MS
/** 7;fC%Fq
* @param totalPage eZa*WI=
* The totalPage to set. 3-
Kgz
*/ w}>%E6UY
publicvoid setTotalPage(int totalPage){ gmRc4o
this.totalPage = totalPage; OL>>/T
} *x|%Nua"
7@fS2mu
} #5@(^N5p`
lx%c&~.DiB
d#rr7O
fd&Fn=!
P_1WJ
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 e$Ds2%SaT
Qh1pX}X
个PageUtil,负责对Page对象进行构造: FBNLszT{L
java代码: 9{jMO
+Y sGH~jX
#&}-
q
RA
/*Created on 2005-4-14*/ -[7+g
package org.flyware.util.page; bE
!SW2:M
1'E=R0`pA
import org.apache.commons.logging.Log; \%a0Lp{ I
import org.apache.commons.logging.LogFactory; 89FAh6u E
L/tpT?$fi
/** ?$f.[;mh
* @author Joa 4H-eFs%5
* yxt"vm;
*/ i<^X z
publicclass PageUtil { Y\]ZIvTSb
)}@D\(/@
privatestaticfinal Log logger = LogFactory.getLog ~v;I>ij
nHdQe
(PageUtil.class); Vke<; k-
*(OG+OkC
/** dw"Es;^
* Use the origin page to create a new page @Z~YFnEJi
* @param page \G gh 95y
* @param totalRecords OTXZdAv
* @return Ib# -M;{
*/ bej(Ds0
publicstatic Page createPage(Page page, int ]->"4,}
S;% &X
totalRecords){ D;pI!S<#
return createPage(page.getEveryPage(), <a6pjx>y
6nW)2LV
page.getCurrentPage(), totalRecords); PlkZ)S7C
} loVg{N:
H
-Mb:4
/** 0~qc,-)3
* the basic page utils not including exception Qo#]Lo> \g
V+E8{|dYL
handler {v|!];i
* @param everyPage ^1S{::
* @param currentPage ks#3
o+
* @param totalRecords z{rV|vQ
* @return page -#|;qFD]
*/ l)%PvLbL
publicstatic Page createPage(int everyPage, int DhyR
Z3S+")^
currentPage, int totalRecords){ >O-KJZ'GV
everyPage = getEveryPage(everyPage); +8Lbz^#
currentPage = getCurrentPage(currentPage); zXY8:+f
int beginIndex = getBeginIndex(everyPage, ZyGoOk
[:y:_ECs6
currentPage); T8o](:B~
int totalPage = getTotalPage(everyPage, m)Plv+R}
fqgp{(`@>
totalRecords); :wC\IwG~CE
boolean hasNextPage = hasNextPage(currentPage, :0J`4
>(Y CZ
totalPage); <YaT r9%w
boolean hasPrePage = hasPrePage(currentPage); su%(!XJQpg
a^R?w|zCX
returnnew Page(hasPrePage, hasNextPage, Bh3F4k2bg7
everyPage, totalPage, }>@\I^Xm,
currentPage, !Km[Qw
k-
i>Q!5
beginIndex); dCd~]CI
} <\&9Odqc
ukiWNF/
privatestaticint getEveryPage(int everyPage){ aK_5@8+ZD
return everyPage == 0 ? 10 : everyPage; F)^0R%{C
} :21d
RA0;f'"`
privatestaticint getCurrentPage(int currentPage){ =:]ps<Qx
return currentPage == 0 ? 1 : currentPage; +{:uPY#1
} cb}zCl
j o
*[[Gu^t^!
privatestaticint getBeginIndex(int everyPage, int d0(zB5'}
E4X6f
currentPage){ y :;.r:
return(currentPage - 1) * everyPage; 9;@p2t*v
} %O\@rws
q1}!O kr"2
privatestaticint getTotalPage(int everyPage, int xuioU
;U* /\+*h
totalRecords){ /v
8"i^;}
int totalPage = 0; Q~N,QMr)k&
sINQ?4_8T
if(totalRecords % everyPage == 0) -<#)
]um
totalPage = totalRecords / everyPage; ?
:H+j6+f
else IoDT
totalPage = totalRecords / everyPage + 1 ; FNQ<k[#K'~
)~U1sW&t
return totalPage; X1@DI_
} |}=eY?iXo
"_WN[jm
privatestaticboolean hasPrePage(int currentPage){ #3&@FzD_P
return currentPage == 1 ? false : true; _S r}3
} Geq]wv8
l2
.S^S
privatestaticboolean hasNextPage(int currentPage, `2.c=,S{
1VJ${\H]
int totalPage){ p D<w@2K
return currentPage == totalPage || totalPage == c*IrZm
p<fCGU
0 ? false : true; 2"ax*MQH<^
} @Xo*TJB
zgb$@JC
94tfR$W;-
} kdNo<x1o
FGV
L[\
a"jE\OZ{+s
rW?WdEg
j9
nw,x$
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。 <%)vl P#@
L `1 ITz
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 `5Y*)
q
!ho^:}m
做法如下: Qq,2V
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ` Ig5*X4|
R"t#dG]1t
的信息,和一个结果集List: sfXFh
java代码: B;9,Qbb
OUBGbld
k|;a"56F
/*Created on 2005-6-13*/ JxVGzb`8
package com.adt.bo; Vl_6nY;
@)Vpj\jM-C
import java.util.List; :60vbO
7#LIG r
import org.flyware.util.page.Page; {nmG/dn{
rS1 gFGrj
/** Nv5^2^Sc=
* @author Joa Sz0PZtJ
*/ ]Uv,}W
publicclass Result { S!?T0c?>
5%,3)H{;t
private Page page; v-8>@s jy8
I}8e"#
private List content; J9T2 p\5
'?rR>$s
/** h#0n2o #
* The default constructor j97+'AKX
*/ tD8fSV
public Result(){ LLx0X
O@
super(); Ca |}i+
} mb*Yw6q
ucl001EK
/** ?N{\qF1Mz
* The constructor using fields }3z3GU8Q-
* A{_CU-,
* @param page alJ0gc2?
* @param content WuK<?1meN
*/ +`>7cy%cZ
public Result(Page page, List content){ 24wDnDyh
this.page = page; &4%pPL\f
this.content = content;
!oz{XWE
} (;fJXgj.
D`XXR}8V
/** uEgR>X>
* @return Returns the content. 2IYzc3Z{9
*/ b!H1|7>
publicList getContent(){ QQAEG#.5
return content; 2$JZ(qnN
} 2|k$Vfz
Hzz{wY
/** GgxPpS<ne
* @return Returns the page. e;6:U85LS
*/ ?8
}pZ_ j
public Page getPage(){ qT?{}I
return page; !Yc:yF
} 99OZK
xOkdu k]
/** QGNKQ`~
* @param content jI,[(Z>
* The content to set. &r[f ;|o
*/ Yo %U{/e
public void setContent(List content){ B~:yM1f@u4
this.content = content; Mnranhe>G
} k _t|)
J
$z!G%PO1%
/** D:k< , {
* @param page J@>|`9T9$
* The page to set. YI0l&'7
*/ NLZ5 5yo$
publicvoid setPage(Page page){ _4oAk @A
this.page = page; ^mC~<pP(
} w,P@@Q E
} r
(m3"Xu6O
2>jk@~Z1:u
3nBZ+n4z
TqJ @l
r QzdHA
2. 编写业务逻辑接口,并实现它(UserManager, !v2/sq$G
|2'WSAWG
UserManagerImpl) N:|``n>
java代码: MXW1:
o"Xv)#g&
?[#w*Am7
/*Created on 2005-7-15*/ {5VJprTbv
package com.adt.service; {n>.Y-=
pYcs4f!?p
import net.sf.hibernate.HibernateException; Zf>:h
yoGG[l2k>s
import org.flyware.util.page.Page; O+&;,R:
?"'+tZ=f6
import com.adt.bo.Result; `Ku:%~$/
NtGJpT4YX
/** #i~P])%gNP
* @author Joa HB#!Dv&'
*/ 7 Td
9mkO
publicinterface UserManager { S\ak(<X
tRPIvq/
public Result listUser(Page page)throws sm"Rp~[i
5~pxu
HibernateException; kmW/{I9,ua
6`-<N !
} |./:A5_h
PM!JjMeQh
(J4( Ge
Dlz0*eHD
nYyKz
Rz
java代码: H6Zo|n
S.[L?uE~F
B _ J2Bf
/*Created on 2005-7-15*/ e
6wevK\
package com.adt.service.impl; @ddCVxd
@D[+@N
import java.util.List; &@xm< A\S
?Xpk"N7
import net.sf.hibernate.HibernateException; j#3IF *"
q-^{2.ftcx
import org.flyware.util.page.Page; !]?kvf-3e
import org.flyware.util.page.PageUtil; !'!\>x$
1Ov oW Nx
import com.adt.bo.Result; \DlMOG
import com.adt.dao.UserDAO; #-b}QhxH
import com.adt.exception.ObjectNotFoundException; [.Fm-$M-
import com.adt.service.UserManager; s Y4wdG
p%iZ6H>G
/** tVf):}<h
* @author Joa AaU!a
*/ |L89yjhWBs
publicclass UserManagerImpl implements UserManager { pFs/ipZX^*
,2 xD>+=
private UserDAO userDAO; t"9r`0>
+9]t]Vrw
/** > {d9z9O
* @param userDAO The userDAO to set. oNYFbZw
*/ Vo[.^0
publicvoid setUserDAO(UserDAO userDAO){ cSv;HN:
this.userDAO = userDAO; E3{kH
7_'\
} Vug[q=i
'b" 7Lzp2
/* (non-Javadoc) w('}QB`xad
* @see com.adt.service.UserManager#listUser Za?BpV~
>B``+Z^2
(org.flyware.util.page.Page) `*0VN(gf'
*/ UdcV<#
public Result listUser(Page page)throws P}=n^*8(I
-`\n/"#X6i
HibernateException, ObjectNotFoundException { \d.\M
int totalRecords = userDAO.getUserCount(); OK-*TPrc
if(totalRecords == 0) /?j
kVy*"
throw new ObjectNotFoundException $mf O:%
7'8G,|&:*
("userNotExist"); 74NL)|M
page = PageUtil.createPage(page, totalRecords); J!|R1
List users = userDAO.getUserByPage(page); InRRcn(
returnnew Result(page, users); =/xx:D/
} mm*nXJ
`tuGy}S2
} U)iBeYW:
.i )n1
E:uTjXt
yW*,Llb5
vV=rBO0a?
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 [5!{>L`
pKLNBR|
询,接下来编写UserDAO的代码: N_FjEZpX
3. UserDAO 和 UserDAOImpl: =b"{*Heuw
java代码: J0f!+]~G3
f8UJ3vB
mBB"e"o
/*Created on 2005-7-15*/ ;*+H&
package com.adt.dao; !M)] 1Y
uT=5zu
import java.util.List; *aFh*-Sj2I
(["V( $
import org.flyware.util.page.Page; oO7)7$|1
ang~_Ec.
import net.sf.hibernate.HibernateException; NYKYj`K
;gAL_/_
/** B7Zi|-F
* @author Joa +~:OUR*>
*/ CRiqY_gBf
publicinterface UserDAO extends BaseDAO { e\-,e+
AuM}L&`i^
publicList getUserByName(String name)throws C%ZPWOc_8
<Voct
HibernateException; WuI$
A5\ Hq
publicint getUserCount()throws HibernateException; n
_x+xVi%
MO| Dwuaf
publicList getUserByPage(Page page)throws CbxWK#aMmB
_KT'W!7
HibernateException; F|'u0JQ)$
{,(iL8,^
} 7+KI9u}-
Yne1MBK
fo~*Bp()-E
M^e}w!U
\"L0d1DK)
java代码: 1D!MXYgm1b
/2*BdE[yG
|TQ4:P1T
/*Created on 2005-7-15*/ =\MAz[IDj
package com.adt.dao.impl; mQSn*;9\T3
)%kiM<})
import java.util.List; d0Ubt
M} ri>o
import org.flyware.util.page.Page; O'@[f{
mC-wPi8
import net.sf.hibernate.HibernateException; @CxgoX^
import net.sf.hibernate.Query; s +qodb+
0r i
import com.adt.dao.UserDAO; 8<ev5af
1_;{1O+B
/** *(5T?p[7
* @author Joa D#`>p
*/ 0%q H=do6
public class UserDAOImpl extends BaseDAOHibernateImpl se]&)%p[
f+1'Ah0'E
implements UserDAO { p*T[(\8{n
E="uDHw+
/* (non-Javadoc) Z.x]6
* @see com.adt.dao.UserDAO#getUserByName 3Of!Ykf=
9%"\s2T
(java.lang.String) {Xr 9]g`
*/ |QR9#Iv
publicList getUserByName(String name)throws ]Wjcr2Wq
;R<V-gab
HibernateException { ,!PV0(F(
String querySentence = "FROM user in class B&1E&Cv_8
f#7=N{wm
com.adt.po.User WHERE user.name=:name"; S,avvY.U\
Query query = getSession().createQuery
{gD`yoPrV
q"S,<I<f
(querySentence); 4M6[5RAW{
query.setParameter("name", name); w-NTw2x,&
return query.list(); Tdz#,]Q
} AGO"),
V,8Z!.MG
/* (non-Javadoc) s5Wb iOF
* @see com.adt.dao.UserDAO#getUserCount() zKaj<Og
*/ bC) <K/Q9
publicint getUserCount()throws HibernateException { rce._w }
int count = 0; a"t~K
String querySentence = "SELECT count(*) FROM 4gVIuF*pS
4vvQ7e7
user in class com.adt.po.User"; G+k wG)K
Query query = getSession().createQuery c6h+8QS
gh
:5
(querySentence); $"MVr5q6
count = ((Integer)query.iterate().next -XK;B--c
(plT/0=^t
()).intValue(); O,vC:av
return count; T{-gbo`Yji
} 1,]FLsuy
W! Hn`T
/* (non-Javadoc) TiG?r$6v%
* @see com.adt.dao.UserDAO#getUserByPage {X_I>)Wg
qHo Hh
(org.flyware.util.page.Page) &N+`O)$
*/ ~_F;>N~
publicList getUserByPage(Page page)throws T(]*jaB
0*oavY*
HibernateException { 02NVdpo[wU
String querySentence = "FROM user in class 4PkKL/E
Q
8;JvCz
com.adt.po.User"; ^SsnCn-e
Query query = getSession().createQuery x
ju*zmu
gX(Xj@=(&
(querySentence); kg7bZ
query.setFirstResult(page.getBeginIndex()) '.>y'=
.setMaxResults(page.getEveryPage()); gN73)uJ0
return query.list(); )54a' Hp
} kUT^o
YU)%-V\
} G]EI!-y
0w< ilJ
sX3qrRY
L$+_
ZitmvcMk
至此,一个完整的分页程序完成。前台的只需要调用 ~ISY( &
:xbj&
l
userManager.listUser(page)即可得到一个Page对象和结果集对象 T\=#y
""|;5kJS4
的综合体,而传入的参数page对象则可以由前台传入,如果用 lFSvHs5
9vwm
RVN
webwork,甚至可以直接在配置文件中指定。 [F;\NJp6?^
mE>{K
下面给出一个webwork调用示例: Tr|PR t
java代码: H Vhd#Q;
UugR
K=}Eupn=
/*Created on 2005-6-17*/ v&d'ABeT
package com.adt.action.user; 2mMi=pv9
,=c(P9}^
import java.util.List; Q>9bKP
%X}vuE[[UC
import org.apache.commons.logging.Log; j8PeO&n>
import org.apache.commons.logging.LogFactory; !>=lah$&
import org.flyware.util.page.Page; #n15_cd
SD:`l<l
import com.adt.bo.Result; ^q0`eS
import com.adt.service.UserService; 4sRg+mMI
import com.opensymphony.xwork.Action; }m%&|:PH
$/5\Hg1
/** eOkiB!G.
* @author Joa nHQ*#&$
*/ .XRe:\8mc
publicclass ListUser implementsAction{ i_l{#*t
(NDC9Lls
privatestaticfinal Log logger = LogFactory.getLog fkImX:|q
hx8pg,X
(ListUser.class); Tp.]{*
.3V L
private UserService userService; @p}_"BHYWt
%hw4IcWJ|
private Page page; KIR3m
)
&,:!gYN
privateList users; zxD=q5in
[Ob'E!;<
/* L+T7Ge
q
* (non-Javadoc) 1@|%{c&+9
* .a(G=fk
* @see com.opensymphony.xwork.Action#execute() i+< v7?:`#
*/ n9k
publicString execute()throwsException{ f#m@eb
Result result = userService.listUser(page); \*qradgx$
page = result.getPage(); wq!9wk9
users = result.getContent(); {<gX~./]c
return SUCCESS; Iw)m9h
} N#)Klq87z
;lrO?sm
/** ADB)-!$xoi
* @return Returns the page. v@8SMOe%
*/ *zDDi(@vtK
public Page getPage(){ gzH;`,
return page; F$|:'#KN
} Tz.okCo]z
PVdN)tG5
/** C?]eFKS."
* @return Returns the users. _s5FYb#
*/ PNo:vRtsq
publicList getUsers(){ I8B0@ZtV
return users; ^;( dF<?'r
} k $8Zg*)
0kls/^ 0,
/** OT=1doDp
* @param page nR@mm
j
* The page to set. j%Z5[{!/,X
*/ _5(p=Zc
publicvoid setPage(Page page){ `'3 De(
this.page = page; f?eq-/U R
} 99By.+~pX
_dCDT$^&r
/** M2d&7>N
* @param users 3&{6+ A
* The users to set. 6-/W4L)?>
*/ ,3MHZPJ?k]
publicvoid setUsers(List users){ !Y7$cU &
this.users = users; Cc`-34/%
} K^tc]ZQ
jTV4iX
/** J.U%W}Hx
* @param userService @icw:68
* The userService to set. cq
gCcO,
*/ AGS(ud{
publicvoid setUserService(UserService userService){ B1E:P`t
this.userService = userService; ; !t?*
} ^J^FGo|M
} 1{d;Ngx
yI07E "9
Fn4yx~0
O:T
49:R}r
|*h{GX.(
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, |]?W`KN0
8f)pf$v`
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 -wl&~}%M
dV'^K%#
么只需要: eX}aa0
java代码: '/0e!x/8
"zTy_0[;
h&d"| <
<?xml version="1.0"?> gp $Rf9\
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork xt"-Jmox
u(f;4`
1.0//EN" "http://www.opensymphony.com/xwork/xwork- +|pYu<OY
iCh8e>+
1.0.dtd"> rLmc(-q
7,Z<PE
<xwork> ;/?w-)n?
#<sK3 PT
<package name="user" extends="webwork- !T
,=kh
y x#ub-A8
interceptors"> ev+H{5W8
h?B1Emlq
<!-- The default interceptor stack name l. l)w
EowzEGq!a5
--> =OPX9oG
<default-interceptor-ref ! os@G
> mJ`904L
name="myDefaultWebStack"/> 'X6Y!VDd
P(Zj}tGN
<action name="listUser" wS&D-!8v
KECW~e`
class="com.adt.action.user.ListUser"> di9OQ*6a7
<param ^u"WWLZ
0nB[Udk?
name="page.everyPage">10</param> FyPG5-
<result qIQ
61><
VQG$$McJ
name="success">/user/user_list.jsp</result> @H+L1H%9n
</action> 9(z) ^G
I2SH
j6-
</package> o&z [d
DS7L}]
</xwork> em )%U
)flm3G2u
\awkt!Wa
-Q?c'e
0a<h,s0"2
8tna<Hx
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 /7p(%vr
41+WIa
L
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。 l`:u5\ rM
1ZYo-a;)
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 T:2f*!r
3k(tv U+eC
?K2}<H-
cTRtMk%^
QUvSeNSp
我写的一个用于分页的类,用了泛型了,hoho %N(>B_t\
#9.%>1{6Y
java代码: t?Qbi)T=z
uW FyI"
;PU'"MeB "
package com.intokr.util; _FcTY5."S
UHU ,zgM
import java.util.List; aot2F60J,
@V5i
/** @H~oOf
* 用于分页的类<br> `"yxmo*0
* 可以用于传递查询的结果也可以用于传送查询的参数<br> 9^?muP<A
* 5/h-Hr
* @version 0.01 T{`VUS/
* @author cheng j;z7T;!i
*/ yJ0%6],^g
public class Paginator<E> { FeO1%#2<y
privateint count = 0; // 总记录数
(#O"
privateint p = 1; // 页编号 I^u~r.
privateint num = 20; // 每页的记录数 Kr1Y3[iNv
privateList<E> results = null; // 结果 oz,.gP%
Buh}+n2]5
/** `^'fS@VA
* 结果总数 *jPd=+d
*/ wQd8/&mmk
publicint getCount(){ dPf7o
return count; 7[mfI?*m
} +TaxH;
cS:O|R#%t
publicvoid setCount(int count){ UpE+WzY
this.count = count; }' Y)"8AIA
} v'Ehr**]+
6~2upy~e
/** *mJ#|3I<
* 本结果所在的页码,从1开始 = _N[mR^
* g)TZ/,NQ{
* @return Returns the pageNo. CxJ3u
*/ w{k ^O7~
publicint getP(){ JsuI&v
return p; +Ss3Ph
} /BQqg08@L
Umz b
/** >$-YNZA
* if(p<=0) p=1 4cPZGZ{U
* q165S
* @param p OgC,oj,!/
*/ (EosLn
h0
publicvoid setP(int p){ 8-k`"QI=
if(p <= 0) 4KR`
p = 1; yZ)9Hd
this.p = p; Ev7v,7`z
} (jj`}Qe3U
bolG3Tf|
/** 9\WtcLx
* 每页记录数量 t1J3'lS
*/ i\b^}m8c.N
publicint getNum(){ 8Yf*vp>T/x
return num; (s&]V49
} OPj NmdeS
DmPsE6G}
/** 2\z|/
Q
* if(num<1) num=1 dW!El^w}
*/ "M[&4'OM
publicvoid setNum(int num){
zp}pS2DU
if(num < 1) *>mjUT}cP
num = 1; "-X8
this.num = num; s2|.LmC3|B
} S1Od&v[R
/^k%sG@?
/** A/UO cl+N
* 获得总页数 dhnX\/
*/ Y~{<Hs
publicint getPageNum(){ %g@\SR.
return(count - 1) / num + 1; DC1.f(cdR
} I%Yq86
|?Edk7`
/** "a~r'+'<
* 获得本页的开始编号,为 (p-1)*num+1 6k>5+ -&_
*/ ^--R#$X
publicint getStart(){ K\fD';
return(p - 1) * num + 1; Y%0rji
} ")vtS}Ekt
Kb{&a
/** U5~aG!E
* @return Returns the results. 6S3D#SY
*/ AzZhIhWl">
publicList<E> getResults(){ 32SkxcfrCK
return results; )AR-b8..o
} ^gp]tAf
)[ZXPD
public void setResults(List<E> results){ T$R#d&t
this.results = results; `L7^f!
} *n&Sd~Mg
#V]8FW
public String toString(){ Jj=N+,km
StringBuilder buff = new StringBuilder W'"?5} (
$t}W,?
(); <8kCmuGlk
buff.append("{"); 6Y,&