Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 a#j^gu$m
*g}&&$b0
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 $+N^ s^
Lu5.$b
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 )x s,
j ZafwBi
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 M- A}(r +J
55en
D
。 YCdxU1V
Z*B(L@H
分页支持类: Kt0Tuj@CY
<;"=ah7A
java代码: cC]1D*Bn
CR=MjmH
%P6!vx:&^b
package com.javaeye.common.util; pZn%g]nRD
CT`X~y10
import java.util.List; }Elce}
h0pr"]sO;$
publicclass PaginationSupport { S?tLIi/
Ku'U^=bVm:
publicfinalstaticint PAGESIZE = 30; SHh(ujz,
X"GQ^]$O
privateint pageSize = PAGESIZE; _L.yt5_
v%Xe)D
privateList items; "xI[4~'`:
,6L>f.V^(U
privateint totalCount; 1i2O]e!
jgIzB1H
privateint[] indexes = newint[0]; 3S?+G)qKo
%tLq&tyeY
privateint startIndex = 0; C_)>VPD
iB-s*b<`~
public PaginationSupport(List items, int 3I(M<sB}
n-Y'LK40Os
totalCount){ v\FD~
setPageSize(PAGESIZE); z$b!J$A1
setTotalCount(totalCount); CxV%/ChJ#
setItems(items); bc-)y3gHU
setStartIndex(0); 55\mQ|.Jn
} :Aw VeX@
xb\:H@92
public PaginationSupport(List items, int tTt~W5lo
TQH#sx
totalCount, int startIndex){ B8Z66#EQ
setPageSize(PAGESIZE); [l:.Q?? )|
setTotalCount(totalCount); Mr(3]EfgO
setItems(items); eW%jDsC
setStartIndex(startIndex); RdHR[Usm
} Tkf !Y?
xcA:Q`c.{
public PaginationSupport(List items, int D$;/
l}s?
2D"/k'iA
totalCount, int pageSize, int startIndex){ q4oZJ -`
setPageSize(pageSize); ,,gYU_V
setTotalCount(totalCount); e+TNG &_
setItems(items); 5c8x:
e@
setStartIndex(startIndex); N5DS-gv
} H2vEFn V
o5uwa{v
publicList getItems(){ KMcP !N.I
return items; TH &B9
} .VT,,0
Is[0ri
publicvoid setItems(List items){ ":ycyN@g
this.items = items; <Vb{QOgc;
} {{\HU0g>&
rg\w!L(
publicint getPageSize(){ =UY@,*q:c
return pageSize; S{6u\Vy
} W!*vO>^1W
mr? ii
publicvoid setPageSize(int pageSize){ \mloR
'
this.pageSize = pageSize; $)!Z"2T
} 4NIfQYC.
$P_Y8:
publicint getTotalCount(){ jYv
!}
return totalCount; 4y]*"(sQ;
} tP-c>|cz
Pl4d(2
7
publicvoid setTotalCount(int totalCount){ 6s;x@g]
if(totalCount > 0){ }=gGs
this.totalCount = totalCount; <*P1Sd.
int count = totalCount / |1o]d$3m
8z"Yo7no
pageSize; sTDBK!9I
if(totalCount % pageSize > 0) FceT'
count++; 6%-2G@6d
indexes = newint[count]; `Ec+i
for(int i = 0; i < count; i++){ MZ'HMYed
indexes = pageSize * ZUycJ-[
#A!0KN;GC2
i; cf9y0
} yyc&'J
}else{ KMV!Hqkk
this.totalCount = 0; O9Aooe4W=
} syF/jWM5
} *O~D lf
G`jhzG
publicint[] getIndexes(){ >\ W" 3.
return indexes; 0dW1I|jR
} vq}V0-
<
J']W7!p
publicvoid setIndexes(int[] indexes){ }O/Nn0,
this.indexes = indexes; {8Ll\j@ "
} aH_&=/-Tz
<,{v>vlw
publicint getStartIndex(){ P\JpE
return startIndex; j*"s~8u4
} H UjmJu6f{
2k_Bo~.
publicvoid setStartIndex(int startIndex){ sdLFBiR
if(totalCount <= 0) {<@~;iq
this.startIndex = 0; /.r($Sg^
elseif(startIndex >= totalCount) 15COwc*k
this.startIndex = indexes ?4_;9MkN
_[x(p6Xp
[indexes.length - 1]; Hi Yx(hY
elseif(startIndex < 0) %}/)_RzQ
this.startIndex = 0; 4J s>yP
else{ hf[K\aAk
this.startIndex = indexes S`::f(e
7j+.H/2
[startIndex / pageSize]; (\j<`"n
} $aG'.0HW
} ]#nAld1cmy
IX}l)t[:(
publicint getNextIndex(){ 39"'Fz?1
int nextIndex = getStartIndex() + f]Vz !hM~
N|DY)W
pageSize; eMs`t)rQ
if(nextIndex >= totalCount) sb1/4u/W
return getStartIndex(); HwHI$IB
else vI-KH:r"{
return nextIndex; MmX42;Pw
} U+KbvkX wj
$jHL8r\e7
publicint getPreviousIndex(){ SNQ+ XtoO
int previousIndex = getStartIndex() - rP'oUV_
&+\wYa,
pageSize; ;(XSw%Y
H
if(previousIndex < 0) o}T]f(>}
return0; IAfYlS#<yD
else , Le_PJY)
return previousIndex; n}l Z
} er53?z7zP.
t/3veDh@
} HV}NT~
Y !`H_Qo
]C!u~A\jq
*q^'%'
抽象业务类 !MbRI
java代码: $z<CkMP!U7
og>f1NwS[
&rn,[w_F[
/** _2|,j\f;L
* Created on 2005-7-12 \1tce`+
*/ nP}/#Wy
package com.javaeye.common.business; IflpM ]
/fX]Yu
import java.io.Serializable; $1axZ~8sS
import java.util.List; HwDb &pP"
,yB-jk?
import org.hibernate.Criteria; 3}"VUS0wh
import org.hibernate.HibernateException; m+o>`1>a
import org.hibernate.Session; LcF0: h'
import org.hibernate.criterion.DetachedCriteria; m_pK'jc
import org.hibernate.criterion.Projections; @FQ@*XD
import &?~> I[^~
-/h$Yb
org.springframework.orm.hibernate3.HibernateCallback; , 7}Ri
import ]|-y[iu
@gZ%>qe
org.springframework.orm.hibernate3.support.HibernateDaoS Y$(G)Fs
j#-74{Y$
J
upport; 7|{QAv
NWKD:{
import com.javaeye.common.util.PaginationSupport; 1r;Q5[@
* 6uiOtH
public abstract class AbstractManager extends Fr3Q"(
j*CnnM#n
HibernateDaoSupport { #oHHKl=M
UOa{J|k>h
privateboolean cacheQueries = false; ;N)qNiJY
cM55
vVd
privateString queryCacheRegion; [\I\).
P|G:h&
publicvoid setCacheQueries(boolean (j2]:BVu
z8gp<5=
cacheQueries){ 9{+B lNZ
this.cacheQueries = cacheQueries; ?f a/}|T
} towQoqv
Z!*Wn`d-k
publicvoid setQueryCacheRegion(String W{k}ogI;
%cBJ haR{(
queryCacheRegion){ '06[@Cw
this.queryCacheRegion = ,\Cy'TSz
hGPjH=^EM
queryCacheRegion; `LNRl'Zm
} ~x824xW
J H6\;G6
publicvoid save(finalObject entity){ P,,@&*
:
getHibernateTemplate().save(entity); d=q2Or
} eQMY3/#
W4Zi?@L>'
publicvoid persist(finalObject entity){ /H}83 C
getHibernateTemplate().save(entity); ?:UDK?
} p`Ax)L\f
`2GHB@S"k
publicvoid update(finalObject entity){ nL\BB&
getHibernateTemplate().update(entity); [^aow-4z
} y%43w4
,;UVQwY
publicvoid delete(finalObject entity){ 'DVPx%p
getHibernateTemplate().delete(entity); ~~>D=~B0'
} >YD?
pDPb/
d6wsT\S
publicObject load(finalClass entity, [03Aej
i/~A7\:8%
finalSerializable id){ x#'#
~EO-G
return getHibernateTemplate().load uQrD}%GI
P.LMu
(entity, id); nd-y`@z
} %|4Nmf$:Og
`NrxoU=
publicObject get(finalClass entity, ]Rz]"JZ\S
"`16-g97
finalSerializable id){ ]>&au8
return getHibernateTemplate().get )~rN{W<s`H
GBN^ *I
(entity, id); ~fEgrF d
} 2}t2k>
TN(1oJ:
publicList findAll(finalClass entity){ 7)z^*;x
return getHibernateTemplate().find("from m\[r6t]V
98G>I(Cw%
" + entity.getName()); HjLY\.S
} CsXIq.9
LC/6'4}_
publicList findByNamedQuery(finalString sAWUtJ
K`D>G<
namedQuery){ IrJCZsk
return getHibernateTemplate M~=9ym
}>>BKn
().findByNamedQuery(namedQuery); V{ECDgP
} 1%t9ic
d XrLeoK
publicList findByNamedQuery(finalString query, "\Z.YZUa\
+wr2TT~
finalObject parameter){ (m25ZhW
return getHibernateTemplate G-xW&wC-
YrFB~z.V
().findByNamedQuery(query, parameter); F:1w%#6av
} ^ola5w D
k#&d`?X
publicList findByNamedQuery(finalString query, )mS
Aog<
gm\P`~+o
finalObject[] parameters){ V~ %!-7?
return getHibernateTemplate c&J,O1){\
,)|nxX
().findByNamedQuery(query, parameters); {IJ,y27
} D!+d]A[r
.sgP3Ah
publicList find(finalString query){ .e~17}Ka}
return getHibernateTemplate().find ESft:3xyw
k9xfv@v}
(query); Wyd,7]'z)Z
} <x *.M"6?
??Q'| r
publicList find(finalString query, finalObject tY~EB.%
{ owK~
parameter){ TDq(%IW
return getHibernateTemplate().find S2'./!3yv
&82Za%
(query, parameter); s sUWr=mD
} -J[*fv@
sFuB[
JJ}
public PaginationSupport findPageByCriteria 4[v
%]g`
IZoS2^:yw
(final DetachedCriteria detachedCriteria){ !8(:G6Ne
return findPageByCriteria 9{]U6A*K0w
vlY83mU.
(detachedCriteria, PaginationSupport.PAGESIZE, 0); bk44qL;8
} JmjqA Dex
:q/%uca9
public PaginationSupport findPageByCriteria K!;Z#$iw[
9@/X;zO
(final DetachedCriteria detachedCriteria, finalint 6w|s1!Bl
>|'u:`A
startIndex){ #`?B:
return findPageByCriteria 7VduewKX8
>08'+\~:b
(detachedCriteria, PaginationSupport.PAGESIZE, -<h4I
aM
y@Z@ eK3
startIndex); $aDAD4mmm
} \R\?`8Orz
Ii FeO
public PaginationSupport findPageByCriteria Fuq ;4UcbL
dj>zy
(final DetachedCriteria detachedCriteria, finalint ?S9? ?y/
e:D8.h+&}
pageSize, QH7"' u6
finalint startIndex){ eg!s[1[_
return(PaginationSupport) WdI9))J2S
Dukvi;\
getHibernateTemplate().execute(new HibernateCallback(){ z3x/Y/X$S
publicObject doInHibernate !tJQ75Hwv
'_oWpzpe
(Session session)throws HibernateException { H\H4AAP5F$
Criteria criteria = @)k/t>r(
|mvY=t
%
detachedCriteria.getExecutableCriteria(session); @K.{o'
int totalCount = EIQ`?8KSR
^,O%E;g^#
((Integer) criteria.setProjection(Projections.rowCount &8$Gyu
A{X:p3$eN
()).uniqueResult()).intValue(); 2t
7':X
criteria.setProjection XT+V> HI
AQ+MjS,
(null); ynY(
List items = >J(._K
i[L5,%5<H
criteria.setFirstResult(startIndex).setMaxResults )S"!)\4 b
GWd71ZtFO
(pageSize).list(); b?i5C4=K
PaginationSupport ps = ^m
pWQ`R
&GYnGrw?@
new PaginationSupport(items, totalCount, pageSize, uIh68UM
b$FK}D5
startIndex); 7W[+e&
return ps; mk.1j x?l
} Hw29V //
}, true); 69< <pm,m
} pY.R?\
X6 E^5m
public List findAllByCriteria(final TP3KT)
BV;dV6`z
DetachedCriteria detachedCriteria){ t^Z-0jH
return(List) getHibernateTemplate jEh Px
CZZwBt$P
().execute(new HibernateCallback(){ 1?I_fA}
publicObject doInHibernate gI~B _0x
9!} ?}`'_
(Session session)throws HibernateException { YOOcHo.F
Criteria criteria = !U::kr=t
U/ds(*g@
detachedCriteria.getExecutableCriteria(session); gug9cmA/Q7
return criteria.list(); >ElK8
} <8)cr0~zy>
}, true); Rp^fY_
} xu%_Zt2/?j
Dxvizd>VU
public int getCountByCriteria(final 1FA:"0lO
(}B3df
DetachedCriteria detachedCriteria){ @=<B8VPJd
Integer count = (Integer) d)>b/0CZ
fM/~k>wl
getHibernateTemplate().execute(new HibernateCallback(){ Ql#y7HW
publicObject doInHibernate @tT2o@2Y^
f?JP=j
(Session session)throws HibernateException { x&p.-Fi
Criteria criteria = )x5t']w`K
4yK{(!&i+
detachedCriteria.getExecutableCriteria(session); '8w}m8{y
return CKE):kHu
MD9 8N{+[|
criteria.setProjection(Projections.rowCount :MaP58dhh
<#nt?Xn
()).uniqueResult(); s,CN<`/>x
} Efp[K}Z^$
}, true); q!;u4J
return count.intValue(); 8&Md=ZvK`
} LA]UIM@
} 6L<Y
jWL%*dJrN
~Z`Cu~7
'[Zgwz;z
I3qTSX-
I|x?
K>
用户在web层构造查询条件detachedCriteria,和可选的 $sxRRem{?
f/95}6M
startIndex,调用业务bean的相应findByCriteria方法,返回一个 YMn*i<m
3d`u!i?/
PaginationSupport的实例ps。 4^Ke?;v
C;3
ps.getItems()得到已分页好的结果集 mWUkkR(/
ps.getIndexes()得到分页索引的数组 8|L;y[v
ps.getTotalCount()得到总结果数 &>f]
ps.getStartIndex()当前分页索引 %63s( ekU
ps.getNextIndex()下一页索引 [a_'pAH
ps.getPreviousIndex()上一页索引 RNo~}#
8,@0~2fz#
+mPVI
5pU/X.lc
6e>P!bo
@?JFqwq!
6$)FQ
U
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ]T<tkvcI
M3G ecjR
,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 ;w7s>(ITZ
h_HPmh5
一下代码重构了。 {TXfi'\
yUjkRT&h
我把原本我的做法也提供出来供大家讨论吧: (u4'*[o\t
7NvnCs
首先,为了实现分页查询,我封装了一个Page类: 3a?|}zr4
java代码: '=0l{hv@
R=2"5Hy=
'':MhRb
/*Created on 2005-4-14*/
x7xMSy
package org.flyware.util.page; B[IWgvB(e
!]3kFWs
/** MTip4L W9
* @author Joa
RnSll-
* bkuJN%
*/ KV)if'
publicclass Page { e I9#JM|2
bcgXpP
/** imply if the page has previous page */ l(9AwVoAR|
privateboolean hasPrePage; ^z`d2it
Jcy+(7lE)
/** imply if the page has next page */ p9 G{Q
privateboolean hasNextPage; 7|xu)zYB
WMa`!Q
/** the number of every page */ Y(u`K=*
privateint everyPage; 9;Q|"
T
VAo`R9^D#
/** the total page number */ O!ilTMr
privateint totalPage;
nDS\2
v@4vitbG9
/** the number of current page */ :='I>Gn
privateint currentPage; Z,tHyyF?j
"ql$Rz8
/** the begin index of the records by the current o%!s/Z1
naM~>N
query */ ~s
yWORiXm
privateint beginIndex; aL*}@|JL"
xI_0`@do
0NK|3]p
/** The default constructor */ Ob{Tn@
public Page(){ GYg.B<Q.
&e78xtA{
} X~cdM1z?
`-JVz{z
/** construct the page by everyPage UfIr"bU6
* @param everyPage -
~4na{6x
* */ $;&l{=e2)
public Page(int everyPage){ D|amKW7
this.everyPage = everyPage; +cbF$,M4
} .C.b5x!
xYZ,.
/** The whole constructor */ .4ZOm'ko{
public Page(boolean hasPrePage, boolean hasNextPage, q6ZewuV.
(I`lv=R"j
`v-O 4Pk
int everyPage, int totalPage, :`4F0
int currentPage, int beginIndex){ a`8]TD
this.hasPrePage = hasPrePage; &Yo|Pj
this.hasNextPage = hasNextPage; S.{
this.everyPage = everyPage; yh/JHo;
this.totalPage = totalPage; 9)8Cf%<(
this.currentPage = currentPage; &6vWz6 !P
this.beginIndex = beginIndex; ~<-mxOe
} =~"X/>'
bT6VxbNS
/** u0]u"T&N!
* @return x4/{XRQ
* Returns the beginIndex. 6{{<+
o
*/ {kBsiSvsA;
publicint getBeginIndex(){ oHr0;4Lg6
return beginIndex; ,
@!X!L
} r{B28'f[
>28l9U
/** *?*~<R
* @param beginIndex vaJl}^T
* The beginIndex to set. ^BM !TQ%!
*/ TtF+~K
publicvoid setBeginIndex(int beginIndex){ PxQQf I>
this.beginIndex = beginIndex; ,"KfZf;?
} ]Y-Y.&b7t
|N^"?bSt
/** )t@9!V
* @return alB'l
* Returns the currentPage. Aix6O=K6
*/ s7HKgj
publicint getCurrentPage(){ C/QmtT~`e
return currentPage; t|V<K^
} &AOGg\
)0/*j]Kf
/** mE5{)<N:C
* @param currentPage AorY#oq
* The currentPage to set. L N
Fe7<y
*/ j "'a5;Sy
publicvoid setCurrentPage(int currentPage){ `U b*rOMu
this.currentPage = currentPage; L ph0C^8
} M^Y[Y@U=p
jf- XVk5q
/** <i4]qO(0u
* @return /t<
&
* Returns the everyPage. o[}Dj6e\t
*/ [\#ANA"
publicint getEveryPage(){ G0|}s&$yL
return everyPage; y631;dU
} 934j5D
%8D>aS U
/** g1|Pyt{
* @param everyPage t0jE\6r
* The everyPage to set. XI ;] c5
*/ t$%<eF@w
publicvoid setEveryPage(int everyPage){ Pc =ei
this.everyPage = everyPage; FwlDP
} !mTq6H12 !
vBOY[>=
/** !'~L dl
* @return /8Y8-&K0
* Returns the hasNextPage. FZn1$_Svr
*/
?ueL'4Mm
publicboolean getHasNextPage(){ sT"ICooc
return hasNextPage; j6EF0/_|e
} -seLa(8F
CuH4~6
/** < K!r\^
* @param hasNextPage AWi>(wk<
* The hasNextPage to set. c+E \e] {
*/ !L8q]]'XM
publicvoid setHasNextPage(boolean hasNextPage){ Sir1>YEm
this.hasNextPage = hasNextPage; MH#"dGGu
} fkp(M
QNINn>2
/** 6IV):S~
* @return &Z[+V)6,,
* Returns the hasPrePage. Pj]^p{>
*/ 'G~i;o 2
publicboolean getHasPrePage(){ .B-b51Uz
return hasPrePage; Q-V8=.
} _AFje
=
g
&
/** t6\H
* @param hasPrePage Pg8boN]}
* The hasPrePage to set. kmC0.\
*/ g%"SAeG<K
publicvoid setHasPrePage(boolean hasPrePage){ 6WQN!H8+^
this.hasPrePage = hasPrePage; z[1uub,)1
} ?g{[U0)
T)sIV5bk
/** k kAg17 ^
* @return Returns the totalPage. y>x"/jzF#
* >n3GvZ5%
*/ &gruYZGK
publicint getTotalPage(){ V\x'w*FP
return totalPage; 2,q*8=?{6P
} ?k4Hk$V
dp^PiyL
/** gJr)z7W'8
* @param totalPage D{Nd2G
* The totalPage to set. n]Yz<#
*/ q[VQ?b~9
publicvoid setTotalPage(int totalPage){ l"E{ ?4
this.totalPage = totalPage; 5I2 h(Td
} j@(S7=^C6%
&WBpd}|+Y
} 2<5LQr
G gA:;f46
X!LiekU!D
WN{8gL&y
^8~TsK~
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 8 <;.[l
DvQV_D
个PageUtil,负责对Page对象进行构造: DJgM>&Y6,
java代码: `Wjq$*
C(v'7H{4cW
#K:iB*
/*Created on 2005-4-14*/ 1="]'!2Is
package org.flyware.util.page; fqbeO 9x
(^FMm1@T
import org.apache.commons.logging.Log; 9)]`le
import org.apache.commons.logging.LogFactory; eA(\#+)X `
Ncbe{}<md
/** O0z-jZ,])
* @author Joa NR(rr.
* USN'-Ah
*/ @xBb|/I
publicclass PageUtil { #&IrCq+
NAE|iyw
privatestaticfinal Log logger = LogFactory.getLog XchD3p+uB
d!: /n
(PageUtil.class); w^&UMX}
PSu]I?WF
/**
dnC"`
* Use the origin page to create a new page /<LjD
* @param page p gLhxc:
* @param totalRecords N?{Zrff2"O
* @return 9NVtvBA
*/ \G v\&_
publicstatic Page createPage(Page page, int -u%o) ;B
nt|n[-}
totalRecords){ /];N 1
return createPage(page.getEveryPage(), u c!6?+0h
,B/TqPP
page.getCurrentPage(), totalRecords); ~h8k4eM
} ,Aq, f$5V
c/bT5TIEWs
/** 6Zw$F3 <
* the basic page utils not including exception u;^H =7R
[= E=H*j
handler vFJ4`Gjw(
* @param everyPage [7`S`\_NK
* @param currentPage UV;I6]$}A7
* @param totalRecords l2Py2ZI-b
* @return page b_{+O qI
*/ `k
I}p
publicstatic Page createPage(int everyPage, int KS~Q[-F1P
g=4P-i3
currentPage, int totalRecords){ `O3#/1+
everyPage = getEveryPage(everyPage); Om:Gun\%
currentPage = getCurrentPage(currentPage); 1iR\M4?Frf
int beginIndex = getBeginIndex(everyPage, AM!P?${a
av(qV$2
currentPage); 7eM6 B#rI
int totalPage = getTotalPage(everyPage, EMH-[EBx
R6;229e
totalRecords); w\d1
boolean hasNextPage = hasNextPage(currentPage, 6I=d0m.io
gPKO-Fsd"
totalPage); |Zn,|-iW
boolean hasPrePage = hasPrePage(currentPage); %iIr %P?
Iu~(SKr=|$
returnnew Page(hasPrePage, hasNextPage, u_ :gqvC=
everyPage, totalPage, 9} C(M?d
currentPage, L)|hjpQ
FN sSJU3ld
beginIndex); U/U_q-z]
} olo9YrHn
T[},6I|!
privatestaticint getEveryPage(int everyPage){ A;C4>U Y
return everyPage == 0 ? 10 : everyPage; O[1Q#
} ,82?kky
2-g 5Gb2|
privatestaticint getCurrentPage(int currentPage){ d<\X)-"
return currentPage == 0 ? 1 : currentPage; +BI%.A`2
} 5 YIk
<Vyl*a{%
privatestaticint getBeginIndex(int everyPage, int /*S6 /#
}F V_jJ
currentPage){ '#lEUlB
return(currentPage - 1) * everyPage; 3WkrG.$[b
} ,0Udz0
REJBm
privatestaticint getTotalPage(int everyPage, int }darXtZKkK
}236{)DuN
totalRecords){ Pa\yp?({q
int totalPage = 0; G7-.d/8|^
\"K:<+RH
if(totalRecords % everyPage == 0) W-RshZ\
totalPage = totalRecords / everyPage; %I)*5 M6
else O'~^wu.
totalPage = totalRecords / everyPage + 1 ; <3k9 y^0
\@6w;tyi
return totalPage; B$97"$#u
} i"!j:YEo
LGRhCOP:
privatestaticboolean hasPrePage(int currentPage){ G
@L`[Wu
return currentPage == 1 ? false : true; r`0oI66B/
} ![%:X)?
G8W^XD
privatestaticboolean hasNextPage(int currentPage, @DR?^
q p
It'PWqZtG
int totalPage){ :,^x?'HK
return currentPage == totalPage || totalPage == Rwmr [g
w 01\KV
0 ? false : true; Z
+}#
Ic
} FO|Eg9l
hdH-VR4
d{'u97GDc
} '! ;Xxe5
5Obv/C
\xZ6+xZd1
R/c-sV
Wzh#dO?7
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。 NydoX9
NzID[8`
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 );z/
@Q
9@p+g`o
做法如下: *zPz)3;
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 G`jJKiC
.)=j~}\
的信息,和一个结果集List: VelX+|w
java代码: l)
)Cvre+
YQfQ[{kp
( v=Z$#l
/*Created on 2005-6-13*/ |Tl2r,(+R
package com.adt.bo; 6x_D0j%^]
-v WXL
import java.util.List; TbR
Ee;1
1,G f;mcQ
import org.flyware.util.page.Page; FVHR
6$$ku
/** a*@4W3;7
* @author Joa /{X2:g {
*/ ~c
GH+M@
publicclass Result { f+dj6!g5/
+@C|u'
private Page page; ? m.Ry
Xu5^ly8p9q
private List content; ?[Qxq34
RZKczZGZg
/** L)Ru]X`
* The default constructor Nj4^G ~_
*/ 7;:Uv=
public Result(){ jJY!;f
super(); }W R?n
} }%eXGdC
#]o#~:S=
/** Rlf#)4
* The constructor using fields M6b6lhg
* )eSD5hOI)
* @param page .3T#:Hl
* @param content tJY3k$YX
*/ lMBXD?,,J
public Result(Page page, List content){ _NJq%-,'
this.page = page; .
!;K5U
this.content = content; 7
S2QTRvH
} +~\c1|f
IOOAaa @(
/** A 4|a{\|$
* @return Returns the content. y]ZujfW7
*/ 41`&/9:"_M
publicList getContent(){ 4m$Xjj`vE
return content; "*aL(R
} dD8f`*"*=
~~'UQnUN4
/** zc#aQ.
* @return Returns the page. 5S?+03h~
*/ [S!_ubP5
public Page getPage(){ )o8]MWT\;
return page; pO_L,~<
} ({AqL#x`u
| sio:QP
/** ~<#!yRy>r
* @param content <jvSV5%
* The content to set. 'hi.$G_R
*/ nZ2mY!*
public void setContent(List content){ >A;9Ee"&
this.content = content; H#;-(`F
} x7]Yn'^'
$R[ggH&
/** AR-&c 3o
* @param page Xy(o0/7F9
* The page to set. #2023Zo]
*/ wfxg@<WR
publicvoid setPage(Page page){ Z>H
y+Q4
this.page = page; dLMKfh/4Q
} qEoa%O
} ?xuhN
G@
J,k|_JO
oopACE>
.UuCTH;6`
u/BCl!`
2. 编写业务逻辑接口,并实现它(UserManager, }vbs6u
hs"=>(P)
UserManagerImpl) o4"7i 9+g
java代码: M1/Rba Q
q-fxs8+m|
t:G67^<3
/*Created on 2005-7-15*/ C"P40VQoo
package com.adt.service; ,:QzF"MV
'bXm,Ed
import net.sf.hibernate.HibernateException; 1c}
%_Z/
f|f9[h'
import org.flyware.util.page.Page; ,NQucp
D|}%(N@sl
import com.adt.bo.Result; Ol~jq;75
U
h'1f7%
/** Q~A25Jf.
* @author Joa 2=TQU33#
*/ Uva
b*9vX
publicinterface UserManager { (*Jcx:rH
B9RB/vHH
public Result listUser(Page page)throws -&u2C}4s
&K_"5.7-56
HibernateException; y[s* %yP3l
8)D5loS
} 8_S<zE`Ha
0OndSa,
<4{,u1!t
p<2A4="&
t@TBx=16
java代码: '@ym-\,
\lnps f
Ls#=R
/*Created on 2005-7-15*/ ]iyJ>fC
package com.adt.service.impl; =!b<@41
G02(dj
import java.util.List; |[tlR`A $
PyD'lsV
import net.sf.hibernate.HibernateException; vPn( ~d_
*.UM[Wo
import org.flyware.util.page.Page; ,&;#$ b5
import org.flyware.util.page.PageUtil; yu'2
El~x$X*
import com.adt.bo.Result; F8J;L](Dq
import com.adt.dao.UserDAO; 8v},&rhPQq
import com.adt.exception.ObjectNotFoundException; "-'w,g
import com.adt.service.UserManager; LP8Stj JP
#[^?f[9r
/** v(?^#C>6W
* @author Joa }2^_Gaj
*/ OA\2ja~+
publicclass UserManagerImpl implements UserManager { $DmWK_A
<Q06<{]R8
private UserDAO userDAO; 8$:4~:]/
/Ot=GhN]
/** u.t(78N
* @param userDAO The userDAO to set. R$<LEwjSw
*/ 8,BNs5
publicvoid setUserDAO(UserDAO userDAO){ _y q"F#,*
this.userDAO = userDAO; J
00%,Ju_
} >;N0( xB
3le/(=&1
/* (non-Javadoc) ,!BiB*
* @see com.adt.service.UserManager#listUser EROf%oaz=
T [
`t?,
(org.flyware.util.page.Page) Q7X6OFl?
*/ ?8g[0/
public Result listUser(Page page)throws T#.5F7$u
K<O1PrC
HibernateException, ObjectNotFoundException { OTA @4~{C
int totalRecords = userDAO.getUserCount(); 2jTP
(b2b
if(totalRecords == 0) ]VifDFL}
throw new ObjectNotFoundException }|rnyYA
&D
"$N"
("userNotExist"); @'.(62v
page = PageUtil.createPage(page, totalRecords); M^\#(0^2@
List users = userDAO.getUserByPage(page); Vd2bG4*=
returnnew Result(page, users); fZ2>%IxG}
} P;D)5yP092
X'4g\)*
} ~7Ey9wRkD
aVI/x5p~
zPp?D_t
*]Nd
I
7]t$t3I`
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 x |
=
NPws^
询,接下来编写UserDAO的代码: };[~>Mzl
3. UserDAO 和 UserDAOImpl: | I_,;c
java代码: <KF|QE
(|_1ku3!
)~1QOl
"~
/*Created on 2005-7-15*/ &>UI {
package com.adt.dao; Y/1KvF4)k
sW[8f
Z71
import java.util.List; \IL/?J
5d
-4|\,=j
import org.flyware.util.page.Page; nPp\IE}:
^EGe%Fq*x]
import net.sf.hibernate.HibernateException; P9~7GFas|
QMoh<[3qu
/** bce>DLF
* @author Joa $;1#gq%
*/ [:-Ltfr
publicinterface UserDAO extends BaseDAO { pp$WM\r
{VBx;A3*I
publicList getUserByName(String name)throws 3okh'P%+
#9Z\jW6b
HibernateException; 0?} ),8v>
-POV#1s
publicint getUserCount()throws HibernateException; (9hCO-r
(0jT#&#
publicList getUserByPage(Page page)throws D"^4X'6
b4GD}kR
HibernateException; ?;pw*s1Atz
Q}GsCmt=)O
} 9ALE6
$2Y'[Dto\
LeBuPR$
413,O~^
V!#+Ti/w4
java代码: )UA$."~O
:<ye:P1s
Y4cIYUSc
/*Created on 2005-7-15*/ x8I=I"Sp
package com.adt.dao.impl; 4LqJ4jo
?-CZJr
import java.util.List; ',L>UIXw
0e1W&
import org.flyware.util.page.Page; SoZ$1$o2
Mg?^ 5`*
import net.sf.hibernate.HibernateException; cn&\q.!fh
import net.sf.hibernate.Query; ]~g6#@l
J%d\ 7
import com.adt.dao.UserDAO; BdcTKC
U)~?/s{v
/** zPWX%1Qr
* @author Joa C$o#zu q-
*/ T#'+w@Q9{9
public class UserDAOImpl extends BaseDAOHibernateImpl \I J\
1&A@Zo5|
implements UserDAO { 5$o]D
T =r7FU
/* (non-Javadoc) <11pk
* @see com.adt.dao.UserDAO#getUserByName lhsd39NM
@/i;/$\
(java.lang.String) ]O'dwC
*/ .v<c_~y
publicList getUserByName(String name)throws i$HA@S
CR*R'KX D%
HibernateException { EgO=7?(pW
String querySentence = "FROM user in class Hn"xn79nc
5MsE oLg
com.adt.po.User WHERE user.name=:name"; B9IqX
Query query = getSession().createQuery }t!,{ZryE1
C2RR(n=N^
(querySentence); 8x$BbK
query.setParameter("name", name); \ FW{&X9a
return query.list(); .a._WZF
} RUHQ]@d#T
R*~<?}Rr
/* (non-Javadoc) ~Xi_bTAyAW
* @see com.adt.dao.UserDAO#getUserCount() vJ96qX
*/ |0 #J=am
publicint getUserCount()throws HibernateException { [iE% P^
int count = 0; !~5;Jb>s[/
String querySentence = "SELECT count(*) FROM HMsTm}d
`OzcL
user in class com.adt.po.User"; TCAtb('D
Query query = getSession().createQuery X;JptF^
'@1o M1
(querySentence); H\]ZtSw8-
count = ((Integer)query.iterate().next *B"p:F7J|
90OSe{
()).intValue(); O>e2MT|#k
return count; o.yuz+
} fY3^L"R
EVc
Ees
/* (non-Javadoc) fD1J@57
* @see com.adt.dao.UserDAO#getUserByPage mY9^W2:
`I+G7KK
(org.flyware.util.page.Page) 3=w$1.B d
*/ vZj:\geV
publicList getUserByPage(Page page)throws
'PW~4f/m
(S/f!Dk&3
HibernateException { h$[}lZDg
String querySentence = "FROM user in class NoS|lT
SP][xdN7
com.adt.po.User"; UFnz3vc
Query query = getSession().createQuery Hts.G~~8
Zcq'u
jU
(querySentence); 7PG&G5
query.setFirstResult(page.getBeginIndex()) J7:VRf|,?(
.setMaxResults(page.getEveryPage()); &Rw4ub3
return query.list(); ql,k 5.l
} (.~#bl
bdh6ii
} #rSm;'%,
QDCu
0M^7#),
_[ml<HW]
` #Qlr+X
至此,一个完整的分页程序完成。前台的只需要调用 !#0Lo->OO
d?dZ=]~C
userManager.listUser(page)即可得到一个Page对象和结果集对象 UH=pQm^W
M0[7>N_
的综合体,而传入的参数page对象则可以由前台传入,如果用 |sd0fTK
dh r)ra]
webwork,甚至可以直接在配置文件中指定。 <GoUth.#
5Vo8z8]t`
下面给出一个webwork调用示例: 8,\toT7
java代码: hM~9p{O
2pR+2p`
`I|$U)'
/*Created on 2005-6-17*/ (V2~txMh
package com.adt.action.user; K=|x"6\
e1$T%?(&[
import java.util.List; QcBuUFf!c
px6[1'|g
import org.apache.commons.logging.Log; 6Y4sv5G
import org.apache.commons.logging.LogFactory; $10"lM[
import org.flyware.util.page.Page; /VFh3n>I2
o^P/ -&T
import com.adt.bo.Result; ZmSe>}B=
import com.adt.service.UserService; G9'Wo.$ t
import com.opensymphony.xwork.Action; ;T1OXuQ
$#R@x.=
/** &''lOS|
* @author Joa (tQ#('(w
*/ "G. L)oD
publicclass ListUser implementsAction{ 9[yW&t;#
$yG>=GN
privatestaticfinal Log logger = LogFactory.getLog s;!TB6b@
R42+^'af
(ListUser.class); lYz{#UX}
m2wGg/F5
private UserService userService; _P6e%O8C#
3[mVPV
private Page page; .Jk[thyU
^P30g2gv>
privateList users; vv0A5p8H
o+{]&V->gN
/* a<%Ivqni
* (non-Javadoc) X@l>mAk
* 9H^$cM9C
* @see com.opensymphony.xwork.Action#execute() MTm}qx@L
*/ {4B{~Qe;
publicString execute()throwsException{ CUIFKM
Result result = userService.listUser(page); +<#0V!DM
page = result.getPage(); Zy!^HS$
users = result.getContent(); (jj=CLe
return SUCCESS; sfb)iH|sW
} "^/3?W>
U^aMh-
/** 7p"4rL
* @return Returns the page. '3B"@^]
*/ ft |W
public Page getPage(){ alr'If@7
return page; .gZ1}2GF=
} D^]g`V*N
.|ZO2MCd
/** -M\ae
* @return Returns the users. h=<x%sie
*/ ,x (?7ZW>
publicList getUsers(){ -^C^3pms
return users; be^+X[
} -zn$h$N4
SSCyq#dl$
/** c,
IAz
* @param page @\ udaZc
* The page to set. _JEe]
*/ -@=As00Bg
publicvoid setPage(Page page){ ~m`j=ot
this.page = page; 42E%&DF
} = Ob-'Syg>
`i~kW
/** o8uak*"{
* @param users yLpsK[)}\
* The users to set. sVT:1 kI
*/ qYba%g9RN(
publicvoid setUsers(List users){ x:wv#Wh:l7
this.users = users; B EN
U
} Q)mYy
TR7j`?
/** Pk2=*{:W
* @param userService Y6+/_$N4|
* The userService to set. (FVHtZi7
*/ H\r-
;,&
publicvoid setUserService(UserService userService){ @$G{t^&os
this.userService = userService; Ms>CO7Nvy
} 3UR'*5|'
} luvxwved
"`6pF8k
uV=ZGr#o
C-2{<$2k
YY4XCkt
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, k-CW?=
lE=&hba
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 dbe\ YE
f;{K+\T
么只需要: 4:zyZu3fm
java代码: rq(9w*MW:
n{*A<-vL
{JGXdp:SB
<?xml version="1.0"?> jjJvyZi~J
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork UlNx5l+k
7!;48\O]w
1.0//EN" "http://www.opensymphony.com/xwork/xwork- i]$/& /
BV"l;&F[
1.0.dtd"> lZ'ZL*
Xd 5 vNmQn
<xwork> S UBrFsA
I+GP`=\
<package name="user" extends="webwork- j|-{*t{/x
s#BSZP
interceptors"> As>-9p>v
r"4&.&6
<!-- The default interceptor stack name e'dx
Y(
]H-5
--> Tebu?bj
<default-interceptor-ref M&SY2\\TB
Z,_EhEm
name="myDefaultWebStack"/> q;Rhx"x>T
1sNZl&
<action name="listUser" ]K-B#D{P
tBjMm8lgb
class="com.adt.action.user.ListUser"> Ewq7oq5:
<param w+][L||4c
N"[r_!
name="page.everyPage">10</param> MwE^.6xl{
<result ,>3b|-C-
Hfo/\\
name="success">/user/user_list.jsp</result> |_\q5?S
</action> oAt{#v
{>h,@
</package> Dzr(Fb
iezY+`x4
</xwork> ?mbI6fYv
*r/o
\pyH
*|B5,Ey
JWsOze8#
dUc?>#TU
3kJ7aBiR<
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 lz:+y/+1
mV;)V8'
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。 GhC%32F
;s^F:O
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 _]Y9Eoz
vSv:!5*
f>[!Zi*
QD*\zB
5?HoCz]l
我写的一个用于分页的类,用了泛型了,hoho z^Y4:^L~I
i*61i0
java代码: Tqm)- |[
jRBKy8?[C
S<o\.&J
package com.intokr.util; \E8CC>Jd
S{S.H?{F
import java.util.List; 8,&pX ga
1$v1:6
/** 7hAc6M$h;
* 用于分页的类<br> A 6j>KTU
* 可以用于传递查询的结果也可以用于传送查询的参数<br> A3A"^f$$
* #eY?6Kjn
* @version 0.01 :pNu$%q
* @author cheng xlm:erP
*/ ^K?Mq1"Db
public class Paginator<E> { AcIw;
c:
privateint count = 0; // 总记录数 K*aGz8N
privateint p = 1; // 页编号 umI6# Vd`=
privateint num = 20; // 每页的记录数 Senb_?
privateList<E> results = null; // 结果 +GlG.6
l~#%j( Yo
/** '-[?iF@l
* 结果总数 t}fU 2Yb
*/ G|LcTV
publicint getCount(){ t}>"nr0
return count; t@+z r3
} 4>Y\Y$3
Rf#t|MW*#
publicvoid setCount(int count){ ;|D8"D6]
this.count = count; %&&;06GU}
} MuP&m{
]-8yZWal
/** 7b
hJt_`Q
* 本结果所在的页码,从1开始 Lb0B m R%0
* F2C v,&'
* @return Returns the pageNo. )(DX]Tr`
*/ 5@`DS-7h
publicint getP(){ v0W/7?D
return p; QvDD
} 4^{~MgQWK+
GcHZ&m4
/** WXX08"
* if(p<=0) p=1 *6QmYq6c<
* c n^z=?
* @param p 2|}KBny
*/ }^Ky)**
publicvoid setP(int p){ (E<QA
if(p <= 0) ?T7ndXX
p = 1; y R_x:,|g
this.p = p; OO-b*\QW
} -n]E\"
_-nIy*', =
/** $|H7fn(r
* 每页记录数量 L<O"36R
*/ EM0]"s@Lf
publicint getNum(){ BLcsIyq
return num; ?vocI
} )jm u*D5N
9p%8VDF=
/** Pskg68W
* if(num<1) num=1 H<C+rAIb
*/ g/jlG%kI}
publicvoid setNum(int num){ tN&_f==e
if(num < 1) FW,@.CX
num = 1; t.6gyrV7><
this.num = num; l ArDOFl]x
} YY9Ub
;eiqzdP
/** )NCSO b
* 获得总页数 Qhsk09K_=4
*/ 6^vHFJ$
publicint getPageNum(){ "6xTh0D
return(count - 1) / num + 1; 4kdQ h]
} SAtK 'Jx[
`ILO]+`5
/** +i6XCN1=
* 获得本页的开始编号,为 (p-1)*num+1 &dvL`
*/ K0z@gWGE
publicint getStart(){ mFeoeI,Jv
return(p - 1) * num + 1; U(u$5
} V0a)9\x(\
*pKj6x
/** :Tn1]a)f6
* @return Returns the results. 0OPpA Ll
*/ <s(<ax30
publicList<E> getResults(){ ,]8$QFf
return results; Q(7M_2e7
} )ZQML0}P;
D$/*Z5Z)]
public void setResults(List<E> results){ iVqa0Gl+}
this.results = results; P4.snRQ
} O/bpm-h`8c
]Q*eCt;l"K
public String toString(){ ZX03FJL7u
StringBuilder buff = new StringBuilder }5a$Ka-
6/&aBE=
(); `6`oLu\l
buff.append("{"); >2@ a\
buff.append("count:").append(count); KvfZj
buff.append(",p:").append(p); /%5X:*:H
buff.append(",nump:").append(num); IiRII)
buff.append(",results:").append {wyf>L0j
8
!+eq5S3
(results); {ZrB,yK
buff.append("}"); n>
O3p
~
return buff.toString(); t}2$no?
} 7(<z= F
(&ABfm/t
} d vTsbs/6
P1Chmg
xXm:S{I