Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 1r};cY6
-8Hc M\b
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 _5H~1G%q
U[|5:qWs
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 3tCTPZy
tjwnFqI
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 Q"B8l[
6^t#sEff]
。 o[}Dj6e\t
\|9B:y'y
分页支持类: sQj]#/yK:
$,J0) ~
java代码: 4H(8BNgzV
+7o1&D*v
P3]K'*Dyd
package com.javaeye.common.util; c|JQ0] K
LT
Pr8^
import java.util.List; hRRxOr#*$
,(a~vqNQW3
publicclass PaginationSupport { ]{q=9DczG(
Nf<f}`
publicfinalstaticint PAGESIZE = 30; Lui6;NY
Q(cLi:)X2
privateint pageSize = PAGESIZE; e@
D}/1~=
rAAx]nQ@
privateList items; deArH5&!
rdd-W>+
privateint totalCount; x s\<!
38T]qz[Sn
privateint[] indexes = newint[0]; Y.) QNTh
-(F}=o'
privateint startIndex = 0; /FE+WA}r
#*/nUbsg
public PaginationSupport(List items, int pi~5}bF!a
05k'TqT{c
totalCount){ #O!2
setPageSize(PAGESIZE); z,$uIv}'@
setTotalCount(totalCount); S6(48/
setItems(items); @--"u_[
setStartIndex(0); -3mIdZ
} v@ OELJX
Z^2SG_pD
public PaginationSupport(List items, int x?V^l*
t6\H
totalCount, int startIndex){ Pg8boN]}
setPageSize(PAGESIZE); kmC0.\
setTotalCount(totalCount); g%"SAeG<K
setItems(items); l[IL~
setStartIndex(startIndex); z[1uub,)1
} :d9GkC
;M0`8MD
public PaginationSupport(List items, int ,hu@V\SKv
HZ%V>88
totalCount, int pageSize, int startIndex){ wkGr}
setPageSize(pageSize); u &1M(~Ub=
setTotalCount(totalCount); i8k} B
o
setItems(items); fMFkA(Of^
setStartIndex(startIndex); &"JC8
} yQUrHxm
jvsSP?]n
publicList getItems(){ Be]z @E1x
return items; 3))CD,|
} $(;Ts)P
b#p0s?*
publicvoid setItems(List items){ .tLRY
this.items = items; v~Dobk/n
} a'|]_`36x
[KYq01cj
publicint getPageSize(){
8|{ZcW
return pageSize; s=-?kcoJ2d
} 6]%=q)oL[
P8ej9ULX,
publicvoid setPageSize(int pageSize){ @}H'2V
this.pageSize = pageSize; ]gVA6B?&9
} Q2Ey RFT
)s^gT]"N
publicint getTotalCount(){ ]S s63Vd
return totalCount; &odQ&%X
} Zf}2c8Vc4
W|@SXO)DY
publicvoid setTotalCount(int totalCount){ 72xf|s=
if(totalCount > 0){ h ChO
this.totalCount = totalCount; yN{**?b
int count = totalCount / jZqa+nG51
[dP<A?s
pageSize; ]~dB|WB
if(totalCount % pageSize > 0) ,&4
[`d
count++; 8A]8yX =
indexes = newint[count]; 0'r}]Mws
for(int i = 0; i < count; i++){ >S`=~4
indexes = pageSize * @HMH>;haE
okRt^qe
i; uKXU.u*C
} V.u^;gr3
}else{ vb0Ca+}}
this.totalCount = 0; nRqP_*]
} ufR>*)_+
} sq#C|v/
U:$zlfV
publicint[] getIndexes(){ /_cpSq
return indexes; 3=ME$%f
} 6zU0 8z0-
lY`WEu
publicvoid setIndexes(int[] indexes){ "~=}&
this.indexes = indexes; T<7}IH$6xE
} E#m^.B-}
YK8l#8K
publicint getStartIndex(){ gM1:*YK
return startIndex; M_E$w$l2<
} 7YTO{E6]d\
D&mPYxXL
publicvoid setStartIndex(int startIndex){ F czia0@z
if(totalCount <= 0) %1;Y`>
this.startIndex = 0; 8cY5:plK
elseif(startIndex >= totalCount) K[noW
this.startIndex = indexes K6B6@
s!YX<V
[indexes.length - 1]; *B&i `tq
elseif(startIndex < 0) ]A-LgDsS
this.startIndex = 0; jK6dI
7h
else{ ?P7QAolrr
this.startIndex = indexes L67yL( d6a
',FVT4OMw
[startIndex / pageSize]; /P3Pv"r|8]
} :k.>H.8+~
} JK^%V\m
U/U_q-z]
publicint getNextIndex(){ olo9YrHn
int nextIndex = getStartIndex() + /8_x]Es/
p|;#frj
pageSize; O[1Q#
if(nextIndex >= totalCount) ,82?kky
return getStartIndex(); 2-g 5Gb2|
else d<\X)-"
return nextIndex; +BI%.A`2
} 5 YIk
YL;*%XmAG
publicint getPreviousIndex(){ =}0>S3a.7
int previousIndex = getStartIndex() - \@ZD.d#
Jn?ZJZ
pageSize; P6^\*xkMr
if(previousIndex < 0) ='eQh\T)
return0; #c<F,` gdi
else [e. `M{(TB
return previousIndex; 2+(SR.oGq
} fEK%)Z:0
=1B;<aZH!
} $Ovq}Rexc
:Z;kMrU
"NSY=)fV
p_g8d&]V
抽象业务类 P)=$0kR3
java代码: =snJ+yn!
!qs~j=;y3
G"yhu +
/** G
@L`[Wu
* Created on 2005-7-12 r`0oI66B/
*/ P]4u`&
package com.javaeye.common.business; 14-uy.0[
@DR?^
q p
import java.io.Serializable; It'PWqZtG
import java.util.List; Q?m= a0g
y7R{6W_U>
import org.hibernate.Criteria; ?y* yl
import org.hibernate.HibernateException; %`dVX
EO
import org.hibernate.Session; Y#-pK)EeU
import org.hibernate.criterion.DetachedCriteria; U3>ES"N
import org.hibernate.criterion.Projections; kf",/?s2Z
import H8qAj
3AuLRI
org.springframework.orm.hibernate3.HibernateCallback;
5&U?\YNLa
import $>l65)(E\
<M3&\
org.springframework.orm.hibernate3.support.HibernateDaoS 1NlpOVq:)
^''3}<Ep
upport; 60p*4>^v
zZCssn;[
import com.javaeye.common.util.PaginationSupport; l(tMo7iPa
DoJ3zYEk
public abstract class AbstractManager extends XlxB%
[*=UH*:'N
HibernateDaoSupport { h4M>k{
0s%{m<
privateboolean cacheQueries = false; 2mvp|<"
/(ArA=#
privateString queryCacheRegion; _H2%6t/V
9[\$\l
publicvoid setCacheQueries(boolean %i9*2{e#~
.TRp74
cacheQueries){ \G]vTK3
this.cacheQueries = cacheQueries; qZ+^ND(I
} oJ}$ /_
/u'M7R
publicvoid setQueryCacheRegion(String b;(BMO,(
y"0!7^
queryCacheRegion){ q&k?$rn
this.queryCacheRegion = 3)py|W%X$
Ba|76OBRJ
queryCacheRegion; ivl_=
} UazUr=|e
<Dp[F|r
publicvoid save(finalObject entity){ gtb,}T=1
getHibernateTemplate().save(entity); mt3j$r{_
} 7;:Uv=
o>4GtvA*
publicvoid persist(finalObject entity){ ?pF uV`Zm
getHibernateTemplate().save(entity); }W R?n
} ;=ERm=
{W# VUB
publicvoid update(finalObject entity){ #]o#~:S=
getHibernateTemplate().update(entity); Jro%zZle
} 1|\/2
M6b6lhg
publicvoid delete(finalObject entity){ )eSD5hOI)
getHibernateTemplate().delete(entity); z2A1h!Me
} 1:iT#~n
?`D/#P
publicObject load(finalClass entity, XF N4m #
V\o&{7!
finalSerializable id){ 0j|JyS:}G
return getHibernateTemplate().load w!^{Q'/,Q
PP)-g0^@
(entity, id); iYxpIqWw
} 5PCKBevV
+q3E>K9a
publicObject get(finalClass entity, _"%-=^_
`~3y[j]kO
finalSerializable id){ rwou[QU
return getHibernateTemplate().get APu cA
yY42+%P
(entity, id); |nj,]pA
} b6UD!tXp
jPNm $Y1
publicList findAll(finalClass entity){ 4 '6HX#J
return getHibernateTemplate().find("from VM[Vhk[
%CiZ>`5n#
" + entity.getName()); UDz#?ZWnd
} +gOv5Eno-
:CAbGs:56
publicList findByNamedQuery(finalString ep2#a#&'
aC2\C=ru_
namedQuery){ N-Nq*
return getHibernateTemplate GE[J`?E]
f'<MDLl
().findByNamedQuery(namedQuery); VBK9te,A
} nZ2mY!*
kMLWF
publicList findByNamedQuery(finalString query, wtw
S>pbplE
finalObject parameter){ =9JKg4I6
return getHibernateTemplate 5 J9,/M0
fgSe]q//
().findByNamedQuery(query, parameter); x:)8+Rn}
} SBBi"U:
("L&iu\`@
publicList findByNamedQuery(finalString query, Bzw!,(u/
"
4U;6 2 jq
finalObject[] parameters){ xui.63/
return getHibernateTemplate 0
))W [
+MfdZD
().findByNamedQuery(query, parameters); 8E|
Nf
} >1Y',0v
Xr@]7: ,
publicList find(finalString query){ HsGyNkr?r
return getHibernateTemplate().find 4>&%N\$*
^l4=/=RR
(query); \We\*7^E
} 8 3wa{m:
sSMcF[]@2I
publicList find(finalString query, finalObject }QL 2#R
8&"@6/)[
parameter){ WU
-_Y^
return getHibernateTemplate().find _JjR=
m
O:Fnxp5@
(query, parameter); _8CE|<Cn
} A%pBvULH
#X(KW&;m
public PaginationSupport findPageByCriteria .;0?r9
IE-c^'W=}m
(final DetachedCriteria detachedCriteria){ jCMr[ G=
return findPageByCriteria AVys`{*c
$i+
1a0%n
(detachedCriteria, PaginationSupport.PAGESIZE, 0); Uva
b*9vX
} H)),~<s
t@TBx=16
public PaginationSupport findPageByCriteria \lnps f
Ls#=R
(final DetachedCriteria detachedCriteria, finalint ^f-?xXPx
Q}N.DM@d3
startIndex){ h98_6Dw(]
return findPageByCriteria v^ a.
b
gm63dE>
(detachedCriteria, PaginationSupport.PAGESIZE, Q}a 1P8?S
5m`@ 4%)zp
startIndex); .&AS-">Z
} ~L G).
8 ]N
public PaginationSupport findPageByCriteria q89#Ftkt
uj_ OWre
(final DetachedCriteria detachedCriteria, finalint DA_[pR
%8 )GuxG*
pageSize, tTT./-*0
finalint startIndex){ )pS1yYLj
return(PaginationSupport) 4 |ryt4B
aD aQ7i
getHibernateTemplate().execute(new HibernateCallback(){ cvR|qHNX
publicObject doInHibernate P| o_/BS
dcMWCK
(Session session)throws HibernateException { p4
#U:_
Criteria criteria = 7.n/W|\
=rV*iLy
detachedCriteria.getExecutableCriteria(session); 5TqT`XTzm
int totalCount = ~N+bD
E-NuCP%|c
((Integer) criteria.setProjection(Projections.rowCount <n iq*
NJG-~w
()).uniqueResult()).intValue(); X&1R6O
criteria.setProjection -'FzH?q:
.u3!%{/v(c
(null); Ds4n>V,o
List items = #:{Bd8PS
OXy>Tlv
criteria.setFirstResult(startIndex).setMaxResults S{7*uK3$
4#$~gTc@
(pageSize).list(); qm-G=EX
PaginationSupport ps = x[+t
sjpcz4|K
new PaginationSupport(items, totalCount, pageSize, bE-{
U/;
`p@YV(
startIndex); ~yH<,e
return ps; *~F\k):>
} tN&x6O+@
}, true); 3%?01$k
} %(GWR@mfC
?\dY!
public List findAllByCriteria(final ?lJm}0>
- Dm/7Sxd`
DetachedCriteria detachedCriteria){ 7q>WO
return(List) getHibernateTemplate HhN;&67~Z
.'md `@t
().execute(new HibernateCallback(){ @B;2z_Y!l
publicObject doInHibernate 12\h| S~
C0o0
l>
(Session session)throws HibernateException { <0OZ9?,dm
Criteria criteria = >=|Dir
6Y^UC2TBs
detachedCriteria.getExecutableCriteria(session); }Yt/e-Yg%r
return criteria.list(); CA7 ZoMB#
} hr&&"d {s
}, true); m}\G.$ h4
} p2N;-
D2 o,K&V
public int getCountByCriteria(final 3fJGJW!zu
f>k<I[C<
DetachedCriteria detachedCriteria){ ]iewukB4
Integer count = (Integer) isaDIl;L/
a%"mgCB
getHibernateTemplate().execute(new HibernateCallback(){ '!*,JG5_
publicObject doInHibernate .lVC>UT
jM8e2z3
(Session session)throws HibernateException { lwEJ)Bv
Criteria criteria = $Q,Fr;
B
} 5~|h%
detachedCriteria.getExecutableCriteria(session); nUi
4!|r
return 5[.Dlpa'7
F-?K]t#
criteria.setProjection(Projections.rowCount T8&
kxp
$Hcp.J[O
()).uniqueResult(); 8W$uw~|dw
} aqq7u5O1r
}, true); w=.w*?>
return count.intValue(); PtySPDClj
} %N#8D<ULd
} lP*_dt9
1Wd?AyTY,
USLG G}R
okfGd=
&
}J27Y;Zp9
{-*+G]
用户在web层构造查询条件detachedCriteria,和可选的 :_;9&[H9ha
kwRXNE(k]_
startIndex,调用业务bean的相应findByCriteria方法,返回一个 tz&'!n}
h2g|D(u)
PaginationSupport的实例ps。 ">vxYi
!+tz<9BBY
ps.getItems()得到已分页好的结果集 m\>531&
ps.getIndexes()得到分页索引的数组 U)~?/s{v
ps.getTotalCount()得到总结果数 zPWX%1Qr
ps.getStartIndex()当前分页索引 C$o#zu q-
ps.getNextIndex()下一页索引 T#'+w@Q9{9
ps.getPreviousIndex()上一页索引 \I J\
u_[^gS7
/QDlm>FM4
W99MA5P
7=yC*]BH-=
l:v:f@M&
G}1?lO_d`
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 hA1\+r
{2<A\nW
,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 OQ&?^S`8',
fC>3{@h}*
一下代码重构了。 <k)@PAV
//63?s+
我把原本我的做法也提供出来供大家讨论吧: 1:]iV}OFqR
`2 X~3im
首先,为了实现分页查询,我封装了一个Page类: c e`3&
java代码: qMT7g LB'1
RD_IGV
B9IqX
/*Created on 2005-4-14*/ ~ B0L7}d
package org.flyware.util.page; iXN"M` nhm
Lc ,te1
/** S-{3'D[Nj
* @author Joa F3*]3,&L
* Q+(}nz4
*/ 8&FnXhZg4
publicclass Page { "Ka2jw,
X]6Hgz66
/** imply if the page has previous page */ ?3bUE\p
privateboolean hasPrePage; S2nF13u
j)IXe 0dMC
/** imply if the page has next page */ >SO !{
privateboolean hasNextPage; C' x?riJ/
,c#IxB/0
/** the number of every page */ T_ifDQX;
privateint everyPage; icW?a9 b&
kfER
/** the total page number */ ld58R
privateint totalPage; f,GF3vu"
jUjgxP*7m
/** the number of current page */ Kn~f$1
privateint currentPage; W=YFe<Q
%Od?(m"&
/** the begin index of the records by the current )G$/II9d
IV$pA`|V
query */ s)Bl1\Q
privateint beginIndex; K5-wuD1
lA[BV7.=7
bDI#' F
/** The default constructor */ bqEQP3t^
public Page(){ ~\A(xmW}
uJ jm50R<
} h=6Zvf<x
[<m1xr4"k
/** construct the page by everyPage 7{HJjH!zx
* @param everyPage >r+Dl\R
* */ Q]WjW'Ry\
public Page(int everyPage){ g{K*EL<
this.everyPage = everyPage; ceN*wkGyB
} emp*j@9
a4HUP*
/** The whole constructor */ H^ _[IkuA%
public Page(boolean hasPrePage, boolean hasNextPage, }RX[J0Prq~
L&3Ak}sh
&Rw4ub3
int everyPage, int totalPage, @]r,cPx0Y
int currentPage, int beginIndex){ bdh6ii
this.hasPrePage = hasPrePage; #rSm;'%,
this.hasNextPage = hasNextPage; QDCu
this.everyPage = everyPage; 0M^7#),
this.totalPage = totalPage; _[ml<HW]
this.currentPage = currentPage; f0rM 4"1
this.beginIndex = beginIndex; ^_FB .y%
} ^|yw)N]Q/
s=0z%~H
/** TVVL1wZ
* @return 9\9:)q
* Returns the beginIndex. w"Gci~]bXU
*/ ">='l9
publicint getBeginIndex(){ MY>mP
return beginIndex; G gmv(!
} HGqT"NJr
YTH3t]
&
/** \9Nd"E[B
* @param beginIndex $'D|}=h<Y
* The beginIndex to set. G'b*.\=
*/ -xg$qvK
publicvoid setBeginIndex(int beginIndex){ 9
cU]@j}2
this.beginIndex = beginIndex; J^tLK T B
} !#l>+9
AD_RU_a9
/** +"1@6,M
* @return YlfzHeN1
* Returns the currentPage. @=CN#D12
*/ =
GUgb2TAT
publicint getCurrentPage(){ }7p`8?
return currentPage; ;&mefaFlWp
} _*\:UBZx6
d{^9` J'
/** UI S\t^pJD
* @param currentPage
fFu+P<?"
* The currentPage to set. w1q-bIU
*/ VJW%y)_[
publicvoid setCurrentPage(int currentPage){ V$U#'G>m
this.currentPage = currentPage; om6'%nXhn
} A")F7F31c
t[HfaW1W
/** fBtTJ+51}
* @return !S6zC >
* Returns the everyPage. xUT]6T0dB
*/ hSQ*_#
publicint getEveryPage(){ S ]_iobWK
return everyPage; 1/b5i8I2v
} )b^yAzL?
1F`1(MYt9
/** a3t[Tk;
* @param everyPage P)7:G?OTx
* The everyPage to set. \@")2o+
*/
DZPg|*KT
publicvoid setEveryPage(int everyPage){ \NE~k)`4j%
this.everyPage = everyPage; klkshlk d
} Zb> UY8
S\$=b_.
/** -U&k%X
* @return N %;bV@A9
* Returns the hasNextPage. ^FO&GM2a
*/ IRWVoCc9/\
publicboolean getHasNextPage(){ D(bQFRBY6"
return hasNextPage; ScN'|Ia.-
} =i'APeNaQ
-8Z;s8ACo
/** B=vBJC)
* @param hasNextPage L!/Zw~
* The hasNextPage to set. {tE9m@[AF
*/ {=3&_/9s){
publicvoid setHasNextPage(boolean hasNextPage){ fXo$1!
this.hasNextPage = hasNextPage; =r1-M.*a.M
} b!lS=zIN
5?] Dn k.o
/** qYba%g9RN(
* @return ,)u1r3@I^
* Returns the hasPrePage. NW=gi
qB
*/ )4O>V?B
publicboolean getHasPrePage(){ qcVmt1"
return hasPrePage; V -X*e
} G;jX@XqZ
&9j*Y
/** 2!kb?
* @param hasPrePage $?Dcp^
* The hasPrePage to set. |3]#SqX
*/ zWO!z=
publicvoid setHasPrePage(boolean hasPrePage){ Z;'5A2
this.hasPrePage = hasPrePage; 5MX7V4ist
} T<ka4
E'g?44vyw
/** >;s!X(6b
* @return Returns the totalPage. u{J\X$]
* lZ'ZL*
*/ Xd 5 vNmQn
publicint getTotalPage(){ c3aBPig\D
return totalPage; rbw~Ml0
} qh~$AJ9sB
+o3 ZQ9
/** 9z'(4U
* @param totalPage )\PPIY>iP
* The totalPage to set. 8"=E0(m
*/ ?B{,%2+
publicvoid setTotalPage(int totalPage){ P*!~Z*"
this.totalPage = totalPage; FlyRcj
} zk m#w
-`cNRd0n
} *L{^em#b
rnSrkn"j{
7W.z8>p
4R}$P1 E
`Lj'2LoER
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 M+l~^E0Wj
P[K42mm
个PageUtil,负责对Page对象进行构造: -IE=?23Do?
java代码: "2_nN]%u-
E0t%]?1
UA3!28Y&E3
/*Created on 2005-4-14*/ W.sH
package org.flyware.util.page; /Z1>3=G by
!QsmT3
import org.apache.commons.logging.Log; {>h,@
import org.apache.commons.logging.LogFactory; Dzr(Fb
iezY+`x4
/** MA+{7 [
* @author Joa nd)`G$gL
* 6^QSV@N|
*/ M<K}H8?
publicclass PageUtil { :G4)edwe
2{A/Fbk
privatestaticfinal Log logger = LogFactory.getLog l\6.f_
_]Y9Eoz
(PageUtil.class); j"Z9}F@
G\C>fwrP_
/** g0k{b
* Use the origin page to create a new page v$~ZT_"(9
* @param page S<o\.&J
* @param totalRecords ]L;X Aj?
* @return 3e?a$~9
*/ seS) `@n
publicstatic Page createPage(Page page, int F3=iyiz6
0czEA
totalRecords){ O[5u6heNMr
return createPage(page.getEveryPage(), ?UBhM,;XK
uuf+M-P
page.getCurrentPage(), totalRecords); oLc
} m%.7l8vT
(;2]`D [x
/** :rnj>U6<>
* the basic page utils not including exception wh#x`Nc
r!)jxIL\
handler F2C v,&'
* @param everyPage %R-KkK<S
* @param currentPage I`[s(C>3@
* @param totalRecords - %`iLu
* @return page vFH1hm
*/ (I ~r~5^
publicstatic Page createPage(int everyPage, int mAuN* (
Na>?1F"KHk
currentPage, int totalRecords){ &DX
everyPage = getEveryPage(everyPage); S)z5=N(Xz
currentPage = getCurrentPage(currentPage); ;0Mg\~T~'
int beginIndex = getBeginIndex(everyPage, wKj0vMW
$?dutbE
currentPage); :'K%&e?7s
int totalPage = getTotalPage(everyPage, .Eg[[K_iD
)/4U]c{-
totalRecords); nI<Ab_EB
boolean hasNextPage = hasNextPage(currentPage, ZfSAXr "(
|<w
Z;d
totalPage); .>+jtp}
boolean hasPrePage = hasPrePage(currentPage); p WLFJH}N
UkgiSv+
returnnew Page(hasPrePage, hasNextPage, '`/w%OEVC5
everyPage, totalPage, U
Y')|2y
5
currentPage, <"}WpT
3`>nQ4zC
beginIndex); _sI\^yZd
} XE.Y?{,R$
Q??nw^8Hi
privatestaticint getEveryPage(int everyPage){ "&N1$$
return everyPage == 0 ? 10 : everyPage; "|%'/p
} `'}c-
Q
2[TssJQ
privatestaticint getCurrentPage(int currentPage){ :P:OQ[$
return currentPage == 0 ? 1 : currentPage; mIkc+X
} *pKj6x
[;qZu`n>
privatestaticint getBeginIndex(int everyPage, int N
Uq'96{Y
XdGA8%^cY
currentPage){ [XDr-5Dm
return(currentPage - 1) * everyPage; #`b5kqQm
} k5TPzm=y{
ma7@vD
privatestaticint getTotalPage(int everyPage, int ;sfk@ec
h;Se.{
totalRecords){ @Sd l~'"
int totalPage = 0; oZ"93]3-
:}}~ $$&
if(totalRecords % everyPage == 0) BZ-)XF'4
totalPage = totalRecords / everyPage; xH/Pw?^
else &s<'fSI
totalPage = totalRecords / everyPage + 1 ; /6d:l>4
0
|Y'@&
return totalPage; ;OY*`(Id
} X/-u$c
o7WK"E!pF'
privatestaticboolean hasPrePage(int currentPage){ bsgr g
return currentPage == 1 ? false : true; p@bcf5'
} i0e aBG]I
0F|DD8tHR
privatestaticboolean hasNextPage(int currentPage, Q2 @Ugt$
Nw|m"VLb
int totalPage){ 4>$weu^
return currentPage == totalPage || totalPage == M}*#{UV2
SM@RELA'Lb
0 ? false : true; L!V6Rfy
} `1qM Sq
-|&5aH]
~lB:xVzn
} R6/vhze4L2
of>"qrdZ
RmcQGQ
K^fH:pV
-+w^"RBV
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 XVNJ3/
GO=3<Q{;
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 )OgQ&,#
D?<R5zp
做法如下: c
DO<z
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 k6PHyt`3'
.P>-Fh,_p
的信息,和一个结果集List: K%/:V
java代码: 6fr@y=s2:
'AjDB:Mt$
Bm&% N?9
/*Created on 2005-6-13*/ \"^.>+
package com.adt.bo; {^qp~0
__N#Y/e ]
import java.util.List; 5\|u]
~b
FELTmQUV
import org.flyware.util.page.Page; I:9jn"
,}hJ)
/** Z UCz-53
* @author Joa c _faW
*/ 5gnmRd
publicclass Result { ;zc,vs
ON~K(O2g(
private Page page; l{b*YUsz>
BvA09lK
private List content; XK7$Xbd
j/+e5.EX/
/** jaq`A'o5
* The default constructor WnL Ma|e
*/ [~_()i=Y
public Result(){ $pOgFA1'
super(); +bv-! rf
} Ar:ezA
2UGnRZ8:1Y
/** -g;cg7O#(
* The constructor using fields KqH_?r`
* a1nj}1M%
* @param page S66..sa
* @param content {~RS$ |
*/ b\^q9fy
public Result(Page page, List content){ s wIJmA
this.page = page; `[*n UdG
this.content = content; Yo$
xz
} fqcFfz6?x
]sf1+3
/** aHvsgp]
* @return Returns the content. 3.^Tm+ C
*/ '3MCb
publicList getContent(){ B}YpIb]d
return content; m2o)/:
} |`50Tf\J
u^!c:RfE?
/** 861!p%y5
* @return Returns the page. _:Jra
*/ n6f
public Page getPage(){ 5sc`L
return page; S`qa_yI)Ed
} n,E=eNc
|VPJaiC~
/** vS$_H<;P
* @param content Mx<?c
* The content to set. KS6H`Mm}/
*/ \&S-lsLY
public void setContent(List content){
UFLN/
this.content = content; ;F:~HrxT}
} =gjq@N]lAW
!PIpvx{aX
/** f;w7YO+$p9
* @param page h/t{=
@
.5
* The page to set. 1 ynjDin<
*/ T1&^IO-F7$
publicvoid setPage(Page page){ ief~*:5
this.page = page; Fu%%:3_
} j.FW*iX1C
} ?tJyQT
a9=pZ1QAG
:{ }]$+|)\
S|pMX87R
\~:Uj~
2. 编写业务逻辑接口,并实现它(UserManager, AUk,sCxd
3i c6!T#t"
UserManagerImpl)
EGKj1_ml
java代码: )t-Jc+*A>
wf=
s-C
^^-uq)A
/*Created on 2005-7-15*/ W_ =
package com.adt.service; SX4"HadV>
P})Iwk|Z
import net.sf.hibernate.HibernateException; 8<VO>WA>E
L:(>ON
import org.flyware.util.page.Page; F {g^4
{4@+
2)l
import com.adt.bo.Result; *nPB+@f
d\R]>
/** fW,,@2P
* @author Joa b&l/)DU
*/ &%ZiI@O-
publicinterface UserManager { TC=djC4$/
o?Wp[{K
public Result listUser(Page page)throws h5:>o
m\}8N
u
HibernateException; EP|OKXRltA
%L\buwjy$
} *r&q;ER
J9kmIMq-C
FHu
-';
c~1X/,biA
nS53mLU)
java代码: *,UD&N_)*6
Dj~]]
Y~</vz+H
/*Created on 2005-7-15*/ y$]gmg
package com.adt.service.impl; 4a&*?=GG
TaZw_)4c
import java.util.List; XYOPX>$T
qJQ!e
import net.sf.hibernate.HibernateException; BDeX5/`U#
fn1G^a=
import org.flyware.util.page.Page; `o.DuvQ
E
import org.flyware.util.page.PageUtil; \1AtBc&
epWO}@
b a
import com.adt.bo.Result; /lC&'h T
import com.adt.dao.UserDAO; sUfYEVjr
import com.adt.exception.ObjectNotFoundException; >|"mhNF
import com.adt.service.UserManager; eu]t.Co[X
Nf#8V|
/** RcASFBNpS
* @author Joa !F|mCEU
*/ (&w'"-`
publicclass UserManagerImpl implements UserManager { lYS+EVcR
me#?1r
private UserDAO userDAO; Z=B6fu*
fcuU,A
/** VPKoBJ&
* @param userDAO The userDAO to set. Nvlfi8.
*/ $ylQ \Y'
publicvoid setUserDAO(UserDAO userDAO){ \G3P[E[
this.userDAO = userDAO; j=%^CRum
} hU}!:6G%[P
n>_EEw2/
/* (non-Javadoc) :N826_q
* @see com.adt.service.UserManager#listUser 6(Qr!<
tj:Q]]\M
(org.flyware.util.page.Page) b)SU8z!NV&
*/ 8fn7!
public Result listUser(Page page)throws PjH[8:,
Xm|Uz`A;
HibernateException, ObjectNotFoundException { f1a >C
int totalRecords = userDAO.getUserCount(); 3H_mR
j9th
if(totalRecords == 0) y;!q E~!3
throw new ObjectNotFoundException `Jvy~T
W;Rx(o>
("userNotExist"); =5UT'3p>
page = PageUtil.createPage(page, totalRecords); LIo3a38n?y
List users = userDAO.getUserByPage(page); hdw-ge m{?
returnnew Result(page, users); (6aSDx
Sc
} 4>uy+"8PO
~{#$`o=
} Br}&
X}Ey6*D:
~\4B 1n7
aKLA_-E
dFd^@b
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 OX"^a$
`m~x*)L#
询,接下来编写UserDAO的代码: _^)Wrf+
3. UserDAO 和 UserDAOImpl: *Cdw"n
java代码: ,&DK*LT8U
.`iG}j)\
ElAho3W
/*Created on 2005-7-15*/ \(nb
>K
package com.adt.dao; -/#VD&MJO=
$`2rtF
import java.util.List; fZ9EE3
yj^LX2x"
import org.flyware.util.page.Page; -xJ_5
KtT.WHr(m
import net.sf.hibernate.HibernateException; <Rs#y:
}~?B>vZS
/** u,zA^%
* @author Joa &=1Ag}l57
*/ qk;vn}auD]
publicinterface UserDAO extends BaseDAO { -8L22t
x[mxp/
/P
publicList getUserByName(String name)throws vhw"Nl
Z~g I )
HibernateException; o -< 5<
02Ftn&bi
publicint getUserCount()throws HibernateException; m=^`u:=
j>2Jw'l;?
publicList getUserByPage(Page page)throws jWn!96NhlL
SIJ:[=5!7
HibernateException; IL:d`Kbqf
&GF|Rr8NXs
} bIFKP
jV(\]g"/=
>&@hm4
`1cGb *b/
z (N3oBW
java代码: QT1(= wK3
ugtzF
}Yi)r*LI3
/*Created on 2005-7-15*/ !]%M
package com.adt.dao.impl; t SST.o3
C~do*rnM^
import java.util.List; p!+7F\
S?X2MX
import org.flyware.util.page.Page; dQoZhE
T;cyU9
import net.sf.hibernate.HibernateException; Wq bfZx
import net.sf.hibernate.Query; g/)$-Z)Nu
}PZz(Ms
import com.adt.dao.UserDAO; R&w2y$
c0J=gZiP
/** /jR]sC)xs
* @author Joa xwjim7#_:
*/ 1E(~x;*)
public class UserDAOImpl extends BaseDAOHibernateImpl N30w^W&
%+WIv+<
implements UserDAO { 'Zq$W]i
-hM
nA)+
/* (non-Javadoc) u
N%RB$G
* @see com.adt.dao.UserDAO#getUserByName _eB?G
f@ &?K<
(java.lang.String) Rw]4/
*/ =)56]ki}
publicList getUserByName(String name)throws -29Sw
$rB20!
HibernateException { |E\0Rv{H3
String querySentence = "FROM user in class }3t bqFiH
CgLS2
com.adt.po.User WHERE user.name=:name"; 2b+0}u>a
Query query = getSession().createQuery /?POIn+0o
"W_C%elg
(querySentence); _1z|QC
query.setParameter("name", name); 4dDDi,)U
return query.list(); =F!DwaZ
} oB9t&yM
wi#]*\N\9
/* (non-Javadoc) -*[?E!F
* @see com.adt.dao.UserDAO#getUserCount() =AFTB<7-^
*/ +/ A`\9QT
publicint getUserCount()throws HibernateException { E"ju<q/Q
int count = 0; 9/lCW
String querySentence = "SELECT count(*) FROM QjW7XVxB#N
RU>Hr5ebo
user in class com.adt.po.User"; p_!;N^y.
Query query = getSession().createQuery O<3i6
8:Yha4<Bv7
(querySentence); $9GRA M.
count = ((Integer)query.iterate().next ^!]Hm&.a
+ahr-v^R<
()).intValue(); MC.,n$O}6
return count; ?Rc+H;x=f
} !6eXJ#~[E
Luxo,Ve
/* (non-Javadoc) U
D9&k^
* @see com.adt.dao.UserDAO#getUserByPage NO4V{}?a
xl%!7?G|$>
(org.flyware.util.page.Page) s5 2c`+
*/ stnyJ9
publicList getUserByPage(Page page)throws lO/<xSjNd
By=/DVm)=
HibernateException { qyP|`Pm4
String querySentence = "FROM user in class zy(i]6
1'5I]D
ec
com.adt.po.User"; 0y$aGAUm
Query query = getSession().createQuery sPCp20x:y8
9`J!]WQ1[
(querySentence); 8ALvP}H
query.setFirstResult(page.getBeginIndex()) -e=p*7']
.setMaxResults(page.getEveryPage()); LGN,8v<W(
return query.list(); !XjvvX"j
} )k F/"'o
Z, Kbt
} Az.k6)~
<!.'"*2
-b>"2B?
8uyUvSB
I)~&6@Jn
至此,一个完整的分页程序完成。前台的只需要调用 15Vb`Vf`N
#C?T
userManager.listUser(page)即可得到一个Page对象和结果集对象 ^7`"wj14
0_HdjK
的综合体,而传入的参数page对象则可以由前台传入,如果用 2e}${NZN
-GkNA"2M[
webwork,甚至可以直接在配置文件中指定。 ~L!*p0dS^
7@g8nv(p
下面给出一个webwork调用示例: V/Hjd`n)`i
java代码: |]a=He;
@Taj++ua
&z;;Bx0s
/*Created on 2005-6-17*/ [@ ]f@Wd
package com.adt.action.user; OE(H:^ZR
!FweXFl
import java.util.List; %H:uE*WZ
qvz2u]IOw
import org.apache.commons.logging.Log; Wjt1NfS&
import org.apache.commons.logging.LogFactory; bS{7 *S
import org.flyware.util.page.Page; ![WX -"lW
Nw@tlT4
import com.adt.bo.Result; DG8LoWZ
import com.adt.service.UserService; >;',U<Wd
import com.opensymphony.xwork.Action; 1xM'5C?~7
?2VY^7N[
/** i^ 9PiP|U
* @author Joa v}hmI']yf
*/ (yFR;5Fo
publicclass ListUser implementsAction{ PMk3b3)Z
^5TSo&qZ
privatestaticfinal Log logger = LogFactory.getLog C+-GE9=
hR3lo;'
(ListUser.class); l-"c-2-!
"J]_B
private UserService userService; nAn/V u
@Md%gEh;&
private Page page; H{'<v|I
:.['e`
privateList users; ^Yei9bXl
}LS:f,1oGp
/*
~YHy'.
* (non-Javadoc) bkkhx,Oi[G
* |w2H5f{fR
* @see com.opensymphony.xwork.Action#execute() *>!O2c
*/ EWPP&(u3
publicString execute()throwsException{ Efi@hdEV
Result result = userService.listUser(page); C=ni5R
page = result.getPage(); P0J3ci}^
users = result.getContent(); @cPb*
return SUCCESS; f3e#.jan
} ((A]FOIbO
8YC\Bw
/** >ir'v5
* @return Returns the page. u2
a
U0k:
*/ &P&LjHFK
public Page getPage(){ V6"<lK8"
return page;
#|fa/kb~
} vCT5do"C&
fk)ts,p?
/** zCKZv|j6
* @return Returns the users. N+x0"~T}I
*/ AOQimjW9a
publicList getUsers(){ /W'GX n
return users; U'zW; Lt
} hK"hMyH^
Ei2Y)_
/** 78>)<$+d
* @param page an^"_#8DA@
* The page to set. `m?%{ \
*/ U>6MT@\
publicvoid setPage(Page page){ {4Y@DQ-
this.page = page; `O(ec
} Tx?,]c,(u
X-9>;Mb~y
/** N-|E^XIV
* @param users <b>@'\w9
* The users to set. *@=in7*c
*/ Mk"+*G
publicvoid setUsers(List users){ MB
:knj
this.users = users; cVJ"^wgBt
} V0 x[sEW
{~>?%]tf
/** kA?a}
* @param userService Yu-e|:
* The userService to set. #+HLb
*/ w\k|^
publicvoid setUserService(UserService userService){ C
J S
this.userService = userService; C{!L +]/
} /%|JP{
} r(iT&uz
Qk<W(
o9G%KO&;D,
L ^} Z:I
0F-X.Dq
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,
RvKP&
S!<YVQq
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 lxy_O0n
|t*(]U2O0
么只需要: t
m?[0@<s
java代码: n"8vlNeW
IY6DZP
S-{[3$
<?xml version="1.0"?> c^vPd]Ed
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork \"B?'Ep;
7l> |G,[c
1.0//EN" "http://www.opensymphony.com/xwork/xwork- D].!u{##
T:q_1W?h]
1.0.dtd"> YO7Y1(`
Wr Ht
<xwork> BDSZ '
){`s&? M0
<package name="user" extends="webwork- Kk1 591'
HQ~`ha.
interceptors"> %JM:4G|q
$ysemDq-a\
<!-- The default interceptor stack name `Bk7W]{L
R>SS\YC'X
--> t!RR5!
<default-interceptor-ref >c%OnA,3
W[BZ/
name="myDefaultWebStack"/> )=l~XV
"a))TV%N
<action name="listUser" 1oD,E!+^d
E8g Xa-hv
class="com.adt.action.user.ListUser"> B*btt+6
<param _#@n^c
"MHm9D?5
name="page.everyPage">10</param> Y$hYW
<result lo*OmAF
\7PPFKS
name="success">/user/user_list.jsp</result> Q\Dx/?g!vx
</action> r!SMF]?SJ
^Gt&c_gH
</package> u~n*P``{
P'.MwS
</xwork> .zQ:u{FT
7S$Am84%
eqbQ,, &
>)*'w!
\MBbZB9@
2g5i3C.q$
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 HA&7
ybl
Jb~$Vrdy
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。 H'k $<S
Y,Dd}an
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 3qJOE6[}%
hw! l{yv
/ivcqVu]
_R&mN\ey5
`i5U&K. 7
我写的一个用于分页的类,用了泛型了,hoho NRu_6~^^
i
,Cvnp6Lv
java代码: eKjmU | H
.j?`U[V%a
Yt&Isi
+
package com.intokr.util; hhd%j6
' i5 VU4?K
import java.util.List; p=%Vo@*]
s}Phw2`1U
/** y4*i
V;"
* 用于分页的类<br> 8*7t1$
* 可以用于传递查询的结果也可以用于传送查询的参数<br> .4on7<-a
* <=.0
P/N
* @version 0.01 Pyh+HD\
* @author cheng \7rAQ[\#V
*/ MU6|>{
public class Paginator<E> { X`i'U7%I
privateint count = 0; // 总记录数 vD<6BQR
privateint p = 1; // 页编号 iUSP+iC,
privateint num = 20; // 每页的记录数 *69{#qN
privateList<E> results = null; // 结果 -e<d//>
e RY2.!
/** oSVo~F
* 结果总数 @>`+eg][?P
*/ <vMna< /d
publicint getCount(){ K$v
SdpC
return count; rEz-\jLD~
} $pW6a %7
iV9wqUkMv
publicvoid setCount(int count){ 'a.n
this.count = count; %Aaf86pkp
} )9/.K'o,dy
A!EmJ
/** j"(o>bv7
* 本结果所在的页码,从1开始 "Tw4'AY'P
* 9/A$3#wF
* @return Returns the pageNo. aAM!;3j]B`
*/ F6>K FU8
publicint getP(){ .*XELP=BT
return p; EUBJnf:q
} CTawXHM
Q{%2Npvq
/** dRwOt
* if(p<=0) p=1 :"m~tU3&
* (w4w
* @param p y8} fj=
*/ WgHl.
:R
publicvoid setP(int p){ m$N`Xj
if(p <= 0) m(0sG(A~
p = 1; 4I7B
#{
this.p = p; \s_lB~"P!3
} rJLn=|uR
3V=(P.A Tm
/** aq~>$CHa
* 每页记录数量 /$NDH]a
*/ y?=W
publicint getNum(){ $ti*I;)h4
return num; U'(Exr[
} L{`S^'P<
5mzOr4*0
/** &UzeNL"]
* if(num<1) num=1 :`u?pc27Sm
*/ WFWQ;U{|
publicvoid setNum(int num){ s
P=$>@3
if(num < 1) Y~I$goT
num = 1; GMk\
l
this.num = num; k^<s|8Y
} TUE*mDRmP
}f
rij1/G
/** 5L ]TV\\
* 获得总页数 [3$L}m
*/ B$A`thQp
publicint getPageNum(){ R-7.q
return(count - 1) / num + 1; $db]b
} 1D2Uomd(
$;O-1# ]
/** L'i0|_
* 获得本页的开始编号,为 (p-1)*num+1 j^4KczJl
*/ zk6al$3R
publicint getStart(){ RYhaQ&1i
return(p - 1) * num + 1; )"( ojh
} 8aDSRfv*
hz:^3F`>/&
/** $'Pn(eZHGv
* @return Returns the results. q%H`/~AYM
*/ G.j R
publicList<E> getResults(){ S8=Am7D]1
return results; $ghAC
} V[9#+l~#
* SAYli+@
public void setResults(List<E> results){ bx!uHL=
this.results = results; 9NUft8QB
} \R"} =7
'K|Jg.2
public String toString(){ k8>(-W"A
StringBuilder buff = new StringBuilder }s*H|z
VSm[80iR0
(); 01N]|F:
buff.append("{"); $? 'JePC
buff.append("count:").append(count); '*4>&V.yX
buff.append(",p:").append(p); Iw07P2
buff.append(",nump:").append(num); @B.;V=8wJ
buff.append(",results:").append Tbf@qid e
8(AI|"A"-
(results); |aAu4
buff.append("}"); oAnNdo
return buff.toString(); A/bxxB7w
} uj8G6'm%
'A^ ;P]y
} tx$i(
O"'.n5>:`
24Y8n