Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 %g$o/A$
./Zk`-OBT
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Lnl(2xD
:K,i\
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 T@B/xAq5!
U[-o> W#
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 9MJG;+B~
2%Ri,4SRb
。 ]L.O8
q'F+OQb1
分页支持类: 3AtGy'NTp
q-2Bt,Y
java代码: ]IQ&>z}<
YQvD|x
V#$RR!X'
package com.javaeye.common.util; !dnH7"
e\l7Iu
import java.util.List; UYJZYP%r
7hcYD!DS
publicclass PaginationSupport { kd(8I_i@
O"9\5(w
publicfinalstaticint PAGESIZE = 30; oxA<VWUNT
zT]8KA
privateint pageSize = PAGESIZE; Af2( 5]
e{K 215
privateList items; ;7V%#-
L|7R9+ZG
privateint totalCount; c
( C%Hld
C`9+6T
privateint[] indexes = newint[0]; I-*S&SiXjI
#&aqKVY
privateint startIndex = 0; 3z?> j]
skViMo
public PaginationSupport(List items, int D2eckLT
D?_Zl;bQ'^
totalCount){ }@+0/W?\.
setPageSize(PAGESIZE); YnAm{YyI
setTotalCount(totalCount); 5coyr`7mP
setItems(items); VA_PvL.9
setStartIndex(0); }!r|1$,kL
} <{cQM$#
\'D0'\:vz
public PaginationSupport(List items, int @o _}g !9=
Qd$nH8ED Y
totalCount, int startIndex){ Ya"a`ozq
setPageSize(PAGESIZE); =s2*H8]
setTotalCount(totalCount); osAd1<EIC
setItems(items); *)T^ChD,
setStartIndex(startIndex); ~Ea} /Au
} "ne?P9'hF
(Zrj_P`0[
public PaginationSupport(List items, int 0&|\N
? 8_
E,U+o $
totalCount, int pageSize, int startIndex){ ,T$U'&;
setPageSize(pageSize); &
G4\2l9
setTotalCount(totalCount); mSF(q78?
setItems(items); E
A1?)|}n
setStartIndex(startIndex); WiR(;m<g
} ]Ie 0S~
J @1!Oq>
publicList getItems(){ )~JHgl
return items; }rw8PZ9
} 6j]0R*B7`Q
]MitOkX
publicvoid setItems(List items){ kfY}S
this.items = items; DU/]
} )_S(UVI5
9IfmW^0
publicint getPageSize(){ ;))+>%SGCt
return pageSize; c9u`!'g`i
} K!Y71_#
Yu^4VXp~M%
publicvoid setPageSize(int pageSize){ ~Otoqu|
this.pageSize = pageSize; mnX2a
}
:KP@RZm
giw &&l=_
publicint getTotalCount(){ hRCJv#]HC
return totalCount; k(G^z
} "_NN3lD)X
R"t,xM
publicvoid setTotalCount(int totalCount){ WO>nIo5Y
if(totalCount > 0){ xr Jg\to{i
this.totalCount = totalCount; @,my7?::oM
int count = totalCount / CxW>~O:
c]o'xd,T8\
pageSize; {]@= ijjf
if(totalCount % pageSize > 0) =K[yT:
count++; [<yaXQxl
indexes = newint[count]; P{>!5|k
for(int i = 0; i < count; i++){ >jLY"
indexes = pageSize * O-hAFKx
@:vwb\azVD
i; `kXs;T6&
} ]Q3ADh
}else{ \?k'4rH
this.totalCount = 0; %XQ(fj>
} -zeG1gr3
} Jk
n>S#SZ
G<J?"oQbRT
publicint[] getIndexes(){ "JV_ 2K_i
return indexes; !F'YDjTot
} wc4{)qDE
V6X 0^g
publicvoid setIndexes(int[] indexes){ D'DfJwA
this.indexes = indexes; v^*K:#<Q!
} o|<!"AD7
ItrDJ'
publicint getStartIndex(){ nMUw_7Y6
return startIndex; Fk7')?
} Am|%lj+1z
aeM+ d`f
publicvoid setStartIndex(int startIndex){ Om2d.7S
if(totalCount <= 0) ?NsW|w_
this.startIndex = 0; WP'!*[z
elseif(startIndex >= totalCount) kxhWq:[c
this.startIndex = indexes 0GCEqQy8
+\
.Lp 5
[indexes.length - 1]; >KhOz[Zg
elseif(startIndex < 0) :':s@gqr
this.startIndex = 0; 9qzHS~l
else{ 0 /U{p,r6`
this.startIndex = indexes p}~JgEE
6O! 2P
[startIndex / pageSize]; i<Zc"v;
} VjZ|$k
} Qpc__dA\
Q/0Tj]D
publicint getNextIndex(){ 7;wd(8
int nextIndex = getStartIndex() + . 3T3EX|G
@lr ztM
pageSize; -x`@6
if(nextIndex >= totalCount) Pu$Tk|
return getStartIndex(); ;iL#7NG-R
else X\qNG]
return nextIndex; Fywv
} #.)0xfGW)n
RMu~l@
publicint getPreviousIndex(){ -k e's
int previousIndex = getStartIndex() - 'zuIBOH`j3
1\2no{Vh
pageSize; >U27];}y
if(previousIndex < 0) fJ!R6D
return0; .4!=p*Y
else `Eo.v#<
return previousIndex; J}K$(;:
} Pw"-S?`(
,R*
]>'
} p6!x=cW
sS'm!7*(3
T}v4*O.,
cU!vsdR3
抽象业务类 [5Mr@f4I
java代码: ~U&AI1t+J
[?N~s:}
Cjlk
/** ~dTrf>R8M
* Created on 2005-7-12 x7<K<k;s
*/ e8?jmN`2
package com.javaeye.common.business; l}A93jSL
M&9+6e'-F
import java.io.Serializable; 60?%<oJ oH
import java.util.List; tW}'g:s
_
*Pf
import org.hibernate.Criteria; +Q"4Migbe@
import org.hibernate.HibernateException; FP4P|kl/9'
import org.hibernate.Session; >@
.
import org.hibernate.criterion.DetachedCriteria; &Hs!:43E-<
import org.hibernate.criterion.Projections; 3{sVVq5Y
import T'Dv.h
[2M'PT3
org.springframework.orm.hibernate3.HibernateCallback; wgGl[_)
import Y\g3hM
uiR8,H9*M
org.springframework.orm.hibernate3.support.HibernateDaoS 3"~!nn0;
07{)?1cod4
upport; t&e{_|i#+
}a(dyr`S
import com.javaeye.common.util.PaginationSupport; p947w,1![
N6i Q8P-
public abstract class AbstractManager extends R%[ c;i
P.9>z7l{
HibernateDaoSupport { lA8`l>I
]Gq !`O1
privateboolean cacheQueries = false; ml
}{|Yz
-r]W
privateString queryCacheRegion; _L=h0H l
oE]QF.n#
publicvoid setCacheQueries(boolean AFE~
v\Gz
d<P\&!R(
cacheQueries){ hv>\gBe i
this.cacheQueries = cacheQueries; Qj3EXb
} mxdr,Idx
O)r4?<Q
publicvoid setQueryCacheRegion(String WOL:IZX%
L$M9w
queryCacheRegion){ cTT L1SW
this.queryCacheRegion = {kR#p %E]
/aZ`[m2
queryCacheRegion; j/?kL{B
} smo~7;
fVpMx4&F
publicvoid save(finalObject entity){ u;2[AQ.
getHibernateTemplate().save(entity); toC^LZgZ_6
} L)
T (<
Qh\60f>0
publicvoid persist(finalObject entity){
H6/$d
getHibernateTemplate().save(entity); [S!/E4>['
} svH !1b
'm
kLCS
publicvoid update(finalObject entity){ &&>ekG9@
getHibernateTemplate().update(entity); Qd3 j%(
} Wg]Qlw`\|
9CD_os\h
publicvoid delete(finalObject entity){ H$UcF1k<
getHibernateTemplate().delete(entity); ~2-1 j
}
r3UUlR/Do
1/J=uH
publicObject load(finalClass entity, 9~[Y-cpoi
F0@gSurg)
finalSerializable id){ k\?Ii<m
return getHibernateTemplate().load &0JI!bR(
n/mG|)Xt
(entity, id); Lt>IX")
} JDT`C2-Q
P@c5pc#|
publicObject get(finalClass entity, aAUvlb
8FY?!C
finalSerializable id){ 7J<5f)
return getHibernateTemplate().get -e:`|(Mo
P\k# >}}
(entity, id); &^Q/,H~S
} c\AfaK^KF
;u)I\3`*!
publicList findAll(finalClass entity){ 1yu4emye4
return getHibernateTemplate().find("from BnasI;yWb
wz%NbLy-
" + entity.getName()); *gWwALGo5
} ?.BC#S)q1
{3aua:q
publicList findByNamedQuery(finalString c5GuM|*7
#KZBsa@p
namedQuery){ {R6ZKB
return getHibernateTemplate $6SW;d+>n
1]b.fD
().findByNamedQuery(namedQuery); 8bld3p"^
} ~b8]H|<'Y
?$4 PVI}
publicList findByNamedQuery(finalString query, Ig>(m49d
Er?&Y,o
finalObject parameter){ r_A$DaC]
return getHibernateTemplate C;^X[x%h7$
~Z'?LV<t
().findByNamedQuery(query, parameter); fI|Nc
} d7bS
wL
i=2N;sAl
publicList findByNamedQuery(finalString query, Z(CkZll
}0Ed]
finalObject[] parameters){ CzrC%x y
return getHibernateTemplate l,5+@i`5i
{"KMs[M
().findByNamedQuery(query, parameters); `<d }V2rdz
} DSn_0D
kE1TP]|
publicList find(finalString query){ `VguQl_,gA
return getHibernateTemplate().find b4N[)%@
7B66]3v
(query); CRy|kkT
} $
$mV d+
5`p.#
publicList find(finalString query, finalObject uoh7Sz5!^
;9QEK]@
parameter){ |P?*5xPB
return getHibernateTemplate().find `r 3
jAlv`uB|G"
(query, parameter); %d9uTm;
} eTcd"Kd/
Cq~dp/V
public PaginationSupport findPageByCriteria {E|$8)58i
e$Pj.>-<=
(final DetachedCriteria detachedCriteria){ mQ"-,mMI
return findPageByCriteria pOoEI+t
iDqoa\
(detachedCriteria, PaginationSupport.PAGESIZE, 0); U| R_OLWAg
} H0vfUF53l
8Z=R)asGS
public PaginationSupport findPageByCriteria 5]:U9ts#
+9sQZB# (
(final DetachedCriteria detachedCriteria, finalint l9Q-iJ
~})e?q;b
startIndex){ (X*^dO
return findPageByCriteria MkXmA`cP
8'y$M] e9n
(detachedCriteria, PaginationSupport.PAGESIZE, 0?|<I{z2
NL+N%2XG7
startIndex); wi{3/
} ('+d.F[109
F#5~M<`.o
public PaginationSupport findPageByCriteria 5'u<iSmBo
R[]Mdt<
(final DetachedCriteria detachedCriteria, finalint EQSQFRk;
2&J)dtqz
pageSize, 5146kp|1
finalint startIndex){ mgU<htMr1
return(PaginationSupport) Q\sK"~@3
]JQULE)
getHibernateTemplate().execute(new HibernateCallback(){ $U-0)4yf
publicObject doInHibernate vo{--+{ky!
%JTpI`
(Session session)throws HibernateException { 4 s9LB
Criteria criteria = t\O16O7S
;*2Cm'8E
detachedCriteria.getExecutableCriteria(session); }4X0epPp;:
int totalCount = ]7c=PC
R`-S/C
((Integer) criteria.setProjection(Projections.rowCount MVUJD{X#
<b*DQ:N
()).uniqueResult()).intValue(); A?OQE9'
criteria.setProjection &_8947
|-~Y#]
(null); Pr
C{'XDlU
List items = a(ZcmYzXU
{Qj~M<@3
criteria.setFirstResult(startIndex).setMaxResults @oGcuE
+:/%3}`
(pageSize).list(); :7;@ZEe
PaginationSupport ps = as=fCuJ
%^6F_F_jS
new PaginationSupport(items, totalCount, pageSize, {?7Uj
w_V P
J
startIndex); b*lkBqs$
return ps; 9%obq/Lb
} YtLt*Ig%
}, true); vW@=<aS Z
} W[r>.7>?h
'$+ogBS
public List findAllByCriteria(final P[fq8lDA
Ab;.5O$y
DetachedCriteria detachedCriteria){ t sRdvFFq
return(List) getHibernateTemplate A^S gI-y|
)D%~`,#pQ
().execute(new HibernateCallback(){ @IZnFHN
publicObject doInHibernate :.`2^
u9p$YJ
(Session session)throws HibernateException { %A0/1{(
Criteria criteria = ql~J8G9
u_Z+;{]Pj
detachedCriteria.getExecutableCriteria(session); j B{8u&kz)
return criteria.list(); >=w)x,0yX
} 2MK-5Kg
}, true); dlnX_+((KC
} ^xk'Z
@>7%qS
public int getCountByCriteria(final WTiD[u
V0Hj8}l;M
DetachedCriteria detachedCriteria){ %B?=q@!QWn
Integer count = (Integer) iH'p>s5L
hgE71H\s
getHibernateTemplate().execute(new HibernateCallback(){ akTk(
publicObject doInHibernate RPbZ(.
+aAc9'k
(Session session)throws HibernateException { I5W~g.<6
Criteria criteria = ;5AcFB
xD=csJ'(
detachedCriteria.getExecutableCriteria(session); ?Z} &EH
return EKN~H$.
j5h-dK
criteria.setProjection(Projections.rowCount b7ZSPXV
NwfVL4Xg
()).uniqueResult(); sa8Vvzvo.
} pQQH)`J|t
}, true); DVeE1Q
return count.intValue(); 2B`JGFcdcB
} #lO Mm9
} b\5F ]r
!bP@n
{K!)Ss
o{[qZc_%
z0Z%m@
V]?R>qhgu
用户在web层构造查询条件detachedCriteria,和可选的 Zb#u0Tq
3__-nV
startIndex,调用业务bean的相应findByCriteria方法,返回一个 /zox$p$?h
`
G
kX
PaginationSupport的实例ps。 \}G^\p6?M
.A|@?p[
ps.getItems()得到已分页好的结果集 >.D4co>
ps.getIndexes()得到分页索引的数组 u]G\H!WkQ
ps.getTotalCount()得到总结果数 3iU=c&P
ps.getStartIndex()当前分页索引 2>59q$|
ps.getNextIndex()下一页索引 JsS-n'gF'
ps.getPreviousIndex()上一页索引 ^kSqsT"
0IWf!Sk
]
Gp\
kU:}&
4{Z)8;QX
h>bx}$q
(QiAisE
O.JN ENZf
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 H0cA6I
%SUQ9\SEs
,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 bs1Rvx1:J%
;9'OOz|+1
一下代码重构了。 . 'yCw#f
'O-"\J\
我把原本我的做法也提供出来供大家讨论吧: ABYcH]m
:2)/FPL6
首先,为了实现分页查询,我封装了一个Page类: d0 /#nz
java代码: ll?X@S
(Awm9|.{+
G]aOHJ:.
/*Created on 2005-4-14*/ kvj#c
package org.flyware.util.page; U`s{Jm
3= ;<$+I6
/** R/a*LSe@&
* @author Joa (4-CF3D
* CTA3*Gn
*/ *gz{.)W
publicclass Page { BD7Ni^qI$
#)VF3T@#'
/** imply if the page has previous page */ a-J.B.A$Z/
privateboolean hasPrePage; Yz93'HDB
-D~%|).'
/** imply if the page has next page */ |vzl. ^"-
privateboolean hasNextPage; K~EmD9
-H-~;EzU
/** the number of every page */ rU(+T0t?I
privateint everyPage; 0Y5_PTWb+Y
Uoix
/** the total page number */ BfiD9ka-z
privateint totalPage; ~7Ux@Sx;
Ssg&QI
/** the number of current page */ YZJyk:H\
privateint currentPage; 9-m=*|p
Qe(:|q_
/** the begin index of the records by the current ku
M$UYTTX
0Wp|1)ljA
query */ mRK>U$v
privateint beginIndex; @9|hMo
]
@fk] ]R
|(^PS8wG
/** The default constructor */ ={Qi0Pvt
public Page(){ |
VDV<g5h
IO:G1;[/2L
} Y\'}a+:@Ph
+x}<IS8
/** construct the page by everyPage ?|Zx!z ($
* @param everyPage bi;1s'Y<D
* */ g<
.qUBPKX
public Page(int everyPage){ Rbv;?'O$L
this.everyPage = everyPage; "-V"=t'
} o#1 $q`Z
Eu04e N
/** The whole constructor */ seeBS/%
public Page(boolean hasPrePage, boolean hasNextPage, El"Q'(:/U
{H'Y `+
o*hF<D$Y
int everyPage, int totalPage, FHI ;)wn=
int currentPage, int beginIndex){ ENY+^7
this.hasPrePage = hasPrePage; BTrn0
this.hasNextPage = hasNextPage; ,UE83j8D^
this.everyPage = everyPage; )dd@\n$6
this.totalPage = totalPage; %D "I
this.currentPage = currentPage; aC)!T
this.beginIndex = beginIndex; x]ot 2
} A&jlizN7
RViuJ;
/** Kx JqbLUC
* @return %H"47ZFxAs
* Returns the beginIndex. L_iFt!
*/ 7. ;3e@s
publicint getBeginIndex(){ y"wShAR
return beginIndex; Pk)1WK7E
} )w%!{hn
R*r#E{!V;
/** S|+o-[e8O
* @param beginIndex 8}| (0mC
* The beginIndex to set. |P}y,pNQ
*/ u,4eCxYE$
publicvoid setBeginIndex(int beginIndex){ nzeX[*
this.beginIndex = beginIndex; JqiP>4Uwm^
} jo@J}`\Zt
8Uxne2e
/** q> C'BIr
* @return V3j= Kf
* Returns the currentPage. 8)I^ t81
*/ H$4:lH&(
publicint getCurrentPage(){ @f_+=}|dc
return currentPage; [!OxZ!
} #Mw8^FST
#>+ HlT
/** Y:a]00&)#Y
* @param currentPage H7:] ]j1
* The currentPage to set. ]OzUGXxo~
*/ ]z9=}=If
publicvoid setCurrentPage(int currentPage){ HyWCMK6b
this.currentPage = currentPage; ?6Y?a2 |
} q'82qY
HHsmLo c4
/** U4B(#2'
* @return wD)XjX
* Returns the everyPage. ~e@z;]CiY
*/ TRq6NB
publicint getEveryPage(){ "9e\c;a
return everyPage; L;I]OC^J
} sLQ^F
DR<9#RRD
/** G'A R`"F
* @param everyPage 0"bcdG<}
* The everyPage to set. ea')$gR
*/ 'b{]:Y
publicvoid setEveryPage(int everyPage){ ~Jz6O U*z
this.everyPage = everyPage; ixD)VcD-f
} CzEd8jeh7
/t"3!Z?BOv
/** [IhYh<i
* @return pIX`MlBdF
* Returns the hasNextPage. ?(i{y~
*/ *!7O~yQ
publicboolean getHasNextPage(){ }9fTF:P
return hasNextPage; mL: sJf
} ) hfpwdQ
oM`0y@QCf
/** L/G6Fjg^
* @param hasNextPage Z?m3~L9L2
* The hasNextPage to set. `+Q%oj#FF
*/ ]GQG~H^
publicvoid setHasNextPage(boolean hasNextPage){ Q$@I"V&G.
this.hasNextPage = hasNextPage; %8~NqS|=
} a!AA]
SI-Ops~e
/** jtc]>]6i
* @return AkQ~k0i}b
* Returns the hasPrePage. %d<"l~<5;
*/ 7O-x<P;
publicboolean getHasPrePage(){ _zi|
return hasPrePage; WEi2=3dV
} 0Z{ZO*rK
~FG]wNgS
/** :X
(=z;B;N
* @param hasPrePage G*P#]eO
* The hasPrePage to set. W|63Ir67
*/
7E~;xn;
publicvoid setHasPrePage(boolean hasPrePage){ fS78>*K
this.hasPrePage = hasPrePage; Z}Ft:7
} W v+?TEP
A{D];pE`
/** Fy-t T]Q9
* @return Returns the totalPage. HRfYl,S,
* wEvVL
*/ ?+}_1x`
publicint getTotalPage(){ 'AS|ZRr/
return totalPage; 2!=f hN
}
Qjv}$`M
bAtSV u
/** 7! INkH]
* @param totalPage 5taT5?n2
* The totalPage to set. P?of<i2E
*/ ExL0?FemWV
publicvoid setTotalPage(int totalPage){ L>4"(
this.totalPage = totalPage; i6Emhji
} mSh[}%swj
&Ys<@M7E:
} .jjG(L
JYbL?N
t=W}SH
%2V? ,zY@
K^<BW(s
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 +*/Zu`kzX
z/@slT
个PageUtil,负责对Page对象进行构造: ?QdWrE_
java代码: PP33i@G
@YTaSz$L
9 X`Sm}i
/*Created on 2005-4-14*/ a'yK~;+_9
package org.flyware.util.page; SbrecZ
)W
_v:?A9
import org.apache.commons.logging.Log; x\G'kEd
import org.apache.commons.logging.LogFactory; o9yJf#-En
dn$!&
/** z/2//mM
* @author Joa A0 C,tVd
* 3eAX.z`D
*/ }Sh?S]]`
publicclass PageUtil { mLLDE;7|}
]:k/Y$O2
privatestaticfinal Log logger = LogFactory.getLog HJ[c M6$2
uo%)1NS!
(PageUtil.class); rlSeu5X6
~
=2PU$u
/** x@;m8z0
* Use the origin page to create a new page 4yr'W8X_
* @param page ywmo#qYe
* @param totalRecords B7E:{9l~s{
* @return u[=r,^YQ
*/ 0gP}zM73
publicstatic Page createPage(Page page, int ShP^A"Do
0)e\`Bv
totalRecords){ A&Usddcp
return createPage(page.getEveryPage(), ~/iKh11
9`X\6s
page.getCurrentPage(), totalRecords); hT&Y#fh
} >rmqBDKaQ
2*l/3VW
/** bUdLs.:
* the basic page utils not including exception Q1I6$8:7
x}I+Iggi
handler J$w<$5UY
* @param everyPage C]`$AqKl
* @param currentPage qvKG-|j
* @param totalRecords z3m85F%dR
* @return page u?<%q!
*/ yfjWbW
publicstatic Page createPage(int everyPage, int Z4w!p?Wqa
6@F9G4<Z
currentPage, int totalRecords){ sW'AjI
everyPage = getEveryPage(everyPage); 17"uf.G
currentPage = getCurrentPage(currentPage); ' ;FnIZ
int beginIndex = getBeginIndex(everyPage, Ma']?Rb`
S3*`jF>q
currentPage); h-K_Lr]
int totalPage = getTotalPage(everyPage, vm7z,FfN
@&3EJ1
totalRecords); lc1(t:"[
boolean hasNextPage = hasNextPage(currentPage, qUW!
G&R
;LPfXpR
totalPage); G3vxjD<DMW
boolean hasPrePage = hasPrePage(currentPage); &P}_bx
UapC"XYJ
returnnew Page(hasPrePage, hasNextPage, aU "8{
everyPage, totalPage, li'YDtMKCY
currentPage, JWhdMU
:tB1D@Cb6
beginIndex); iDz++VNV
} Sc1 8dC0
8hz^%vm
privatestaticint getEveryPage(int everyPage){ G kl71VX
return everyPage == 0 ? 10 : everyPage; %i9E @EV
} gw3K+P
`O!X((
privatestaticint getCurrentPage(int currentPage){ /hH
return currentPage == 0 ? 1 : currentPage; lH x^D;m6
} RYQR(v
t?-n*9,#S
privatestaticint getBeginIndex(int everyPage, int BB!THj69a6
j<99FW"@e
currentPage){ fo#fg8zX%
return(currentPage - 1) * everyPage; BxWPC#5
} HU8900k+
;!mzyb*
privatestaticint getTotalPage(int everyPage, int M4oy
r?lf($D*
totalRecords){ "fCu=@i
int totalPage = 0; p;59?
gx8ouOh
if(totalRecords % everyPage == 0) k"T}2 7
totalPage = totalRecords / everyPage; FxtQXu-g
else F|o:W75
totalPage = totalRecords / everyPage + 1 ; iohop(LZ
T@:Wp4>69
return totalPage; 9~5uaP$S
} jrlVvzZ
~ Ei $nV
privatestaticboolean hasPrePage(int currentPage){ ,]ma+(|
return currentPage == 1 ? false : true; UXc-k
} a}BYov
6ryak!|[
privatestaticboolean hasNextPage(int currentPage, u~M
q*
4n!aW?%
int totalPage){ .9 on@S
return currentPage == totalPage || totalPage == z0p*Z&
hk(ZM#Bh
0 ? false : true; <EB+1GFuI
} [#<-ZC#T*
@fZ,.2ar
|mdVdD~go
} (
iBl
3s,g*
7a=gH2]&
*/)c?)"
o/$}
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。 * J7DY f
L
O_k@3
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 SO|NaqWa
[fya)}
做法如下: @Q
]=\N:
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 yYIf5S`V]
L3u&/Tn2
的信息,和一个结果集List: LEbB(x;@
java代码: <ktrPlNuM
53;}Nt#R
xjuN-
/*Created on 2005-6-13*/ d6?j`~[7#-
package com.adt.bo; ]_mb7X>
lk^Ol&6
import java.util.List; ~:rl=o }
k$z_:X
import org.flyware.util.page.Page; (Y.k8";)`
G\/zkrxmv
/** Zw
26
* @author Joa IXMop7~
*/ ~rE|%o
publicclass Result { LvH4{B
=\&;Fi]
private Page page; =V,mtT
DbBcQ%
private List content; ~9a<0Mc?
I+%[d^,
/** )0.kv2o.
* The default constructor }>pknc?
*/ 8O5s`qKMYT
public Result(){ ]}<}lI9
super(); fIx+ILs
} 4x=v?g&
zsEc(
/** 9|^2",V
* The constructor using fields {k>&?Vd!
* <$A
* @param page q~b&
* @param content . oF
&Ff/[
*/ |sJ[0z
public Result(Page page, List content){ vjbASFF0=
this.page = page; f
O}pj:
this.content = content; guq{#?}
} 9Z@hPX3.
Gvt G(u~
/** O40?{v'
* @return Returns the content. ?hZAxR\
*/ pz!Zs."f)
publicList getContent(){ 2RVN\?s:
return content; 7X`g,b!
} m4[ ;(1
|{z:IQLv
/** FZ{h?#2?
* @return Returns the page. [SjqOTon{
*/ %+aCJu[k(z
public Page getPage(){ (+w*[qHe
return page; h"[AOfTE$
} MD}w Y><C
f&NgS+<K$
/** -V*R\,>
* @param content 9@SC}AF.
* The content to set. afCW(zHp
*/ / H[=5
public void setContent(List content){ Hck]aKI+
this.content = content; G*?8MTP8![
} a(m2n.0'>
e[{0)y>=
/** fF!Yp iI"
* @param page h/QXPdV
* The page to set. qJf?o.Pv
*/ poc`q5i+
publicvoid setPage(Page page){ -mbt4w
this.page = page; F#3Q_G^/
} j"8ZM{aO
} SpIv#?
[$ubNk;!z
lB8-Z ow
:tc@2/>!O
I
}a`0Y&{
2. 编写业务逻辑接口,并实现它(UserManager, ")1:F>
o@_q]/Mh
UserManagerImpl) \,'m</o~,
java代码: :p1u(hflS
7zl5yKN
]
7[
3>IN
/*Created on 2005-7-15*/ v8w q,CYV
package com.adt.service; vRYQ{:
mtpeRVcF
import net.sf.hibernate.HibernateException; T )&A2q
<jBF[v9*m(
import org.flyware.util.page.Page; Ucb F|vkI
xBj9yu
import com.adt.bo.Result; 1>.Ev,X+e
\:P>le'1
/** DcS+_>a\{l
* @author Joa lwR<(u31e
*/ ]]HNd7Vh
publicinterface UserManager { 5p,RI&nlN
W Tcw4
public Result listUser(Page page)throws ;_XFo&@
nd`1m[7MNu
HibernateException; FBG4pb9=~
B5`EoZ
} `C,n0'PL.
x[|}.Ew
>^O7
\Zb;'eDv
!@5 9)
java代码: x
o;QCOH
;t)3F
qfX6TV5J}!
/*Created on 2005-7-15*/ 44J]I\+
package com.adt.service.impl; Mg+2.
8%
M.JA.I@XC
import java.util.List; `T1
g%aYDl
import net.sf.hibernate.HibernateException; W
PC]%:L"
.zf~.R;>
import org.flyware.util.page.Page; gZVc 5u<
import org.flyware.util.page.PageUtil; &L3M]
]|#+zx|/D
import com.adt.bo.Result; "BAK !N$9
import com.adt.dao.UserDAO; g9OY<w5s]
import com.adt.exception.ObjectNotFoundException; BqEI(c6
import com.adt.service.UserManager; D=TvYe
O/^%2mG
/** t <~h'U
* @author Joa >:SHV W
*/ g%o(+d
publicclass UserManagerImpl implements UserManager { OUE(I3_
REQ\>UO_
private UserDAO userDAO; iG$!6;w<
XMZ,Y7
/** {.`vs;U
* @param userDAO The userDAO to set. @?ebuj5{e
*/ rDtY[
publicvoid setUserDAO(UserDAO userDAO){ \Zk;ikEY
this.userDAO = userDAO; cUk7i`M;6
} `Uq#W+r,
aNsBcov3O
/* (non-Javadoc) 7lTC{7C57
* @see com.adt.service.UserManager#listUser gE-tjoJ
UJUEYG
(org.flyware.util.page.Page) bt SRtf
*/ \eTwXe]Pv
public Result listUser(Page page)throws Fk7?xc
"> ypIR<
HibernateException, ObjectNotFoundException { $L`d&$Vh
int totalRecords = userDAO.getUserCount(); 'JtBZFq
if(totalRecords == 0) >\R+9p:o
throw new ObjectNotFoundException /|w6:;$;mn
`6;?9NI
("userNotExist"); e
v}S+!|U
page = PageUtil.createPage(page, totalRecords); + SzU
List users = userDAO.getUserByPage(page); RIR\']WN
returnnew Result(page, users); x%=si[P
} q$L%36u~/
'$Dn
} NCXRevE
P.se'z)E
W<{h,j8
|o"?gB}Dh
sQ3[<
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 QP==?g3
JBj]najN
询,接下来编写UserDAO的代码: xh-o}8*n"
3. UserDAO 和 UserDAOImpl: z9f-.72"X
java代码: /A\8 mL8
'd0~!w
810|Tj*U%
/*Created on 2005-7-15*/ c?Y*Y
package com.adt.dao; UsG~row:!
:]K4KFM
import java.util.List; cdH>n)
E,Z$pKL?
import org.flyware.util.page.Page; XTs8s12
_~m5^Q&
import net.sf.hibernate.HibernateException; L<c4kw
t|?ez4/{z
/** j a[Et/r
* @author Joa J`Q>3]wL
*/ $GV7o{"&
publicinterface UserDAO extends BaseDAO { 3m[vXr?
6 3iUi9P
publicList getUserByName(String name)throws MR7}s4o
p>,|50|
HibernateException; YpHg&|Fr
@)+AaC#-
publicint getUserCount()throws HibernateException; gk4;>}
Z3e| UAif
publicList getUserByPage(Page page)throws /V8#[9K
yqs4[C
HibernateException; C.:<-xo
u]wZQl#-
} .8g)av+
Eh`7X=Z7E
Ufj`euY
,^r9n[M4M
)iX~}7
java代码: o#)C^xlQ
'c&Ed
T.F!+
/*Created on 2005-7-15*/ hW')Sp
package com.adt.dao.impl; P;y45b
RU{twL.B
import java.util.List; ? V1*cVD6i
yu {d! {6
import org.flyware.util.page.Page; t,Lrfv])
>{]%F*p4
import net.sf.hibernate.HibernateException; G5_=H,Vmd
import net.sf.hibernate.Query; umfD>" ^I
~D+bh~
import com.adt.dao.UserDAO; # +>oZWVc
ldcqe$7,
/** 68|E9^`l
* @author Joa iU918!!N
*/ LP^$AAy
public class UserDAOImpl extends BaseDAOHibernateImpl z
kP_6T09
f5"k55 }
implements UserDAO { YMyfL8bO
~NgA
/* (non-Javadoc) b6M[q_
* @see com.adt.dao.UserDAO#getUserByName tFn)aa~L
n8 0?N}
(java.lang.String) JG.y,<xW
*/ )m+W
j
publicList getUserByName(String name)throws ;;Y!^^g
pX<`+t[
HibernateException { v"$L702d$\
String querySentence = "FROM user in class tT8%yG}
2|y"!JqE1
com.adt.po.User WHERE user.name=:name"; +/7?HGf
Query query = getSession().createQuery u#fM_>ML
/62!cp/F/D
(querySentence); ,KZ~?3$yj
query.setParameter("name", name); !n!*/[}X
return query.list(); 8nqG<!,q
} s[*rzoA
#zy:a%
/* (non-Javadoc) Es`Px_k
* @see com.adt.dao.UserDAO#getUserCount() DK~xrU'
*/ ~Cttzn]pR
publicint getUserCount()throws HibernateException { (x|T+c"bAX
int count = 0; G>=*yqo
String querySentence = "SELECT count(*) FROM nPtuTySG
bs&43Ae
user in class com.adt.po.User"; }K>d+6qk5
Query query = getSession().createQuery \K{
z
iMh#TUlQEQ
(querySentence); tjS@meT
count = ((Integer)query.iterate().next GA)`-*.R
C=xa5Y
()).intValue(); P; no?
return count; ,Vax&n+J
} }#+^{P3 ;
Po0A#Z l
/* (non-Javadoc) kazzVK5x
* @see com.adt.dao.UserDAO#getUserByPage 0> E r=,e
rXq.DvQ
(org.flyware.util.page.Page) c#]4awHU
*/ 3`?7<YJ
publicList getUserByPage(Page page)throws T<>,lQs(a
.43'HV
HibernateException { Y-z(zS^1
String querySentence = "FROM user in class 1H`,WQ1mG
=I5>$}q_&,
com.adt.po.User"; 'oVx#w^mf
Query query = getSession().createQuery n&/
`
On?v|10r'
(querySentence);
l&zilVVm
query.setFirstResult(page.getBeginIndex()) >|=ts
.setMaxResults(page.getEveryPage()); G4;Oi=
return query.list(); $wa{~'
} Vp\,CuQ
S13nL^=i
} C.P*#_R
MjRHA^b
e%M;?0j
Y|qTyE%
{S\{Ii6
至此,一个完整的分页程序完成。前台的只需要调用 ?j.,Nw4FC
{YC@T(
userManager.listUser(page)即可得到一个Page对象和结果集对象 3,w_".m`#
~8+ Zs
的综合体,而传入的参数page对象则可以由前台传入,如果用 1GRCV8"Z^
+`0k Fbx
webwork,甚至可以直接在配置文件中指定。 JR|ck=tq
1&OW4_
下面给出一个webwork调用示例: HJH{nz'Lw
java代码: .Hm>i
>:!5*E5?
/N.b%M]!
/*Created on 2005-6-17*/ pki%vRY
package com.adt.action.user; r5/0u(\LB
FV!q!D
import java.util.List; T::85
8,%^
M9zBP
import org.apache.commons.logging.Log; 2,F.$X
import org.apache.commons.logging.LogFactory; ;(%QD
3 >
import org.flyware.util.page.Page; @HC Vmg:
OT*mO&Z
import com.adt.bo.Result; I{2hfKUe`
import com.adt.service.UserService; @mBQ?;qlK
import com.opensymphony.xwork.Action; >U>(`r*
UkC!1Jy
/** T-L||yE,h
* @author Joa vr l-$ii
*/ u=s p`%?
publicclass ListUser implementsAction{ l)\! .X
_[3D
privatestaticfinal Log logger = LogFactory.getLog }X6m:#6
$%Kfq[Q
(ListUser.class); +\A,&;!SR
3hH<T.@)
private UserService userService; w&#]-|$
@. l@\4m
private Page page; {P./==^0
(ZizuHC
privateList users; F>l]
9!P|m
?l )[7LR4
/* Avc%2+
* (non-Javadoc) T^KKy0ZGM
* }0z)5c
* @see com.opensymphony.xwork.Action#execute() SH$PwJ U
*/ %> eiAB_b
publicString execute()throwsException{ 7}>E J
Result result = userService.listUser(page); j^JPZ{ej?
page = result.getPage(); LRA8p<Rs
users = result.getContent(); L2z[
return SUCCESS; SnfYT)Ph
} /3T1U
Gd=RyoJl
/** KpGhQdR#
* @return Returns the page. ?`ZUR&
20
*/ =,8]nwgo
public Page getPage(){ HV|,}Wks6s
return page; r19
pZAc
} h]gp ^?=
n>YKa)|W`
/** da(<K}
* @return Returns the users. PZ9I`P!C
*/ tsjrRMR
publicList getUsers(){ cwg"c4V
return users; z:*|a+cy
} H{wl% G
L4HI0Mx
/** /4Gt{ygSr
* @param page jLluj
* The page to set. lo+A%\1
*/ :F?C)F
publicvoid setPage(Page page){ 4B.*g-L
this.page = page; vs4>T^8e
} ga +dt
y)@wjH{6
/** L8B!u9%
* @param users K|,
.C[
* The users to set. 7.oM J
*/ fHFE){
publicvoid setUsers(List users){ z}
#JK?u
this.users = users; 4r}51 N\
} ?@86P|19
;Y, y 4{H3
/** ZECfR>`x
* @param userService e^voW"?%
* The userService to set. hVY$;s
*/ k_#)Tw*
publicvoid setUserService(UserService userService){ 9'B `]/L
this.userService = userService; WyiQoN'q
} Zh~'9 JH
} yWSGi#)1
h376Be{P
<hyKu
TLH1>pY&
eR>oq,
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, Bzf^ivT3L
2?Vd 5xkt
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 'g\4O3&_
L4W5EO$
么只需要: R|(a@sL
java代码: 9 68Ez
Pq$n5fZC!
1% ` Rs
<?xml version="1.0"?> Di{de`
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork wCBplaojJ
:ws<-Qy
1.0//EN" "http://www.opensymphony.com/xwork/xwork- p_4<6{KEt
m&3xJuKih
1.0.dtd"> ~}
~4
/;$[E
<xwork> OyIw>Wfv
"AqB$^S9t
<package name="user" extends="webwork- 8oGRLYU N
-~w'Xo #
interceptors"> $??I/6
R=?[Nz
<!-- The default interceptor stack name d'> x(Yi
.%-8 t{dt
--> c+ie8Q!
<default-interceptor-ref o8MZiU1Xf
h";L
name="myDefaultWebStack"/> 53h0UL
ca9X19NG
<action name="listUser" er\|i. Y
%C]>9."
class="com.adt.action.user.ListUser"> zH
r_!~
<param Z\sDUJ
]4e;RV-B
name="page.everyPage">10</param> %yC,^
<result v$9y,^p@e
pgo$61
name="success">/user/user_list.jsp</result> DmcZta8n]
</action> yhJ@(tu.Gd
:4|4 =mkr
</package> !)$Zp\Sg
~TtiO#,t
</xwork> `]aeI'[}R
rm_Nn8p,
@4#vm@Yf_
wd6owr
&^nGtW%a 9
vDvFL<`vmD
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 nk:)j:fr
,zc(t<|-y
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。 \M-OC5fQv
rC5O")I<
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 `vV7c`K?
2mU.7!g)
7>RY/O;Z,
,,r>,Xq6
wIgS3K
我写的一个用于分页的类,用了泛型了,hoho Bw.i}3UT6
4p wH>1
java代码: -\MG}5?!
FI.\%x
d(K+);!
package com.intokr.util; v[<T]1=LRC
Vvo7C!$z
import java.util.List; 6u%&<")4HP
dN6?c'iN?2
/** 7p[n
* 用于分页的类<br> qP
,EBE
* 可以用于传递查询的结果也可以用于传送查询的参数<br> '"Nr, vQo
* X3&
Jb2c2
* @version 0.01 1~gCtBRM
* @author cheng PY'2h4IL
*/ y7<|_:00
public class Paginator<E> { @)}L~lb[)
privateint count = 0; // 总记录数 Y-9I3?ar
privateint p = 1; // 页编号 c@Is2
9t*
privateint num = 20; // 每页的记录数 l-3~K-k<@
privateList<E> results = null; // 结果 TqQ[_RKg2
Ort(AfW
/** +7a6*;\ y
* 结果总数 \7_y%HR
*/ zm# ?W
publicint getCount(){ iow"n$/
return count; 4Tc~b3\!Y
} /kG_*>.Z
/_.|E]
publicvoid setCount(int count){ jWgX_//!
this.count = count; s#MPX3itK
} FTldR;}(
%2h>-.tY
/** 8XaQAy%d]
* 本结果所在的页码,从1开始 |BYRe1l6l
* iRBfx
* @return Returns the pageNo. GX%g9f!O
*/ )B*t
:tN
publicint getP(){ kf9X$d6
return p; m[2gdJK
} ig"L\ C"T
bK7J} 8hH
/** &3&HY:yF
* if(p<=0) p=1 g{LP7D;6
* H*6W q
* @param p V~#tuv
*/ r|Z{-*`
publicvoid setP(int p){ 3XKf!P
if(p <= 0) k{0o9,
p = 1; ipz5 H*
this.p = p; !~Z"9(v'C
} ,//S`j$S
8EY:tzw
/** (%9$! v{3
* 每页记录数量 0 {mex4
*/ k=^xVQuI
publicint getNum(){ ?cZlN!
return num; [Qr"cR^
} R#KU^]"(
ULW~90
/** :KO2| v\
* if(num<1) num=1 Va8&Z
*/ JS77M-Ac
publicvoid setNum(int num){ 6C)_
if(num < 1) xD$\,{
num = 1; .C(tMF]D,
this.num = num; JI5Dy>u:
} 'q.!|G2U
B<-Wea
/** (.,G=\!
* 获得总页数 Ca\6vR
*/ ,?3G;-
publicint getPageNum(){ z{>Rc"%\
return(count - 1) / num + 1; GthYzd:'hJ
} 4+ig'
|o
%)wjR/o
/** ?Ob3tUz2
* 获得本页的开始编号,为 (p-1)*num+1 ^}r1;W?n
*/ T0
{L q:
publicint getStart(){ r*Xuj=
return(p - 1) * num + 1; 28nFRr
} SAz
~K=b\xc^
/** Mp]rUPK
* @return Returns the results. pJ{Y
lS{
*/ < vP=zk
publicList<E> getResults(){ ?#fQ~ s
return results; .^g p?
} 'PHl$f*k
+h$
9\
public void setResults(List<E> results){ _-\#i
this.results = results; 4I7>f]=)
} #/]nxW.S
;Xw~D_uv
public String toString(){ d'2A,B~_*
StringBuilder buff = new StringBuilder HTtnXBJ)*H
saAF+H/=
(); YS ][n_
buff.append("{"); qWw=8Bq
buff.append("count:").append(count); o(HbGHIP
buff.append(",p:").append(p); j<x_ &1
buff.append(",nump:").append(num); W%J\qA
buff.append(",results:").append +v\oOBB)
NO3/rJ6-
(results); j#6.Gq
buff.append("}"); qb4z
T
return buff.toString(); e;jdqF~v!
} o}!PQ#`M
ME dWLFf
} UI#h&j5pW
/E>e"tvss
[!z,lY>