Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 0x Vue[ep
5!r?U
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 cn$E?&-
\4q%
n
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 AF4:v<EN
(^'TT>2B
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 RLN>*X
Gb6t`dSzz
。 }g:y!pk
ST3aiyG
分页支持类: gG0P &9xz
Kc+;"4/#q
java代码: K.?~@5%
ve2GRTO^aC
n$Z@7r
package com.javaeye.common.util; s+>VqyHgf
U+t|wK
import java.util.List; Gxu&o%x[
h&\%~LO.
publicclass PaginationSupport { bv`gjR
-b"7WBl
publicfinalstaticint PAGESIZE = 30; yjODa90!G
7@u0;5p|
privateint pageSize = PAGESIZE; *ktM<N58
|?n=~21"1O
privateList items; utxT$1iJn~
P 8DY*B k
privateint totalCount; )cnB>Qul
5|!x0H;
privateint[] indexes = newint[0]; -o<L%Y<n2
rxu
6 #v F
privateint startIndex = 0; >s}bq#x
a;J{'PHu
public PaginationSupport(List items, int 5
T1M:~u i
_D:#M
totalCount){ Z-`j)3Y
setPageSize(PAGESIZE); wkK61ah6
setTotalCount(totalCount); 0[@9f1Nk4
setItems(items); c#M'Mye
setStartIndex(0); $:kG>R@\t
} \TSt
3!M;Z7qF]
public PaginationSupport(List items, int :B?XNo
oR>o/$z$)g
totalCount, int startIndex){ ;/#E!Ja/u
setPageSize(PAGESIZE); YB/A0 J
setTotalCount(totalCount); T_bk%
setItems(items); kVk^?F
setStartIndex(startIndex); &K5wCNX1
} i.Iiwe0G
>;}np
F>
public PaginationSupport(List items, int Fx2z lM&
>VnkgY
totalCount, int pageSize, int startIndex){ "h'0&ZP~_
setPageSize(pageSize); })O^xF~
setTotalCount(totalCount); W!pLk/|ls
setItems(items); <Y9vc:S
setStartIndex(startIndex); w4U]lg<}E
} 7Wb:^.d
g
YRF%].A%2
publicList getItems(){ A2VN%dB
return items; s0"S;{_#
} r+fR^hv
K*Y.mM)
publicvoid setItems(List items){ :nYl]Rm
this.items = items; #W,BUN}
} ^& ZlV
ab8uY.j
publicint getPageSize(){ 1TbY,3W
return pageSize; VyH'7_aU
} y6ntGrZ}$
6>ZUx}vYj
publicvoid setPageSize(int pageSize){ <d~P;R(@
this.pageSize = pageSize; DytH} U"
} kD:O$8[J8
S0nBX"$u
publicint getTotalCount(){ rmmN2+H
return totalCount; ,:UoE
} Z- ;<R$
l`8S1~j
publicvoid setTotalCount(int totalCount){ 1a4HThDXP
if(totalCount > 0){ PVvNu5k
this.totalCount = totalCount; '" LrGvkZ
int count = totalCount / bFk >IifN
+h^>?U,
pageSize; |
Zx
if(totalCount % pageSize > 0) X=)Ue
count++; S(Md
indexes = newint[count]; Q{6Bhx *>
for(int i = 0; i < count; i++){ :U!kn b"/>
indexes = pageSize * UR6.zE4=_
,<n >g;
i; xlG/$`Ab
} YIo$
}else{ z><=F,W
this.totalCount = 0; {Y-<#U~iH
} "1>I/CM
} !a?$
o@j]yA.5)
publicint[] getIndexes(){ [mphiH/
return indexes; IFNs)*
} T6MlKcw,t
6j{9\
R
publicvoid setIndexes(int[] indexes){ pMM,ox"
this.indexes = indexes; f$$l,wo
} $}&Y$w>S
2iHD$tw
publicint getStartIndex(){ 2='gC|&s6
return startIndex; ;n_ |t/=
} ,2T&33m
U8L%=/N>B
publicvoid setStartIndex(int startIndex){ DJ;il)^
if(totalCount <= 0) x>vC;E${"
this.startIndex = 0; 8 hx4N
elseif(startIndex >= totalCount) fH?e9E4l
this.startIndex = indexes 5BnO-[3
(@*[^@ipV
[indexes.length - 1]; tcyami6D4
elseif(startIndex < 0) t%Hg8oya
this.startIndex = 0; xayo{l=uGv
else{ wJM})O%SQ
this.startIndex = indexes TUoEk
,K=\Y9l3
[startIndex / pageSize]; 8px@sXI*`
} ,> lOmyh
} . (G9mZFV
8enlF\I8g
publicint getNextIndex(){ jY'svD~
int nextIndex = getStartIndex() + ;Ak<O[
p`:hY`P
pageSize; PjZsMHW%
if(nextIndex >= totalCount) A g=>F5
return getStartIndex(); ZaJg$
else mne4u W
return nextIndex; -
y[nMEE
} >+y[HTf-
rZ`ob x\S
publicint getPreviousIndex(){ 9r.Os
int previousIndex = getStartIndex() - N"SFVc_2
*YmR7g |k
pageSize; sFv68Ag+
if(previousIndex < 0) Z18T<e
return0; nNJU@<|{*
else ?g
gl8bzA
return previousIndex; GlkTpX^b
} rOd<nP^`\
pEgQ)
9\
} -d]-R?mQ
("-Co,4ey
"F?p\I)(
[4L[.N@
抽象业务类 #DK@&Gv
java代码: ^\=<geEj
Zp@j*P
:YaEMQJ^
/** .CGPG,\2
* Created on 2005-7-12 l,j7I3&~%
*/ KvENH=oh
package com.javaeye.common.business; J'c]':U
_'DT)%K
import java.io.Serializable; iJ n<
import java.util.List; x"xl3dRu
?'ID7mL
import org.hibernate.Criteria; -xs@rV`
import org.hibernate.HibernateException; q5C(/@)^
import org.hibernate.Session; )D'SfNx#{
import org.hibernate.criterion.DetachedCriteria; ^o&3 +s}M
import org.hibernate.criterion.Projections; GJ"S*30
import q6DuLFatc*
dsck:e5agZ
org.springframework.orm.hibernate3.HibernateCallback; V4I5PPz~
import 02B *cz_K
50r3Kl0
org.springframework.orm.hibernate3.support.HibernateDaoS vN#?>aL
{Q9?Q?
upport; 'J\nvNm
jb;!"HC
import com.javaeye.common.util.PaginationSupport; -PX Rd)~
NG3!09eY
public abstract class AbstractManager extends q.sErr[zc
}j<:hDQP
HibernateDaoSupport { y4sKe:@2
}-YM>q
privateboolean cacheQueries = false; 4WCWu}
dH:z_$Mg
privateString queryCacheRegion; yOR]r+8
[7x,&
publicvoid setCacheQueries(boolean #dyz
E D0\k $
cacheQueries){ "#zSk=52z
this.cacheQueries = cacheQueries; Do1 Ip&X
} .\Gl)W
g7\MFertR^
publicvoid setQueryCacheRegion(String ay~c@RXW
{"{kWbXZ
queryCacheRegion){ matW>D;J
this.queryCacheRegion = h-r\1{Q1]
Fg` P@hC
queryCacheRegion; "^M/iv(
} :
:;YS9e
aumWU{j=
publicvoid save(finalObject entity){ }%e"A4v
getHibernateTemplate().save(entity); \S#Mc
} &1nZ%J9
!O|d,)$q
publicvoid persist(finalObject entity){ WcRTv"4&
getHibernateTemplate().save(entity); h8Wv t's
} ^a+W!
k;EG28
publicvoid update(finalObject entity){ r?cDyQE
getHibernateTemplate().update(entity); _0HCtx ;
} vG E;PwR
r 0mA
publicvoid delete(finalObject entity){ m~7[fgN2
getHibernateTemplate().delete(entity); MU_8bK9m
} )?_x$GKY
`D
*U@iJ
publicObject load(finalClass entity, _8zZ.~)
2;8I0BH*'
finalSerializable id){ [l~Gwaul>
return getHibernateTemplate().load ;MSdTHN"
72Zp%a=
(entity, id); VtM:~|v
} )|52B;yZx
GFA D
publicObject get(finalClass entity, YdgDMd-1
NT(gXEZ
finalSerializable id){ r.-U=ql
return getHibernateTemplate().get Ug}dw a
Sr$&]R]^
(entity, id); -@*[
} j%w}hGW%,
6?B'3~r
publicList findAll(finalClass entity){ K;uOtbdOK
return getHibernateTemplate().find("from R0yPmh,{
M:[rH
" + entity.getName()); }uZtAH|
} [K 5#4k
`vbd7i
publicList findByNamedQuery(finalString MxXf.iX&
+V2\hq[{
namedQuery){ %P3|#0yg0
return getHibernateTemplate #.Q3}[M
9^yf'9S1
().findByNamedQuery(namedQuery); |ZJ<J)y
} D./!/>@f
rN$U%\.I
publicList findByNamedQuery(finalString query, W#|30RU.G
$!?tJ@{
finalObject parameter){ 2il)@&^
return getHibernateTemplate z2.9l?"rfQ
.8.4!6~@
().findByNamedQuery(query, parameter); x6n( BMr
} ^4G%*-
G`;YB
publicList findByNamedQuery(finalString query, GbFtX\s+5j
]t2zwHo#
finalObject[] parameters){ OEZ`5"j
return getHibernateTemplate N*^iOm]Y
?$chO|QY
().findByNamedQuery(query, parameters); zcqv0lM '
} rnOg;|u8
vk:k ~
publicList find(finalString query){ YGdzA]3>
return getHibernateTemplate().find ^-wdIu~p?
n0\k(@+k
(query); ~8oti4
} kzkrvC+u
H$@5\pP>
publicList find(finalString query, finalObject {fd/:B 7T
hXAgT!ZD
parameter){ H\>0jr`
return getHibernateTemplate().find ^i"~6QYE
a+-X\qN
(query, parameter); r
9~Wh
$
} YK{E=<:
},]G +L;R
public PaginationSupport findPageByCriteria W{El^')F
Z&Qz"V>$
(final DetachedCriteria detachedCriteria){ uc~/l4~N
return findPageByCriteria }EMds3<
R(^2+mV?
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 7A,lQh
} xs}3=&c(
_o+z#Fn z
public PaginationSupport findPageByCriteria M+|J;caX
DN X-\
(final DetachedCriteria detachedCriteria, finalint 7Rq|N$y.3
n5NwiSE
startIndex){ 2 -C*RHRx
return findPageByCriteria I$y6N"|
QjIn0MJ)Xm
(detachedCriteria, PaginationSupport.PAGESIZE, @CB&*VoB
r3}Q1b&
startIndex); 2{Johqf
} *x<3=9V
?cB:1?\j
public PaginationSupport findPageByCriteria <i$ud&D
\/8oua_)
(final DetachedCriteria detachedCriteria, finalint m~f J_
.7K<9K +P
pageSize, SDbR(oV
finalint startIndex){ Ovhd%qV;Y
return(PaginationSupport) ]ZI ?U<0
^o8o
getHibernateTemplate().execute(new HibernateCallback(){ l ~C=yP(~
publicObject doInHibernate w=Yc(Y:h
uE=pq<
(Session session)throws HibernateException { `zP{E T_Y
Criteria criteria = Chs#}=gzi
w9aLTLv-
detachedCriteria.getExecutableCriteria(session); B)`@E4i
int totalCount = N?3BzI%?
dRGgiQO
((Integer) criteria.setProjection(Projections.rowCount '
X9D( ?O
/@O$jlX5I
()).uniqueResult()).intValue(); -tH ^Deo
criteria.setProjection GF/!@N
Vb++K0CK
(null); +FBUB
List items = 5*hA6Ex7
(/[wM>q:r
criteria.setFirstResult(startIndex).setMaxResults 1"fbQ^4`
T!YfCw.HZ
(pageSize).list(); ls ,;ozU
PaginationSupport ps = V"u .u
DQ`\HY
new PaginationSupport(items, totalCount, pageSize, (X?et
&
[B1h0IR
startIndex); ' 2:HBJ
return ps; (WuJ9
} [rO TWN
}, true); rYfN
} +#RqQ8\
\\(3gB.Gd
public List findAllByCriteria(final B.Y8O^rx
sMDHg
DetachedCriteria detachedCriteria){ _0Z8V[
return(List) getHibernateTemplate [9H986=
d8Sr,t+
().execute(new HibernateCallback(){ ]b&O#D9
publicObject doInHibernate #HyE-|_C
;Ob`B@!=b
(Session session)throws HibernateException { 2S@aG%-)
Criteria criteria = gw_]Y^U
I=c}6
detachedCriteria.getExecutableCriteria(session); f2]O5rXp
return criteria.list(); TD^w|U.
} !WgVk7aP`
}, true); ;a9`z+ K
} 7\<}378/^
d#cEAy
public int getCountByCriteria(final 5 `A^"}0
5-B % 08T
DetachedCriteria detachedCriteria){ 48g`i
Integer count = (Integer) }HLV'^"k
)Q5ja}-{V
getHibernateTemplate().execute(new HibernateCallback(){ |HfN<4NL
publicObject doInHibernate eZvG
zcCGREe=
(Session session)throws HibernateException { oeA}b-Ct0
Criteria criteria = Jf3xK"in
@q++eGm\Q
detachedCriteria.getExecutableCriteria(session);
c W^
return _@A%t&l
H+?@LPV*N
criteria.setProjection(Projections.rowCount ykBq?Vr
Scz/2vNi`
()).uniqueResult(); Kn`-5{1B|
} 586lN22xM
}, true); q6AL}9]9
return count.intValue(); t +h}hL
} )Q)H!yin
} bSm*/Q
Cp!Qd e
7 P/1'f3
i"OY=iw-N
S*Hv2sl
Yue#
用户在web层构造查询条件detachedCriteria,和可选的 Sc,ajT
3c[< #]8S
startIndex,调用业务bean的相应findByCriteria方法,返回一个 Y8@TY?
hNUkaP
PaginationSupport的实例ps。 GI[XcK^*w
`\M}~
ps.getItems()得到已分页好的结果集 aC,?FWm
ps.getIndexes()得到分页索引的数组 g?>V4WF
ps.getTotalCount()得到总结果数
v7#`b}'W
ps.getStartIndex()当前分页索引 @z<IsAE
ps.getNextIndex()下一页索引 p#+Da\qmx
ps.getPreviousIndex()上一页索引 2/f!{lz ](
HE.YfD)
5"^Z7+6
z8*{i]j
4u+4LB*
D\ kd6
2y#[uSqB
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 M 0Vs9K=
Ns5'K^
,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 SE0&CV4
]h4r@L3
一下代码重构了。 =b/:rSd$NA
y25L`b
我把原本我的做法也提供出来供大家讨论吧: -;W`0k^
@*"H{xo.U
首先,为了实现分页查询,我封装了一个Page类: "Wn8}T*
java代码: )I(2t 6i
&p83X
w[hT,$n
/*Created on 2005-4-14*/ OTV$8{
package org.flyware.util.page; I*OJPFZ^4
QNxY`
/** bY!1t}ALh
* @author Joa L)-1( e<x
* TV[@!E a
*/ H?$gHZPI
publicclass Page { (GB*+@
:7 OhplI
/** imply if the page has previous page */ Rt3/dw(p
privateboolean hasPrePage; #J|DW C!#d
!rPU5y*
/** imply if the page has next page */ ~=i<O&nai
privateboolean hasNextPage; jPA^SxM
U^Ulj/%6
/** the number of every page */ `2PvE4]%p
privateint everyPage; M#o'h c
:~4M9
/** the total page number */ .xV^%e?H
privateint totalPage; AH'4k(-
fUa[3)I
/** the number of current page */ 4elA<<
privateint currentPage; Jx3fS2
! w2BD^V-
/** the begin index of the records by the current MVXy)9q
Ew>lk9La(
query */ $4u8"n e)
privateint beginIndex; #{x4s?
AroYDR,3+
|Wz`#<t
/** The default constructor */ CaqqH`/E4
public Page(){ L{uQ:;w1
/ &#b*46
} C{2y*sx
hB??~>i3
/** construct the page by everyPage p$_X\,F
* @param everyPage t;L7H E@Y
* */ d[$YTw
public Page(int everyPage){ =L9;8THY
this.everyPage = everyPage; Wj"GS!5
} wLOS,=
09sdt;V Q
/** The whole constructor */ W'}^m*F
public Page(boolean hasPrePage, boolean hasNextPage, E-"b":@:
Xot2L{EIUE
+~f5dJyk`
int everyPage, int totalPage, 1YJ@9 *l
int currentPage, int beginIndex){ I_3{i`g
this.hasPrePage = hasPrePage; SPo}!&p$~
this.hasNextPage = hasNextPage; P2=u-{?~
this.everyPage = everyPage; ew
4pAav
this.totalPage = totalPage; q:-1ul
this.currentPage = currentPage; cC7&]2X +f
this.beginIndex = beginIndex; w i=&W
} mt*/%>@7R
G[ gfD\
/** w
.+B h
* @return |jJ9dTD8/
* Returns the beginIndex. ?
H7?>ZE
*/ sQgJ`+Y8_
publicint getBeginIndex(){ _a-At
return beginIndex; n2;Vrs,<1&
} B(qwTz 51
yYn7y1B
/** %w#8t#[,6
* @param beginIndex c'&\[b(m
* The beginIndex to set. #B&%Y6E5
*/ E0aJ~A(Hv
publicvoid setBeginIndex(int beginIndex){ TT3\c,cs
this.beginIndex = beginIndex; 3&"+)*/ m
} r(DW,xoK0
`PI?RU[g*
/** f}uW(:f
* @return ]Yx&
* Returns the currentPage. BfdS3VrZ/
*/ Xn*>qm
publicint getCurrentPage(){ 8Y&_X0T|
return currentPage; se`^g
,]P
} =q?s B]n
zsmlXyP'e!
/** 1y7FvD~ v
* @param currentPage jzAXC^FS
* The currentPage to set. -@?4Tfl
*/ .BrYz:#A
publicvoid setCurrentPage(int currentPage){ 23*OuY
this.currentPage = currentPage; NkY7Hg0
} v/~Lf i
FN"Ye*d
/** #Z1
<lAy
* @return *rv7#!].
* Returns the everyPage. MoMxKmI
*/ WI\jm&H r
publicint getEveryPage(){ +5qY*$dn
return everyPage; ,B,:$G<
} vG#,J&aW
v#b( 0G
/** -Gd@baV
* @param everyPage ` <IaQY
* The everyPage to set. 5"2pU{xmK
*/ '-M9v3itC
publicvoid setEveryPage(int everyPage){ &"mWi-Mpl
this.everyPage = everyPage; re@;6o
} EN;4EC7tE
:XCRKRDLE
/** eh}I?:(a?
* @return cs7K^D;.V
* Returns the hasNextPage. G}#p4\/
*/ :[!b";pR
publicboolean getHasNextPage(){ ]Ia}H+ &
return hasNextPage; NXSjN~aG2
}
( =t41-l
|0xP'(
/** OXD*ZKi8
* @param hasNextPage BT*{&'\/
* The hasNextPage to set. %hN7K
*/ J{e`P;ND
publicvoid setHasNextPage(boolean hasNextPage){ OSIf>1
this.hasNextPage = hasNextPage; x yyEaB
} UKzXz0
IyoitIbLl
/** u
-A_l<K
* @return cn2SMa[@S
* Returns the hasPrePage. (R-(
*/ dlCmSCp%
publicboolean getHasPrePage(){ `{ ` W-C
return hasPrePage; ^\7GFpc
} Mc/=
Fs
2|$G<f
/** W
#V`|JA
* @param hasPrePage CM4#Nn=i~
* The hasPrePage to set. - sL4tMP
*/ !;E{D
publicvoid setHasPrePage(boolean hasPrePage){ Hl=M{)q@
this.hasPrePage = hasPrePage; p61F@=EL
} @f`s%o
iG+=whvL
/** H/$oGhvl
* @return Returns the totalPage. '.IR|~ Y
* ASULg{
*/ V~]&1
publicint getTotalPage(){ ^EcwY- Qr
return totalPage; ; ~#uH7k
} k`NXYf:
:[?65q{
/** {"mb)zr
* @param totalPage >N-l2?rE
* The totalPage to set. ".sRi
*/ kS<9cy[O
publicvoid setTotalPage(int totalPage){ nJcY>Rp?
this.totalPage = totalPage; QS%t:,0lp
} MTAq}8
DTz)qHd#X
} i^}ib
RQbN
"Zu>cbE
Ug8>|wCE
<Y+>a#T
~qkn1N%'
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 2k+u_tj>
1)J'
pDa
个PageUtil,负责对Page对象进行构造: rnRWL4
java代码: y;=/S?L.:
"GB493=v
U[|o!2$
/*Created on 2005-4-14*/ 8XD_p);Oy
package org.flyware.util.page; |6 E
!wW
N7-LgP
import org.apache.commons.logging.Log; J
Mm'JK?
import org.apache.commons.logging.LogFactory; Ah_0o_Di
C~R,,
/** cHX~-:KOr
* @author Joa 0`Y"xN`'i
* @o>3
Bv.
*/ #PQhgli
publicclass PageUtil { ky I~
>DoP2]
privatestaticfinal Log logger = LogFactory.getLog zszx~LSvIT
h~s h!W8
(PageUtil.class); =O>E>Q
:Hj #1-U
/** q@XxCP]
* Use the origin page to create a new page iyP0;$
* @param page kerBy\^
* @param totalRecords TnJJ& "~3b
* @return I\@`AU
*/ {QVs[
J1
publicstatic Page createPage(Page page, int
>f*Zf(F
.svlJSx
totalRecords){ [U_
return createPage(page.getEveryPage(), 8y'.H21:;
C=&;4In
page.getCurrentPage(), totalRecords); K(rWM>Jv
} MS;^@>|wj
F?XiP.`DR
/** qz8Jvgu?
* the basic page utils not including exception fr<V])
(lt{$0
handler PG@6*E
* @param everyPage 5G l:jRu
* @param currentPage V;uFYt;E
* @param totalRecords k:#u%Z
* @return page .~fov8
*/ DhN<e7c`
publicstatic Page createPage(int everyPage, int y\ax?(z
sF~!qag4q'
currentPage, int totalRecords){ qv3% v3\4
everyPage = getEveryPage(everyPage); w]O,xO
currentPage = getCurrentPage(currentPage); b{}ao
int beginIndex = getBeginIndex(everyPage, uA~?z:~=
=h|xlT
currentPage); jbp?6GW
int totalPage = getTotalPage(everyPage, nJY3 1(p
l`."rei%)
totalRecords); bp>M&1^KY
boolean hasNextPage = hasNextPage(currentPage, d0;<Cw~Tl
Zu|qN*N4
totalPage); 6rMNp"!
boolean hasPrePage = hasPrePage(currentPage); Or:P*l
mq+<2 S
returnnew Page(hasPrePage, hasNextPage, ]MnQ3bWq"j
everyPage, totalPage, sf8F h
currentPage, 6Cgc-KNbk
.q|k459oi
beginIndex); NR98]X
} _
qU-@Y$
<KFl4A~
privatestaticint getEveryPage(int everyPage){ 2*a5pFkb
return everyPage == 0 ? 10 : everyPage; i9D<jkc
} nhRpb9f`1@
Kiq[PK
privatestaticint getCurrentPage(int currentPage){ cFr`9A\-n
return currentPage == 0 ? 1 : currentPage; _kdt0Vr,L
} F
h+g@ u6
q_Z6s5O
privatestaticint getBeginIndex(int everyPage, int Z6 E_Y?
kY{;(b3Q
currentPage){ KO[,C[;|j
return(currentPage - 1) * everyPage; 2b&Fu\2Dmv
} HNd? '
;e$YM;;d
privatestaticint getTotalPage(int everyPage, int >DR$}{IV
WJy\{YAG
totalRecords){ j[Gg[7q{y
int totalPage = 0; | z?c>.
fT{%zJU
if(totalRecords % everyPage == 0) }z5u^_-m
totalPage = totalRecords / everyPage; ~W-5-Nl{s
else 5
Q/yPQN
totalPage = totalRecords / everyPage + 1 ; %Ot*k%F
}J $\<ZT
return totalPage; a"^rOiXR{
} CIj7'V
]A:8x`z#F
privatestaticboolean hasPrePage(int currentPage){ 2YK2t<EO
return currentPage == 1 ? false : true; w9675D+
} V/BU(`~i
pj Md
privatestaticboolean hasNextPage(int currentPage, f<M!L>+M6
|IDZMd0
int totalPage){ r!~6.
return currentPage == totalPage || totalPage == |q
c <C&O
d&naJ)IoF)
0 ? false : true; Wpc8T="q
} %:Z_~7ZR
yw >Frb5p
Ho1 V)T>
} ANTWWs}
7m8(8$-6
eVj7%9
A45!hhf
k|^`0~E
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。 5]K2to)>`
!\!j?z=O8
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 u}89v1._Jn
b-Ru UfUn0
做法如下: I8Y
#l'z
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 a3L-q>h
k:URP`w[X=
的信息,和一个结果集List: (*9-Fa
java代码: OoQLR
~ 1~|/WG
%DM0Z8P$B-
/*Created on 2005-6-13*/ Z9eP(ip
package com.adt.bo; 1Cw
HGO
xqfIm%9i}
import java.util.List; A2SDEVU
L~C:1VG5
import org.flyware.util.page.Page; -_= m j
<u/(7H
/** nO#x"
* @author Joa e-#Vs{?|r
*/ u:H:N]
publicclass Result { ?in)kL
h4Xz"i{z
private Page page; PJ\k|
*,28@_EwY
private List content; 6Ad=#MM
WEtPIHruyt
/** !|8"}ZF
* The default constructor &@=W+A=c~
*/ #7@p
public Result(){ qG +PqK;
super(); J~C=o(r
} U$;UW3-
-b|"%e<'
/** V[n,fEPBr
* The constructor using fields =_CH$F!U
* 6[?5hmc"w
* @param page MaPI<kYQv
* @param content -A zOujSS
*/ UG[r /w5(F
public Result(Page page, List content){ T3I{D@+0
this.page = page; BN~ndWRK
this.content = content; RFX{]bQp9
} M3r;Pdj2r
VOIni<9y
/** eD7qc1*G
* @return Returns the content. mtdy@=?1Y
*/ ?!O4ia3nFk
publicList getContent(){ @8$z2
return content; HiBI0)N}
} i.\ e/9]f
iB` EJftI!
/** Mmg~Fn
* @return Returns the page. i[:cG
*/ #\_8y`{x
public Page getPage(){ ]LEaoOecu
return page; J57; X=M
} F)v
.R
l7,1\
/** Pm,.[5uc
* @param content x2'pl
(^
* The content to set. =3!o_
*/ p$uPj*
public void setContent(List content){ |(AFU3~
this.content = content; O<E8,MCA[a
} ~@(C+ 3,
X?XB!D7[
/** K)5j
* @param page aNA]hl
* The page to set. ,HI%ym
*/ Io[NN aF|
publicvoid setPage(Page page){ _3< P(w{
this.page = page; qDU4W7|T`
} >|yP`m
} #Ge_3^'
i,S1|R
xaVn.&Wl
r?!:%L
BC\W`K
2. 编写业务逻辑接口,并实现它(UserManager, "eqzn KT%u
gS8+S\2
UserManagerImpl) ~X3x-nAt
java代码: v1Q78P
w`=O
'0d
r)OiiD"
/*Created on 2005-7-15*/ -*i_8`
package com.adt.service; u0A$}r$L
2dcvB]T!
import net.sf.hibernate.HibernateException; .FC+
ifu!6_b.
import org.flyware.util.page.Page; /sj*@HF=
Cs
y,3XG
import com.adt.bo.Result; ?~4x/d%
W)J MV
/** ?c+$9
* @author Joa *8po0s
*/ >]_^iD]*t
publicinterface UserManager { :0QDV~bs
T\g+w\N
public Result listUser(Page page)throws 'nBP%
vZ811U~}
HibernateException; GC' e
ir"t@"Y;o
} vhAgX0k
a2tEp+7?
O"Nr$bS(Y
RRV%g!
tfZ@4%'
java代码: g(;OUkj$Zp
ZWo~!Z [Y
k54\H.
/*Created on 2005-7-15*/ `-OzjbM
package com.adt.service.impl; Ff(};$/&W
NkO+)=
import java.util.List; `GdH ,:S>
{Dk!<w I)
import net.sf.hibernate.HibernateException; d;]mwLB0
;{L[1OP%e
import org.flyware.util.page.Page; `:*2TLxIk
import org.flyware.util.page.PageUtil; 4(LLRzzW
h`dQOH#
import com.adt.bo.Result; Bv!{V)$
import com.adt.dao.UserDAO; Wbei{3~$Y"
import com.adt.exception.ObjectNotFoundException; 8'jt59/f
import com.adt.service.UserManager; ENIg_s4
s1[&WDedM
/** NjpWK;L
* @author Joa u[Kz^ga<
*/ vdC0tax
publicclass UserManagerImpl implements UserManager { [l3\0e6-/
F8"J<VJ7
private UserDAO userDAO; iw3\`,5
=CJ`0yDQ>
/** }7(+#ISK6
* @param userDAO The userDAO to set. !%ju.Xs8
*/ E;{RNf|
publicvoid setUserDAO(UserDAO userDAO){ m*A b<$y
this.userDAO = userDAO; HY
FMf3
} e15yDwvB
z<%bNnSO
/* (non-Javadoc) c:u*-lYmK%
* @see com.adt.service.UserManager#listUser eZqEFMBTm
&1yJrj9y
(org.flyware.util.page.Page) 0NGth(2
*/ z k/`Uz
public Result listUser(Page page)throws 6PYt>r&TO
cWZITT{A
HibernateException, ObjectNotFoundException { tWTHyL
int totalRecords = userDAO.getUserCount(); #~)A#~4O
if(totalRecords == 0) _.Hj:nFHz
throw new ObjectNotFoundException `;+x\0@<
kSzap+ nB?
("userNotExist"); GEF's#YWK
page = PageUtil.createPage(page, totalRecords); j?m(l,YD|*
List users = userDAO.getUserByPage(page); yRyXlZC
returnnew Result(page, users); grzmW4Cw
} wbAwmOiZ
Gd_0FF .
} ,v
K%e>e&
{VW\EOPV~
L6PgWc;m
ch]Qz[d
T`":Q1n
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 <O0tg[ub
i0K 2#}=^
询,接下来编写UserDAO的代码: PdqvXc
3. UserDAO 和 UserDAOImpl: ?Y3i-jY
java代码: 1F,U^O
oo\^}jb
%%}l[W
/*Created on 2005-7-15*/ AXHY$f|
package com.adt.dao; rHB>jN@$
Y3DqsZ@
import java.util.List; t!Cz;ajNi
x\8g ICf
import org.flyware.util.page.Page; ?.Vuet
iL);bv W
import net.sf.hibernate.HibernateException; 1>rQ).eT
!DFTg4xb
/** pNOE
KiJ
* @author Joa ~6n|GxR.[
*/ PiM(QR
publicinterface UserDAO extends BaseDAO { }6\,kFc
F_'{:v1GW
publicList getUserByName(String name)throws UX63BA
@3KSoA"^
HibernateException; )VkVZf | S
ocWl]h].
publicint getUserCount()throws HibernateException; "h_f-vP
f&4+-w.:V|
publicList getUserByPage(Page page)throws y EfAa6
s(3u\#P
HibernateException; m_oUl(pk
ejZ-A?f-K
} 9;v3
(U+:
y/Y}C.IWp)
\Hrcf +`
hGY-d}npAJ
/)J]ItJlz
java代码: W7WHDL^
\99'#]\_/E
]NTQF/
/*Created on 2005-7-15*/ G<-KwGy,D
package com.adt.dao.impl; 4AJT)I.
%<nGm\
import java.util.List; 8iaMr278W
&?bsBqpN
import org.flyware.util.page.Page; ~/K&=xE
NzyEsZ]$
import net.sf.hibernate.HibernateException; ai$l7]7
import net.sf.hibernate.Query; pP":,8Q{
^g6v#]&WA
import com.adt.dao.UserDAO; aSIb0`(3
hbJy<e1W
/** =t-Ud^3
* @author Joa !9
kNL
*/ |OF3O,5z
public class UserDAOImpl extends BaseDAOHibernateImpl #oTVfY#
g]L8Jli
implements UserDAO { }C_g;7*
1q!k#Cliu
/* (non-Javadoc) 1$03:ve1
* @see com.adt.dao.UserDAO#getUserByName J' P:SC1
k
6[
(java.lang.String) eK1l~W%
*/ TxK
v!-1
publicList getUserByName(String name)throws \A\
,c`6-
HibernateException { {z_cczJ-
String querySentence = "FROM user in class yJC:
bD1xi
/c=8$y\%@
com.adt.po.User WHERE user.name=:name"; s3JzYDpy
Query query = getSession().createQuery A'jL+dI.
Q"
h]p
(querySentence); cI8\d 4/py
query.setParameter("name", name); 33lh~+C
return query.list(); u->[y1JY
} V=+|]`
,)xtl`fc
/* (non-Javadoc) Ne|CWUhO
* @see com.adt.dao.UserDAO#getUserCount() $!9U\Au>2
*/ V)~b+D
publicint getUserCount()throws HibernateException { Z1q<) O1QX
int count = 0; !%t@wQ]\hG
String querySentence = "SELECT count(*) FROM `;}qjm0a
nw/g[/<;
user in class com.adt.po.User"; Zc_F"KJL
Query query = getSession().createQuery ;q9Y%*
{=
&&J@:
(querySentence); -FZNk}
count = ((Integer)query.iterate().next 1VFCK&
#]c_2V
()).intValue(); F-:AT$Ok
return count; `$1A;wg<
} 3n7>qZ.d
0AWxU?$A4
/* (non-Javadoc) "B__a(
* @see com.adt.dao.UserDAO#getUserByPage }o!b3*#
WP\kg\o
(org.flyware.util.page.Page) j7g>r/1eE
*/ ^^ix4[1$Z
publicList getUserByPage(Page page)throws J#wf`VR%
apJXRH`
HibernateException { "})OLa
String querySentence = "FROM user in class [^a7l$fmi
Mj>QV(L8t
com.adt.po.User"; 3+'vNc
Query query = getSession().createQuery Bj6%mI42hl
z [[qrR
(querySentence); )
4t%?wT
query.setFirstResult(page.getBeginIndex()) #s\yO~F-
.setMaxResults(page.getEveryPage()); ~P}ng{x4z
return query.list(); cy6YajOk7
} 9
AD*
Da[#X`Kp$
} Y]6dYq{k
cCiDe`T\F
t3.;qDy
\25EI]
:&&s*_
至此,一个完整的分页程序完成。前台的只需要调用 \>oy2{=;'
7R5ebMW
V
userManager.listUser(page)即可得到一个Page对象和结果集对象 *\:sHVyG(
eW<NDI&b
的综合体,而传入的参数page对象则可以由前台传入,如果用 )xU+M{p-os
6X'0 T}
webwork,甚至可以直接在配置文件中指定。 7fWZ/;p
8H};pu2
下面给出一个webwork调用示例: e:MbMj6`
java代码: /:
-&b#+
,\+N}F^
Y<Ae_yLa
/*Created on 2005-6-17*/ mmjWLrhlu
package com.adt.action.user; ?vWF[ DRd'
_
j'm2BAO
import java.util.List; P(b~3NB)
$rQ7"w J
import org.apache.commons.logging.Log; TEer>gD:v
import org.apache.commons.logging.LogFactory; G,WLca[
import org.flyware.util.page.Page; ]!"7k_
j7I?K
:op=
import com.adt.bo.Result; kene'
aDm
import com.adt.service.UserService; ,V5fvHPH)8
import com.opensymphony.xwork.Action; hd/'>]
'.%Omc
/** EUrIh2 .Z
* @author Joa 3e-E/6zH6
*/ }3WP:Et
publicclass ListUser implementsAction{ Jc]k\U
SCn)j:gH;
privatestaticfinal Log logger = LogFactory.getLog NuF?:L[
7nxH>.,Q>
(ListUser.class); -e"kJd&V
xp^Jp
private UserService userService; l%0-W
c*<BU6y
private Page page; "ig)7X+Wz|
~A%+oa*2~
privateList users; ?c"iV
^g2Vz4u
/* M'X,7hZ
* (non-Javadoc) @!ja/Y^
* !YO'u'4<aK
* @see com.opensymphony.xwork.Action#execute() Mg}/gO%o
*/ B )\;Ja
publicString execute()throwsException{ q TWQ!
Result result = userService.listUser(page); Ur1kb{i
page = result.getPage(); }{PG^ Fc<P
users = result.getContent(); icVB?M,m
return SUCCESS; >bmdu\j5R
} b,jo94.G
Hd-g|'^K
/** 805oV(-
* @return Returns the page. P%R9\iajH
*/ ;ioF'ov
public Page getPage(){
Zf??/+[
return page; fpO2bD%$8
} l LBzY`j
M= 3w
/** ]TtID4qL
* @return Returns the users. =l]
lwA-
*/ Ed_Fx'
publicList getUsers(){ 5~[][VV^
return users; 5D7k[+6
} nsq7dhq
T^$`Z.
/** W"t^t|H'~
* @param page b>#dMRK
* The page to set. ;/ |tU
o$
*/ psiuoYf
publicvoid setPage(Page page){ heWQPM|s
this.page = page; Ix(,gDN
} CZy3]O"qW
g{>0Pa1?C
/** .Tw:Y,G
* @param users V`c,U7[/
* The users to set. Ut/%+r"s
*/ y
La E]
publicvoid setUsers(List users){ 8NNs_~+x}
this.users = users; ;V f{3
} 5vS[{;<&
tU!Yg"4Q
/** fb[lL7
* @param userService Z rgv*
* The userService to set. +.rOqkxJ
*/ S|6i]/
publicvoid setUserService(UserService userService){ 4Xwb`?}-
this.userService = userService; nHZhP4W
} E*,nKJu'r
} 6u`$a&dR'l
A|U0e`Iw
nC?Lz1re
VT~%);.#
Q$k#q<+0
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, B
o%Sl
w7q6v>
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 E1w8d4P,G
|S<!'rY
么只需要: gg#lI|
java代码: ~oK0k_{~
g2M1zRm;
\W=Z`w3
<?xml version="1.0"?> ^;[_CF_
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork
$Tt.r
@W==)S%O
1.0//EN" "http://www.opensymphony.com/xwork/xwork- ;"RyHow
V)u#=OS
1.0.dtd">
MpJ\4D5G
SL+n y(y
<xwork> eQ6wEeB9
XVo+ <&
<package name="user" extends="webwork- 2\#$::B9
Z TB6m`
interceptors"> 0xvSi9
bJ6H6D>
<!-- The default interceptor stack name z/p^C~|}
4L97UhLL
--> tWaGCxaE
<default-interceptor-ref 7A$mZPKh
O@dK^o
name="myDefaultWebStack"/> bTAY5\wB
,C_MB1u
<action name="listUser" ,K30.E
OJM2t`}_t
class="com.adt.action.user.ListUser"> 9q[[
,R
<param B|M@o^Tf
0~DsA Ua
name="page.everyPage">10</param> [T/S/@IT
<result 0=40}n&`
pbwOma2
name="success">/user/user_list.jsp</result> 7*WO9R/
</action> 7:JGr O
F8/n;
</package> Qs8yJH`v
@$%.iQ7A;
</xwork> yOP$~L#TWs
0&\71txrzg
a^[s[j#^,
h\~!!F
+;oR_]l
}6{00er
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 8f%OPcr&
WOeLn[
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 1L?W+zMO
8A-*MU`+
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 9.#")%_p
#8BI`.t)j
X_Pbbx_j
z-sq9Qp&x
GyFA1%(o
我写的一个用于分页的类,用了泛型了,hoho \~U:k4
e~R_ bBQ0
java代码: a6It1%a+
n%02,pC6,
y;P%=MP
package com.intokr.util; i 2[8^o`_
,&* BhUC
import java.util.List; YOvhMi
2jkma :$'
/** a`eb9o#
* 用于分页的类<br> Bw[#,_
* 可以用于传递查询的结果也可以用于传送查询的参数<br> zQu9LN
* #%#N.tB5
* @version 0.01 I\[z(CHg@
* @author cheng ;DKJ#tS}"
*/ -0NkAQrg
public class Paginator<E> { [I<J6=
privateint count = 0; // 总记录数 wCj)@3F
privateint p = 1; // 页编号 hwi_=-SL
privateint num = 20; // 每页的记录数 Nm%#rZrN~Q
privateList<E> results = null; // 结果 Uw3wR!:
/pLf?m9
/** oBo |eRIt|
* 结果总数 K,*z8@
*/ CqU ^bVs
publicint getCount(){ QXy=|
return count; \E05qk_;K
} ]<Q&
Bcb
'4*:
publicvoid setCount(int count){ qamq9F$V
this.count = count; M}=>~TA@
} !g#y$
KhL%ov
/** }"kF<gG1
* 本结果所在的页码,从1开始 D& &71X '
*
q$K}Fm1C
* @return Returns the pageNo. ?@6Zv$vZ
*/ 'coY`B; 8
publicint getP(){ 3RFU
return p; Wdj|RKw
} )vuIO(8F#
$) qL=kR
/** P{StF`>Y
* if(p<=0) p=1 w:R#F(
'B
* N!-P2) @
* @param p :6o|6MC!
*/
7$IR^
publicvoid setP(int p){ zzd PR}VG
if(p <= 0) ?papk4w
p = 1; w2lO[o~x}
this.p = p; (eHTXk*V`
} S&J5QZjC
\
*g3j
/** 3Lv5>[MnN
* 每页记录数量 S{{wcH$n'i
*/ :1]J{,VG
publicint getNum(){ 1vJj?Uqc
return num; |PGTP#O<
} 95ix~cH3q
TWfkr
/** Ya!PV&"Z
* if(num<1) num=1 z*cKH$':
*/ )gAqWbkB
publicvoid setNum(int num){ Kt/:caD
if(num < 1) RfT)dS+rAh
num = 1; y,qn 9
this.num = num; LIyb+rH#yg
} wk1/&
WB `h)
/** zp``e;gY
* 获得总页数 vM:c70=
*/ _({wJ$aYC
publicint getPageNum(){ # 00?]6`z
return(count - 1) / num + 1; {V8uk$
} u?'J1\z
p$*P@qm
/** ~I~lb/
* 获得本页的开始编号,为 (p-1)*num+1 F9A5}/\
*/ =&DuQvN,
publicint getStart(){ sJ5#T iX
return(p - 1) * num + 1; %D%
Ok7s})
} +NeoGnj
$)6M@S
/** Wo,93]
* @return Returns the results. 0 ;4 YU%u
*/ nu2m5RYx
publicList<E> getResults(){ >q ,Z*s>?
return results; (''w$qq"D
} ]c6h'}
,zZ@QW5
public void setResults(List<E> results){ ^a1k"|E?f
this.results = results; z2#k/3%o=
} -*kZ2grLt
kN 0N18E
public String toString(){ <5G 4|l
StringBuilder buff = new StringBuilder ]x%sX|Rj
jc,Qg2
(); -av=5hm
buff.append("{"); n{M-t@r7
buff.append("count:").append(count); K;>9K'n
buff.append(",p:").append(p); jBd=!4n
buff.append(",nump:").append(num); J2Qt! -
buff.append(",results:").append h*3{IHAQ
5Z=GFKf|
(results); Il#ST
buff.append("}"); _c(h{dn
return buff.toString(); %:OX^^i;
} nEbZ8M
E*s _Y
} f6PYB&<1
Rv.IHSQUo
#wkSru&LS