Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~ drS} V
LvH4{B
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根
~9,,~db
#l\=}#\1Wb
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#llgi~
~9a<0Mc?
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 j\[dx^\=
x*/tyZg6
。 [64:4/<}
Sxt"B
分页支持类: 7{e
4c
r_)' Ps
java代码: P%V'4p c
GfxZ'VIn
fa
jGZyd0:
package com.javaeye.common.util; :KSV4>X[%a
rKe2/4>0X
import java.util.List; fy>{QC\
u:6Ic)7'
publicclass PaginationSupport { .LPV#&
y2Q&s9$Do
publicfinalstaticint PAGESIZE = 30; .KB^3pOpx
|k )=0mCz
privateint pageSize = PAGESIZE; @wGPqg
SB;&GHq"n
privateList items; |IeTqEu9
Fd%#78UEo}
privateint totalCount; {g'(~ qv
c?(4t67|
privateint[] indexes = newint[0]; vONasD9At
a5dLQxb
privateint startIndex = 0; -P(efYk
jnkR}wAA
public PaginationSupport(List items, int !hA-_
6+#Ydii9E
totalCount){ MD}w Y><C
setPageSize(PAGESIZE); f&NgS+<K$
setTotalCount(totalCount); -V*R\,>
setItems(items); ,Q3T
Tno
,
setStartIndex(0); 9a[9i}_
} m<<+
?(@
7r_j
public PaginationSupport(List items, int 6+:iy'-
~dyTVJ$
totalCount, int startIndex){ oM
X
setPageSize(PAGESIZE); 8 `v-<J
setTotalCount(totalCount); n2"a{Ofhlf
setItems(items); +RHS!0
setStartIndex(startIndex); ^rB8? kt
} aj-Km`5r}
k%]3vRo<
public PaginationSupport(List items, int YU'k#\gi*
=Pyj%4Rs
totalCount, int pageSize, int startIndex){ $f$SNx)),
setPageSize(pageSize); |QF7
uV
setTotalCount(totalCount); n QF(vTDN
setItems(items); lne|5{h
setStartIndex(startIndex); BwN0!lsF3
} E'f{i:O"~
juP7P[d$qW
publicList getItems(){ \,'m</o~,
return items; :p1u(hflS
} 0G(/Wb"/
U"~>jZKk
publicvoid setItems(List items){ D5gFXEeh
this.items = items; s-NX o
} eFB5=)ld
` _6C{<O
publicint getPageSize(){ H-!,yte
return pageSize; 9sM!`Lz{
} 6lZ3tdyNo
&Gc9VF]o
publicvoid setPageSize(int pageSize){ (fhb0i-
this.pageSize = pageSize; 4V"E8rUL(
} zF@/K`
h7*J9[$
publicint getTotalCount(){ [DYQ"A=)d
return totalCount; Ky`qskvu
} _kC-dEGf!y
i9:C4',sw0
publicvoid setTotalCount(int totalCount){ !K#qe Y}
if(totalCount > 0){ a)!o @
this.totalCount = totalCount; b35fs]}u-6
int count = totalCount / xEa\f[.An
HRpte=`q
pageSize; 7kC^
30@T3
if(totalCount % pageSize > 0) 2/U.|*mH
count++; qRu~$K
indexes = newint[count]; -D<< kra
for(int i = 0; i < count; i++){ Q@= Q0
indexes = pageSize * zWnX*2>b
xPdG*OcX!
i; \wmN
} .w:DFk^E]b
}else{ PgAf\.48a
this.totalCount = 0; pP1|&`}ux
} ,S\CC{!
} S0$8@"~=
MnmVl"(/
publicint[] getIndexes(){ hy9\57_#
return indexes; 1l9G[o
*
} Oz.HH
EX*HiZU>
publicvoid setIndexes(int[] indexes){ 4a&RYx
this.indexes = indexes; 2bz2KB5>
} //B&k`u
;2G*wR
publicint getStartIndex(){ &.3"Uo\#
return startIndex; &*o=I|pQ
} }ZYd4h|g\z
3s*mbk[J
publicvoid setStartIndex(int startIndex){ XMZ,Y7
if(totalCount <= 0) {.`vs;U
this.startIndex = 0; @?ebuj5{e
elseif(startIndex >= totalCount) P|`8}|}a
this.startIndex = indexes zg>zUe
bA
SV4E0c>
[indexes.length - 1]; C-xr"]#]
elseif(startIndex < 0) v{RZJ^1
this.startIndex = 0; #{0HYg?(f
else{ W@>% {eE
this.startIndex = indexes &{5,:%PXw
sVQ|*0(J0r
[startIndex / pageSize]; bt SRtf
} \eTwXe]Pv
} Fk7?xc
0mp/Le5
publicint getNextIndex(){ _!#@@O0p/h
int nextIndex = getStartIndex() + =<C:d
XE RUo
pageSize; 50h!
X9
if(nextIndex >= totalCount) 3F"lXguS
return getStartIndex(); /*~EO{o
else qfF~D0}
return nextIndex; D'>_I.
} |*Yr<zt
f^3*)Ni
publicint getPreviousIndex(){ Xc++b|k
int previousIndex = getStartIndex() - +:2klJ
l03B=$
pageSize; wKh4|Ka
if(previousIndex < 0) hwuiu*
return0; ]Ee?6]bN
else goNG' o %|
return previousIndex; %jJG>T
} s3N'02G
MBK^FR-K
} [>3./YH`
/A\8 mL8
!"e5h`/ADM
B^=-Z8
抽象业务类 c?Y*Y
java代码: UsG~row:!
:]K4KFM
Z9E\,Ly
/** 3ZuZ/=
* Created on 2005-7-12 !vi>U|rh
*/ D_ 2:k'4
package com.javaeye.common.business; ]|pe>:gf'
_oL?*ks
import java.io.Serializable; te`$%NRl
import java.util.List; W ~<^L\Lu
sFKX-S~:
import org.hibernate.Criteria; AOZP*\k
import org.hibernate.HibernateException; Y;eZ9|Ht9
import org.hibernate.Session; [|wZ77\
import org.hibernate.criterion.DetachedCriteria; -:^U_FL8un
import org.hibernate.criterion.Projections; n)/z0n!\
import ZmqKQO
QpH'PYy
org.springframework.orm.hibernate3.HibernateCallback; W-f=]eWg
import >gQ>1Bwvi
uh_RGM&
org.springframework.orm.hibernate3.support.HibernateDaoS *tFHM &a
C.:<-xo
upport; u]wZQl#-
.8g)av+
import com.javaeye.common.util.PaginationSupport; ~%F9%=
z|uDy2
public abstract class AbstractManager extends .#!lP/.eQP
;LfXi 8)
HibernateDaoSupport { %Qgw7p4
hW')Sp
privateboolean cacheQueries = false; P;y45b
OnziG+ak
privateString queryCacheRegion; $p8xEcQdU#
T~?Ff|qFC
publicvoid setCacheQueries(boolean X #dmo/L8
T"Y+m-<%
cacheQueries){ v~+(GqR=+
this.cacheQueries = cacheQueries; g'f@H-KCD
} tIi&;tw]
BR_1MG'{)$
publicvoid setQueryCacheRegion(String ldcqe$7,
68|E9^`l
queryCacheRegion){ iU918!!N
this.queryCacheRegion = f%JIp#B
ITQA0PISL
queryCacheRegion; w(Ovr`o?9t
} )}R0Y=e
yN0Vr\r2
publicvoid save(finalObject entity){ ]! &FKy
getHibernateTemplate().save(entity); }Bh8=F3O
Q
} Y Uc+0
`7Q<'oK
publicvoid persist(finalObject entity){ gaxsv[W>^
getHibernateTemplate().save(entity); +^ac'Y)A
} P:S .~Jq
A 'be8
publicvoid update(finalObject entity){ @s&71a
getHibernateTemplate().update(entity); Q} JOU
} BVQqY$>
m 0C@G5
publicvoid delete(finalObject entity){ u#fM_>ML
getHibernateTemplate().delete(entity); /62!cp/F/D
} !n!*/[}X
8nqG<!,q
publicObject load(finalClass entity, s[*rzoA
g =hg%gRy"
finalSerializable id){ Paq4
return getHibernateTemplate().load 2qNt,;DQ
$Wol?)z
(entity, id); j_[tu!~
} +E+p"7
rKc9b<Ir
publicObject get(finalClass entity, s^TZXCyF o
n6>#/eUH
finalSerializable id){ ]cvwIc">
return getHibernateTemplate().get 0auYG><=
FUzzB94a
(entity, id); CW K7wZM
} uZYF(Yu
}tuC}
publicList findAll(finalClass entity){ t3ZOco@~P
return getHibernateTemplate().find("from <=&`ZH
gg/-k;@ Rf
" + entity.getName()); 59L\|OR
} v~C
Czg
:4w ?#
publicList findByNamedQuery(finalString Hio0HL-
S+6.ZZ9c
namedQuery){ M0"_^?
return getHibernateTemplate y<3-?}.aZ
e{H=dIa+
().findByNamedQuery(namedQuery); Zl!kJ:0
} MJ)RvNF
8W7J3{d
publicList findByNamedQuery(finalString query, I][*j
1.hyCTnI
finalObject parameter){ Ee#q9Cx^J
return getHibernateTemplate ?UR0:f:}oc
}v{LRRi
().findByNamedQuery(query, parameter); $wa{~'
} Vp\,CuQ
S13nL^=i
publicList findByNamedQuery(finalString query, ^DLfY-F+j
@1j
finalObject[] parameters){ Rv>-4@fMJ
return getHibernateTemplate t}4,]ms
W@IQ^
}E
().findByNamedQuery(query, parameters); ,qwuLBW
} Dy&i&5E.-l
= svN#q5s
publicList find(finalString query){ q<<v,ihh
return getHibernateTemplate().find wJqMa9|
o/)h"i0P
(query); G_JA-@i%
} 372rbY
tOD6&<
publicList find(finalString query, finalObject /nsX]V6i
pki%vRY
parameter){ r5/0u(\LB
return getHibernateTemplate().find FV!q!D
T::85
(query, parameter); 8,%^
M9zBP
} gJ{)-\
;(%QD
3 >
public PaginationSupport findPageByCriteria Ax@$+/Z!
~~P5k:
(final DetachedCriteria detachedCriteria){ Om@;J%u/
return findPageByCriteria 5DZ#9m/
5tkAFb4P
(detachedCriteria, PaginationSupport.PAGESIZE, 0); "k@/3
} \)[j_^
& .j&0WE
public PaginationSupport findPageByCriteria ?V=ZIGj
JbbzV>
(final DetachedCriteria detachedCriteria, finalint ,0 sm
qDIZJh
startIndex){ U)gH}0n&
return findPageByCriteria =WATyY:s
_VN?#J)o
(detachedCriteria, PaginationSupport.PAGESIZE, 6 "sSo j
]6`%
startIndex); O bS3
M
} !.gIHY
ITBE|b
public PaginationSupport findPageByCriteria
(ZizuHC
3$R1ipb
(final DetachedCriteria detachedCriteria, finalint e !Y~Qy
P@B]
pageSize, x9g#<2w8
finalint startIndex){ p6@)-2^
return(PaginationSupport) n\DV3rXI9
{tZ.v@
getHibernateTemplate().execute(new HibernateCallback(){ m
s\}
publicObject doInHibernate {\5
[q-h|m
(Session session)throws HibernateException { eym4=k ~
Criteria criteria = "8MF_Gu):
7$=InK
detachedCriteria.getExecutableCriteria(session); KpGhQdR#
int totalCount = "+s++@
z
GefTdO.&
((Integer) criteria.setProjection(Projections.rowCount D>q9 3;p
GVn!O1jio
()).uniqueResult()).intValue();
Otuf]B^s
criteria.setProjection S\=Nn7"
)t#W{Gzfmh
(null); eauF~md,
List items = 0h_|t-9j
Yq
KCeg
criteria.setFirstResult(startIndex).setMaxResults %u'ukcL7
uXvtfc
(pageSize).list(); 0,")C5j
PaginationSupport ps = ZE}}W_
:I#V.
new PaginationSupport(items, totalCount, pageSize, &QgR*,5eo
SJ,v?=S!
startIndex); C'x&Py/#
return ps; :o3N;*o>)0
} T~e.PP
}, true); ,J@
} S1_RjMbYM
#6=
public List findAllByCriteria(final rILYI;'o
lf,5w
DetachedCriteria detachedCriteria){ ?caSb=f
return(List) getHibernateTemplate [W&T(%(W-
4r}51 N\
().execute(new HibernateCallback(){ 77Dn97l)&
publicObject doInHibernate 7@Qcc t4A
ZECfR>`x
(Session session)throws HibernateException { zDG b7S{
Criteria criteria = z0 3K=aZ
9'B `]/L
detachedCriteria.getExecutableCriteria(session); WyiQoN'q
return criteria.list(); |6-nbj
} 2>%=U~5
}, true); HRA|q
} x%B%f`]8
GbI/4<)l}
public int getCountByCriteria(final a7opCmL
%N._w!N<5n
DetachedCriteria detachedCriteria){ 6gDN`e,@
Integer count = (Integer) W>r+h-kR
J&_n9$
getHibernateTemplate().execute(new HibernateCallback(){ RA 6w}:sq7
publicObject doInHibernate ;xTpE2 -~
SXh-A1t
(Session session)throws HibernateException { wCBplaojJ
Criteria criteria = PKz':_|
p_4<6{KEt
detachedCriteria.getExecutableCriteria(session); m&3xJuKih
return ~}
~4
/;$[E
criteria.setProjection(Projections.rowCount !ohN!P7&
"AqB$^S9t
()).uniqueResult(); tH4B:Bgj!
} 2 %]X+`+O
}, true); AbM'3Mkz
return count.intValue(); HoAy_7-5
} 2=}FBA,2
} tuX|\X
ueNS='+m
yHaGkm
c71y'hnT
sLk-x\P]|
\;Weizq5
用户在web层构造查询条件detachedCriteria,和可选的 er\|i. Y
6A ah9
startIndex,调用业务bean的相应findByCriteria方法,返回一个 |.dRily+
|w=zOC;v
PaginationSupport的实例ps。 ['D]>Ot68
U<XG{<2
ps.getItems()得到已分页好的结果集 "dlVk~
ps.getIndexes()得到分页索引的数组 x{n=;JD
ps.getTotalCount()得到总结果数 7_t'( /yu
ps.getStartIndex()当前分页索引 zQ PQ
ps.getNextIndex()下一页索引 E{(;@PzE
ps.getPreviousIndex()上一页索引 xIn:ZKJ'
:4|4 =mkr
!)$Zp\Sg
XWw804ir
Zd+bx*rD
/9X7A;O
Hn:Crl y#
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 b.938#3,
dh\P4
,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 MQ2_`pi
mE[y SrV
一下代码重构了。 I-)4YQI
An@t?#4gxi
我把原本我的做法也提供出来供大家讨论吧: ;*J
xSu >
首先,为了实现分页查询,我封装了一个Page类: ,r}6iFu
java代码: ,,r>,Xq6
7:@'B|
AXB7oV,xt
/*Created on 2005-4-14*/ Ys7]B9/1O
package org.flyware.util.page; 'GScszz
;{6~Bq9
/** < %Y}R\s?
* @author Joa ,x $,l
* ^zr`;cJ+c
*/ Y/oHu@
_
publicclass Page { pCG}ZKa
fqd^9wl>P6
/** imply if the page has previous page */ D_MmW
privateboolean hasPrePage; lquLT6]
VU#7%ufu&
/** imply if the page has next page */ jiGTA:v
privateboolean hasNextPage; pfPz8L.7
wuBPfb
/** the number of every page */ !u hT
privateint everyPage; Gm`8q}<I
.)3 <Q}>
/** the total page number */ k3|Z7eW}[
privateint totalPage; ^z\cyT%7t
p<%d2@lp
/** the number of current page */ _0I@xQj-
privateint currentPage; \U0'P;em
E{@[k%,_
/** the begin index of the records by the current qgB_=Q#E
9H~n_
query */ $VR{q6[0S?
privateint beginIndex; gDzK{6Z}
u&e~1?R
A}w/OA97RO
/** The default constructor */ 3c%caK
public Page(){
b2*TgnRq
`@%LzeGz
} ` %}RNC
-RLOD\ZBh
/** construct the page by everyPage ;@J}}h'y
* @param everyPage (At$3b6
* */ @+DX.9
public Page(int everyPage){ fsXy"#mOkD
this.everyPage = everyPage; d_CT$
} VaPG-n>Vf
R!1p^~/
/** The whole constructor */ {)Xy%QV
public Page(boolean hasPrePage, boolean hasNextPage, j1Ezf=N6`
4z)]@:`}z
{[F A#
int everyPage, int totalPage, )gi9f1n`
int currentPage, int beginIndex){ d5 -qZ{W
this.hasPrePage = hasPrePage; <naz+QK'
this.hasNextPage = hasNextPage; [B3RfCV{
this.everyPage = everyPage; SWLo|)@[/
this.totalPage = totalPage; /@5YW"1
this.currentPage = currentPage; 13f)&#, F
this.beginIndex = beginIndex; )}vl\7=
} P
{'b:C
`_h&glMJ,q
/** R#KU^]"(
* @return ULW~90
* Returns the beginIndex. <N@Gu!N8
*/ *ui</+
publicint getBeginIndex(){ x^CS"v7
return beginIndex; Wl4%GB
} =V5%+/r +f
5-M-X#(
/** AwN!;t_0+N
* @param beginIndex s^SJY{
* The beginIndex to set. LQ% `c
*/ t<qiGDJ<d
publicvoid setBeginIndex(int beginIndex){ N g,j#
this.beginIndex = beginIndex; }7X%'Bg=M
} TC"<g
$xQL]FmS
/**
7Lt)nq-b
* @return .V*^|UXbHi
* Returns the currentPage. EK'!}OGCG
*/ 2pAW9R#UV-
publicint getCurrentPage(){ v0y(58Rz.
return currentPage; 0IpmRH/
} /tLVX} &
;rS{:
/** KlqY@Xt
* @param currentPage Js;h%
* The currentPage to set. hOeRd#AQK
*/ z)"=:o7
publicvoid setCurrentPage(int currentPage){ ~XIb\m9H
this.currentPage = currentPage; ,0k;!YK
} f!"w5qC^
E_`=7i
/** @XVTU
* @return ;G!q Y
* Returns the everyPage. Ep}s}Stlr}
*/ W8<%[-r
publicint getEveryPage(){ %$mA03[MQ
return everyPage; ZB{Em B0W
} liSmjsk
`{Ul!
/** [
3HfQ
* @param everyPage c9Yrw^
* The everyPage to set. 8_F1AU? u
*/ <QvOs@i*
publicvoid setEveryPage(int everyPage){
@8
6f
this.everyPage = everyPage; A=4OWV?
} /j^
0`hdMLONR
/** 9VT;ep
* @return Je{ykL?N
* Returns the hasNextPage. v2?ZQeHr_(
*/ 5)E @F9N
publicboolean getHasNextPage(){ S[N5 ikg
return hasNextPage; T;uX4,|(
} 6nQq
+q oRP2
/** b]y2+A.n
* @param hasNextPage _g.{MTQ
* The hasNextPage to set. Z}QB.$&
*/ % `3jL7|
publicvoid setHasNextPage(boolean hasNextPage){ ]?*wbxU0
this.hasNextPage = hasNextPage; $C\BcKlmv
} :%.D78&
?8$Q-1=
/** z @Y;r=v
* @return oQ# 8nu{k
* Returns the hasPrePage. m2o0y++TjW
*/ ]tD]Wx%
publicboolean getHasPrePage(){ SdWV3
return hasPrePage; &o*A{
} l\mPHA23
OYd !v`<
/** `]X>V,
* @param hasPrePage +0~YP*I`/
* The hasPrePage to set. d5.4l&\u
*/ 2|L&DF:G
publicvoid setHasPrePage(boolean hasPrePage){ PdCEUh\>y
this.hasPrePage = hasPrePage; 9my^Y9B
} yw!{MO
]3gSQ7
/** xUvs:
* @return Returns the totalPage. 99S^f:t
* dscgj5b1~
*/ P%6~&woF
publicint getTotalPage(){ <m m[S
return totalPage; i$@:@&(~Y
} T|p"0b A
yZRzIb_
/** N$DkX)Z
* @param totalPage VnzZTGs
* The totalPage to set. d@^ZSy>L2
*/ u"8yK5!
publicvoid setTotalPage(int totalPage){ Q@niNDaW2
this.totalPage = totalPage; zTp"AuNHN
} w@pPcZ>z/
=WLY 6)]A
} SIllU
yr6V3],Tp
"zc l|@
R=dC4;
O=lzT~G|4
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 [ }:$yg
nu^436MSOa
个PageUtil,负责对Page对象进行构造: ]yu:i-SfP
java代码: G6/m#
>0gW4!7Y
pJ=#zsE0
/*Created on 2005-4-14*/ ;*N5Y}?j'
package org.flyware.util.page; ),)lzN%!
<GJbmRc|
import org.apache.commons.logging.Log; m[$_7a5
import org.apache.commons.logging.LogFactory; Bwrx *J
dveiQ
/** 5\v3;;A[
* @author Joa CAe!7HiR
* ;`Z{7'^U
*/ GVz6-T~\>
publicclass PageUtil { FlQGgVN
@c#(.=
privatestaticfinal Log logger = LogFactory.getLog 7P
T{lT
*I+Q~4
(PageUtil.class); ==B6qX8T
,I9bNO,%JK
/** BWNi [^]
* Use the origin page to create a new page >eaaaq9B-
* @param page so;
]&
* @param totalRecords bLL2
* @return \^LFkp
*/ <$YlH@;)`a
publicstatic Page createPage(Page page, int Lr+$_ t}r
u?"Vm
totalRecords){ >ef6{URy<
return createPage(page.getEveryPage(), 6LZCgdS{
H+#FSdy#
page.getCurrentPage(), totalRecords); *v`eUQ:
} &[9709 (=
r^ XVB`v
/** jCY%|
* the basic page utils not including exception :]"V-1#}
gIfh3 D=yX
handler uO**E-`
* @param everyPage DH=hH&[e(d
* @param currentPage FwK]$4*
* @param totalRecords [ )F<V!
* @return page N#]ypl
*/ f^e)O$N9]
publicstatic Page createPage(int everyPage, int 3^ClAE"8
7=uj2.J6
currentPage, int totalRecords){ zCA2X
!7F
everyPage = getEveryPage(everyPage); maZ)cW?
currentPage = getCurrentPage(currentPage); xo)P?-
int beginIndex = getBeginIndex(everyPage, [UR-I0 s!/
6Zo}(^Ovz
currentPage); /1 dT+>
int totalPage = getTotalPage(everyPage, ^
9sjj
W)/#0*7
totalRecords); 5G#n"}T
boolean hasNextPage = hasNextPage(currentPage, ("@!>|H
F@t3!bj9
totalPage); <b.D&
boolean hasPrePage = hasPrePage(currentPage); #Z #-Ht
x^ni1=kU
returnnew Page(hasPrePage, hasNextPage, b>W%t
everyPage, totalPage, s"|Pdc4
currentPage, V#HuIgf-
im8 CmQ
beginIndex); /FII07V
} :s,Z<^5a)g
n<,BmVQ
privatestaticint getEveryPage(int everyPage){ ,uvRi)O>a
return everyPage == 0 ? 10 : everyPage; zA 3_Lx!
} kM6
Qp
NbobliC=
privatestaticint getCurrentPage(int currentPage){ |)&%A%m
return currentPage == 0 ? 1 : currentPage; GyIV
Hby
} #cJ@uqR
(Z*!#}z`
privatestaticint getBeginIndex(int everyPage, int .`lCWeHN
6863xOv{T
currentPage){ 1oS/`)
return(currentPage - 1) * everyPage; h8P)%p
} u,
ff>/1
s7<AfaJPF
privatestaticint getTotalPage(int everyPage, int #spCtZE
| Iib|HQ)
totalRecords){ ^~dWU>
int totalPage = 0; H|*m$|$,
[
3Gf2_
if(totalRecords % everyPage == 0) ,}PgOJZ
totalPage = totalRecords / everyPage;
XX@ZQcN
else dG{A~Z z
totalPage = totalRecords / everyPage + 1 ; Y*^[P,+J*}
0@(&eH=
return totalPage; eRYK3W
} \RiP
*hx
privatestaticboolean hasPrePage(int currentPage){ vdZW%-A&\
return currentPage == 1 ? false : true; d$RIS+V
} `A >@]d
+TJCLZ..
privatestaticboolean hasNextPage(int currentPage, M{@(G5
zda 3
,U2o
int totalPage){ -~0^P,yQ
return currentPage == totalPage || totalPage == hrn+UL:d
P?\6@_ Z
0 ? false : true; @- xjfC\d
} ]'}L 1r
G2D$aSh
,hVli/
} x4 yR8n(
pb}*\/s
&HW9Jn
KwS@D9bok
tc! #wd+u
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。 uYN`:b8
WLT"ji0w2
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 TxD#9]Q`
*p U x8yB
做法如下: | (93gJ
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 vQCy\Gi
}j%5t ~Qa
的信息,和一个结果集List: XZ7Lk)IR
java代码: " x-j~u?
TDh5lI
N['.BN
/*Created on 2005-6-13*/ tA;}h7/Lc~
package com.adt.bo; 8=l%5r^cq
kj_c%T
]/
import java.util.List; wp_0+$?s
Upe%rC(
import org.flyware.util.page.Page; u_enqC3
b;n[mk
/** J zl6eo[;
* @author Joa ,F|f. 7;
*/ ]DcFySyv
publicclass Result { HtFDlvdy]
:>
'+"M2r
private Page page; r&CiSMS*
l**X^+=$
private List content; 6Oq7#3]
UNYqft4
/** #e"[^_C@!
* The default constructor "sTRS*
*/ )8AXm
public Result(){ @]j1:PN-
super(); A"]YM'.
} f#;> g
.nJz G
/** :X=hQ:>P
* The constructor using fields >7|VR:U?B
* Ac@VGT:9
* @param page s[jTP(d)8
* @param content uT"rq:N
*/ K0~rN.C!0
public Result(Page page, List content){ 9w"*y#_
this.page = page; A^g(k5M*
this.content = content; dN q$}
}
];m_4
LV Ge]lD
/** Xvu(vA
* @return Returns the content. tw;}jh
*/ 1Mzmg[L8
publicList getContent(){ 'L'R9&o<X
return content; 5!
{D!
} 6Mf0`K
?9/G[[(
/** o&%g8=n%
* @return Returns the page. .*oU]N%K=
*/ i5Ggf"![
public Page getPage(){ 23PGq%R
return page; **%37
} lxx2H1([
"jZ-,P=
/** .#gzP2 [q
* @param content MtdG>TzUn
* The content to set. ^q5#ihM
*/ XS#Qu=,-
public void setContent(List content){ Hl"N}
this.content = content; #mdc [.
} o!Zb0/AP)
K+eM
/** js(pC@<q5
* @param page .('SW\u-
* The page to set. Z@HEj_n
*/ [txE .7p
publicvoid setPage(Page page){ j#|ZP-=1_
this.page = page; -@'FW*b
} q9"96({\@
} i1UsIT
e'~3oqSvR
Q,g\
E GU2fA7x
ytImB`'\
2. 编写业务逻辑接口,并实现它(UserManager, 5m@V#2^P
?<!|
UserManagerImpl) oH@78D0A
java代码: |yCMt:Hk
6k%f
KlEpzJ98
/*Created on 2005-7-15*/ 2y4bwi
package com.adt.service; *dQSw)R
ES[G
import net.sf.hibernate.HibernateException; >4TO=i
i-1op> Y
import org.flyware.util.page.Page; &C}*w2]0S
=_CzH(=f#
import com.adt.bo.Result; 3o*YzwRt
-).C
/** )0`C@um
* @author Joa hN_]6,<\
*/ X|dlt{Gf
publicinterface UserManager { yi[x}ffdE
Rq -ZL{LR7
public Result listUser(Page page)throws -"x$ZnHU
]Wup/o
HibernateException; W/N7vAx X
z{q`G wW
} ).O)p9
KNl$3nX
UMi~14& ;
W?&%x(6M
tQVVhXQ7
java代码: @7}W=HB
7V>M]
Xw1*(ffk
/*Created on 2005-7-15*/ *~`(RV
package com.adt.service.impl; ?6!LL5a.
+`4A$#$+y
import java.util.List; T{"(\X$
6]N.%Y[(
import net.sf.hibernate.HibernateException; bA 2pbjg=
@ Qe0! (_=
import org.flyware.util.page.Page; Z+SRXKQ
import org.flyware.util.page.PageUtil; \U0Q<ot/7
637:
oT_`O
import com.adt.bo.Result; ceA9){
import com.adt.dao.UserDAO; }V>T M{
import com.adt.exception.ObjectNotFoundException; Om&Dw|xG8
import com.adt.service.UserManager; ~DWl s.
vO=fP_
/** #yen8SskB
* @author Joa 4-w{BZuS
*/ ZCw]m#lS
publicclass UserManagerImpl implements UserManager { =4!mAo}
$G>. \t
private UserDAO userDAO; ]:;&1h3'7
}H4RR}g
/** 'w/hw'F6
* @param userDAO The userDAO to set. ]9-\~Mwh
*/ 2oW"'43X
publicvoid setUserDAO(UserDAO userDAO){ XW9!p.*.U
this.userDAO = userDAO; ,4rPg]r@
} }Jw,>}
]n~V!hl?A
/* (non-Javadoc) }JfjX'
* @see com.adt.service.UserManager#listUser ?2a $*(
k)u[0}
(org.flyware.util.page.Page) =Qq+4F)MD
*/ BUFv|z+H
public Result listUser(Page page)throws =a!=2VN9y
& kIFcd@
HibernateException, ObjectNotFoundException { :&Nbw
int totalRecords = userDAO.getUserCount(); p_ =z#
if(totalRecords == 0) 6*?F @D2&
throw new ObjectNotFoundException $>gFf}#C
E^PB)D(.
("userNotExist"); i4Jc.8^9$
page = PageUtil.createPage(page, totalRecords); oU|c.mYe
List users = userDAO.getUserByPage(page); 8t`?#8D}
returnnew Result(page, users); 0x7'^Z>-oe
} 9L9sqZUB
|{;G2G1[
} s{++w5s
:,^gj
K,]=6Rj
R+| h w;
)[ ,A_3E
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 g0
[w-?f
.hiSw
询,接下来编写UserDAO的代码: -di o5a
3. UserDAO 和 UserDAOImpl: 0c&+|>!
java代码: o
K@"f9
e)ZUO_Q$
d _
e WcI
/*Created on 2005-7-15*/ Q\)F;: |
package com.adt.dao; p<2,=*2
_wcNgFx
import java.util.List; BY*Q_Et
E4!Fupkpf
import org.flyware.util.page.Page; %\DX#.
GfG|&VNlz
import net.sf.hibernate.HibernateException; 'S~5"6r
~
1 pr~
/** (t.Nk[
* @author Joa x"(KBEK~
*/ edV\-H5<
publicinterface UserDAO extends BaseDAO { +V+a4lU14
/=h` L,
publicList getUserByName(String name)throws p'fYULYE
{$r[5%L\H
HibernateException; ] - .aL
b[yiq$K/
publicint getUserCount()throws HibernateException; *H122njH+T
F/Pep?'
publicList getUserByPage(Page page)throws OZT.=^:A
#%s#c0TX
HibernateException; VX/#1StC
fh{`Mz,o
} q;U,s)Uz^
9kojLqCT
7KPwQ?SjT
3F0 N^)@
V1?]|HTQcT
java代码: kLY^!
C>~TI,5a3
{)"vN(mX
/*Created on 2005-7-15*/ P$sxr
package com.adt.dao.impl; {T8Kk)L
m68*y;#
import java.util.List; V:27)]q
S$k&vc(0
import org.flyware.util.page.Page; +{>=^9%X
$|@ r!/W
import net.sf.hibernate.HibernateException; PX99uWx5]
import net.sf.hibernate.Query; >MK98(F
{U1m.30n
import com.adt.dao.UserDAO; *J{+1Ev~$p
H1T.(M/"
/** 6Iw\c
* @author Joa TKjFp%
*/ ~4"dweu?
public class UserDAOImpl extends BaseDAOHibernateImpl o.\oA6P_
rbQR,Nf2x
implements UserDAO { <1pEwI~
}i2V.tVB-
/* (non-Javadoc) Ha ]YJ}
* @see com.adt.dao.UserDAO#getUserByName 5?L<N:;J_
KU;9}!#
(java.lang.String) Q &t<Y^B
*/ xCKRxF
publicList getUserByName(String name)throws 0g\(+Qg^
WKU=.sY
HibernateException { SB7c.H,
String querySentence = "FROM user in class PzGWff!*n
[:V$y1
com.adt.po.User WHERE user.name=:name"; %UM
*79
Query query = getSession().createQuery _~pbqa,
5PW^j\G-f
(querySentence); rGkyGz8>
query.setParameter("name", name); c)tfAD(N8x
return query.list(); uGt-l4
} <,(,jU)j
KYP!Rs/j.
/* (non-Javadoc) d %#b:(,
* @see com.adt.dao.UserDAO#getUserCount() c"Sq~X
*/ p:%loDk
publicint getUserCount()throws HibernateException { .~}1+\~5
int count = 0; X jX2]
String querySentence = "SELECT count(*) FROM xKC[=E>z
yEoV[K8k
user in class com.adt.po.User"; JCaOK2XT;
Query query = getSession().createQuery W%)Y#C
9/7u*>:
(querySentence); tl].r|yl
count = ((Integer)query.iterate().next ;>YzEo
$g7<Y*t[
()).intValue(); !a<ng&H^U
return count; +MLVbK
} gNhQD*+>{
KdlQ!5(?X
/* (non-Javadoc) LDD|(KLR*.
* @see com.adt.dao.UserDAO#getUserByPage UDni]P!E
l+R+&b^
(org.flyware.util.page.Page) -(#iIgmP
*/ Q&V;(L62!
publicList getUserByPage(Page page)throws gdoLyxQ
-gWZwW/lD
HibernateException { PT9*)9<L
String querySentence = "FROM user in class h}EPnC}
rbCAnwA2
com.adt.po.User"; 7yba04D)
Query query = getSession().createQuery Lxk[;j+
{_Gs*<.
(querySentence); ZW}_Qs
query.setFirstResult(page.getBeginIndex()) mQ=#nk$~g
.setMaxResults(page.getEveryPage()); nLiY%x`S
return query.list(); `g})|Gx
} )Z
VD+X
3 9|MX21k
} &I406Z f7y
Tqk\XILG N
iyp=lLk
yA>nli=
FE{FGMq
至此,一个完整的分页程序完成。前台的只需要调用 LDg?'y;2
LrK,_)r:~
userManager.listUser(page)即可得到一个Page对象和结果集对象 T5:G$-qL(
6DWgl$[[
的综合体,而传入的参数page对象则可以由前台传入,如果用 [h:T*(R?
]d%8k}U
webwork,甚至可以直接在配置文件中指定。 eN~=*Mn(za
3{h_&Gbo'D
下面给出一个webwork调用示例: !L8#@BjU
java代码: (b6NX~G-:
:\}(&
>
/OJ`c`>Q:
/*Created on 2005-6-17*/ e*n@j
package com.adt.action.user; 'Qo*y%{@5
L~>i,
import java.util.List; yH}s<@y;7
y|q3Wa
import org.apache.commons.logging.Log; BRYHX.}h\A
import org.apache.commons.logging.LogFactory;
JSg$wi8
import org.flyware.util.page.Page; Y)a^(!<H<
evJ.<{M
import com.adt.bo.Result; pXK^Y'2C!
import com.adt.service.UserService; &yol_%C
import com.opensymphony.xwork.Action; 0{[,E.
C{bgkzr
/** ,'iE;o{Tu
* @author Joa
gRT00
*/ (2
a`XwR
publicclass ListUser implementsAction{ .-X8J t
:U(A;U1,
privatestaticfinal Log logger = LogFactory.getLog ~| 6[j<ziL
K}U-w:{
(ListUser.class); WSY}d
Vr
Zoc0!84<z
private UserService userService;
EUgs6[w 4
zZC9\V}R
private Page page; V,?yPi$#E
-FlzEZ
privateList users; ED&
`_h7?
/Qk4
/* kn"(A.R
* (non-Javadoc) f0aKlhEC
* gOOPe5+ J
* @see com.opensymphony.xwork.Action#execute() Vl!6W@g
*/ (NnH:J`
publicString execute()throwsException{ 0k(a VkZ I
Result result = userService.listUser(page); 19KQlMO.G
page = result.getPage(); 9]wN Bd
users = result.getContent(); m7>JJX3=<
return SUCCESS; [\b0Lem
} ")HFYqP>9
~<OSYb
/** L`EBfz\n
* @return Returns the page. )Iq <+IJ
*/ :Qf '2.h)
public Page getPage(){ w(TJ*::T
return page; QW~1%`
} V}NbuvDB@
'anG:=
/** .Twk {p
* @return Returns the users. ,$+V
*/ yN
s,Ll~
publicList getUsers(){ Vr1<^Ib
return users; e2W".+B1
} r!a3\ep
H_<C!OgR
/** f &wb
* @param page "{Eta
* The page to set. y[_Q-
*/ _8)*]-
publicvoid setPage(Page page){ ,tJ"
5O3-
this.page = page; 'D"C4;X
} 2Jmz(cH%
1&(V
/** ;x1PS
* @param users ; XN{x
* The users to set. f_Av3
*/ X=8{$:
publicvoid setUsers(List users){ M b1sF
this.users = users; WPG(@zD
} M*HnM(
f\>M'{cV
/** @Sbe^x
* @param userService *lw_=MXSK
* The userService to set. <)-Sj,
*/ ,47Y9Kz9
publicvoid setUserService(UserService userService){ ;<2G
this.userService = userService; 4G>H
} U,- 39mr
} h"lv7;B$
^vO+(p
@qlK6tE`
o\pVp bB
2nIw7>.}f
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, BC<^a )D=
O,h ;hQZ
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 :|8M`18lZ
{"QNJq#:
么只需要: Um-[~-
java代码: k<{{*
Ab"@714@
xzZ38xIhV
<?xml version="1.0"?> o;R2p $
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork hL;(C)(
FXN/Yq
1.0//EN" "http://www.opensymphony.com/xwork/xwork- ><$d$(
in- HUG
1.0.dtd"> 6U,O*WJ%e
dl@%`E48w
<xwork> ouFYvtF g
l
+OFw)8od
<package name="user" extends="webwork- u=7J/!H7^
7.#F,Ue_0T
interceptors"> R1GEh&U{
\\dMy9M-
<!-- The default interceptor stack name | Aw%zw1@
Qq;Foa
--> t+iHQfuP9A
<default-interceptor-ref %H&@^Tt a
m~d]a$KQ5-
name="myDefaultWebStack"/> 1@1U/ss1
=i*;VFc
<action name="listUser" ]4]6Qki
%)I{%~u0
class="com.adt.action.user.ListUser"> aV|hCN~
<param LS*y
g^{@'}$
name="page.everyPage">10</param> m(#LhlX
<result ?fjuh}Q5h
}h!f eP
name="success">/user/user_list.jsp</result> Midy"
</action> /}
WDU
7 Vo$(kj
</package> kB|B
`FTy+8mw
</xwork> =mpVYA
v`zJb00DT
D9
|n)f
\GZM&Zd
Ksj -zR;
fNt`?pWH
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 {~sDYRX
A}N?/{y)G
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。 I3mGo
lXiKY@R#
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 P5nO78
ime\f*Fg
ua]o6GlO
_EMwm&!
$?<Z!*x
我写的一个用于分页的类,用了泛型了,hoho \uC15s<
u!X|A`o5i
java代码: qHrA%k^!2O
DSk/q-'u
F,dx2ZPIs?
package com.intokr.util; 5^lxj~ F
W$OG(m!W>
import java.util.List; s1NKLt
FUjl8b-|
/** W7\f1}]H
* 用于分页的类<br> }w<7.I
* 可以用于传递查询的结果也可以用于传送查询的参数<br> *HO}~A%Lx
* CcFn.omA
* @version 0.01 3.W@ }
* @author cheng 3#&7-o
*/ O_DtvjI'
public class Paginator<E> { 6%Pdy$ P
privateint count = 0; // 总记录数 Vz~nT
privateint p = 1; // 页编号 (Cd\G=PK
privateint num = 20; // 每页的记录数
L0@SCt
privateList<E> results = null; // 结果 s4SG[w!d
9qz6]-K
/** a]/>ra5{
* 结果总数 I@%t.%O Jp
*/ >JCM.I0_|
publicint getCount(){ 3`.7<f`
return count; 2.zsCu4lj.
} 5>j)kx=J9
i9A+gtd
publicvoid setCount(int count){ [[Fx[
this.count = count; pDcjwlA%
} 7cO n9fIE
H_ox_
u}
/** Nkl_Ho,
* 本结果所在的页码,从1开始 ,Bo>E: u
* H77"
* @return Returns the pageNo. mkF"
*/ _D_LgH;}
publicint getP(){ ^8Q62
return p; G *;a^]-
} 1ilBz9x*!
V8-oYwOR
/** wK-3+&,9
* if(p<=0) p=1 z3M6V}s4
* w1"nffhO
* @param p %r6y
;vAf
*/ xA$nsZ]
publicvoid setP(int p){ l0cA6b
if(p <= 0) ~-m "
p = 1; \z7SkZt,GT
this.p = p; rT5Ycm@
} 9Z'8!$LYg
a@* S+3
/** 4^Q:
* 每页记录数量
{=QiZWu
*/ qt
2d\f
publicint getNum(){ S. q].a
return num; QC;^xG+W
} W.0L:3<"
Z%Zd2
v
/** `Ru3L#@
* if(num<1) num=1 ugx%_x6
*/ fUQ6Z,9
publicvoid setNum(int num){ ?Poq2
if(num < 1) ehG/zVgn
num = 1; Ve!fU
this.num = num; !M]\I &
} sZm$|T0
i21Gw41p:
/** i?e`:}T
* 获得总页数 $Gv9m
*/ /BV03B
publicint getPageNum(){ c#]q^L\x
return(count - 1) / num + 1; <_Q:'cx'
} hq/k*;
MxcFvo*LCp
/** wz.6du6-
* 获得本页的开始编号,为 (p-1)*num+1 Nn"+w|v[ev
*/ {aJJ`t
publicint getStart(){ >Ll$p0W
return(p - 1) * num + 1; pd8Nke
} 'ao"9-c
s)2fG\1
/** Ch%m
* @return Returns the results. -O!Zxg5x
*/ y>|{YWbp?
publicList<E> getResults(){
\qR %%S
return results; ADk8{L{UU
} H0R&2#YD
%T9 sz4V
public void setResults(List<E> results){ DHT&,=
this.results = results; TdGnf
} BQ2wnGc
BC;:
public String toString(){ (N=5.7"T
StringBuilder buff = new StringBuilder { e5/+W
tP%{P"g3^
(); GMZv RAui
buff.append("{"); j"@93D~
buff.append("count:").append(count); *[R
eb%
buff.append(",p:").append(p); j>/ ,$H
buff.append(",nump:").append(num); U Gpu\TB
buff.append(",results:").append x5WW--YR+
4[-*~C|W5
(results); ee#):
-p
buff.append("}"); fb:j%1WF
return buff.toString(); /q$,'^.A
} IMl!,(6;
^~HQC*
} ?EK?b
s
~ Yngkt
13&0rLS