Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 oFi_
op
wBlo2WY
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ` yYYyB[
mVd%sWD
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 O +u?Y
n`X}&(O
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 ._[uSBR'
o_sb+Vn|
。 GUps\:ss
xyrlR;Sk
分页支持类: E h+m|A
-KL5sK
java代码: AIG5a$}&
0TqIRUz "C
}vEMG-sxX
package com.javaeye.common.util; $EnBigb!
\'6%Ld5km
import java.util.List; IP!`;?T=
|Sv}/P-
publicclass PaginationSupport { r]deVd G
x"P@[T
publicfinalstaticint PAGESIZE = 30; ncpNesB
{#,?K
privateint pageSize = PAGESIZE; Hyb_>n
Ce:w^P+
privateList items; 9*S9~
avY<~-44B
privateint totalCount; *&~(>gNF,
J|u_45<
privateint[] indexes = newint[0]; eWr2UXv$
b/d1(B@
privateint startIndex = 0; 7;a
w7~cY=
public PaginationSupport(List items, int !l$k6,WJi
E/2_@&U:}
totalCount){ -
WQ)rz
setPageSize(PAGESIZE); MDoV84Fh
setTotalCount(totalCount); hm0MO,i"
setItems(items); |`' WEe2
setStartIndex(0); Mu@(^zW
} dN@C)5pm5`
4t 0p!IxG
public PaginationSupport(List items, int L=gG23U&
'yR\%#s6
totalCount, int startIndex){ 0lU
pil
setPageSize(PAGESIZE); W)AfXy
setTotalCount(totalCount); <=!FB8 .
setItems(items); Q[9W{l+
setStartIndex(startIndex); EUbyQL
} ^@)*voP#G
sZ0)f!aH:_
public PaginationSupport(List items, int 6$t+Q~2G!
rQ(u@u;
totalCount, int pageSize, int startIndex){ H#3Ma1z
setPageSize(pageSize); %zN~%mJG
setTotalCount(totalCount); 8{ )N%r
setItems(items); |(=b
setStartIndex(startIndex); Y+gNi_dE
} }[y_Fr0
;pqS|ayl
publicList getItems(){ sY* qf=
return items; i^)JxEPr w
} x,c\q$8yH
,"5xKF+cS
publicvoid setItems(List items){ zqLOwzMlLx
this.items = items; or(P?Ro
} _$yS4= .
(8(P12l
publicint getPageSize(){ Ej<`HbJ'Q
return pageSize; 6 )lWuY]e
} >gDKkeLD
6%MM)Vj+u
publicvoid setPageSize(int pageSize){ PJAM_K;
this.pageSize = pageSize; m,Mg
} w$aejz`[
rnC<(f22
publicint getTotalCount(){ Wf=hFc1_@
return totalCount; mcWN.
} NW`Mc&
IO"q4(&;P4
publicvoid setTotalCount(int totalCount){ Y ^5RM
if(totalCount > 0){ &(NW_<(
this.totalCount = totalCount; GmZ2a-M
int count = totalCount / A`V:r2hnb
b<BkI""b
pageSize; $Zj3#l:rK
if(totalCount % pageSize > 0) ue -a/a
count++; ,D' bIk
indexes = newint[count]; 2
;Q|h$n
for(int i = 0; i < count; i++){ [6%y RQ_
indexes = pageSize * N`LY$U+N|
k;HI-v
i; =-!B4G$
} ckbD/+
}else{ ,<;.'r
this.totalCount = 0; yS4nB04`=
} W,.Exh
} @4>?Y=#
Fyc":{Jd
publicint[] getIndexes(){ /KhY,G'Z
return indexes; nM`pnR_
} 5yf`3vV|3@
Nk?L<'
publicvoid setIndexes(int[] indexes){ @e+qe9A|
this.indexes = indexes; ]T%wRd5&-
} c22L]Sxo
&7KX`%K"D
publicint getStartIndex(){ l?KP/0`
return startIndex; A6#v6 iT
} \n-.gG
R".*dC,0'B
publicvoid setStartIndex(int startIndex){ %Z yt;p2
if(totalCount <= 0) 1t7T\~+F
this.startIndex = 0;
WDh*8!)
elseif(startIndex >= totalCount) 4qyPjAG
this.startIndex = indexes u9{Z*w3L7
XW*d\vDun
[indexes.length - 1]; avd`7eH2
elseif(startIndex < 0) ki]i[cdk
this.startIndex = 0; !lI1jb"
else{ Olr'n% }
this.startIndex = indexes o6 8;-b'n
Wbi12{C
[startIndex / pageSize]; ]F4|@+\9
} SKJ'6*6
} Su k;##I
uC"Gm;0
publicint getNextIndex(){ .WlZT-
int nextIndex = getStartIndex() + (o!i9)
<^adt
*m
pageSize; 3MoVIf1
if(nextIndex >= totalCount) _+qtH< F/
return getStartIndex(); hD7Lgi-N)W
else ];Y tw6A
return nextIndex; j`-9.
} /+f3jy:d
m!:sDQn{3
publicint getPreviousIndex(){ MQVEO5
int previousIndex = getStartIndex() - ?DC;Hk<
P,7beHjf
pageSize; :BUr8%l
if(previousIndex < 0) /?:q9Wy
return0; OZno 3Hn
else 7/FF}d
return previousIndex; 6"V86b0)h}
} =Ka :i>
7@ mP;K0
}
II(P
I(+%`{Wv
{Pe+d3Eoo
g#[,4o;
抽象业务类 :JzJ(q/
java代码: qa5 T(:8
3@mW/l>X
n#)kvr
/** uG4Q\,R
* Created on 2005-7-12 k
E-+#p
*/ LS4E.Xdn
package com.javaeye.common.business; {(^%2dk83C
"ax"k0
import java.io.Serializable; >('Z9<|r:
import java.util.List; Ve4@^Jy;
` MXGEJF
import org.hibernate.Criteria; C8
"FTH'
import org.hibernate.HibernateException; >FReGiK$T
import org.hibernate.Session; p}h9>R
import org.hibernate.criterion.DetachedCriteria; ]s~%1bd
import org.hibernate.criterion.Projections; axdRV1+s
import KJ8Qi+cZ
&y.6Hiy&
org.springframework.orm.hibernate3.HibernateCallback; 1'9YY")#
import G1/
BY??X=
org.springframework.orm.hibernate3.support.HibernateDaoS n }4L q^$
s
F3M= uz
upport; '0/[%Q
Ozs&YZ
import com.javaeye.common.util.PaginationSupport; ph=U<D4
gR8vF
public abstract class AbstractManager extends |=ljN7]!
FY <77i
HibernateDaoSupport { B e2yS]U
7|q _JdKoU
privateboolean cacheQueries = false; F[==vte|
Ixv/xI
privateString queryCacheRegion; 1<3!
!<j)D_
publicvoid setCacheQueries(boolean Q)}z$h55
73kL>u
cacheQueries){ B;xGTl@8
this.cacheQueries = cacheQueries; )>rHM6-W
} glP
W9q,f
Y!lc/[8
publicvoid setQueryCacheRegion(String %%f(R7n
JM Ikr9/$
queryCacheRegion){ '.d]n(/lZd
this.queryCacheRegion = rgXD>yu(
$+@xwuY'+
queryCacheRegion; ,N`D{H"F
} 9U~sRj=D
#dxS QmG
publicvoid save(finalObject entity){ s+XDtO
getHibernateTemplate().save(entity); 6`;+| H<$
} xEvm>BZi
:pPn)j$
publicvoid persist(finalObject entity){ Hnc<)_DF
getHibernateTemplate().save(entity); ]~-vU{
} UIi`bbJ
y]TNjLpo$
publicvoid update(finalObject entity){ D!CuE7}
getHibernateTemplate().update(entity); YUsMq3^&
} 4m3pF0k
ZMI
vzQYI
publicvoid delete(finalObject entity){ DX%D8atrr
getHibernateTemplate().delete(entity); ~6-6aYhe
} y<A%&
E5F0C]hq
publicObject load(finalClass entity, ;IX*4E'4s
Y]>Qu f.!
finalSerializable id){ k=):>}
return getHibernateTemplate().load !_SIq`5]@
1I -LGe[Q
(entity, id); \w+a Q?e_
} FkJX)
Ar VNynQ
publicObject get(finalClass entity, a#G]5TZ
d T*8I0\+
finalSerializable id){ #cD20t
return getHibernateTemplate().get '4}c1F1T_
I~.d/!>Z
(entity, id); K:g:GEDgf
} @"E{gM@B
DTR/.Nr'K
publicList findAll(finalClass entity){ V9Gk``F<RZ
return getHibernateTemplate().find("from ]~A<Q{
;&%G)f
" + entity.getName()); :u$+lq
} 5};$>47m
r9d dVD
publicList findByNamedQuery(finalString g2'Q)w
Pqm)OZE?
namedQuery){ ?dcR!-3
return getHibernateTemplate (ATCP#lF
!(wH}ti
().findByNamedQuery(namedQuery); :&oUI&(o
} =!cI@TI
[Ifhh2
publicList findByNamedQuery(finalString query, 7berkU0P
:9Vd=M6,
finalObject parameter){ g}]EIv{
return getHibernateTemplate \O7Vo<B&D
t9Nu4yl
().findByNamedQuery(query, parameter); 5@{+V!o,
} o-D,K dY
)5Bkm{v3
publicList findByNamedQuery(finalString query, Dxwv\+7]
X0.-q%5
finalObject[] parameters){ Fc"&lk4e
return getHibernateTemplate Kx;DmwX-
X}5aE4K/
().findByNamedQuery(query, parameters); k<M~co;L
} P;dp>jL
426)H_wx
publicList find(finalString query){ g}-Ch#
return getHibernateTemplate().find Z{w{bf1&A
WSY&\8
(query); f2#9E+IQ
} ecH-JPm'
Vd{h|=J
publicList find(finalString query, finalObject |
3`qT#p{
>Ufjmm${
parameter){ 7\
<4LX
return getHibernateTemplate().find ,Dz2cR6
$<UX/a\sH
(query, parameter); e<>Lr
} r]{fjw(~
ZHshg`I`
public PaginationSupport findPageByCriteria rI:KZ}GZ
Hr$oT=x[
(final DetachedCriteria detachedCriteria){ Z w5\{Z0
return findPageByCriteria /)i)wxi
hG,gY;&[6
(detachedCriteria, PaginationSupport.PAGESIZE, 0); afEp4(X~
} @Y>3 -,o,S
{/BEO=8q2
public PaginationSupport findPageByCriteria eh'mSf^=p
^gFjm~2I
(final DetachedCriteria detachedCriteria, finalint wS2iyrIB
lO9{S=N
startIndex){ K]bS:[34 R
return findPageByCriteria %uGA+ \b
LIH>IpamN
(detachedCriteria, PaginationSupport.PAGESIZE, 'KGY;8<x]
YF{K9M!
startIndex); AEwb'
} UBRMV
s
*eXO?6f%s^
public PaginationSupport findPageByCriteria 'w%N(N tq
ZZC=
7FB
(final DetachedCriteria detachedCriteria, finalint ?E2k]y6<
YeJ95\jf
pageSize, ](0Vm_es
finalint startIndex){ )
WIlj
return(PaginationSupport) >V(2Ke Y
L1Q QU
getHibernateTemplate().execute(new HibernateCallback(){ *vhm
publicObject doInHibernate !BEOeq@2.
pOI+
(Session session)throws HibernateException { savz>E&
Criteria criteria =
3r em"M
N0RFPEQ~
detachedCriteria.getExecutableCriteria(session); _ga!TQ:
int totalCount = TiBE9
k7{fkl9|#
((Integer) criteria.setProjection(Projections.rowCount <(p1
j0_Q
xN"KSQpu
()).uniqueResult()).intValue(); 5,AQ~_,'\
criteria.setProjection G^mk<pH
N2&aU?`e
(null); Mty]LMK
List items = _z4rx
3n:<oOV
criteria.setFirstResult(startIndex).setMaxResults 9jPb-I-
Bh' vr3|
(pageSize).list(); a3c4#'c|D
PaginationSupport ps = ^YIOS]d>8#
T4!]^_t^
new PaginationSupport(items, totalCount, pageSize, |I\A0a a
3X!~*_iC
startIndex); .hJ8K#r
return ps; 2FVKgyV
} *VlYl"
}, true); J$I1*~I4v
} \[oHt:$do
.V.N^8(:a
public List findAllByCriteria(final &HXSO,@
>A,WXzAK}S
DetachedCriteria detachedCriteria){ ewY[vbF
return(List) getHibernateTemplate Ro1' L1:
kxn;;
().execute(new HibernateCallback(){ =h_gj >
publicObject doInHibernate =!CuCV7$1O
H0(zE*c~
(Session session)throws HibernateException { (&*F`\
Criteria criteria = E7h}0DX
w%_BX3GTO
detachedCriteria.getExecutableCriteria(session); 0 j.Sb2
return criteria.list(); wwAT@=X*}
} ;&!dD6N
}, true); W_
6Jl5]
} rODKM-7+
PjP%,-@1
public int getCountByCriteria(final .~U9*5d
m5p~>]}fYF
DetachedCriteria detachedCriteria){ ;Pa(nUE@
Integer count = (Integer) /r%+hS
P&tK}Se^V
getHibernateTemplate().execute(new HibernateCallback(){ jFXU
xf
publicObject doInHibernate VxFy[rP
$ B9=v
(Session session)throws HibernateException { Qm.kXlsDI
Criteria criteria = `SwnKg
lewDR"0Kx
detachedCriteria.getExecutableCriteria(session); +n, BD C;
return Xp~]kRm9
X2uX+}h*tA
criteria.setProjection(Projections.rowCount }gW}Vr <
19.cf3Dh
()).uniqueResult(); qc6IH9i`
} #~x5}8
}, true); YzZF^q^I
return count.intValue(); HIq1/)
} *e6|SZ &3
} 4PWr;&
mb/[2y <
,2TqzU;
4cQ5E9
`+.I
QC4T=E]`j
用户在web层构造查询条件detachedCriteria,和可选的 iW?9oe
x3s^u~C)(w
startIndex,调用业务bean的相应findByCriteria方法,返回一个 ^PQV3\N
V)2_T!e%*
PaginationSupport的实例ps。 V8yX7yx
OkZ! ZS
h
ps.getItems()得到已分页好的结果集 rl%Kn^JJ~
ps.getIndexes()得到分页索引的数组 w4'K2 7
ps.getTotalCount()得到总结果数 \vsrBM
ps.getStartIndex()当前分页索引 4c=kT@=jX
ps.getNextIndex()下一页索引 42CMRGv
ps.getPreviousIndex()上一页索引 &%X Jf~IQ
[bv@qBL
kkBU<L2
H040-Q;S'
^qqHq
h!K2F~i{P
C/waH[Yzan
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ({KAh?
DH9?2)aR
,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 #`4^zU)
t4/eB<fP
一下代码重构了。 Noxz kpMF
k6L373e#Q
我把原本我的做法也提供出来供大家讨论吧: <88}+j
t!SQLgA
首先,为了实现分页查询,我封装了一个Page类: mzxvfXSF
java代码: 3c ^=<i
%
' 1'1T5x~
m]d6@"Z.
/*Created on 2005-4-14*/ 0Eu$-)
package org.flyware.util.page; HoE.//b
R%_H\-wo
/** ,,_K/='m
* @author Joa ~|{)h^]@
* u7zB9iQ&
*/ "!Oh#Vf
publicclass Page { \G=R hx f
|C6(0fgWd
/** imply if the page has previous page */ WFB|lNf&
privateboolean hasPrePage; qV8\/7'A0a
T0v@mXBQ
/** imply if the page has next page */ jnp6qpY{
privateboolean hasNextPage; tW.>D;8
J
s<MJ4r>/
/** the number of every page */ OO\biYh o
privateint everyPage; q\t>D
_lU
<Mn7`i
/** the total page number */ x]><}!\<&
privateint totalPage; K:
o|kd
#X@<U <R
/** the number of current page */ QGv:h[b_
privateint currentPage; 0tm_}L$g=b
.cT$h?+jyl
/** the begin index of the records by the current XBWSO@M'
Hv gK_'
query */ ok%a|Zz+]
privateint beginIndex; yCkW2p]s,K
}:9|*m<$t
%Di7u- x
/** The default constructor */ D*T$ v
public Page(){ 'x,GI\;?
lmtQr5U
} YNgR1:l
_
U8OIXN
/** construct the page by everyPage Z_V&IQo-7
* @param everyPage U??f<
* */ _2gT1B
public Page(int everyPage){ z^!A/a[[!
this.everyPage = everyPage; GkGC4*n
} !/Bw,y ri<
COan)<Ku
/** The whole constructor */ *4hOCQ[
public Page(boolean hasPrePage, boolean hasNextPage, 1_j<%1{sZ
|+;K hC
HDSA]{:sl
int everyPage, int totalPage, mWN1Q<vn,l
int currentPage, int beginIndex){ {F(-s"1;xO
this.hasPrePage = hasPrePage; LF9aw4:>Ou
this.hasNextPage = hasNextPage; ,LW(mdIe(
this.everyPage = everyPage; ndKvJH 4
this.totalPage = totalPage; )kL`&+#>
this.currentPage = currentPage; @wB'3q}(
this.beginIndex = beginIndex; im4e!gRE
} VO @
4A6
>Oi2gPA
/** cFI7}#,5
* @return >G4HZE
* Returns the beginIndex. fbHWBb
*/ vSYunI
publicint getBeginIndex(){ /]k ,,&
return beginIndex; n&YW".iG
} ^T}}4I_Y
`u p-m=zA
/** c>u>Pi;Z
* @param beginIndex \sHy. {
* The beginIndex to set. hyk|+z`B
*/ 1C}pv{0:&
publicvoid setBeginIndex(int beginIndex){ RFZU}.*K$
this.beginIndex = beginIndex; ')P2O\YS
} vR%j#v|s
iL7-4Lv#
/** eN<>#:`
* @return VW{aUgajO
* Returns the currentPage. "o^bN 9=
*/ ^Hz
publicint getCurrentPage(){ WIEx
'{
return currentPage; L)kb (TH
} $tDCS
gJ FR1
/** u_}`y1Xu#
* @param currentPage V_ +}^
* The currentPage to set. ibZt2@GB)I
*/ &jXca| wAR
publicvoid setCurrentPage(int currentPage){ n=<NFkeX
this.currentPage = currentPage;
Z;j/K
} !F0rd9
*}
*!+C3
/** BB2_J=wA
* @return xQNw&'|UU
* Returns the everyPage. p|&ZJ@3
*/ ShL1'Z}^{
publicint getEveryPage(){ rQu
return everyPage; 1&X}1
} 3o+KP[A
ULp)T`P
/** ffmG~$Yh_
* @param everyPage Y=P9:unG
* The everyPage to set. %+AS0 JhB
*/ k%EWkM)?
publicvoid setEveryPage(int everyPage){ ,~?A,9?%:
this.everyPage = everyPage; 8 *4@-3Sx
} MuDFdbtR
]^iFqQe
/** l 8O"w&
* @return A5CdLwk
* Returns the hasNextPage. ]4Nvh\/P9
*/ ]%gp?9wy
publicboolean getHasNextPage(){ <u6c2!I{
return hasNextPage; RpHpMtvNo/
} =]=B}L`
??%)|nj.
/** P_,v5Qx"-
* @param hasNextPage pY^pTWs(
* The hasNextPage to set. ((Vj]I%
;
*/ _oQtk^fp
publicvoid setHasNextPage(boolean hasNextPage){ f:_=5e
+
this.hasNextPage = hasNextPage; [:AB$l*
} =jJ H^Y2
0L!er%GM
/** |?\gEY-Se
* @return Wr]O
* Returns the hasPrePage. ?"()>PJx
*/ ]XmQ]Yit
publicboolean getHasPrePage(){ oHxGbvQc
return hasPrePage; v*&Uk'4E
} kxwNbxC
1Z\(:ab13
/** m,\i
* @param hasPrePage /0Z|+L9Jo
* The hasPrePage to set. q $t&|{
*/ ^$e0t;W=
publicvoid setHasPrePage(boolean hasPrePage){ A;odVaH7
this.hasPrePage = hasPrePage; x}v1X`6b
} }$^]dn@
WLE%d]'%M
/** _GE=kw;:
* @return Returns the totalPage. 2>\b:
* pI
&o?n
*/ %,33gZzf
publicint getTotalPage(){ !A~d[</]m
return totalPage; AnRlH
} 66/Z\H^d
[ }{w
/** tJff+n>
* @param totalPage 4S'[\ZJO
* The totalPage to set. -UJ?L
*/ 5(423"(y
publicvoid setTotalPage(int totalPage){ #>BX/O*D
this.totalPage = totalPage; /j11,O?72
} ^)|&|
&j3`
)N
} <F ew<r2
!IN@i:m
-RGPtD@
\$j^_C>
mU>&ql?e
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 vuXS/ d
q1STRYb
个PageUtil,负责对Page对象进行构造: J`W-]3S#
java代码: {wcO[bN
\N? 7WQ
I|Z/`9T
/*Created on 2005-4-14*/ `N$!s7M
package org.flyware.util.page; yji>*XG
O)O Uy
import org.apache.commons.logging.Log; N ,+(>?yE
import org.apache.commons.logging.LogFactory; 8qN"3 Et
l^ARW
E
/** !5&%\NSv
* @author Joa ?d4Boe0-a2
* `%oIRuYG]j
*/ lu]o34
publicclass PageUtil { wDMjk2YN
%Z7%jma
privatestaticfinal Log logger = LogFactory.getLog kffZElV
Qo.Uqz.C
(PageUtil.class); jP+ pA e
mW~P!7]
/** zi
}(^~Fe
* Use the origin page to create a new page R5~gH6K|
* @param page jQ?LHUE
* @param totalRecords +1/b^Ac
* @return Fom>'g*
*/ q4k.f_{
publicstatic Page createPage(Page page, int PS$k >_=t
nS.2C>A
totalRecords){ ;gUXvx~~r
return createPage(page.getEveryPage(), 9_UN.]
'y.JcS!|
page.getCurrentPage(), totalRecords); x#mtS-sw2Q
} qU -!7=}7
;%WdvnW
/** 1A^1@^{m'
* the basic page utils not including exception 5,R`@&K3D
E M Q4yK
handler j=9ze op
%
* @param everyPage &{ ZSE^
* @param currentPage !R6ApB4ZI
* @param totalRecords csDQva\
* @return page yUe+":7k.
*/ P6YQK+
publicstatic Page createPage(int everyPage, int _=EZ `!%
r|fO7PD
currentPage, int totalRecords){ AkA!:!l
everyPage = getEveryPage(everyPage); h55>{)(E
currentPage = getCurrentPage(currentPage); L M
/Ga
int beginIndex = getBeginIndex(everyPage, Y\(;!o0a
{cR=N~_EO
currentPage); gu<V(M\
int totalPage = getTotalPage(everyPage, C
) ?uE'
=X@o@1
totalRecords); % O%xpSYr
boolean hasNextPage = hasNextPage(currentPage, jct./arK
3D_"yZ
totalPage); OH6n^WKY
boolean hasPrePage = hasPrePage(currentPage); NXI[q'y
k>5 O`Y:
returnnew Page(hasPrePage, hasNextPage, 0
iRR{a<
everyPage, totalPage, "!KpXBc,>
currentPage, 3=-
})X;
~5 >[`)
beginIndex); /:p8I6;
} 3?`"
@G*.1;jO
privatestaticint getEveryPage(int everyPage){ pbLGe'
return everyPage == 0 ? 10 : everyPage; )yj:PY]
} BJ5}GX!
CVQB"L
privatestaticint getCurrentPage(int currentPage){ re`t ]gzb
return currentPage == 0 ? 1 : currentPage; Gx'TkU=
} iM5vrz`n
<kbyZXV@K
privatestaticint getBeginIndex(int everyPage, int 2f,2rW^i
Fm3t'^SqF
currentPage){ .=<$S#x^Hb
return(currentPage - 1) * everyPage; 8\Hr5FqB(
} XUSvhr$|
o~1 Kp!U
privatestaticint getTotalPage(int everyPage, int 4l @)K9F
[BDGR
B7d"
totalRecords){ op @iGC+
int totalPage = 0; f /y`
euQ.ArF
if(totalRecords % everyPage == 0) ; Lql_1
totalPage = totalRecords / everyPage; i9m*g*"2
else |B^G:7c
totalPage = totalRecords / everyPage + 1 ; }V`mp
yI)~]K
r
return totalPage; >NM\TLET~
} D7?C
r;gP}H ?
privatestaticboolean hasPrePage(int currentPage){ FWY2s(5p
return currentPage == 1 ? false : true; L1#Ij#
} AK-}V4C/A
O#_b7i
privatestaticboolean hasNextPage(int currentPage, <Q5Le dN
g^~Kze
int totalPage){ I%lE;'x
return currentPage == totalPage || totalPage == z`U Ukl}T
,Em$ !n
0 ? false : true; e3m*i}K}
} ;[$n=VX`
h(' )"
%y<]Yzv.
} ]%dnKP~
nH[+n `{o
pq!%?m]
B'weok
80B>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。 (@sp/:`6
f CcD&<%
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 -?a<qa?$
,mFsM!|
做法如下: P?ep]
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Qt+:4{He
"Ty/k8?
的信息,和一个结果集List: mpay^.(%
java代码: uCP>y6I
Ru\_dr2yI}
yTBS=+X
/*Created on 2005-6-13*/ }1H=wg>\
package com.adt.bo; Z)"61)
)
!<\Br
import java.util.List; s8gU7pT49
Mi7y&~,
import org.flyware.util.page.Page; Y}STF
Qx`~g,wk8
/** GdmmrfXB
* @author Joa y'M#z_.z
*/ &tI#T)SSs
publicclass Result { _|{aC1Y!V
V5rp.~
private Page page; nCxAQ|P?
=y]$0nh
private List content; SZ!=`a]
FG-L0X
/** @R2at
* The default constructor ljJ>;g+
*/ "^CXY3v
public Result(){ )Hw:E71h2
super(); }nx=e#[g%2
} hfM;/
S"2qJ!.u
/** aP()|js
* The constructor using fields 5,KWprb
* /2uQCw&x-
* @param page 5\4g>5PD
* @param content g"8 .}1)~r
*/ }At{'8*n
public Result(Page page, List content){ P`SnavQBt
this.page = page; 15H6:_+=0
this.content = content; X" R<J#4
} -V<t-}h.
6vy7l(%
/** 1(dj[3Mt
* @return Returns the content. Qo0H
*/ JhK/']R
publicList getContent(){ M:SO2Czz
return content; %!j:fJ()
} j|_E$L A\
z4U9n'{
/** )LHj+B
* @return Returns the page. b\55,La
*/ pxINw>\Qv
public Page getPage(){
yfNX7
return page; ?w&SW{ I
} 34AP(3w
2&(sa0*y
/** |$lwkC)O
* @param content N=1JhjVk"
* The content to set. 90N`CXas
*/ .m4;^S2cO
public void setContent(List content){ j
-O2aL
this.content = content; :VA.Q rKW
} IO$z%r7
\l#>dq "Y
/** *wbZ;rfF
* @param page sKaE-sbJY
* The page to set. \k8rxW
*/ $a;]_ Y
publicvoid setPage(Page page){ |Rzy8j*
this.page = page; r4 dOK] 0
} GR4?BuY,
} HRa@
~4,I7c7
6gO9 MQY
V`hu,Y;%
2s ,8R
2. 编写业务逻辑接口,并实现它(UserManager, QP I+y8N=
4jmK].
UserManagerImpl) SpTdj^ ]4>
java代码: I?!rOU=0
M~
h8Crz
=d;Vk
/*Created on 2005-7-15*/ Yn51U6_S
package com.adt.service; ekSY~z=/u
fp>.Owt%.
import net.sf.hibernate.HibernateException; QGnxQ{ko
vxlOh.a|/L
import org.flyware.util.page.Page; }k$4/7ri
v[k5.\No
import com.adt.bo.Result; OJ>.-"
V2&^!#=s
/** obClBO)@Y
* @author Joa (il0M=M
*/ ]hw-Bu\{
publicinterface UserManager { :Waox"#=g
x ,/TXTZ6
public Result listUser(Page page)throws ]n1dp2aH
"AueLl)
HibernateException; yf1CXldi
>
dZ3+f
} ]L_w$ev'
8pZ<9t'
IfdI|ya
UV7%4xM5v
M7}Q=q\9
java代码: $+=
<(*
aC=['a>)
Z)<
wv&K
/*Created on 2005-7-15*/ Iq5pAHm>M6
package com.adt.service.impl; ReB7vpd
x!TZ0fq0
import java.util.List; Jn}n*t3
{Q(}DI
import net.sf.hibernate.HibernateException; $K}.
+`vVO
g$37;d3Tx
import org.flyware.util.page.Page; [uuj?Rbd
import org.flyware.util.page.PageUtil; mNmUUj9z
L^Wz vv]
import com.adt.bo.Result; nL`9l1
import com.adt.dao.UserDAO; Rs;15@t@
import com.adt.exception.ObjectNotFoundException; xp \S2@<
import com.adt.service.UserManager; xN->cA$A
rs8\)\z
/** +a)E|(cN
* @author Joa mB 55PYA
*/ AHh#Fx+K
publicclass UserManagerImpl implements UserManager { TR vZ
9M$/=>^
Z
private UserDAO userDAO; J\co1kO9/
sa-9$},z4
/** Q\_{d0
0
* @param userDAO The userDAO to set. mw$Y
*/ F4I6P
publicvoid setUserDAO(UserDAO userDAO){ 6vs3O
this.userDAO = userDAO; w<nv!e?
} eD#XDK
(|h:h(C
/* (non-Javadoc) J1F{v)T'?
* @see com.adt.service.UserManager#listUser Iin#Wd-/
u=K2Q4
(org.flyware.util.page.Page) Di(9]:+
*/ [s6C
ZcL
public Result listUser(Page page)throws 7nE"F!d+0
1=GI&f2I
HibernateException, ObjectNotFoundException { /XpSe<3
int totalRecords = userDAO.getUserCount(); Lk,+Tfk"
if(totalRecords == 0) [~%`N*G
throw new ObjectNotFoundException [/9(NUf
P'[<AZ
("userNotExist"); [1Dm<G
u@
page = PageUtil.createPage(page, totalRecords); .Ao0;:;(2-
List users = userDAO.getUserByPage(page); )iE"Tl
returnnew Result(page, users); D'i6",Z>
} !C&%T]
:=. *I
} F+aQ $pQ
p8>%Mflf
8C&x MA^
|r=DBd3
8I#D`yVKc
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 ;bjnL>eW
NB)t7/Us
询,接下来编写UserDAO的代码: v|@1(
3. UserDAO 和 UserDAOImpl: TipHV;|e
java代码: 3)E(RyQA3
zJl_ t0
o0Gx%99'
/*Created on 2005-7-15*/ "sbBe73 m
package com.adt.dao; C3"&sdLb$
9M2f!kJP$
import java.util.List; tbur$00
UzQ$B> f
import org.flyware.util.page.Page; |rPAC![=
IC~ljy]y_
import net.sf.hibernate.HibernateException; >4)g4~'n!
L#j/0IHD
/** CT"Fk'B'
* @author Joa TmP8q
*/ 7'.s7&
'7
publicinterface UserDAO extends BaseDAO { MUwVG>b8J~
OlGR<X
publicList getUserByName(String name)throws $KQ,}I
>>V&yJ_
HibernateException; )Vk:YL++
rO^xz7K^
publicint getUserCount()throws HibernateException; LknVqZ|k
$c=&0yt5
publicList getUserByPage(Page page)throws wRbw
Bl4 dhBZoO
HibernateException; %$9:e
J?
qS]G&l6QF
} +Jq`$+%C
p7 [(z
sp{j!NSL
,"H?hFQ
2f{kBD
java代码: BE4\U_]a3
3^ ~Zj95M
6/7F">@j
/*Created on 2005-7-15*/ {PmzkT}LF
package com.adt.dao.impl; taV|YP$
.zwVCW,u
import java.util.List; 5"2@NL
3 2y[
import org.flyware.util.page.Page; ;tr)=)q&
%8<2>
import net.sf.hibernate.HibernateException; npj5U/
import net.sf.hibernate.Query; {X]9^=O"
m)k-uWc$C
import com.adt.dao.UserDAO; o16~l]Z|f
am(#Fa
/** E7LbSZ
* @author Joa *h])mqhB
*/ hU+#S(t>b
public class UserDAOImpl extends BaseDAOHibernateImpl 24O
d] f
~Jxlj(" 0(
implements UserDAO { `D"1
gD}{A
s
kY0 \V
/* (non-Javadoc) *vD/(&pQ1:
* @see com.adt.dao.UserDAO#getUserByName pLo;#e8'f
5 iv@@1c
(java.lang.String) N.vG]%1"
*/ .S(^roM;+
publicList getUserByName(String name)throws V^WQ6G1
x3_,nl
HibernateException { CQjV!d0j
String querySentence = "FROM user in class Tz2x9b\82
lXw;|dGF
com.adt.po.User WHERE user.name=:name"; &gJW6<
Query query = getSession().createQuery rNxG0^k(
d(\ 1 }l
(querySentence); IY~
{)X
query.setParameter("name", name); ec#_olG%
return query.list(); A` =]RJ
} %Au T8
> `0| X
/* (non-Javadoc) dkETM,
* @see com.adt.dao.UserDAO#getUserCount() E4hq}
*/ JqQ3C}z
publicint getUserCount()throws HibernateException { "LXXs0
int count = 0; tRkrV]K
String querySentence = "SELECT count(*) FROM L#[HnsLp_
Y'?Iznb
user in class com.adt.po.User"; 83B\+]{hD
Query query = getSession().createQuery @ljZw(
2,+@#q
(querySentence); rx{#+iw
count = ((Integer)query.iterate().next <%he
o
l(.7t'
()).intValue(); )!BB/'DRQ
return count; l;XUh9RF`A
} CCC4(v
7%W!k zp>
/* (non-Javadoc) rffVfw
* @see com.adt.dao.UserDAO#getUserByPage 7jhl0
B6-AIPb
(org.flyware.util.page.Page) `Uu^I
*/ bx1G
CD
publicList getUserByPage(Page page)throws fQ^h{n
u|(aS^H=q
HibernateException { UzXDi#Ky
String querySentence = "FROM user in class "pR $cS
:p,c%"8
com.adt.po.User"; F>p%2II/
Query query = getSession().createQuery 9Y;}JVS
)kFme=;
(querySentence); _.u~)Q`6
query.setFirstResult(page.getBeginIndex()) Q,ZkeWQ7%
.setMaxResults(page.getEveryPage()); c>M_?::)0
return query.list(); "X\q%%P=?
} R9S7_u
D86K$IT
} ?U7&R%Lh`
N;%j#(v
j
s9^"wN YQ
h;&&@5@lM
,"4X&>_f
至此,一个完整的分页程序完成。前台的只需要调用 OFJJ-4[_3
5;r({J
userManager.listUser(page)即可得到一个Page对象和结果集对象 rjq -ZrC%
Q&\ZC?y4
的综合体,而传入的参数page对象则可以由前台传入,如果用 #sozXza\G
0b!fWS?,k0
webwork,甚至可以直接在配置文件中指定。 ,:\zXESy4
Yqq$kln
下面给出一个webwork调用示例: 18l~4"|fk
java代码: XyN`BDFi
2d,wrC<'$
h9@gs,'
/*Created on 2005-6-17*/ X7(rg W8
package com.adt.action.user; rElG7[+)p
lk5_s@V
l
import java.util.List; &@Ji+
#)IdJ]
import org.apache.commons.logging.Log; /jn:e"0~
import org.apache.commons.logging.LogFactory; [C*Xk{e
import org.flyware.util.page.Page; 74</6T]^
?Vb=4B{~
import com.adt.bo.Result; ^^W`Lh%9
import com.adt.service.UserService; 5Lo==jHif
import com.opensymphony.xwork.Action; `0/gs
(5CX *)R
/** oQE_?">w
* @author Joa [m@e^6F0U
*/ `pn-fk
publicclass ListUser implementsAction{ .-gm"lB
mAtG&my)
privatestaticfinal Log logger = LogFactory.getLog 9 ;! uV>-H
e3bAT.P
(ListUser.class); M\x7=*\
./z"P]$
private UserService userService; jw&}N6^G
2gNBPd )I
private Page page; ,&
{5,=
t2U]CI%
privateList users; $(!D/bvJ
bC>yIjCTn
/* wN%DM)*k
* (non-Javadoc) Rg!aKdDl$
* c"_H%x<[
* @see com.opensymphony.xwork.Action#execute() v:so85(S<
*/ d%"@#bB
publicString execute()throwsException{ mYU dh L^
Result result = userService.listUser(page); =Am*$wGI
page = result.getPage(); JhhT7\h(
users = result.getContent(); L< nkI
return SUCCESS; pR^Y|NG!
} mqfEs0~I
4w/t$lR
/** "#"Fp&Z7
* @return Returns the page. 0Ci"tA3"
*/ #h|,GvmF<b
public Page getPage(){ `qy6qKl
N
return page; y*TNJJ|
} 4N^Qd3[d
]idD&5gd
/** A0 w `o
* @return Returns the users. !n?*vN=S
*/ @R Yb-d
publicList getUsers(){ @=|
b$E
return users; YnL?t-$Gg
} 3[g++B."pC
e"8m+]
/** %l$&_xV-
* @param page \(v_",
* The page to set. h[v3G<C ~r
*/ nfPl#]ef*
publicvoid setPage(Page page){ 88LbO(q\d
this.page = page; GeW$lA I
}
i{x0#6_Y
|
3/p8
/** ~{tZ;YZ
* @param users ^T
J
* The users to set. Xcpm?aTo
*/ !/lYq;$R
publicvoid setUsers(List users){ oL/^[TXjH
this.users = users; ,f""|X5
} A2FU}Ym0=
#YMp,i
/** ^T1-dw(
* @param userService blkJm9]v
* The userService to set. ~0$F
V
*/ >WS&w;G
publicvoid setUserService(UserService userService){ .L|ax).D
this.userService = userService; (dprY1noC
} 7 QJcRZ[lU
} CoN/L`.SN
uTt:/gm
Xr6 !b:UX
.*ovIU8
J^a"1|
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, 0mi[|~x=
}EG(!)u
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 %H~gN9Vn#@
<R8Z[H:bV
么只需要: NB#*`|qt
java代码: m8A_P:MQq
1KR|i"
`ha:Gf
<?xml version="1.0"?> 9{#|sABGD
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork ._nKM5.
>^ar$T;Ys
1.0//EN" "http://www.opensymphony.com/xwork/xwork- Oydmq,sVe(
PGhZ`nl
1.0.dtd"> w1G.^
h4i$z-!
<xwork> io'Ovhf:
odn`%ok
<package name="user" extends="webwork- [1MEA;
A>2p/iMc
interceptors"> YYh_lAS>
v fDb9QP
<!-- The default interceptor stack name ?C2;:ol
-d)n0)9
--> <\EfG:e
<default-interceptor-ref -{%''(G
cTTE]ix]
name="myDefaultWebStack"/> s@iCfX U
rB?cm]G=
<action name="listUser" "uC*B4`
D.!7jA#
class="com.adt.action.user.ListUser"> wKbymmG
<param 4TE ?mh}
~{Bi{aK2
name="page.everyPage">10</param> mnjA8@1
<result !c($ C
]w_)Spo.
name="success">/user/user_list.jsp</result> ;qK6."b`;
</action> ZHasDZ8
L:Eb(z/D
</package> S$WM&9U
mK4|=Q
</xwork> (*BW/.Fq
8E[`H
XCriZ|s
sR.j~R
S>E.*]_
%MNV 5UA[w
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 N
Z`hy>LF^
AMz=HN
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 < z)G& h@
xrnH=>.;m
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 E%B Gf}h
c<e\JJY5?
+Bfi/ >
v{Vesf
[+z:^a1?V
我写的一个用于分页的类,用了泛型了,hoho qKC*jDW
Y_sVe
java代码: ![^h<Om
zmRK%a(
,eCXT=6
package com.intokr.util; 5 ZPUY
eUlb6{!y?
import java.util.List; zK?[dO
-+|[0hpw
/** )xy6R]_b
* 用于分页的类<br> yw!`1#3.
* 可以用于传递查询的结果也可以用于传送查询的参数<br> [CX?Tt
* GR
`ncI$z
* @version 0.01 'bPo 5V|
* @author cheng _9r{W65s
*/ d?Cl04
public class Paginator<E> { t@M] ec
privateint count = 0; // 总记录数 0B/a$NC
privateint p = 1; // 页编号 \'*`te:{
privateint num = 20; // 每页的记录数 ?UDO%`X
privateList<E> results = null; // 结果 i]pG}SJ
%WR"85
/** MGDv4cFE.
* 结果总数 ts>}>}@vc
*/ o#/iR]3
publicint getCount(){ tb3fz")UC
return count; (=V[tI+Ngt
} vW3Zu B
*DzPkaYD>
publicvoid setCount(int count){ HH@xnd
this.count = count; Un{ln*AR\
} 3HR]T Q%r
W=]",<
/** W[<":NX2
* 本结果所在的页码,从1开始 \;gt&*$-
* ,6\f4/
* @return Returns the pageNo. mkzk$_
*/ u6T?oK9j
publicint getP(){ Q}]kw}b
return p; #)}bUNc'
} tdF[2@?+
DNBpIC5&6
/** #!# X3j
* if(p<=0) p=1 ^VPl>jTg
* ?<^AXLiKV
* @param p CT%m_lN
*/ }/3pC a
publicvoid setP(int p){ bKZ#>%|:o
if(p <= 0) 9yw/-nA
p = 1; )0MshgM
this.p = p; 8;&S9'ci
} [=3tAPpzK
}(EOQ2TI
/** K(fLqXE%
* 每页记录数量 f<p4Pkv
*/ lILtxVBO2o
publicint getNum(){ |ZlT>u
return num; X`QW(rq
} b7sE
]Ja8i%LjOG
/** 2BA9T nxC
* if(num<1) num=1 [Fj+p4*N
*/ E?4@C"Na
publicvoid setNum(int num){ r tmt 3
if(num < 1) -7z y
num = 1; @"Fp;Je\bN
this.num = num; Zbh]SF{3F
} 5po'(r|U
1za'u_
/** $"{3yLg
* 获得总页数 ^H6d;n
*/ b_gN?F7_
publicint getPageNum(){ 05VOUa*pb
return(count - 1) / num + 1; PeUd
} 'S4EKV]
L[Yp\[#-q
/** Y\Qxdq
* 获得本页的开始编号,为 (p-1)*num+1 (X_ ,*3Yxk
*/ u$=ogp=0
publicint getStart(){ ~73i^3yf
return(p - 1) * num + 1; C6V&R1" s
} _Z66[T+M
Zjic"E1
/** nB@iQxcz
* @return Returns the results. ?}3PJVy?
*/ .4C[D{4
publicList<E> getResults(){ q?-3^z%u
return results; ]pR fY9w
} +>WC^s
7?!Z+r
public void setResults(List<E> results){ '0_j{ig
this.results = results; <.=#EV^i
} f{^M.G@
;?L!1wklA
public String toString(){ ZkB6bji
StringBuilder buff = new StringBuilder !`
M;#
lO2T/1iMTW
(); !(]dz~sM
buff.append("{"); l'7Mw%6{
buff.append("count:").append(count); Z'}(t,
buff.append(",p:").append(p); Z]aK'
buff.append(",nump:").append(num); /y9J)lx
buff.append(",results:").append G V:$;
2l)9Lz=;L
(results); lsB9;I^+x
buff.append("}"); Y1fy2\<'
return buff.toString(); uh5Pn#da^
} QlRoe|{
zY1s7/$i
} ]~prR?
oEQ{m5O9
xMNNXPz(