Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 G"-V6CA[
4^:dmeMZ`
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 XxdD)I
1hi,&h
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 %$Py @g
V?"U)Y@Y
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 w+*rbJ
J(/J;PW
。 >]gB@tn[
Ij.mLO]
分页支持类: YzM/?enK}T
YlG#sBzl
java代码: h?OSmzRLd
- ry
WTl0}wi
package com.javaeye.common.util; sH2xkUp
j#P4&
import java.util.List; Vh?vD:|
+4T.3Njjn
publicclass PaginationSupport { 2YWO'PL
kJO Z;X=9/
publicfinalstaticint PAGESIZE = 30; uaKbqX
W?E,"z
privateint pageSize = PAGESIZE; +MaEet
Ax~
i`
privateList items; z(^dwMw}
"a'I^B/
privateint totalCount; k{F6WQ7
f-[.^/
privateint[] indexes = newint[0]; $E^sA|KcT
F-ofR]|)>
privateint startIndex = 0; J>#yA0QD2
PyHL`PZZ
public PaginationSupport(List items, int UukY9n];]
t5K#nRd Z:
totalCount){ \eQPvkx2
setPageSize(PAGESIZE); %P<fz1
setTotalCount(totalCount); h;r^9g
setItems(items); \vc&V8
setStartIndex(0); *)^ZUk
} mdrqX<x'~
<6+B;brh
public PaginationSupport(List items, int V3VTbgF
L1Yj9i
totalCount, int startIndex){ k$J!,!q
setPageSize(PAGESIZE); =B;qy7?
setTotalCount(totalCount); UCj+V@{
setItems(items);
u0oTqD?
setStartIndex(startIndex); yW7>5r
} fiSX( 9
w;AbJCv2
public PaginationSupport(List items, int zIS ,N '
P2s\f;Dwr
totalCount, int pageSize, int startIndex){ [`tNa Vg
setPageSize(pageSize); o::9M_;
setTotalCount(totalCount); #sjGju"#_
setItems(items); d*k5h<jM
setStartIndex(startIndex); P()W\+",n
} 2MYez>D
saQ
~v@
publicList getItems(){ &;JeLL1J
return items; T5T[$%]6
} Da6l=M
~/aCzx~
publicvoid setItems(List items){ AFYdBK]
this.items = items; \' A-
Lp
} 7AGUi+!ICl
/.A"HGAk
publicint getPageSize(){ ,`a8@
return pageSize; })uyq_nz
} V7gL*,3>=
awQGu,<N
publicvoid setPageSize(int pageSize){ HP<a'| r
this.pageSize = pageSize; OR|Jc+LT
} 152s<lu1Z
j!k$SDA-
publicint getTotalCount(){ Q/j#Pst
return totalCount; +N2ILE8[<
} {dE(.Z?]!#
?GLCd7TP
publicvoid setTotalCount(int totalCount){ T4ugG?B*
if(totalCount > 0){ ZzR0k
this.totalCount = totalCount; pg_H' 0R
int count = totalCount / ~Ij/vyB_
.V_5q:tu
pageSize; L
9cXgd
if(totalCount % pageSize > 0) 6jm/y@|F!
count++; w6Mv%ZO_
indexes = newint[count]; 4:b'VHW.
for(int i = 0; i < count; i++){ " L,9.b
indexes = pageSize * 8+Gwv
SDU
fN<Y3^i"
i; Q4]Od{[
} Hm|N{
}else{ t pxk8Ys
this.totalCount = 0; j:2F97
} Wy/h"R\=
} dShGIH?
q3K}2g
publicint[] getIndexes(){ }mUb1b
return indexes; Qr6PkHU
} Pl`Nniy
1B~Z1w
publicvoid setIndexes(int[] indexes){ q68m*1?y
this.indexes = indexes; }&6:0l$4!
} ,\RR@~u'
4HGS
publicint getStartIndex(){ Q+QD,
return startIndex; c"1Z,M;G
} R)isWw4
0&2`)W?9
publicvoid setStartIndex(int startIndex){ # Oq.}x?i
if(totalCount <= 0) Y)(yw \&v
this.startIndex = 0; e VQ-?DK
elseif(startIndex >= totalCount) m"'`$ /_
this.startIndex = indexes WlGT&m&2
YGc:84S
[indexes.length - 1]; 88?O4)c
elseif(startIndex < 0) WNKP';(a@G
this.startIndex = 0; tL<.B
else{ 7~k=t!gTY
this.startIndex = indexes &" J;
WA:r4V
[startIndex / pageSize]; N&Ho$,2s
} yg~@}_C2_
} H?xYS|
n
cKoW5e|u
publicint getNextIndex(){ )%n$_N n
int nextIndex = getStartIndex() + {c*5 )x!
gA@Zx%0j
pageSize; G\V*j$}!
if(nextIndex >= totalCount) HXZ,"S
return getStartIndex(); ]bpgsW:Xu
else Q[|*P ] w
return nextIndex; (vchZn#
} uaU2D-ft"
)E^4U9v),
publicint getPreviousIndex(){ S3E5^n\\
int previousIndex = getStartIndex() - #V#!@@c;?
<dr2 bz
pageSize; 2\gIjXX"
if(previousIndex < 0) b>k2@
return0; &Vgpv#&Cfx
else |(PS
bu
return previousIndex; *vvm8ik
} pv-c>8Wb6
"h7Dye
} 4i+%~X@p
MOnTp8
{ w sT
UF*R1{
抽象业务类 3T4HX|rC
java代码: ('Uj|m}9
<1<xSr
S9r+Nsn
/** j:/Z_v'
* Created on 2005-7-12 {>~9?Xwh
*/ 10OkrNQ
package com.javaeye.common.business; *kYGXT,f]
pIYXYQ=Z
import java.io.Serializable; V'MY+#
import java.util.List; %2g<zdab
_nxH;Za
import org.hibernate.Criteria; DX+zK'34
import org.hibernate.HibernateException; vZ.<OD4
import org.hibernate.Session; 1+XM1(|c`
import org.hibernate.criterion.DetachedCriteria; Y#~A":A
import org.hibernate.criterion.Projections; FU>KiBV#
import BzO,(bd!PI
: T7(sf*!*
org.springframework.orm.hibernate3.HibernateCallback; ; D/6e6
import c:>&YGmhu
p:W]
org.springframework.orm.hibernate3.support.HibernateDaoS , c{ckm
}*xjO/Ey
upport; !U1
vW}H
7Zdg314
import com.javaeye.common.util.PaginationSupport; g=@d!]Z~[
*L$_80
public abstract class AbstractManager extends 72yJv=G
7}6CUo
HibernateDaoSupport { BK6
X)1R
!Hl] &
privateboolean cacheQueries = false; [w|Klq5
JTm'fo[
privateString queryCacheRegion; *KY:U&*
x-X~'p'f
publicvoid setCacheQueries(boolean bE'{zU}o
DF4CB#
cacheQueries){ .SER,],P
this.cacheQueries = cacheQueries; gD4vV'|
} cy;i1#1rO
[YHtBM:y
publicvoid setQueryCacheRegion(String ,p#B5Dif/
-D'XxOI
queryCacheRegion){ `?3f76}h
this.queryCacheRegion = S)j(%g
L/C~l3
queryCacheRegion; 4R\jZ@D
} >Bf3X&uS
-bHlFNRm
publicvoid save(finalObject entity){ cGgfCF^`
getHibernateTemplate().save(entity); y#iz$lX R
} NLG\*mQ
.O5V;&,
publicvoid persist(finalObject entity){ 'o#oRK{#
getHibernateTemplate().save(entity); Rk3
bZvj3
} 2HN*j~>i~
igk<]AwxS
publicvoid update(finalObject entity){ T>rmm7F
getHibernateTemplate().update(entity); /r"<:+
} .7gh2K
%\T,=9tD\
publicvoid delete(finalObject entity){ B\)Te9k'
getHibernateTemplate().delete(entity); 3c3;8h$k
} ?{B5gaU9F
kex V~Q
publicObject load(finalClass entity, nv@z;#&
7)r]h?
finalSerializable id){ rD SYR\cg
return getHibernateTemplate().load *S:~U
kF~(B]W(
(entity, id); Dn 0L%?_
} .
c+m(Pk
|zpy!X 3
publicObject get(finalClass entity, |;wc8;
YxJQ^D`
finalSerializable id){ ?1JY6v]h4
return getHibernateTemplate().get NOXP}M
ZxwrlaA
(entity, id); /#M1J:SV
} iiIns.V
c2M
publicList findAll(finalClass entity){ EXr2d"
return getHibernateTemplate().find("from h'
!C
rBTg"^jsw
" + entity.getName()); 6Qt(Yu*s
} b3E1S+\=~
/h+ W L
publicList findByNamedQuery(finalString (is' ,4^b
$e7%>*?m
namedQuery){ v7
*L3Ol
return getHibernateTemplate qsep9z.
l1DJ<I2
().findByNamedQuery(namedQuery); ;kk[x8$
} .b3h?R*&
[q2:d^_FA
publicList findByNamedQuery(finalString query, <.n,:ir
$lf/Mg_H
finalObject parameter){ CsA (oX
return getHibernateTemplate $kTm"I
j*?8w(!
().findByNamedQuery(query, parameter); ^:{8z;w!(
} Q/4-7
T(?w}i
publicList findByNamedQuery(finalString query, -K=.A*}
l&+O*=#Hh
finalObject[] parameters){ v}j5G,
[-
return getHibernateTemplate Hp=BnN
M\m:H3[
().findByNamedQuery(query, parameters); IAH"vHM
} <!Cjq,Sk7
wkx9@?2*
publicList find(finalString query){ qhGz2<}_j
return getHibernateTemplate().find w<`0D)mQ
q8d](MaX
(query); 0* F` h
} (`dz37@*
uAA2G\3
publicList find(finalString query, finalObject M/p9 I
gp
{O2=K#J
parameter){ ]H !ru
return getHibernateTemplate().find L8h3kT
_gqqPny4$
(query, parameter); [WR"#y
} a*5KUj6/TL
*ai~!TR
public PaginationSupport findPageByCriteria ?4R%z([X7
w UxFE=ia
(final DetachedCriteria detachedCriteria){ A,_O=hA2I
return findPageByCriteria fY&TI}Y
D ;> 7y}\
(detachedCriteria, PaginationSupport.PAGESIZE, 0); BwWSztJ+B
} n/5T{ NfG
1- s(v)cxh
public PaginationSupport findPageByCriteria wH o}wp
"KP]3EyPc
(final DetachedCriteria detachedCriteria, finalint eTp|!T
|iHMAo
startIndex){ / rc[HbNg.
return findPageByCriteria Wm6qy6HR
AE77i,Xa
(detachedCriteria, PaginationSupport.PAGESIZE, \:J=tAC
[=(8yUV'G
startIndex); }e$
} */M`KPW
e El)wZ,A
public PaginationSupport findPageByCriteria =\.*CY|;N
Np+PUu>
(final DetachedCriteria detachedCriteria, finalint +Xs E
j2Dw7"f3
pageSize, BFW b0;+
finalint startIndex){ kAEq +{h
return(PaginationSupport) I*N"_uKU
|qMG@
getHibernateTemplate().execute(new HibernateCallback(){ 5c]:/9&
publicObject doInHibernate *Mhirz%iD
/8e}c`
(Session session)throws HibernateException { <{cY2cx~3
Criteria criteria = S&}7XjY
QZ&(e2z
detachedCriteria.getExecutableCriteria(session); Xeq9Vs zg
int totalCount = m&gd<rt/
j<~Wp$\i7>
((Integer) criteria.setProjection(Projections.rowCount f/J/tt
>Y08/OAI.2
()).uniqueResult()).intValue(); E'aOHSAg
criteria.setProjection `*vO8v
\B4H0f
(null); fc3 nQp7
List items = }%Mdf6LS64
1]:,Xa+|S
criteria.setFirstResult(startIndex).setMaxResults mzK0$y#*o
p*c(dkOe8
(pageSize).list(); 'l^Bb#)"
PaginationSupport ps = ;=,-C;`
yDqwz[v b
new PaginationSupport(items, totalCount, pageSize, 7_ix&oVI
k3$'K}=d
startIndex); xZ {6!=4!
return ps; sR9$=91`
} 3`reXms*{
}, true); "v:k5a(
} Nx.9)MjI
ltuV2.$
public List findAllByCriteria(final @
3=pFYW)
dnLjcHFj&
DetachedCriteria detachedCriteria){ c]Epg)E
return(List) getHibernateTemplate @}4>:\es
~Yd[&vpQ
().execute(new HibernateCallback(){ hOB<6Tm[
publicObject doInHibernate 8~O#@hB~3
clU ?bF~e1
(Session session)throws HibernateException { W~mo*EJ'^
Criteria criteria = w0g@ <(
3
@]n8*n
detachedCriteria.getExecutableCriteria(session); L!xFhVA<
return criteria.list(); ~}b0zL
} 3yRvs;nWS
}, true); d=bKNA90
} 2B$dT=G
neu+h6#H
public int getCountByCriteria(final HjK8y@j
q+9^rQ
DetachedCriteria detachedCriteria){ 68?&`/t
Integer count = (Integer) FBl,Mky
sX6\AYF1M
getHibernateTemplate().execute(new HibernateCallback(){ :? B4q#]N
publicObject doInHibernate >Y4^<!\v
o`n8Fk}i
(Session session)throws HibernateException { Xd:{.AXW
Criteria criteria = &C
MBTY#u
q*lk9{>
detachedCriteria.getExecutableCriteria(session); N>3{!K>/Y:
return (DvPdOT+3
H&ek"nP_
criteria.setProjection(Projections.rowCount \9,lMK[b
a.<XJ\
()).uniqueResult(); RTVU3fw
}
6xx.Z3v
}, true); JYNnzgd
return count.intValue(); EC$F|T0f
} ?:/J8s
[O
} di_UJ~
>A D!)&c
?M4ig_
oU1N>,
2#$7!`6K
<9>L^GgXA
用户在web层构造查询条件detachedCriteria,和可选的 kq=Htbv7
P4"BX*x
startIndex,调用业务bean的相应findByCriteria方法,返回一个 2n>mISy+
w;@v#<q6
PaginationSupport的实例ps。 vULDKJNHX
^kK")+K
ps.getItems()得到已分页好的结果集 S".|j$
ps.getIndexes()得到分页索引的数组 _K?v^oM#
ps.getTotalCount()得到总结果数 NblPVxS
ps.getStartIndex()当前分页索引 NUiv"tAY
ps.getNextIndex()下一页索引 H8"RdKwg?
ps.getPreviousIndex()上一页索引 K
@&c
Ow?~+)
4
]NaH *\q
&O+S[~
Wp
=
]YO
]gHrqi%
n. N0Nhd
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 kxe{HxM$Z
9Q(Lnu
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 _@\-`>J
>H euf"V
一下代码重构了。 y46sL~HRv
I@N/Y{y#
我把原本我的做法也提供出来供大家讨论吧: n=rmf*,?
Dp*:oMATx0
首先,为了实现分页查询,我封装了一个Page类: CA|W4f}
java代码: ;(E]mbV'=
'GW~~UhdW
#lFsgb
/*Created on 2005-4-14*/ *@lVesC2
package org.flyware.util.page; lnl>!z
%QDAog
/** ^,'KmZm=
* @author Joa /FTP8XHwL)
* \K2S.j
*/ ]\ZJaU80I~
publicclass Page { cPL6(&7
U>n.+/ss
/** imply if the page has previous page */ )@B!
privateboolean hasPrePage; sFfargl
1N]-WCxQ
/** imply if the page has next page */ 1(aib^!B
privateboolean hasNextPage; !=vsY]
&_QD1 TT
/** the number of every page */ !Y^B{bh
privateint everyPage; G^P9_Sw]d3
}e"2Nc_UG
/** the total page number */ IH=%%AS
privateint totalPage; r,,* k E
V-%jSe<
/** the number of current page */ xjDaA U,
privateint currentPage; [A uA<
}i;!p
Ue$
/** the begin index of the records by the current (ia+N/$u
4GJx1O0Ol
query */ 7m(9|Y:Q.
privateint beginIndex; ]nS9taEA
j}%C;;MPH
0ZAtBq.s
/** The default constructor */ ac43d`wpK
public Page(){ KmF+3g~#s
L@ N\8mf
} rt! lc-g%/
gepYV}
/** construct the page by everyPage .GDY
J9vi
* @param everyPage L~M6ca"
* */ q>a/',m
public Page(int everyPage){ oM}P Wf-
this.everyPage = everyPage; bsWDjV~
} 6~Zq
!\Q/~p'jS
/** The whole constructor */ FefS]G
public Page(boolean hasPrePage, boolean hasNextPage, }?d
l.=eq
1B`0.M'd
@aoHz8K
int everyPage, int totalPage, `yb,z
int currentPage, int beginIndex){ yc$8X sns
this.hasPrePage = hasPrePage; 5~omZ,qe
this.hasNextPage = hasNextPage; !B*d,_9c
this.everyPage = everyPage; <Y#EiC.
this.totalPage = totalPage; IPh_QE2g
this.currentPage = currentPage; ~u80v h'
this.beginIndex = beginIndex; pdR&2fp
} ld23^r
,OO0*%
/** 6n.C!,Zmn
* @return N5GQ2V
* Returns the beginIndex. A!5)$>!o
*/ !eB&3J
publicint getBeginIndex(){ )x&}{k6 %
return beginIndex; `ZAGseDd~
} !*|`-woE
A?OaP
/** tB{O6=q
* @param beginIndex R<-(
* The beginIndex to set. c_bIadE{
*/ 8|p*T&Cn&
publicvoid setBeginIndex(int beginIndex){ !xh.S#B
this.beginIndex = beginIndex; K1Wiiw
} H`ZUI8-
lo!_;`v=U
/** 6tmn1:
* @return E MKv)5MH
* Returns the currentPage. ng[ZM);
*/ {oN7I'>
publicint getCurrentPage(){ 8U>f/dxLOO
return currentPage; :<Y, f(c
} m-No 8)2yA
"# mr?h_
/** B?J#NFUb
* @param currentPage x5}Ru0Z
* The currentPage to set. VDq?,4Kb
*/ g&V1<n\b+
publicvoid setCurrentPage(int currentPage){ eu|cQ^>
this.currentPage = currentPage; GoNX\^A
} BI-xo}KI
f#UT~/~bL2
/** Ey!+rq}
* @return
( XoL,lJ
* Returns the everyPage. n089tt=TE
*/ xW\iME
publicint getEveryPage(){ 3Vl?;~ :5
return everyPage; |};P"&
} Fh4kd>1D
t)O$W
/** ,9W|$2=F
* @param everyPage "?GA}e"R
* The everyPage to set. 4b B)t#
*/ SablF2doa
publicvoid setEveryPage(int everyPage){ wQX,a;Br
this.everyPage = everyPage; UmSy p\i
} $5`P~Q'U
;|f|d?Q\
/** s1xl*lKX%
* @return E1'HdOh&z
* Returns the hasNextPage. WBgS9qiB
*/ |Psi?'4
publicboolean getHasNextPage(){ ~4\J}Kn
return hasNextPage; Re{vO&.
} 3U0>Y%m| ,
p#UrZKR
/** tB_GEt2M
* @param hasNextPage e:E:"elr]
* The hasNextPage to set. >'^Tp7\
*/ Pvq74?an`
publicvoid setHasNextPage(boolean hasNextPage){ |<l
sv
this.hasNextPage = hasNextPage; |Fk>NX
} gUs.D_*
|?=K'[5
/** m?]XNgT
* @return tO$/|B74Bz
* Returns the hasPrePage. \Q"j^4
*/ ykv,>nSXLL
publicboolean getHasPrePage(){ o.ntzN
return hasPrePage; )A}u)PH4O
} HrH-e=j
~.?,*q7
/** Lj"@JF;c
* @param hasPrePage "&s9;_9
* The hasPrePage to set. Fy^=LrH=D
*/ a7+w)]r
publicvoid setHasPrePage(boolean hasPrePage){ p0jQQg
this.hasPrePage = hasPrePage; ;by`[)
} M<R3Jz T
K!c "g,S
/** PT7-_r
* @return Returns the totalPage. tONX<rA|]
* 5hN`}Ve
*/ 50#iC@1
publicint getTotalPage(){ ?6;9r[ p
return totalPage; `52+.*J+%
} N8!V%i?
_?"P<3/iF
/** N?Byp&rqI<
* @param totalPage V(hM@ztN
* The totalPage to set. YIjY?
*/ AI{Tw>hZ
publicvoid setTotalPage(int totalPage){ V2As 5
this.totalPage = totalPage; I!FIV^}Z(
} .ME>ICA
}^!8I7J.
} 37OU
pZo:\n5o
<$6r1y*G
6V{Sf9V|
87; E#2
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 F|+Qi BO
RLy(Wz3%
个PageUtil,负责对Page对象进行构造: z TYHwx
java代码: rC`pTN
?A4zIJ\
S T#9auw
/*Created on 2005-4-14*/ [{iPosQWj
package org.flyware.util.page; L|B/'
LqNt.d @
import org.apache.commons.logging.Log; Yatd$`,hW
import org.apache.commons.logging.LogFactory; X:N`x
_"_
21uB
/** > 2)@(f~g
* @author Joa 4eFqD;
* WP5cC@x
*/ WC&V9Yk
publicclass PageUtil { Fru&-T[
w)C/EHF
privatestaticfinal Log logger = LogFactory.getLog #mT\B[4h
z):LF<
(PageUtil.class); O*Gg57a
55Pe&V1=
/** 4S%s=vw
* Use the origin page to create a new page JM&`&fsOC{
* @param page '80mhrEutG
* @param totalRecords azhilUD8
* @return o,r72>|
*/ |Y-{)5/5}
publicstatic Page createPage(Page page, int M `O=rH
}
Nm{+!}cC
totalRecords){ ;H' ,PjU
return createPage(page.getEveryPage(), 7)RDu,fx
D02'P{
page.getCurrentPage(), totalRecords); S_eD1iY2-
} dDu8n+(8 L
ZVX1@p
/** As{Q9o5j/
* the basic page utils not including exception %I^schE*
/1y\EEc
handler 14~#k%zO(
* @param everyPage t.rlC5
k
* @param currentPage .8%&K0
* @param totalRecords D6I-:{ws
* @return page ;S_Imf0$v
*/ R$Rub/b6
publicstatic Page createPage(int everyPage, int p=XEMVqm
c9ye[81
currentPage, int totalRecords){ "cZ ){w
everyPage = getEveryPage(everyPage); 1La?x'{2MP
currentPage = getCurrentPage(currentPage); @
^q}.u`
int beginIndex = getBeginIndex(everyPage, c)j60y
<)$e*HrI
currentPage); Nf5zQ@o_y
int totalPage = getTotalPage(everyPage, +@^FUt=tq
-<6b[YA
totalRecords); %zKTrsMZ
boolean hasNextPage = hasNextPage(currentPage, SpO%nZ";g8
j'uzjs[
totalPage); ]."t
boolean hasPrePage = hasPrePage(currentPage); 6ys|'<?
+Pc2`,pw|
returnnew Page(hasPrePage, hasNextPage, Fy*t[>
everyPage, totalPage, 5(>ux@[qI:
currentPage, HIqe~Vc
6Z@?W
beginIndex); a9uMgx}
} F2>W{-H+
'F%h]4|1
privatestaticint getEveryPage(int everyPage){ P(bds
return everyPage == 0 ? 10 : everyPage; lqcPV) n
} (j(hr'f
<CcSChCg
privatestaticint getCurrentPage(int currentPage){ 782 oXyD
return currentPage == 0 ? 1 : currentPage; E{'Y>gB6
} kr\#CW0?
ok1w4#%,
privatestaticint getBeginIndex(int everyPage, int Sa-" G`
N^{}Qvrr
currentPage){ #z61I"kU
return(currentPage - 1) * everyPage; (sW$2a
} 1j]vJ4R_\
pK"iTc#\X
privatestaticint getTotalPage(int everyPage, int RGLJaEl !
L=@8Zi!2<
totalRecords){ ?X+PNw|pf
int totalPage = 0; U]&/F{3
im
8{
+KNqz
if(totalRecords % everyPage == 0) V$_.&S?(Y
totalPage = totalRecords / everyPage; GMY[Gd
else bt"5.nm
totalPage = totalRecords / everyPage + 1 ; gDjAnz#
k*rG^imX
return totalPage; E&ReQgBft
} mLV0J '
q26qY5D
privatestaticboolean hasPrePage(int currentPage){ /&E]qc*-p
return currentPage == 1 ? false : true; k/M{2Po+
} R"{P#U,HNO
5,BvT>zFY
privatestaticboolean hasNextPage(int currentPage, YB_fy8Tfx
dtBr#Te
int totalPage){ *|^||
bd
return currentPage == totalPage || totalPage == T5-Yqz
v=daafO
0 ? false : true; zhe~kI
} O[$XgPM
HOr Xxxp1^
gX`C76P!
} sw50lId
oz%{D@CF
4WPco"xH!
bduHYs+rq
SB:z[kfz|
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 a{Y8hR
(/S6b
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 y"iK)SH
5'[yw:P-8
做法如下: 4m%Yck{R
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 _z\qtl~3
;<=z^1X9
的信息,和一个结果集List: T#KVN{O
java代码: ;)vs=DK:)
4 g8t
_`Dz%(c
/*Created on 2005-6-13*/ /PpZ6ne~[
package com.adt.bo; mj ,Oy
keJ-ohv)
import java.util.List; !>fi3#Fi
16"L;r
import org.flyware.util.page.Page;
r@Xh8
r;
N.vkM`Z
/** 5*O]`Q7
* @author Joa \*#E4`Y
*/ sUZ2A1J}
publicclass Result { ?SX0e(+}}
o}Zl/&(
private Page page; d 1 O+qS
_@Y17L.
private List content; ;(s.G-9S
k~]\kv=
/** nIl<2H]F`
* The default constructor kZQ$Iv+^(
*/ -];Hb'M.!e
public Result(){ &>Z p}.V
super(); CWkAc5
} /4 .]L~
GFZx[*+%%z
/** zTze%
* The constructor using fields G 'CYvV
* :Ek3]`q#
* @param page ~{D:vj4>
* @param content *B+YG^Yu^
*/ {#l@9r%
public Result(Page page, List content){ '~7 6Y9mv
this.page = page; ;{rl
Y>
this.content = content; {\kDu#18Ld
} u
&{|f
_LLE~nUK"/
/** BtP*R,>
* @return Returns the content. tHo/Vly6Z
*/ }J:WbIr0!
publicList getContent(){ ]K%D$x{+\
return content; Y0nuwX*{
} g%d&>y?1r
yXA]E.K!
/** RH<C:!F^
* @return Returns the page. 0Y\7A
*/ D"n
3If%
public Page getPage(){ |Vc:o_n7
return page; @_Ly^'
"
} ]TKM.[[
h9 3
/** s}":lXkrw
* @param content /J'dG%
* The content to set. <*&2b
*/ 0N3S@l#,\A
public void setContent(List content){ [u`9R<>c"U
this.content = content; +yu^Z*_
} q,eXH8 x
N%`Eq@5
/** wB W]w
* @param page V~qlg1h
* The page to set. oNBYJ]t
*/ :#p!&Fi
publicvoid setPage(Page page){ zf^F.wW
this.page = page; atWAhN
} rDWqJ<8
} h3:dO|Z
:n<<hR0d
S#,
E)h/
}!g^}BWWp
eEkbD"Q
2. 编写业务逻辑接口,并实现它(UserManager, '|N9xLm
We,~P\g
UserManagerImpl) '5"`H>[
java代码: k`Ifd:V.y
YNi3oG]h
:j0r~*z-
/*Created on 2005-7-15*/ ZN?UkFnE
package com.adt.service; afa7'l=^i
&za~=+
import net.sf.hibernate.HibernateException; 6~v|pA jY
B%Spmx8
import org.flyware.util.page.Page; BpKgUwf;C
i&?do{YQ)
import com.adt.bo.Result; .J3Dk=/
5zH?1Z~*
/** bbU{ />yW
* @author Joa L3-tD67oa
*/ ~V4&l3o
publicinterface UserManager { 2 9=L7
8"g.Z*
public Result listUser(Page page)throws ]%5DuE\M8\
i3} ^j?jA2
HibernateException;
*u%4]q
Ng3 MfbFG
} GlVD!0
l`R/WC
0oi
=}lV
cTeEND)
#ab=]}2W_g
java代码: W@x
UR-}51
7=ZB?@bU~
=/rIXReY
/*Created on 2005-7-15*/ <j.bG 7
package com.adt.service.impl; 3J{`]v5`
\}e1\MiZ
import java.util.List; WeTs va+
rE
bC_<
import net.sf.hibernate.HibernateException; ?q<"!U|e
mu/O\'5
import org.flyware.util.page.Page; ?Q]{d'g(sx
import org.flyware.util.page.PageUtil; }I'g@Pw9[
MD,}-m
import com.adt.bo.Result; 6 /Apdn1[
import com.adt.dao.UserDAO; XY8s \DK
import com.adt.exception.ObjectNotFoundException; G8lR_gD"!
import com.adt.service.UserManager; {qCmZn5
p_jDnb#
/** g(Jzu'
* @author Joa <;.Zms${@
*/ o~F @1
publicclass UserManagerImpl implements UserManager { 'Z+~G
Q+[e)YO)
private UserDAO userDAO; d\dt}&S 5
|wZ8O}O{E
/** v3+\Aq
* @param userDAO The userDAO to set. 78\:{i->ta
*/ {@9y%lmrh
publicvoid setUserDAO(UserDAO userDAO){ ~: f9,
this.userDAO = userDAO; rs3Uk.Z^'
} 5[M?O4mi
/}Y>_87
/* (non-Javadoc) >yn%.Uoh@
* @see com.adt.service.UserManager#listUser |Q^ZI
$LZf&q:\]*
(org.flyware.util.page.Page) PqIGc
*/ dvk?A$
public Result listUser(Page page)throws l'(Cxhf.W
m El*{]
HibernateException, ObjectNotFoundException { l/_3H\iM
int totalRecords = userDAO.getUserCount(); d(w
$! $"h
if(totalRecords == 0) t#~r'5va
throw new ObjectNotFoundException cX@~Hk4=\
LF0gy3
("userNotExist"); hq/\'Z&!+P
page = PageUtil.createPage(page, totalRecords); hFP$MFab
List users = userDAO.getUserByPage(page); Roy0?6O
returnnew Result(page, users); 5,'?NEyw
} vfJ}t#%UH
UHz*Tfjb
} {>G\3|^D
3KfZI&g
abUn{X+f~
7Rj!vj/
Gu<3*@Ng
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 cU5x8[2
\0Zm3[
询,接下来编写UserDAO的代码: 9tXLC|yl?
3. UserDAO 和 UserDAOImpl: N<:5 r
java代码: t(CdoE,6
J
/'woc
S)z
jfJR
/*Created on 2005-7-15*/ X",fp
package com.adt.dao; z?h\7
R
O1coay
import java.util.List; :N%cIxrqP
)ye[R^!}
import org.flyware.util.page.Page; Fg?Gx(g4
o)cd!,h
import net.sf.hibernate.HibernateException; +}>whyX1
(80]xLEBL
/** EKk~~PhW 8
* @author Joa ()K%Rn
*/
C+,;hj
publicinterface UserDAO extends BaseDAO { \^?BC;s^C
4>{q("r,
publicList getUserByName(String name)throws PX[taDN
{LY$
HibernateException; ?
8S0
rZe"*$e
publicint getUserCount()throws HibernateException; *(s+u~, I
i=reJ(y-
publicList getUserByPage(Page page)throws 75@){ :
T^aEx.`O}`
HibernateException; "4H&wHhT!
06pLa3oi
} f/?#
1
AGn:I??
\)DP(wC
5P
-IZ8~$
RERum
java代码: R(=Lhz6R4
#DwTm~V0"
q*Yh_IT.I
/*Created on 2005-7-15*/ $91c9z;f^
package com.adt.dao.impl; cG,B;kMjo
OTL=(k
import java.util.List; q0.+ F4
@ ILG3"
import org.flyware.util.page.Page; ln'7kg
G7pj.rQ
import net.sf.hibernate.HibernateException; ly}6zOC\
import net.sf.hibernate.Query; %(Nu"3|$K=
qWHH%
L;
import com.adt.dao.UserDAO; +e`f|OQ
(i1FMd}G
/**
.rD@Q{e50
* @author Joa x<"1T
w5e
*/ 05LVfgJ'q
public class UserDAOImpl extends BaseDAOHibernateImpl IBcCbNs!
\ZigG{
implements UserDAO { 7qA0bUee5
L|qQZ=
/* (non-Javadoc) gV):3mWC
* @see com.adt.dao.UserDAO#getUserByName JaXT
B"e
?5Wj y
(java.lang.String) tU>wRw=d
*/ (#BkL:dg
publicList getUserByName(String name)throws EQSOEf[
xM8}Xo
HibernateException { ';hU&D;s
String querySentence = "FROM user in class $]%;u: Sa
HlqCL1\<
com.adt.po.User WHERE user.name=:name"; #25Z,UU
Query query = getSession().createQuery Al09R,I;
^G[xQcM73
(querySentence); Sav]Kxq{
query.setParameter("name", name); Ds9pXgU(Z
return query.list(); %2f``48#
} ^I~2t|}
d=o|)kV
/* (non-Javadoc) A07g@3n
* @see com.adt.dao.UserDAO#getUserCount() J_C<Erx[O
*/ );_g2=:#
publicint getUserCount()throws HibernateException { 5DK>4H:
int count = 0; +(x^5~QX
String querySentence = "SELECT count(*) FROM .X\p;~H
5
X|q&0W=
user in class com.adt.po.User"; k*(c8/<.d
Query query = getSession().createQuery ^ llZf$`
n .ZLR=P4
(querySentence); ];Z)=y,vM
count = ((Integer)query.iterate().next :'91qA%Wr
:6S!1roi
()).intValue(); _G|hKk^,
return count; Yz=(zj
} %'a%ynFs
"+/%s#&
/* (non-Javadoc) N:GS fM@g
* @see com.adt.dao.UserDAO#getUserByPage F B9PIsFS
seC]=UJh#>
(org.flyware.util.page.Page) 4sasf94
*/ |iKk'Rta4
publicList getUserByPage(Page page)throws mE'y$5ZxY
GR@!mf
HibernateException { -$**/~0zU
String querySentence = "FROM user in class 91qk0z`N
k"\%x=#
com.adt.po.User"; nDuf<mw
Query query = getSession().createQuery 'bJ!~ML&
NdGIH/Y;M
(querySentence); LSQWveZz
query.setFirstResult(page.getBeginIndex()) C,~wmS )@
.setMaxResults(page.getEveryPage()); R''nZ/R
return query.list(); zI$^yk-vn
} 6E/>]3~!
gF-<%<RV
} >/mi#Y6
0D/u`-
B4 yU}v
w`=_|4wFw
~XN--4%Q
至此,一个完整的分页程序完成。前台的只需要调用
UhN16|x
L9Sd4L_e
userManager.listUser(page)即可得到一个Page对象和结果集对象 [ -"o5!0<
d0Xb?-
}3M
的综合体,而传入的参数page对象则可以由前台传入,如果用 =F'p#N0_2
yI/2 e [
webwork,甚至可以直接在配置文件中指定。 $&~/`MxE
fZ1v|
下面给出一个webwork调用示例: oNQ;9&Z,^2
java代码: kP~'C'5Ys
59mNb:<
~,+n_KST;
/*Created on 2005-6-17*/ E
.^5N~.
package com.adt.action.user; nfpkWyI u{
_J(n~"eR
import java.util.List; ?T=]?[
D,q=?~
import org.apache.commons.logging.Log; 1{+x >Pv:
import org.apache.commons.logging.LogFactory; nX4R
import org.flyware.util.page.Page; BC*vG=a
uT'_}cw
import com.adt.bo.Result; F}3<q
import com.adt.service.UserService; VH[r@Pn
import com.opensymphony.xwork.Action; L08>9tf`
W%LTcm
/** 2{;&c
* @author Joa ?~~sOf AP
*/ zvjVM"=G
publicclass ListUser implementsAction{ f?8cO#GU
o&uO ]
privatestaticfinal Log logger = LogFactory.getLog 'f&o%5]
Ft%HWGE
(ListUser.class); r>73IpJI
{Hncm
private UserService userService; 06DT2
r_C|gfIP
private Page page; =B4,H=7Spf
1=BDqSZ@9
privateList users; lOIBX@K E
<!b~7sZkTc
/* +Qy*s1fit
* (non-Javadoc) ?#8',:
* ]=\Mf<
* @see com.opensymphony.xwork.Action#execute() L%](C
*/ $YZsaw
publicString execute()throwsException{ Y[%1?CREP
Result result = userService.listUser(page); Rs+rlJq
page = result.getPage(); +5J "G/f
users = result.getContent(); k.bzh.
return SUCCESS; *hVbjI$
} tP; &$y.8
u I$|M
/** s( @w1tS.
* @return Returns the page. FR~YO|4?
*/ 5
o:VixZf
public Page getPage(){ yXU-@~
return page; NGYliP,.6
} ,w~0U
H I/]s^aL
/** m"Y;GzqQl
* @return Returns the users. 6OYXcPW'
*/ ,#3}TDC
publicList getUsers(){ =Y`P}vI]w%
return users; cBf9-k
} @$FE}j_
M99#\0=/
/** /lAB
* @param page p:M#F:
* The page to set. x_9<&Aj6
*/ TR!^wB<F
publicvoid setPage(Page page){ 9k\`3SE
this.page = page; }* iag\
} B{|g+c%
J6x\_]1:*
/** j,Sg?&"%=
* @param users W-wy<<~f
* The users to set. H
<CsB
*/ QX(x6y>Q
publicvoid setUsers(List users){ EubR]ckB
this.users = users; ?f v?6r
} `x:znp} '
PoMkFG6
/** M0!;{1
* @param userService o?\)!_Z|
* The userService to set. gr %8
O-n
*/ ?]gZg[
publicvoid setUserService(UserService userService){ 4GJ1P2
this.userService = userService; <4jQbY;
} zx^]3}
} kTQ:k
}%B
b ABx'E
9@AGx<S1
3nuf3)
H e]1<tx
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, `}o4 &$
`NA[zH,w3
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 WtI1h `Fo
r`u}n
么只需要: pM~Xh ]/
java代码: R_h(Z{d
j&E4|g (
K#M
h
<?xml version="1.0"?> /H.QGPr
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork mY-Z$8r
||
?B1
1.0//EN" "http://www.opensymphony.com/xwork/xwork- GkMNV7"m
J#Fe"
1.0.dtd"> iU^ 4a
2'g< H-[
<xwork> 7=XQgbY/
aKs!*uo0H
<package name="user" extends="webwork- hTI8hh
BOJh-(>I
interceptors"> \Ekez~k{`
3(P^PP8
<!-- The default interceptor stack name "_+X#P
x
@_YEK3l]l
--> FW7+!A&F
<default-interceptor-ref o^~6RZ
Y~1}B_
name="myDefaultWebStack"/> R7*Jb-;$!
sb4)@/Q7j
<action name="listUser" )ufHk
~C5iyXR
class="com.adt.action.user.ListUser"> *pP"u::S
<param L1BpkB
Lhl)p P17
name="page.everyPage">10</param> x$CpUy{6
<result :w_F<2d0
0
AX**q$'R
name="success">/user/user_list.jsp</result> d_J?i]AP|'
</action> 0!=e1_
!|_
CXm
T|
</package> wI>JOV7
E E?v~6"&
</xwork> ,2JqX>On>Y
;0E"4(S.q1
qh$D;t1=
q^sMJ
6uDA{[OH
*"
<tFQ
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 jbIWdHZ/US
js`zQx'
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。 QXJD'c
$ajw]2kx
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 y NV$IN%
JoW*)3Z
XeDU
,
PkDL\Nqe
u-UUF
我写的一个用于分页的类,用了泛型了,hoho iN<5[ztd
^S ,E "Q
java代码: k6JB%m\E
ZfT%EPoZ:
} Q1$v~
package com.intokr.util; `RGZ-Q{_
lNsPwyCoj
import java.util.List; h83ho
~$r^Ur!E\
/** pE `Q4:<A
* 用于分页的类<br> 1bzPBi
* 可以用于传递查询的结果也可以用于传送查询的参数<br> S-2xe?sb
* w** .8]A"N
* @version 0.01 h>mQ; L
* @author cheng 7]e]Y>wZap
*/ $#R.+B
public class Paginator<E> { &tMvs<q,
privateint count = 0; // 总记录数 mf}?z21vD
privateint p = 1; // 页编号 nr&G4t+%Hv
privateint num = 20; // 每页的记录数 czMLvPXRx
privateList<E> results = null; // 结果 GsDSJz
@TgCI`E
/** !LIWoa[ F.
* 结果总数 :@:R4Ac
*/ EzNmsbtZ(
publicint getCount(){ aF'Ik XG d
return count; 0RoI`>j'
} =1yUH9\,b
K:'pK1zy
publicvoid setCount(int count){ &)s
A(
this.count = count; ?'T>/<(
} 00;=6q]TA
$6y1';A
/** ;uoH+`pf
* 本结果所在的页码,从1开始 ][G<CO`k
* ybS7uo
* @return Returns the pageNo. ~-M7
*/ c"O\fX
publicint getP(){ EiJSLL
return p; 9,y&?GLP
} @Wx_4LOhf
d=>5%$:v
/** |AFF*]e S
* if(p<=0) p=1 HwU \[f
* =z=Guvcn`
* @param p ;U20g:K
*/ gVG :z_6
publicvoid setP(int p){ i}wu+<Mk
if(p <= 0) PFPfLxna
p = 1; #h r!7Kc;N
this.p = p; +,|-4U@dl
} k.lnG5e
<CA
lJ
/** l>=c]
* 每页记录数量 /u #9M {
*/ (9cIU2e
publicint getNum(){ L3<XWpv
return num; #e9B|Y?b
} .5dZaI)
,Y`C7Px
/** 8tdUnh%/
* if(num<1) num=1 Upv2s:wa}z
*/ Z&.FJZUP
publicvoid setNum(int num){ 8AefgjE
if(num < 1) iOJgZuP
num = 1; G %#us3x
this.num = num; {Ua5bSbh
} :_e.ch:4
7PisX!c,h
/** (yX Vp2k
* 获得总页数 @8CD@SDv
*/ Vm6^'1CY
publicint getPageNum(){ B'
:ZX-Q)
return(count - 1) / num + 1; M.IV{gj
} (>8fcQUBb
lZ.,"F@
/** %hTe%(e
* 获得本页的开始编号,为 (p-1)*num+1 Ko%rB+d
*/ +pFz&)?
publicint getStart(){ aoJ&< vl3
return(p - 1) * num + 1; 2#E;5UYu
} >Y\4v}-
R 7{r Y
/** KK] >0QAY
* @return Returns the results. PkVXn
*/ XBr>K>(
publicList<E> getResults(){ lhjPS!A~
return results; bX6*/N
} C u?$!|V
ZO;]Zt]
public void setResults(List<E> results){ N\Hd3Om
this.results = results; QU#/(N(U#T
} ;J5oO$H+68
X'u`\<&W
public String toString(){ ~]yqJYiid^
StringBuilder buff = new StringBuilder IcIMa
PAc~p8S
();
"Km`B1f`
buff.append("{"); +Rh'VZJs
buff.append("count:").append(count); J`V6zGgW
buff.append(",p:").append(p); V2y[IeSQ
buff.append(",nump:").append(num); T }8aj
buff.append(",results:").append HwGtLeB"
jG^~{7#
(results); # / 4Wcz<
buff.append("}"); zCQv:.0L
return buff.toString(); cbteNA!>
} ::5-UxGL<2
S4(IYnwN
} 1";~"p2(
MUo?ajbqOd
<T}#>xHs3