Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 }|x]8zL8G
fIFB"toiPE
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 PI }A')Nq.
_7 n+j
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
l_$~~z ~
x; :[0(st}
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 ==c\* o
2p@S-Lp
。 Vj`9j. 5
3{
`fT5]U
分页支持类: @1rF9<
4g
eoow]me
java代码: ;o#dmG
{-H6Z#b[
/EWF0XV!
package com.javaeye.common.util; m,Os$>{Ok
jH\@Oc;7
import java.util.List; t R*JM$T
sgFpZk
publicclass PaginationSupport { N=-hXgX^
8r+R~{
publicfinalstaticint PAGESIZE = 30; `y
m^0x8
/J1O{L
privateint pageSize = PAGESIZE; Av7bp[OD
hO\_RhsRy?
privateList items; O+c@B}[!
HlLF<k~}
privateint totalCount; K+PzTGWq^
nB"q
privateint[] indexes = newint[0]; >H[&Wa+_
4RJ8 2yq-
privateint startIndex = 0; Fj-mo>"
i3N _wv{
public PaginationSupport(List items, int ;PGC9v%i
;,4 Z5+
totalCount){ J?u",a]|H"
setPageSize(PAGESIZE); ,Rz,[KI|
setTotalCount(totalCount); Z=4Krfn
setItems(items); if
r!ha+8!
setStartIndex(0); USJ4qv+-
} d{I|4h
U3az\E)HV
public PaginationSupport(List items, int G23Mr9m5O
"\]kK@,
totalCount, int startIndex){ ^=}~
setPageSize(PAGESIZE); vD^^0-Pk6
setTotalCount(totalCount); +u:8#!X$RD
setItems(items); 'R99kL/.N
setStartIndex(startIndex); ey@y?X=
} D9+a"2|3<
}mk9-7
public PaginationSupport(List items, int B$_F)2%m;
6t<~. 2'
totalCount, int pageSize, int startIndex){ `%"zq"1`0
setPageSize(pageSize); C.FGi`rrm
setTotalCount(totalCount); <j-Bj$3
setItems(items); _)ZAf%f?
setStartIndex(startIndex); ;9/6X#;$
} .9S
s=u0M;A0Q
publicList getItems(){ S\MD]>4
return items; LX!16a@SxA
} Y:ZI9JK?
X_!Sm
publicvoid setItems(List items){ ;xXHSxa:=W
this.items = items; b8feo'4Z
} #AFr@n
0+m"eGwTm
publicint getPageSize(){ (<=qW_iW
return pageSize; lD _
u
} gU0}.b
p%G4Js.
publicvoid setPageSize(int pageSize){ ;XZ5r|V}
this.pageSize = pageSize; DbH{;
Fb
} u3dh MnUn
AW!|xA6'`:
publicint getTotalCount(){ L_=J(H|
return totalCount; 2<qq[2
} (3&@c!E
)p).}"
publicvoid setTotalCount(int totalCount){ [`yiD>
if(totalCount > 0){ b'St14_
this.totalCount = totalCount; ;_%61ZI?M<
int count = totalCount / 1Hy
Yono8M;9*
pageSize; ~BaU2S@y
if(totalCount % pageSize > 0) Cx}
Yp-
count++; oy;N3
indexes = newint[count]; WIQt5=-
for(int i = 0; i < count; i++){ 69`9!heu
indexes = pageSize * H7H'0C
Gg{@]9
i; 4;7<)&#h
} >8#(GXnSt
}else{ o.Mb~8Yu
this.totalCount = 0; ec)G~?FH
} I,l%6oPa
} ^{zwIH2I]
iShB^
publicint[] getIndexes(){ 0/#XUX 4
return indexes; "mSDL:$
} O_FT@bo\
.KIAeCvl\
publicvoid setIndexes(int[] indexes){ Q4Hf!v]r
this.indexes = indexes; pz:$n_XC}
} 9 %,_G.
`Z{;
c
publicint getStartIndex(){ I`5F&8J{
return startIndex; L` V6\Ix(I
} o`DBzC
u> %r(
publicvoid setStartIndex(int startIndex){ !-|&
if(totalCount <= 0) ? Ls]k
this.startIndex = 0; 3|[:8
elseif(startIndex >= totalCount) P(VQ D>G
this.startIndex = indexes >6@*%LM
"a?k #!E
[indexes.length - 1]; 6T;C+Y$
elseif(startIndex < 0) lF 8B+
this.startIndex = 0; Ra;e#)7X
else{ U-Fr[1I6p
this.startIndex = indexes 5lxC**NA
<(>v|5K0]
[startIndex / pageSize]; i6h:%n]Io
} 3r%I *
} b,#cc>76\
aEy_H-6f
publicint getNextIndex(){ t8U)za
int nextIndex = getStartIndex() + TEE$1RxV(
E"x 2 jP
pageSize;
;TEZD70r
if(nextIndex >= totalCount) YEXJh!X
return getStartIndex(); 9 /t}S6b{
else 66[yL(*+
return nextIndex; H
\.EKZ
} 0;!aO.l]K
tZk@ RX
publicint getPreviousIndex(){ (=)+as"u9*
int previousIndex = getStartIndex() - >M[rOu
(d
U@BVVH?,o
pageSize; <*3wnpj_
if(previousIndex < 0) h7~&rWb
return0; l9qq;hhGP,
else dGQy=T:
return previousIndex; VrQw;-rQ
} Wa2V Z
$kZ,uvKN
} :c!7rh7O
kD >|e<}\
SdnqM`uFo
aS'G&(_
抽象业务类 DJr 8<u
java代码: "P&|e|7
#Ru+|KL
%Kw5b ;
/** ?N,a {#w
* Created on 2005-7-12 2a (w7/W:
*/ }]=b%CPJh+
package com.javaeye.common.business; f|m.v
+7k
Jn'q'+
import java.io.Serializable; FnvN 4h{S
import java.util.List; .: 87B=
K%2,z3ps
import org.hibernate.Criteria; FOquQr1cF
import org.hibernate.HibernateException; n`vqCO7@'
import org.hibernate.Session; e&<#8;2X
import org.hibernate.criterion.DetachedCriteria; IW$&V``v
import org.hibernate.criterion.Projections; oT\B-lx
import ;}.jRmnJ
!}l)okQH<#
org.springframework.orm.hibernate3.HibernateCallback; ",#rI+ el
import wZE[we^Q"
RLw=y{%p
org.springframework.orm.hibernate3.support.HibernateDaoS D<5gdIw
/U N%P2>^1
upport; *yiJw\DRN
sN5x\9U
import com.javaeye.common.util.PaginationSupport; NV36Q^Am[
HTQ.kV
public abstract class AbstractManager extends p%xo@v(
{|%5}\%
HibernateDaoSupport { 4{}u PbS
NO`LSF
privateboolean cacheQueries = false; tN3Xn]
iBV*GW
privateString queryCacheRegion; qAivsYN*
.NQoqXR
publicvoid setCacheQueries(boolean J4 !Z,-
m-, '
cacheQueries){ Z!wDh_
this.cacheQueries = cacheQueries; ##}a0\x|
} d0MX4bhZ
j9y,UT
publicvoid setQueryCacheRegion(String E+JGqk
KD-0NO=oL
queryCacheRegion){ AJCWp4,
this.queryCacheRegion = X
H{5E4P
,y:q]PR
queryCacheRegion; }b)?o@9}:
} Pkc4=i,`A
|os2@G$
publicvoid save(finalObject entity){ xotq$r
getHibernateTemplate().save(entity); M}(4>W
} QTcngv[
R?Iv<(I
publicvoid persist(finalObject entity){ $v-lG(
getHibernateTemplate().save(entity); x03G Jy5
} ]A<\d
14s+&
publicvoid update(finalObject entity){ 0EPF;
Xx
getHibernateTemplate().update(entity); \n`UkxZn+
} g RSM~<
[M FV:Z
publicvoid delete(finalObject entity){ P@k
;Lg"
getHibernateTemplate().delete(entity); *Ty>-aS1
} :3Ty%W&&
G5TdAW
publicObject load(finalClass entity, {;f`t3D
}..}]J;To
finalSerializable id){ D dt9`j
return getHibernateTemplate().load 2>ce(4Gky
5C#&vYnq
(entity, id); n)$ q*IN"
} @^k$`W;
:L*CL 8m
publicObject get(finalClass entity, l]oGhM;
z#D@mn5\a
finalSerializable id){ J@!Sf7k42
return getHibernateTemplate().get zh*NRN
hh:0m\@<
(entity, id); _Xsn1
} i"Ct}7i
"W\
#d
publicList findAll(finalClass entity){ &NHIX(b6
return getHibernateTemplate().find("from D2>=^WP6+
"84.qgYaG
" + entity.getName()); OwSr`2'9
} top3o{4
8Ln:y'K
publicList findByNamedQuery(finalString MbYa6jrF
iOjmj0
namedQuery){ xqbI~jV#
return getHibernateTemplate dgX 0\lKpf
VdVca1Z
().findByNamedQuery(namedQuery); 1G{$ B^
f
} j%[|XfM
QL_bg:hs
publicList findByNamedQuery(finalString query, i`Lt=)@&
AHn^^'&x[
finalObject parameter){ s )~Q@ze2
return getHibernateTemplate _F,@mQ$!
7F)HAbIS
().findByNamedQuery(query, parameter); h %MPppCEa
} l~ F,i n.
0fi+tc30
publicList findByNamedQuery(finalString query, !. q*bY
s7a\L=#p(
finalObject[] parameters){ DX4
95<6*
return getHibernateTemplate =1`
k9yA#
().findByNamedQuery(query, parameters); <Ni]\-*
} UL"JwqD
KZ/}Iy>As
publicList find(finalString query){ |JuXOcr4
return getHibernateTemplate().find hb`bQ
A6TNtXk
(query); 96MRnj*Y[
} `(*5yX C
HbZ3QW P
publicList find(finalString query, finalObject - bFz
7/Ve=7]
parameter){ 1eiH%{w
return getHibernateTemplate().find i]9SCO
OEq8gpqY
(query, parameter); }v=q6C#Q>
} el+euOV
7th&C,c&
public PaginationSupport findPageByCriteria hj0uv6t.c
a/>={mbKi
(final DetachedCriteria detachedCriteria){ lFI"U^xC
return findPageByCriteria .i[Tp6'%,
o6B!ikz 8
(detachedCriteria, PaginationSupport.PAGESIZE, 0); sx*(JM}Be
} +de.!oY
LLaoND6
public PaginationSupport findPageByCriteria o*5|W9
0r:8ni%cL
(final DetachedCriteria detachedCriteria, finalint ]<++w;#+x
ph^qQDA
startIndex){ B-r9\fi,
return findPageByCriteria r95$B6
-I\_v*nA
(detachedCriteria, PaginationSupport.PAGESIZE, D/@:wY
IE'OK
startIndex); )oHIRsr
} Q0ev*MS9Z
{[)J~kC+
public PaginationSupport findPageByCriteria 1Voo($q.
]2K>#sn-]
(final DetachedCriteria detachedCriteria, finalint `,\WhJ?9
p]=8=pE<
pageSize, 9dy"Y~c
finalint startIndex){ ];zi3oS^
return(PaginationSupport) o8Q(,P
GW.s\8w
getHibernateTemplate().execute(new HibernateCallback(){ ed>_=i
publicObject doInHibernate <J?i+b
G8akMd]2
(Session session)throws HibernateException { $\m=-5 0-
Criteria criteria = y~p7&^FeR
F}i rCi47c
detachedCriteria.getExecutableCriteria(session); !Y`nKC(=z
int totalCount = 36&7J{MU
@: %}clZ
((Integer) criteria.setProjection(Projections.rowCount %# J8cB
RQ}x7</{
()).uniqueResult()).intValue(); ;) (qRZd6
criteria.setProjection Qzb8*;4?FF
&$vDC M4
(null); }Ct_i'Ow
List items = p5G O@^i
4?72TBl]
criteria.setFirstResult(startIndex).setMaxResults fN8A'p[
N#]f?6*R
(pageSize).list(); <NT /+>:2
PaginationSupport ps = _xUiHX<
>N+e c_D^
new PaginationSupport(items, totalCount, pageSize, Y5PIR9 -
zS|%+er~zO
startIndex); ]<W1edr
return ps; *C's7O{O
} LFV;Y.-(h
}, true); HHa7Kh|-H
} +(UrqK4Av
C=%go1! $
public List findAllByCriteria(final 8m-jU
5u
ruF+X)
DetachedCriteria detachedCriteria){ <(#cPV@j
return(List) getHibernateTemplate b\]"r x
(
Gash3}+
().execute(new HibernateCallback(){ N |7<*\o
publicObject doInHibernate "0zMx`Dh
D.R5-
(Session session)throws HibernateException { [9aaHf@'
Criteria criteria = l<z[)fE{uS
Kq6m5A]z
detachedCriteria.getExecutableCriteria(session); ~iF*+\
return criteria.list(); p~Dm3^Y
} UxD1+\N6?
}, true); sOU_j4M{
} R0*DfJS:Z
uTB;Bva
public int getCountByCriteria(final otX#}} +
&v3r#$Hj[
DetachedCriteria detachedCriteria){ 988aF/c
Integer count = (Integer) XD%?'uUQ_
HRx#}hN?+
getHibernateTemplate().execute(new HibernateCallback(){ P{QRmEE
publicObject doInHibernate nb0<.ICF%R
5g/^wKhKG
(Session session)throws HibernateException { K2:r7f
Criteria criteria = ]DC]=F.
rv|k8
detachedCriteria.getExecutableCriteria(session); "eh"'Z
return \+L_'*&8
J,m.LpY
criteria.setProjection(Projections.rowCount /x-Ja[kL
UkXc7D^jwm
()).uniqueResult(); f_.1)O'83
} gtjgC0
}, true); EsA^P2?_+
return count.intValue(); Q7c_;z_
} bp$8hUNYz-
} alHwN^GhP
o)S>x0|[
$V`O%Sz
Ldir'FW
B>a`mFM
]~kqPw<R
用户在web层构造查询条件detachedCriteria,和可选的 b39;Sv|#
>k _Z]J6Pd
startIndex,调用业务bean的相应findByCriteria方法,返回一个 !v`q%JW(
uVOpg]8d
PaginationSupport的实例ps。 ZpI _/
_%i|*
ps.getItems()得到已分页好的结果集 ufEt"P-X.
ps.getIndexes()得到分页索引的数组 ']+H P9i$
ps.getTotalCount()得到总结果数 ,u~\$Az6
ps.getStartIndex()当前分页索引 Wc`Vcn1
ps.getNextIndex()下一页索引 ;J?^M!l2=
ps.getPreviousIndex()上一页索引 Zd~s5
l*% voKZG
4Z]^v4vb
'*-X3p
;CAB.aB~
EY2s${26%
B#EF/\5
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 o#0NIn"GS/
5\QNGRu"
,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 -@^SiI:C
R+!2 j
一下代码重构了。 #Kn7
xn[
bmT J
我把原本我的做法也提供出来供大家讨论吧: mO> [kb"V'
IwWo-WN7.
首先,为了实现分页查询,我封装了一个Page类: /_jApZz
java代码: T("Fh}
NG5H?hVN=
5bZ`YO
/*Created on 2005-4-14*/ >(%im:_
package org.flyware.util.page; K<+AJ(C
* k=L
/** 0Vy*
0\{S
* @author Joa j#!J
hi
* s/ZOA[Yux
*/ fCEd
:Kr
publicclass Page { _}JygOew
rRC3^X`u
/** imply if the page has previous page */ X]y 3~|K
privateboolean hasPrePage; rM>&!?y+
@X\nY</E#M
/** imply if the page has next page */ g`J? 2
_]
privateboolean hasNextPage; "OK(<x]3;>
JZP2NB_xt
/** the number of every page */ YT&_{nL#\
privateint everyPage; $V5Ol6@2
kN>d5q9b%X
/** the total page number */ 7Jc=`Zm'
privateint totalPage; zWjGGTP~3&
3_Oq4 /
/** the number of current page */ n]8_]0{qi
privateint currentPage; #NL1N_B
zROyG
/** the begin index of the records by the current D-,sF8{ i
cteHuRd
query */ h)A+5^:^
privateint beginIndex; L{gFk{@W
>u4uV8S
`L9o!OsQ
/** The default constructor */ sBSBDjk[
public Page(){ =1+I<Ljk
!7bC\ {
} dm,b ZHo
qRB%G<H
/** construct the page by everyPage -,4_ &V
* @param everyPage *r9I
1W
* */ \nxt\KD
public Page(int everyPage){ <T0-m?D_$
this.everyPage = everyPage; R^8Opf_UN
} < W&~tVv
2]4R`[#
/** The whole constructor */ Po^2+s(fY
public Page(boolean hasPrePage, boolean hasNextPage, n\cP17dr
88G[XkL$2
;=uHK'{
int everyPage, int totalPage, AKAAb~{
int currentPage, int beginIndex){ 0/] @#G2
this.hasPrePage = hasPrePage; 7r}gS2d
this.hasNextPage = hasNextPage; #c!(97l6o
this.everyPage = everyPage; KCCS7l/
this.totalPage = totalPage; D=dY4WwG
this.currentPage = currentPage; $X\BO&
this.beginIndex = beginIndex; 4Nq n47|>e
} y8<,>
=BGc@:2
/** z,]fR
* @return A#jiCIc
* Returns the beginIndex. $B$=,^)3
*/ XUSfOf(
publicint getBeginIndex(){ <F=j6U7
return beginIndex; b0KorUr
} K7_)!=DcX
_Yh4[TT~/
/** ~CM{?{z;
* @param beginIndex ff:&MsA|,
* The beginIndex to set. 8{d`N|k
*/ T-5T`awf
publicvoid setBeginIndex(int beginIndex){ >StvP=our
this.beginIndex = beginIndex; 1eb1Lvn
} =,0E3:X^
q_oYI3
/** Ap97 Zcw
* @return m?M(79u[
* Returns the currentPage. VVe>}
*/ F;~ #\X
publicint getCurrentPage(){ k)4|%
return currentPage; *dK A/.g
} oY0*T9vv+
|u$AzI
/** -k<.Q=]<t
* @param currentPage @*2FG\c<
* The currentPage to set. uF^+}Y ZT
*/ C ch1"j<k$
publicvoid setCurrentPage(int currentPage){ mIr{Wocx
this.currentPage = currentPage; 2r*
o
} `*N0 Lbl]
qKSM*k~
/** f}+G;a9Nj
* @return sxsM%Gb?H
* Returns the everyPage. 5`z{A
*/ ,cm2uY
publicint getEveryPage(){ W)9KYI9u
return everyPage; {) .=G
} PD/~@OsxU
I&(cdKY
z
/** O~t5qnu/}
* @param everyPage 0{B5C[PTG
* The everyPage to set. L50`,,WF
*/ [tBIABr
publicvoid setEveryPage(int everyPage){ tDi=T]-bt
this.everyPage = everyPage; %9zcc)cP
} m' aakq
G! 87F/
/** IO6i
* @return s*!2oj
* Returns the hasNextPage. jf$t
*/ ".@SQgyb0
publicboolean getHasNextPage(){ g`&pQ%|=
return hasNextPage; :V_$?S
} goHr#@
/Fv1Z=:r
/** zBoU;d%p>
* @param hasNextPage }~ +
* The hasNextPage to set. JT:9"lmJz,
*/ Az)P&*2:'`
publicvoid setHasNextPage(boolean hasNextPage){ ;N/c 5+
this.hasNextPage = hasNextPage; YobIbpo
} 5jsnE )
Gu%`__
/** =ecv;uu2
* @return _zpn+XVdQ
* Returns the hasPrePage. IC{>q3
*/ I|`K;a
publicboolean getHasPrePage(){ [6-l6W
return hasPrePage; AX1\L|tJS
} ->j9(76 "
Lv_6Mf(
/** 8XY4
* @param hasPrePage Q%
dpGI
* The hasPrePage to set. RL&*.r&
*/ KlrKGmy,)
publicvoid setHasPrePage(boolean hasPrePage){ N.&K"J
this.hasPrePage = hasPrePage; w1GCjD*y
} qrdA?VV
o?%x!m>
/** xpS#l"dr
* @return Returns the totalPage. c/hml4
* kQH!`-n:T
*/ .<j8>1
publicint getTotalPage(){ I5bi^!i
return totalPage; pw$I~3OFd
} 'l;?P
|YlUt~H>
/** $[>wJXj3R
* @param totalPage CId`6W
* The totalPage to set. C&;'Pw9H
*/ F^aD!O ~
publicvoid setTotalPage(int totalPage){ PDir?'
this.totalPage = totalPage; / _cOg? o
} Et- .[
HQE#O4
} ,Tr12#D:
n;q7?KW8
o%|1D'f^
K]7@%cS
|C(72t?K
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 "qDEI}
.&[nS<~`
个PageUtil,负责对Page对象进行构造: <<A@69"4n
java代码: JN8k x;@
s0`uSQ2X
\J13rL{<
/*Created on 2005-4-14*/ 7"QcvV@p
package org.flyware.util.page; +(P;4ZOmB
G_o/ lIz"
import org.apache.commons.logging.Log; Onc!5L
import org.apache.commons.logging.LogFactory; G!Uq#l>
)q=1<V44d
/** JRo{z{!O6
* @author Joa V,Gt5lL&/!
* aI\VqOt]
*/ -I|yi'
publicclass PageUtil { tb=(L
<<`."RY#0
privatestaticfinal Log logger = LogFactory.getLog KS|$_-7u
Y0b.utR&
(PageUtil.class); <e=0J8V8,i
wWm#[f],?
/** vx
,yz+yP
* Use the origin page to create a new page $]T7Iwk
* @param page |fJ,+)_(
* @param totalRecords ?(|!VLu
* @return 7v?Ygtv
*/ 2GD%=rP2]
publicstatic Page createPage(Page page, int J[B8sa
PCU6E9~t2
totalRecords){ *".7O*jjV
return createPage(page.getEveryPage(), 59ivL6=3
BPPhVE
page.getCurrentPage(), totalRecords); 7;_5[_
} xp39TiXJ*
0qTa @y
/** 'Gc6ZSLM
* the basic page utils not including exception ~bwFQYY=
8=SNLO
handler Xr~r`bR=
* @param everyPage o2.!
G
* @param currentPage Mdy H/.Te
* @param totalRecords :,7VqCh3@
* @return page KE^_09
*/ I|PiZ1]2Y
publicstatic Page createPage(int everyPage, int bWyXDsr+
:*8@MjZ4
currentPage, int totalRecords){ Z2`e*c-[E
everyPage = getEveryPage(everyPage); MJD4#G
currentPage = getCurrentPage(currentPage); NH?s
int beginIndex = getBeginIndex(everyPage, :Ert57@l
xA-G&oC]<T
currentPage); {:rU5 !n
int totalPage = getTotalPage(everyPage, ())|x[>JS+
oZ=e/\[K
totalRecords); G>!"XK:fB
boolean hasNextPage = hasNextPage(currentPage, J:Qp(s-N^:
S1=c_!q%9
totalPage); r|P4|_No
boolean hasPrePage = hasPrePage(currentPage); Jsw<,uTD
A1Zu^_y'
returnnew Page(hasPrePage, hasNextPage, ZWr\v!4
everyPage, totalPage, @4Y>)wn&;
currentPage, ` n_ Z
Y6CadC
beginIndex); m2V4nxw]Qp
} jK{CjfCNz
PEBQ|k8g&
privatestaticint getEveryPage(int everyPage){ w|M?t{
return everyPage == 0 ? 10 : everyPage; S=my;M-
} z1L.
<oeHZD_OR
privatestaticint getCurrentPage(int currentPage){ aE;!mod
return currentPage == 0 ? 1 : currentPage; ^@)+P/&
} Y<|L|b6
9sRP8Nj|
privatestaticint getBeginIndex(int everyPage, int ?,Hk]Rl3
8!T^KMfz
currentPage){ CtE".UlCA
return(currentPage - 1) * everyPage; zL_X?UmV
} d~n+Ds)%F
6\]-J*e>
privatestaticint getTotalPage(int everyPage, int Pjx9@i
Gis'IX(
totalRecords){ 4RzG3CJdS
int totalPage = 0; sC}/?^q
jQ[Z*^"}
if(totalRecords % everyPage == 0) 7kb`o
y;(^
totalPage = totalRecords / everyPage; 5Ut0I]h|z
else B kC(9[Ei
totalPage = totalRecords / everyPage + 1 ; jb*#!m.l
m4%m0"Z
return totalPage; J=Jw"? f
} Y>z(F\
<fyv^e
privatestaticboolean hasPrePage(int currentPage){ 7'<4'BGzl]
return currentPage == 1 ? false : true; [s2%t"H-y
} '-*r&:
Dg]i};
privatestaticboolean hasNextPage(int currentPage, KYeA=
Mc\lzq8\ 1
int totalPage){
&hF>}O
return currentPage == totalPage || totalPage == mg3jm
~ PP GU1
0 ? false : true; '}}DPoV
} l@GpVdrv
q6,xsO,+
qItI):9U
} %tu{`PN<
w%$n)7<*
0lBl5ke
sG}9 l1
wbpxJtJB
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 tC&y3!k2jR
wUSWB{y
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 }M1<a4~
7>4t{aRf_8
做法如下: ](W#Tj5-
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Xau.4&\d
*]EcjK%
的信息,和一个结果集List: ROfmAc
java代码: .Kv@p jOr
O}%=c\Pb
<Q8bn?Z
/*Created on 2005-6-13*/ _}\&;
package com.adt.bo; : Z.mM5
a RV!0?fS
import java.util.List; |g9^]bT
n|F`6.G
import org.flyware.util.page.Page; .3Ap+V8?
kBT cND|
/** j9qN!.~mM
* @author Joa b/G0EcRw+
*/ s}A]lY
publicclass Result { ]~oM'?&!
`W/6xm(X5;
private Page page; w gufk{:
y_nh~&
private List content; 7X.1QSuE
ar{e<&Bny
/** >Te{a*`"m:
* The default constructor dxd}:L~z
*/ K}zw%!ex
public Result(){ >y=%o~
super(); w8on3f;6n#
} UC0 yrV
#2dmki"~(
/** G' b p
* The constructor using fields Ky=&C8b<
* i0R=P[
* @param page |[V(u
* @param content =];FojC6I
*/ 1HZexV
public Result(Page page, List content){ v:+se6HY?p
this.page = page; 6$zUFIk
this.content = content; <&NR3^Eq
} XYn$yR\dj
gf!j|O ;
/** /2z2a-!r
* @return Returns the content. E^qKkl
*/ z4<h)hh"k6
publicList getContent(){ A76=^iw
return content; R:fu n,
} )Qo6bei!
QR#,n@fE
/** ^=@%@mR/[C
* @return Returns the page. U9If%0P
*/ @GEvI2Vf.0
public Page getPage(){ yWs/~5[F
return page; }`eeIt I+
}
1|`9Hp6
57#:GN$EL
/** X$xqu\t7
* @param content "47nc1T+n
* The content to set. 8=?I/9Xh
*/ -8TLnl~[
public void setContent(List content){ Di L@NU!$q
this.content = content; @tP,l$O&
} Zs4N0N{
=l\D7s
/** w?R6$n`
* @param page 4f1*?HX&
* The page to set. !nd*U}q
*/ -V+fQGZe
publicvoid setPage(Page page){ ;<* VwXJR
this.page = page; f&,.h"bS
} [m4<j
} ':fVb3A[*d
[g/g(RL
H<q:+
,JjTzO
J0x)m2
2. 编写业务逻辑接口,并实现它(UserManager, y K{~
P--#5W;^oB
UserManagerImpl) 0 8U:{LL
java代码: 7<)
.luV
QM$?}>:
@U9ov >E
/*Created on 2005-7-15*/ m/{rmtA4
package com.adt.service; w,P2_xk`
:8rqTBa`
import net.sf.hibernate.HibernateException; /!LfEO
lKa}Bcd
import org.flyware.util.page.Page; v<c8qg
_LS=O@s^
import com.adt.bo.Result; 4}0s^>R
a]Lr<i8#%
/** YlYTH_L>E
* @author Joa 2#rF/!`^
*/ TN0dfba[
publicinterface UserManager { avT>0b:
U_!6pqFc
public Result listUser(Page page)throws {:? -)Xq
=A,i9Z&
HibernateException; _qGkTiP
6 g!t1%Kb
} #]C r
zLe
^v`|0z\
+`9T?:fu
p_}OtS;
U>{z*D
java代码: | 0&~fY
Xl}>mbB
Mbi)mybM
/*Created on 2005-7-15*/ lT%o6qgT
package com.adt.service.impl; BO1Mz=q
/6f$%:q
import java.util.List; {!<zk+h$
PB`94W
import net.sf.hibernate.HibernateException; 6.k2,C4dT<
f-3lJ?6
import org.flyware.util.page.Page; }?H |9OS
import org.flyware.util.page.PageUtil; d-c+KV
1c\$ziB
import com.adt.bo.Result; DSQ2z3s2
import com.adt.dao.UserDAO; ,Z3.Le"
import com.adt.exception.ObjectNotFoundException; "d{ |_Cf
import com.adt.service.UserManager; C^uXJ~8
pE`BB{[@
/** h nyZXk1|
* @author Joa X${k
*/ `"
publicclass UserManagerImpl implements UserManager { eE7+fMP{
j]jwQRe
private UserDAO userDAO; 5Zh
/D0!|
)K%AbKn
/** $L3UDX+F
* @param userDAO The userDAO to set. k/*r2 C
*/ g<tr |n
publicvoid setUserDAO(UserDAO userDAO){ Y>IEB,w
this.userDAO = userDAO; jy6%
CSWQ
} \# #~Tq
3 p")
/* (non-Javadoc) 0dXWy`Mn
* @see com.adt.service.UserManager#listUser XC~|{d
A?Uyj
(org.flyware.util.page.Page) 7=}`"7i~
*/ Y68oBUd_E
public Result listUser(Page page)throws g"F vD_
3>-^/
HibernateException, ObjectNotFoundException { }]/"auk
int totalRecords = userDAO.getUserCount(); mhVSZhx|
if(totalRecords == 0) rBT#Cyl
throw new ObjectNotFoundException P)Sw`^d
`vUilh ^c
("userNotExist"); z#*fELV
page = PageUtil.createPage(page, totalRecords); EdLbVrN,
List users = userDAO.getUserByPage(page); Z+E@B>D7A^
returnnew Result(page, users); YQ;?N66
} wOn.m
|tyVC=${
} )]?sCNb
]^E<e!z={$
QYDSE
fyh9U_M);w
Koo%mr
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 `cCsJm$V"
}c^`!9
询,接下来编写UserDAO的代码: &pV'/
3. UserDAO 和 UserDAOImpl: RlC|xj"l%
java代码: O*X]oX
MoavA
3`
ljQru ^(u
/*Created on 2005-7-15*/ KP%A0
package com.adt.dao; ~CQsv`
/n&w|b%
import java.util.List; G
D$o|l]\
up#W"`"
import org.flyware.util.page.Page; zXIVHC,"{
VPet1hAy
import net.sf.hibernate.HibernateException; bU7n1pzW,o
X6kCYTJYF
/** H)ud?vB6
* @author Joa MQ7N8 @!t
*/ ,eW K~ pa
publicinterface UserDAO extends BaseDAO { b:SjJA,HM
nd}[X[ay
publicList getUserByName(String name)throws w9G (^jS6
pxDkf|*
HibernateException; Et}S*!IS
Se{}OG)
publicint getUserCount()throws HibernateException; /0A9d-Qd<
]MKW5Kq
publicList getUserByPage(Page page)throws XShi[7
-c{O!z6sX
HibernateException; 'S;INs2|->
At@H
} J>y}kzCz
8KiG(6*Q
LhKaqR{
Nawph
bbCH(fYbu
java代码: NO+.n)etGb
AY<(`J{
HRn
Q*
/*Created on 2005-7-15*/ K&3,J7&&
package com.adt.dao.impl; ^ ~'&K e
'1+s^Q'pc
import java.util.List; d| ;S4m`
0%&ZR=y(G
import org.flyware.util.page.Page; B]iPixA6
piULIZ0
import net.sf.hibernate.HibernateException; n@[_lNa4GD
import net.sf.hibernate.Query; Se{x-vn?p
z@Pv~"
import com.adt.dao.UserDAO; l|RBO+}
KPHtD4
/** K2|2Ks_CS
* @author Joa |Tv}leJF
*/ Xt}
4B#
public class UserDAOImpl extends BaseDAOHibernateImpl H{hd1
$lVR6|n
implements UserDAO { o^+2%S`]
Lz6b9W
/* (non-Javadoc) B>C+qj@
* @see com.adt.dao.UserDAO#getUserByName =S+*=j A
Z(F['Zf
(java.lang.String) [ICFPY6
*/ S#Q0aGj
publicList getUserByName(String name)throws JJe8x4
!:Z
lVIA
HibernateException { >-oB%T
String querySentence = "FROM user in class WVZ](D8Gc]
Bm"-X:='
com.adt.po.User WHERE user.name=:name";
X} {z7[
Query query = getSession().createQuery e%[0
NVo
K-,4eq!
(querySentence); zbY2gq@?
query.setParameter("name", name); LY:%k|L9
return query.list(); R.x^
} W>#[a %R
RG&t0%yj}
/* (non-Javadoc) kx{LY`pY
* @see com.adt.dao.UserDAO#getUserCount() Lh@0|k
*/ Fc&3tw"g
publicint getUserCount()throws HibernateException { :Oiz|b(
int count = 0; 2JdzeJb
String querySentence = "SELECT count(*) FROM /aTW X
qPQ6`rD\
user in class com.adt.po.User"; &u+l`F^Z
Query query = getSession().createQuery ES}V\k*}
2x5^kN7
(querySentence); ~%chF/H
count = ((Integer)query.iterate().next _"%hcCMw
d4~;!#<
()).intValue(); - f?8O6e
return count; XQ3"+M_KG
} ]J1oY]2~
yopC
<k
/* (non-Javadoc) =cR"_ Z[8X
* @see com.adt.dao.UserDAO#getUserByPage e j,)<*
mO=A50_&,Q
(org.flyware.util.page.Page) O*7vmPy
*/ %g_)_ ~
publicList getUserByPage(Page page)throws 8KyRD1 (-R
_jb'HP
HibernateException { J5TT+FQ
String querySentence = "FROM user in class "hmLe(jo}
]-j.\+(*
com.adt.po.User"; oBO4a^D
Query query = getSession().createQuery 9r.h^
PZ>(cvX&
(querySentence); \wV^uS
query.setFirstResult(page.getBeginIndex()) O=[Q>\p
.setMaxResults(page.getEveryPage()); N_^PoX935O
return query.list(); u{- @,-{
} q4#$ca[_ak
5rb<u>e{
} R$ra=sL`
S,Z~-j
|*/-~5"
C 547})
tzShds
至此,一个完整的分页程序完成。前台的只需要调用 :5sjF:@
g#k@R'7E
userManager.listUser(page)即可得到一个Page对象和结果集对象 \ 5.nr*5
)n6,uTlOw
的综合体,而传入的参数page对象则可以由前台传入,如果用 u`CHM:<<?
<z#.J]
webwork,甚至可以直接在配置文件中指定。 z]2MR2W@X
Oq^t[X'
下面给出一个webwork调用示例: Z9G4in8
java代码: G|oO
G} f9:G
O3V.4tp
/*Created on 2005-6-17*/ ZO!h!2*
package com.adt.action.user; (%c&Km7K
Gf
+>AjU'
import java.util.List; 4bCA"QM[[
4_D
*xW
import org.apache.commons.logging.Log; )&DsRA7v
import org.apache.commons.logging.LogFactory; {,!!jeOO
import org.flyware.util.page.Page; -{}(U
]=o1to-
import com.adt.bo.Result; ZZw2m@T>
import com.adt.service.UserService; fH@cC`
import com.opensymphony.xwork.Action; IL`LIJ:O
/lC,5y
/** /mA\)TL|]
* @author Joa O>N/6Z
*/ {)iiu
publicclass ListUser implementsAction{ Im?/#t X
k8\KCKql
privatestaticfinal Log logger = LogFactory.getLog 3@nIoN'z
Q<NQ9lX
(ListUser.class); ]4ck)zlv
x<`^4|<
private UserService userService; lVuBo&
b<!' WpY-
private Page page; a@Vk(3Rx_
vz(=3C[
privateList users; g(auB/0s
'qUM38 s
/* 9M^5<8:
* (non-Javadoc) @~Ys*]4UE
* a~ RY 8s
* @see com.opensymphony.xwork.Action#execute() ^q_wtuQ
*/ |"PS e~ u
publicString execute()throwsException{ GSs?!BIC
Result result = userService.listUser(page); V?Q45t Ae
page = result.getPage(); ,Ne9x\F
users = result.getContent(); qzNXz_#+u
return SUCCESS; ySI}Nm>&=
} A;5_/ 2
Hs$HeAp;
/** n*ROlCxV
* @return Returns the page. mU(v9Jpf7
*/ {sxdDl
public Page getPage(){ _k :BY
return page; ck%.D%=
} wpp!H<')
H
"Io!{aKU
/** @{UUB=}9
* @return Returns the users. ~Ad2L*5S
*/ ]8R@2L3s
publicList getUsers(){ mZXtHFMu
return users; }
xA@3RT
} $IS!GS&:
&^K(9"
/** ).`v&-cK4E
* @param page |Xm$O1Wa
* The page to set. Nmd{C(^o
*/ Pwj|]0Y@
publicvoid setPage(Page page){ Q=>5@sZB
this.page = page; J+Fev.9>
} z .\r7
{chZ&8)f
/** Cg?Mk6 i
* @param users >itNa.K
* The users to set. aeI0;u
*/ SUIJ{!F/
publicvoid setUsers(List users){ TQKcPVlE
this.users = users; pZK 1G
} oK-d58 sM
l5=ih9u
/** _&\'Va$
* @param userService CshME\/
* The userService to set. XkkzY5rxOc
*/ jUKMDlH
publicvoid setUserService(UserService userService){ PYWFz
this.userService = userService; rNJU &
.]
} Cse`MP
} h~]e~u V
E:M,nSc)53
ykJ+LS{+
[<{r~YFjWW
?H,f|nc
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, 0HU0p!yt&
n*ShYsc
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 i/n
ee_
ZO/Jf Jn~
么只需要: 7FPSBvU#/
java代码: 0{%@"Fb0O
QEbf]U=
<uS/8MP{
<?xml version="1.0"?> 9XtO#!+48
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork -C(Yl=
CJCxL\
1.0//EN" "http://www.opensymphony.com/xwork/xwork- spm)X-[1
9 Xl#$d5
1.0.dtd"> IO9|o!&>
P (7Q8i'
<xwork> zj]
g^c;
(B$>o.(JA
<package name="user" extends="webwork- !ry+{v+A
`pCy:J?d>l
interceptors"> j!!s>7IZ
{wA8!5Gu
<!-- The default interceptor stack name B0gD4MX/
`:~Wu/Ogr
--> gCPH>8JwS0
<default-interceptor-ref 9O-~Ws ;
13Z,;YW
name="myDefaultWebStack"/> HyWR&0J
'" %0UflJS
<action name="listUser" f 42F@M(:
~7KH/%Z-
class="com.adt.action.user.ListUser"> wG7>2*(
<param @ :PMb Ub
:x[()J~N
name="page.everyPage">10</param> Ri`6X_xU
<result Mb[4_Dc
@$^4Av-
name="success">/user/user_list.jsp</result> $ .$nv~f
</action> 5EVypw?]x
hZ>m:es
</package> t7u*j-YE
J;>~PXB
</xwork> {_*G"A 9
S .x>w/
c CDT27@
|5dNJF8;Q
6Y\TVRR
W ).Kq-
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 W?aP%D"(i
J|^XD<Y
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 :vEfJSA
1<
1;<Vr<.
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 x+za6e_k"
56c[$ q
5vR])T/S0
z&9MkbH1
O.QR1
我写的一个用于分页的类,用了泛型了,hoho `W@jo~y<
L-}Uj^yF
java代码: pGR3
3b0|7@_E
ohx$;j
package com.intokr.util; |4pl}:g/Z
?qSwV.l]d
import java.util.List; t CO?<QBE
1Dhe!
n#
/** VK*`&D<P
* 用于分页的类<br> ke;=Vg|
* 可以用于传递查询的结果也可以用于传送查询的参数<br> Z:AB(c
* f'5
6IT
* @version 0.01 nt()UC`5
* @author cheng $MQ<QP
*/ /{[<J<(8
public class Paginator<E> { yF6AI@y
privateint count = 0; // 总记录数 W/t,7lPFb
privateint p = 1; // 页编号 c u";rnj
privateint num = 20; // 每页的记录数 2
yANf
privateList<E> results = null; // 结果 :/5GHfyj
B/@LE{qUn
/** @XtrC|dkkE
* 结果总数 4OJD_
*/ J!~kqNI
publicint getCount(){ `^^t#sT
return count; 2(~Zl\
} ..nVViZ
wy:Gy9\
publicvoid setCount(int count){ '-N5F
this.count = count; H? z~V-8
} 2BF455e
O>nMeU
/**
*BM#fe
* 本结果所在的页码,从1开始 ackeq#
* P`Now7!
GW
* @return Returns the pageNo. D4hT Hh
*/ U*yOe*>
publicint getP(){ rA?<\*
return p; ]v>[r?X#V
} 6qTMHRI
T!9AEG
/** B?^~1Ua9Zv
* if(p<=0) p=1 J;wBS w%1
* Q=DMfJ"
* @param p l"`VvW[
*/ _e>N3fT
publicvoid setP(int p){ @VIY=qh
if(p <= 0) wY%t# [T3
p = 1; t@MUNW`Q
this.p = p; ^;s/4
} C%E~9_w
J|
wk})?
/** FF^h(Ea
* 每页记录数量 1Vz^?t:
*/ "PN4{"`V
publicint getNum(){ VKYljY0#
return num; b|Ge#o
} C_q2bI
oO3^9?Z
/** svxjad@l/
* if(num<1) num=1 V*2*5hx
*/ {4/*2IRN9h
publicvoid setNum(int num){ /\mYXi\
if(num < 1) LQ%QFfC
num = 1; E.Th}+
this.num = num; $vO<v<I'Gb
} #m<uG5l`
'4#NVXVQm
/** >cmz JS
* 获得总页数 &3"ODAp'
*/ I Ij:3HP
publicint getPageNum(){ :XAyMK7
return(count - 1) / num + 1; yN `&oya
} t$VRNZ`dy
"0 %fR"
/** ?,v&
o>*
* 获得本页的开始编号,为 (p-1)*num+1 j(;ou?Uh
*/ tg 'g R
publicint getStart(){ : 4-pnn
return(p - 1) * num + 1; Dmy=_j?ej
} _!,2"dS
XHKLl?-
/** V"K.s2U^
* @return Returns the results. `DSFaBj,
*/ gs i2
publicList<E> getResults(){ KTmwkZcfYD
return results; q)C
Xu
} zx:;0Z:S6>
6+ptL-Zt<
public void setResults(List<E> results){ c'VCCXe
this.results = results; ~(tt.l#
} Uy|!f]"?
$'d,X@}8
public String toString(){ yk4py0xVl
StringBuilder buff = new StringBuilder
ac@\\2srV
Hl(W'>*oL
(); *w^!\
buff.append("{"); 1/ j>|
buff.append("count:").append(count); (gvnIoDl0
buff.append(",p:").append(p); 3"my!}03
buff.append(",nump:").append(num); #"TYk@whWf
buff.append(",results:").append jZmL7
V
e&ZH 1^O
(results); 1TfFWlf[B
buff.append("}"); =Xid"$
return buff.toString(); jg%mWiKwK7
} Oi~Dio_?
G[>CBh5
} (yuOY/~k/
wK fq'W{
@QnKaZ8jW