Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 p_g`f9q6D
?].MnwYo
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 uDP:kM
p<{P#?4 g
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 tsJR:~
M2-`p
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 SAdE9L =d
^?Mp(o
。 @lF?+/=$
t^KQ*8clG
分页支持类: Ku%tM7 ad
Ny^f'tsA
java代码: }%8ZN :
L2,2Sn*4i
Z3weFbCH
package com.javaeye.common.util; gu!!}pwV9
$3PDe
import java.util.List; pa1<=w
5E-;4o;RI(
publicclass PaginationSupport { M2 |!,2
(^35cj{s
publicfinalstaticint PAGESIZE = 30; O7Jux-E1C
0\{dt4nW&O
privateint pageSize = PAGESIZE; 4hy-M>!D|
%+=;4tHJ
privateList items; *qm|A{FQR
CYLab5A
privateint totalCount; N.vWZ7l8
zXx/\B$&d*
privateint[] indexes = newint[0]; Lo%vG{yTr
-dixiJ=
privateint startIndex = 0; Ba@~:
UuWIT3W>%
public PaginationSupport(List items, int ce9P-}d
} Xo#/9
totalCount){ ["<Xh0_
setPageSize(PAGESIZE); {#qUZ z-
setTotalCount(totalCount); zPa2fS8
setItems(items); $C;i}q#
setStartIndex(0); b^Z2Vf:k]
} G;}WZy
D[/fs`XES
public PaginationSupport(List items, int ?@9v+Am!
L@{'J
totalCount, int startIndex){ s|e.mZk/
setPageSize(PAGESIZE); ud r\\5
setTotalCount(totalCount); U-9Aq
setItems(items); h(HpeN%`#
setStartIndex(startIndex); x*7A33@i
} "-$}GUK?Z
.Qx5,)@9
public PaginationSupport(List items, int M5ZH6X@5
x<gmDy*
totalCount, int pageSize, int startIndex){ <E4(KE
setPageSize(pageSize); Tse#{
setTotalCount(totalCount); ~^1y(-cw
setItems(items); UHZ&7jfl
setStartIndex(startIndex); \{ @m
} k_,7#:+
`FPQOa*%3
publicList getItems(){ 5G}4z>-]F)
return items; fA6IW(_bi
} f%,S::%Ea
K9#kdo1 2
publicvoid setItems(List items){ Nn[*ox#i
this.items = items; uaF-3
} oZiW4z*Wh
k~8-Eu1
publicint getPageSize(){ m"n74cxS
return pageSize; hn8xs5vN
} 7HDc]&z
HLW_Y|QaFo
publicvoid setPageSize(int pageSize){ 'z.
GAR
this.pageSize = pageSize; $Y|OGZH8E
} |reA`&<q
!FL"L
9
publicint getTotalCount(){ ]zol?
return totalCount; 9r].rzf9
} R'k`0
<?KPyg2
publicvoid setTotalCount(int totalCount){ =7<JD}G
if(totalCount > 0){ /yG34) aB
this.totalCount = totalCount; =HCEUB9Fs
int count = totalCount / -i`jS_-Cv-
+& B?f
pageSize; .t_t)'L
if(totalCount % pageSize > 0) teJt.VA7)
count++; 7\6g>4J^`
indexes = newint[count]; ;d6Dm)/(
for(int i = 0; i < count; i++){ mH$tG
$
indexes = pageSize * 0V1GX~2
TmG);B}
i; 7%Y`j/
} +-j-)WU?,
}else{ V'&;r'#O
this.totalCount = 0; D5lQ0_IeW
} VvyRZMR
} tP@NQCo
X<L=*r^C,=
publicint[] getIndexes(){ \ASt&'E
return indexes; c*)T4n[e
} %
"(&a'B
Zk=,`sBC
publicvoid setIndexes(int[] indexes){ iwK.*07+
this.indexes = indexes; <gF]9%2E
} k_7m[o
;7P'>j1?U
publicint getStartIndex(){ )dkU4]
return startIndex; |8k1Bap`z
} sF
{,n0<8
q6>eb
publicvoid setStartIndex(int startIndex){ L
BbST!
if(totalCount <= 0) "N}t =3i$
this.startIndex = 0; JY"jj}H]|
elseif(startIndex >= totalCount) ,.<mj !YE
this.startIndex = indexes [./FzlA s
?@ oF@AEx=
[indexes.length - 1]; KW .4 9
elseif(startIndex < 0) 3+ 6Ed;P
this.startIndex = 0; 1p}Wj*mc
else{ l{[@Ahb}?
this.startIndex = indexes '0HOL)cIz
O-(V`BZe
[startIndex / pageSize]; .?45:Ey~g
} QOB^U-cW
} I\Op/`_=E
Gm|-[iUTG]
publicint getNextIndex(){
]=~dyi
int nextIndex = getStartIndex() + OS z71;j
cyCh^- <l@
pageSize; uV5uZ
if(nextIndex >= totalCount) zgwez$
return getStartIndex(); $:~;U xh=
else \l59/ZFan
return nextIndex; Ixa0;nxj
} q^aDZzx,z
YbZbA >|
publicint getPreviousIndex(){ |[.-pA^
int previousIndex = getStartIndex() - 8%9 C<+.R
/.SG? 5t4
pageSize; MKBDWLCB
if(previousIndex < 0) c2P}P* _
return0; j.q}OK
else 3uuIISK
return previousIndex; m{Q
#f\<
} ;xwcK-A
X!]v4ma`
} 9nG^_.}|
2o SM|
XO
<0;9|
h5P_kZJ
抽象业务类 ;XN|dq
java代码: K7RAmX
P6v ANL-B
{ M**a
/** 1&dtq,|N
* Created on 2005-7-12 E=8'!
*/ zy,SL
|6:
package com.javaeye.common.business; 83vMj$P
`dvg5qQ
import java.io.Serializable; 3}|[<^$
import java.util.List; ,\M77V
YlrN^rO
import org.hibernate.Criteria; K0gQr.J53
import org.hibernate.HibernateException; ]X6<yzu&+l
import org.hibernate.Session; ;%e)t[5
import org.hibernate.criterion.DetachedCriteria; 4LTm&+(5
import org.hibernate.criterion.Projections; %,T*[d&i
import ;iKLf~a a
'7?Y+R@|L
org.springframework.orm.hibernate3.HibernateCallback; x%EGxs;>^
import vJ&_-CX
4}H+hk8-
org.springframework.orm.hibernate3.support.HibernateDaoS 8US#SI'x
Lwl1ta-
upport; -EiTP:A
Rl ]x:
import com.javaeye.common.util.PaginationSupport; IJ Jp5[w
E{\CE1*
public abstract class AbstractManager extends cB uuq
r!Eh}0bL
HibernateDaoSupport { OijuOLt
NxHUOPAJc
privateboolean cacheQueries = false; X)3(.L
JWb +
privateString queryCacheRegion; aC,adNub
p":u]Xgb
publicvoid setCacheQueries(boolean ;E.]:Ia~
z=>fBb>w7
cacheQueries){ d,^O[9UWo
this.cacheQueries = cacheQueries; !UoA6C:
} c>LP}PGk
&>\;4E.O5
publicvoid setQueryCacheRegion(String *V2;ds.~
1/97_:M0~F
queryCacheRegion){ <st<oR'
this.queryCacheRegion = roQI;gq^
W![K#r5T
queryCacheRegion; $S#Z>d*1!
} \ptO4E
GQbr}xX.#
publicvoid save(finalObject entity){ On*I.~
getHibernateTemplate().save(entity); <U3X4)r
} @vl$[Z|
!8G)`'
publicvoid persist(finalObject entity){ NVMn7H}>
getHibernateTemplate().save(entity); B'yjMY![
} [BE_^d5&
=>
(g_\
publicvoid update(finalObject entity){ Q4cCg7|0
getHibernateTemplate().update(entity); (l99a&]t
} DzpWU8j
e}uK"dl(
publicvoid delete(finalObject entity){ @AZNF+
\W$
getHibernateTemplate().delete(entity); ,iyy2
} :H&Q!\a
uz!8=,DFw
publicObject load(finalClass entity, ({E,}x
u !BU^@ P
finalSerializable id){ 9Vt
^q%DC
return getHibernateTemplate().load C!+D]7\j
@7nZjrH
(entity, id); Jinh#iar
} PLz{EQ[cV
{?`rGJ{f
publicObject get(finalClass entity, (7g"ppf
_mqU:?Q5
finalSerializable id){ bL7Gkbs&|
return getHibernateTemplate().get Cu+p!hV
{]dxFhe)
(entity, id); :TTq
} 1X)#iY
Tksv7*5$
publicList findAll(finalClass entity){ d_`MS@2
return getHibernateTemplate().find("from rnK]3Ust
Wr[LC&
" + entity.getName()); x Q"uC!Gu4
} q1VKoKb6\:
T~xVHk1
publicList findByNamedQuery(finalString (u 7Lh>6%
6y^
zC?
namedQuery){ \Eh5g/,[
return getHibernateTemplate Zv
%>m
~<_#%R!
().findByNamedQuery(namedQuery); S>dHBR#AD
} V48_aL
?$/::uo
publicList findByNamedQuery(finalString query, qArR5OJ
ZjxF@`H
finalObject parameter){ jemb/:E
return getHibernateTemplate 5ngs1ZF@
&4OJJ9S
().findByNamedQuery(query, parameter); Ar>B_*dr
} )|=1;L
nFlN{_/
publicList findByNamedQuery(finalString query, fK7
?"^`/
xo@1((|z
finalObject[] parameters){ @K]`!=vUk
return getHibernateTemplate EGD{nE
@{@b^tk
().findByNamedQuery(query, parameters); v\w*VCjoV
} xdO3koE:
7g*!6-W[
publicList find(finalString query){ HAH\#WE
return getHibernateTemplate().find *<^C0:i(
b]u=Iza
(query); x@Gg fH<l
} M5VW1Ns
^KbR@Ah
publicList find(finalString query, finalObject Vs"b
9Z-2MF
parameter){ |.9PwD8~VD
return getHibernateTemplate().find %X_A# 9
'
wl})
(query, parameter); nT|WJ%
} a~yiLq
Kz;Ar&^`N
public PaginationSupport findPageByCriteria bVcJ/+Yx|
QDxs+<#
(final DetachedCriteria detachedCriteria){ N #v[YO`.
return findPageByCriteria HW[&q
1HO;~NJ]m
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 2(d
} @|(cr: (=H
;jgf,fbM
public PaginationSupport findPageByCriteria Pjh;;k|V
R_j.k3r4d
(final DetachedCriteria detachedCriteria, finalint [lIX&!T"
\8#[AD*@s2
startIndex){ IS8 sJ6")
return findPageByCriteria V~PGmn[V
:NLY;B`
(detachedCriteria, PaginationSupport.PAGESIZE, ?*V\
-7jg
uV gA <*0
startIndex); e^*&&
} 'Qt[cW
D<v<
:
public PaginationSupport findPageByCriteria :'r*
5EX
|gV~U~A]
(final DetachedCriteria detachedCriteria, finalint L/fXP@u
;*rGZ?%*
pageSize, 5%D`y|
finalint startIndex){ l8E))oz1T
return(PaginationSupport) t5 >ma:^j
Ju>QQOxi|
getHibernateTemplate().execute(new HibernateCallback(){ %rB,Gl:)g
publicObject doInHibernate 1a9' *[
[`tOhL
(Session session)throws HibernateException { 8@vq.z}
Criteria criteria = :#vA5kC
Vw;iE=L
detachedCriteria.getExecutableCriteria(session); <
R"Y^]P=
int totalCount = MVMJl ">
!43nL[]
((Integer) criteria.setProjection(Projections.rowCount +m
J G:n
A23K!a2u&
()).uniqueResult()).intValue(); \@PMj"p|:
criteria.setProjection i$pUUK
8/2Wq~&
(null); UK
OhsE
List items = F$>#P7ph\a
t[k ['<G
criteria.setFirstResult(startIndex).setMaxResults :&5u)
BUZ74
(pageSize).list(); [e,xC!2
PaginationSupport ps = \u.5_
g
>? o5AdZ
new PaginationSupport(items, totalCount, pageSize, H`<u2fo|p
1<h@^s ;
startIndex); /7B3z}rd
return ps; R[ F`b
} H5]q*D2
}, true); _&(Wz0
} 8r}tf3xMCM
#l>r9Z71
public List findAllByCriteria(final ^XyC[ G@[
;xq;c\N
DetachedCriteria detachedCriteria){ @<P;F
return(List) getHibernateTemplate =WN8><K!
Qv,ORm
h5
().execute(new HibernateCallback(){ Wv3p!zW3I
publicObject doInHibernate tM@%EO
KdiJ'K.
(Session session)throws HibernateException { E5gt_,j>
Criteria criteria = D7R;IA-w
%A
5s?J?
detachedCriteria.getExecutableCriteria(session); L?N:4/0;!
return criteria.list(); <> HI(6\@Z
} D0\*WK$
}, true); 7.{+8#~nV
} F6{
O
`?&C5*P
public int getCountByCriteria(final
w)go79
c 9gm%
DetachedCriteria detachedCriteria){ Lniz>gSc
Integer count = (Integer) ;U0w<>4L
J}Z\I Y,
getHibernateTemplate().execute(new HibernateCallback(){ u YFy4E3
publicObject doInHibernate JWu0VLo
0(5qVJ12
(Session session)throws HibernateException { 3#fg
2
Criteria criteria = 5a6d3u/
{2xc/
detachedCriteria.getExecutableCriteria(session); ='I2&I,)
return {'P?wv
=sAOWI,8!
criteria.setProjection(Projections.rowCount 7F]oK0l_
-iy17$
()).uniqueResult(); }K.)yv n
} V
7 p{'C
}, true); rk+s[Qi~
return count.intValue(); 9~ V(wG
} `j2|aX
%Z*
} `,FA3boE
`)=sQ2P
*ax&}AHK[/
}uD*\.
ZDK+>^A)
"2!5g )iO
用户在web层构造查询条件detachedCriteria,和可选的 q.hpnE~#lh
W)2k>cS
startIndex,调用业务bean的相应findByCriteria方法,返回一个 KVC18"|f
aB&a#^5CI
PaginationSupport的实例ps。 gW G>}M@
\= 6dF,V
ps.getItems()得到已分页好的结果集 x;JC{d#
ps.getIndexes()得到分页索引的数组 x'i~o'
ps.getTotalCount()得到总结果数 aE]RVyG@L
ps.getStartIndex()当前分页索引 t:'^pYN:g
ps.getNextIndex()下一页索引 'eQ*?a43
ps.getPreviousIndex()上一页索引 ;x)f;!e+
9D5v0Qi
h ^zcM_
d<_IC7$u>
rb.:(d)T
)\e0L/K@
LK|rLoia:
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 xs)SKG*
O8*yho
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 1OFrxSg
=dQ46@
一下代码重构了。 ~c,+)69"T
ZB$,\|^6
我把原本我的做法也提供出来供大家讨论吧: hs)_h^P
fQf d1=4
首先,为了实现分页查询,我封装了一个Page类: 5'rP-z~
u
java代码: P1qnU
p1s&
y0:d
N@? z&urQi
/*Created on 2005-4-14*/ R"`<ZY6(Ou
package org.flyware.util.page; R4f_Kio
G7#<Jo<8
/** xCU
pMB7
* @author Joa ?Ql<s8
* !M7727
*/ C%P"\>5@
publicclass Page { x*_'uP oS
&K"qnng/y
/** imply if the page has previous page */ lt C
privateboolean hasPrePage; >{h/4T@
"V4ru&a
/** imply if the page has next page */ covK6SH
privateboolean hasNextPage; y $>U[^G[
5F5)Bh
/** the number of every page */ 8 }OII\
privateint everyPage; [@/x
35#"]l"
/** the total page number */ ]#O~lq
privateint totalPage; Kb#Z(C9
csv;u'
/** the number of current page */ O1z3(
privateint currentPage; mm`yu$9gbP
ESY\!X:|
/** the begin index of the records by the current *edhJUT
Z=144n 1
query */ G8CM
privateint beginIndex; JN<u4\e{-&
X./7b{Pax
u`Zj~t
/** The default constructor */ Z2{G{]EV(
public Page(){ /80RO:'7
\ci[<CP
} =(as{,j
c ^+{YH;k
/** construct the page by everyPage L%[b6<
* @param everyPage &_<!zJ;Hn
* */ ^14a[ta/'
public Page(int everyPage){ Z'\{hL S
this.everyPage = everyPage; `< cn
} iFB {a?BE
iy,jq5uw
/** The whole constructor */ j
!rQa^
public Page(boolean hasPrePage, boolean hasNextPage, ":Ll.=!
kKNrCv@64d
0bI}
s`sr
int everyPage, int totalPage, ty)~]!tA
int currentPage, int beginIndex){ ]n&Eb88
this.hasPrePage = hasPrePage; #s]` jdc
this.hasNextPage = hasNextPage; GPU,.s"&(
this.everyPage = everyPage; R(cM4T.a
this.totalPage = totalPage; MN. $a9m
this.currentPage = currentPage; r|0wIpi6Q
this.beginIndex = beginIndex; :"~n`
Q2[
} C1SCV^#
$n9Bp'<
/** {-e|x&-
* @return 3q$"`w
* Returns the beginIndex. ]=T-Cv=t
*/ A{KF<Omu
publicint getBeginIndex(){ &-M}:'
return beginIndex; UNKr
FYl
} /UPe@
YhFd0A?]
/** 0%GQXiy
* @param beginIndex f-l(H="e
* The beginIndex to set. }*M>gvPo
*/ x`gsD3C
publicvoid setBeginIndex(int beginIndex){ 4^AdSuV
this.beginIndex = beginIndex; Qj',&b
} .l ufE
e"ur+7
/** |qX[Dk
* @return )i*- j=
* Returns the currentPage. tU>?j1
*/ H.]rH,8
publicint getCurrentPage(){ 4ai|*8.
return currentPage; _|vY)4B4U
} <gbm
1iEe
YgW 50)q^
/** wYLJEuS|
* @param currentPage gOKF%Ej31T
* The currentPage to set. T9O3$1eqfo
*/ L<MH:
publicvoid setCurrentPage(int currentPage){ A&/YnJ"
this.currentPage = currentPage; NE2P
"mY
} ubQZTA x
jxNnrIA
/** Avn)%9
* @return MWron_xg
* Returns the everyPage. z~O:w'(g
*/
hV7]/z!d
publicint getEveryPage(){ AvEd?
return everyPage; 1o%E(*M4I
} uQ'Izdm
)xj!7:n)
/** F{"4cyoou
* @param everyPage )r.4`5Rc
* The everyPage to set. QO(P_az3mg
*/ !f!HVna
publicvoid setEveryPage(int everyPage){ N@r`+(_t
this.everyPage = everyPage; A/w7(
} y ZR\(\?<
;f+bIYQz
/** Y5?OJO{h"
* @return LyWgaf#/d
* Returns the hasNextPage. 2qxede
*/ hqVxvS"
publicboolean getHasNextPage(){ ;@l5kdZx`
return hasNextPage; @eU5b63jM
} 78-D/WY/X
6y+}=)J
/** EQ>] ~
* @param hasNextPage W$ag
|WV
* The hasNextPage to set. QC^#ns&
*/ *wD| eK7
publicvoid setHasNextPage(boolean hasNextPage){ xY94v
this.hasNextPage = hasNextPage; OX[pK_:`l
} /yNLFL"
}hyl)?*~
/** pGdo:L?
* @return 1&Ruz[F5
* Returns the hasPrePage. GFppcL@a
*/ P{gy/'PH,
publicboolean getHasPrePage(){ C3>`e3v
return hasPrePage; -N~eb^3[c
} S<bsrS*$
;j^C35
/** 8ZPjzN>c6
* @param hasPrePage mKN#dmw6
* The hasPrePage to set. N!iugGL
*/ 5}MjS$2og
publicvoid setHasPrePage(boolean hasPrePage){ 1DT}_0{0Q
this.hasPrePage = hasPrePage; Qq*Ks
5
} C.Ty\@U
[OK(
/** J.^%VnrFO9
* @return Returns the totalPage. _m2p>(N|
* @^UnrKSd
*/ l11+sqg
publicint getTotalPage(){ $>=?'wr
return totalPage; CZ4Nw]dtR
} a15kFun
,J)wn;@
/** aq-R#q
* @param totalPage B(B77SOb
* The totalPage to set. .qGfLvx%
*/ gOL-b9W
publicvoid setTotalPage(int totalPage){ |QcE5UC
this.totalPage = totalPage; 7;x}W-`iF
} %MH!L2|
^a{cK
} CE;J`;
CP"
5KI lU78
$2'Q'Mx[gd
v3]mZ}W$
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 wi$,Y.:
^DH*\ee
个PageUtil,负责对Page对象进行构造: *p Q'w
java代码: Vnvfu!>(
vE<z0l
GZCX m+
/*Created on 2005-4-14*/
0V[`zOO(o
package org.flyware.util.page; #$;i 4a
Y `ySNC
import org.apache.commons.logging.Log; E@%9u#
import org.apache.commons.logging.LogFactory; Tw+V$:$$
nXFPoR)T
/** (`me}8
* @author Joa xq-TT2}<L
* pf[m"t6G~
*/ sm9/sX!
publicclass PageUtil { u-%|ZSg
!Un&OAy.!
privatestaticfinal Log logger = LogFactory.getLog _Z{EO|L
P'Diie
(PageUtil.class); 8k|&&3_[?
[,86||^
/** dDxb}dx8
* Use the origin page to create a new page 5g\>x;cc
* @param page @4xV3Xkf&C
* @param totalRecords .bloaeu-
* @return :Cdqj0O3u
*/ J*FUJT
publicstatic Page createPage(Page page, int EPu-oE=HW4
UZJ<|[
totalRecords){ +pG[
[}/
return createPage(page.getEveryPage(), v_L2>Pa.
K2
b\9}
page.getCurrentPage(), totalRecords); Uuq*;L
} n3B#M}R
CD:$22*]
/** .mwB'Ll
* the basic page utils not including exception +]dh`8*8>1
H&_drxUq;L
handler G%FLt[
* @param everyPage S\"#E:A
* @param currentPage ]21`x
* @param totalRecords x*7Q
* @return page "
.<>(bE
*/ s=[T,:Z
publicstatic Page createPage(int everyPage, int ^sqTgrG
u}QcyG^
currentPage, int totalRecords){ U"L7G$
everyPage = getEveryPage(everyPage); MR3\7D+9y
currentPage = getCurrentPage(currentPage); Y6:b
int beginIndex = getBeginIndex(everyPage, 3$f+3/l
$rV4JROb
currentPage); pr?k~Bn
int totalPage = getTotalPage(everyPage, ;]\>jC
$/#F9>eZ
totalRecords); 2m{d>
boolean hasNextPage = hasNextPage(currentPage, -50Qy[0. "
sEzl4I
totalPage); Fz.Ij'8.H
boolean hasPrePage = hasPrePage(currentPage); Da-U@e!
V ah&)&n
returnnew Page(hasPrePage, hasNextPage, R8bKE(*rxj
everyPage, totalPage, 0i3Z7l]
currentPage, {baG2Fe1`b
X`JoXNqm
beginIndex); wmB_)`QNP
} me ,lE-
M'|?*aNK
privatestaticint getEveryPage(int everyPage){ W87kE?,
return everyPage == 0 ? 10 : everyPage; 4H*M^?h\#
} h-+vNhH
?d' vIpzO!
privatestaticint getCurrentPage(int currentPage){ U+-R2w]#q_
return currentPage == 0 ? 1 : currentPage; 7#+>1 "\
} C'.^2s#e8
/CXQ&nwY9=
privatestaticint getBeginIndex(int everyPage, int <IO@Qj1*
S;iJQS
currentPage){ TD.t)
return(currentPage - 1) * everyPage; Dn[u zY6
} t>}(`0
VOGx
privatestaticint getTotalPage(int everyPage, int z2~\
b3G
?<efKs
totalRecords){ -Dy":/Bk
int totalPage = 0; +F]=Z
>qS2ha
if(totalRecords % everyPage == 0) Plj >+XRO
totalPage = totalRecords / everyPage; )<(3 .M
else }U ue}VOA
totalPage = totalRecords / everyPage + 1 ; J;*2[o.N
Mb:>
return totalPage; !uW;Ea?
} 8DkZ@}
o3cE.YUF
privatestaticboolean hasPrePage(int currentPage){ PS$g*x
return currentPage == 1 ? false : true; 0iI|eE o
} M3!4,_!~
!QlCt>{
privatestaticboolean hasNextPage(int currentPage, 9Ecc~'f
pmc)$3u
int totalPage){ ib%'{?Q.
return currentPage == totalPage || totalPage == k2/t~|5
h{ T{3
0 ? false : true; Vl/fkd,Z
} ^Eif~v
te;VGpv.
:_[pZ;-@
} y*e({fio_
sL],@z8<k
{RN-rF3w
hMyN$7Z
:"'*1S*
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。 O`Y@U?^N
s0m k<>z
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 /HVxZ2bar
*FFD G_YG?
做法如下: 0@wXE\s
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)2ESX
8Om4G]*|,
的信息,和一个结果集List: XwIhD
java代码: %^l&:\ hy
R>hL.+l.
k>F>y|m
/*Created on 2005-6-13*/ \3T[Cy|5|
package com.adt.bo; d>O/Zal
PQ 2rNY6
import java.util.List; a
y$CUw
pfQ3Y$z
import org.flyware.util.page.Page; YBL.R;^v
w1LZ\nA<
/** gjzU%{T?
* @author Joa ',!>9Dj
*/ r0s(MyI
publicclass Result { {hoe^07XK
4+:'$Nw
private Page page; Ctbc!<@o
:A+}fBIN
private List content; "a-;?S&
mhI
/** {7Hc00FM
* The default constructor 7c83g2|%
*/ %awr3h>$
public Result(){ S59^$
super(); tA^CuJR
} HV{W7)
0:$pJtx"
/** O~|Y#T
* The constructor using fields xy]oj
* z.;!Pj
* @param page r<B
pX["
* @param content &q +l5L"
*/ C=t9P#g*.
public Result(Page page, List content){ =7F?'&LC
this.page = page; 0nZQ"{x
this.content = content; B:ugEAo_
} y?Pw6;e.
{a]u
/** 4'"WD0
* @return Returns the content. =R)w=ce
*/ 8?ip,Q\
publicList getContent(){ 9\uBX.]x
return content; [#%@,C
} u/ri
{neP{
I~4!8W-Y
/** ?kS#g
* @return Returns the page. `A<2wd;
*/ K{:[0oIHc
public Page getPage(){ x,HD,VQR/
return page; 55/)2B2J
} KE-0/m4yJ
)hC3'B/[Y
/** & jm1
* @param content mV+9*or
* The content to set. lUdk^7:M
*/ tT+W>oA/M
public void setContent(List content){ F<b/)<Bm=
this.content = content; Rh%@N.Z*
} _w2%!+'
h]/3doP
/** gAgF$H .
* @param page z
pDc~ebh
* The page to set. \Nk578+AA
*/ sQ+s3x1y
publicvoid setPage(Page page){ 0"Zxbgu)
this.page = page; ,y@WFRsx
} R ^ZOcONd-
} mY]o_\`
cPkP/3I]h
S VypR LVB
5}a.<
K+~1z>&
2. 编写业务逻辑接口,并实现它(UserManager, 5!aI~(3<
~[=d{M!$W
UserManagerImpl) D=K{(0{"/,
java代码: G
@EEh.s9
v`S ;.iD
O*lE0~rJ
/*Created on 2005-7-15*/ IC1nR
u2I
package com.adt.service; DXQ]b)y+N
c}s#!|E0v
import net.sf.hibernate.HibernateException; *=tA },`\7
y6Ez.$M
import org.flyware.util.page.Page; LW#U+bv]Dq
+S'm<}"1
import com.adt.bo.Result; 8_pyfb
'}:(y$9.`
/** ].sD#~L_
* @author Joa C-g,uARX(r
*/ /1_O5'5+v
publicinterface UserManager { wPq9`9 #
.hUlI3z9
public Result listUser(Page page)throws WJ^]mpH9
E!uQ>'iq.
HibernateException; Qg0%rbE
(" +clb`
} =uEpeL~d;+
2vhP'?;K
HD3WsIim*
Z!*6;[]SfG
~NLthZ(O
java代码: ?zfm"o
KK{_s=t%<
lM#,i\8Q
/*Created on 2005-7-15*/ QO>';ul5
package com.adt.service.impl; 7]ySj<1
aX*9T8H/
import java.util.List; @pH6FXVGzt
]z#)XW3#i
import net.sf.hibernate.HibernateException; =)Fb&h]G^
5z\,]
import org.flyware.util.page.Page; F_I!qcEQ
import org.flyware.util.page.PageUtil; %Y"pVBc
?uU_N$x
import com.adt.bo.Result; $zF%F.rln
import com.adt.dao.UserDAO; l]j;0 i
import com.adt.exception.ObjectNotFoundException; EPR85[k
import com.adt.service.UserManager; Q [C26U
$$EEhy
/** 1OqVV?oz
* @author Joa o+)y!
*/ <L<^uFB
publicclass UserManagerImpl implements UserManager { u /DE
q*tGlM@R?
private UserDAO userDAO; !\'H{,G
:{VXDT"
/** i7cUp3
* @param userDAO The userDAO to set. *e<}hmDr
*/ Uq`6VpZ
publicvoid setUserDAO(UserDAO userDAO){ _+Sf+ta
this.userDAO = userDAO; o^Lq8u;i*
} E" >`
LbYIRX
/* (non-Javadoc) [9V}>kS)
* @see com.adt.service.UserManager#listUser B#+n$5#FK
+-9-%O.(;
(org.flyware.util.page.Page) wm Ie x
*/ nkTdn
public Result listUser(Page page)throws gsUF\4A(J
!YI<A\P
HibernateException, ObjectNotFoundException { o!U(=:*b
int totalRecords = userDAO.getUserCount(); Zu~w:uNmU
if(totalRecords == 0) u&[L!w
throw new ObjectNotFoundException 9
W|'~r
FP}I+Ys
("userNotExist"); o|q5eUh=EY
page = PageUtil.createPage(page, totalRecords); @vXXf/
List users = userDAO.getUserByPage(page); ew~?&=
returnnew Result(page, users);
U@CAQ?
} B}. :7,/0
nK)1.KVN
} *|y$z+g/
WRwx[[e6z
Hc[@c)DH
uqU&k@
yla-X|>
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 t_*x.{x-
{QaO\{J=
询,接下来编写UserDAO的代码: 4;
0#Z^p
3. UserDAO 和 UserDAOImpl: !]E]Xd<
java代码: $ZZ?*I
K=E+QvSG
gat;Er
/*Created on 2005-7-15*/ VH<d[Mj
package com.adt.dao; WPAUY<6f
;\6@s3
import java.util.List;
kPiY|EH
mEu2@3^E }
import org.flyware.util.page.Page; N~fE&@-
ULBEe@s
import net.sf.hibernate.HibernateException; =wW M\f`=
|=0w_)Fa]
/** </@5>hx/
* @author Joa x
DNu'
*/ j@^zK!mO
publicinterface UserDAO extends BaseDAO { c
q[nqjC=
-Eig#]Se3
publicList getUserByName(String name)throws =:xX~,qmv
ARt{ 2|
HibernateException; !8T04988j
B|yz~wuS
publicint getUserCount()throws HibernateException; hN~H8.g
'+Z Jf&Ox
publicList getUserByPage(Page page)throws w{|`F>f9
*s-s1v
HibernateException; );_ /0:
oU @!R
} U<Qi`uoj!
+N7<[hE;
lJ]QAO
K*2s-,b *
u\=
05N6G
java代码: Otx>S' 5
<[-{:dH,5
I )vR
/*Created on 2005-7-15*/ Z 4i5,f
package com.adt.dao.impl; Ha/Qz'^S;
= Ul"{T<
import java.util.List; S.B?l_d^
nM:<l}~v{
import org.flyware.util.page.Page; U`8Er48X
mMOgx
import net.sf.hibernate.HibernateException; XP0;Q;WF}
import net.sf.hibernate.Query; rQGInzYp
KK1?!7
import com.adt.dao.UserDAO; !Q_Wbu\U
G`jvy@
/** b_6cK#
* @author Joa 7FyE?
*/ GnUD<P=I
public class UserDAOImpl extends BaseDAOHibernateImpl [KHlApL
QV HI}3~
implements UserDAO { ='w 2"4
2Xk;]-T!
/* (non-Javadoc) r|*_KQq
* @see com.adt.dao.UserDAO#getUserByName B(vCi^
a#i|)[
(java.lang.String) + 9|0\Q
*/ 00f'G2n
publicList getUserByName(String name)throws .5!`wwVi
,7:-V<'Yv
HibernateException { [7HBn
String querySentence = "FROM user in class 1 I.P7_/
~Ey+
com.adt.po.User WHERE user.name=:name";
FXn98UF Y
Query query = getSession().createQuery "4Q_F3?_`
UcD<vg"p
(querySentence); Ayg^<)JWh
query.setParameter("name", name); mDZA\P_
return query.list(); (~{Y}n]s
} 94dd )/a
v<g~EjzCf
/* (non-Javadoc) febn?|@
* @see com.adt.dao.UserDAO#getUserCount() u/S>*E
*/ w xte
publicint getUserCount()throws HibernateException { 7B\NP`l
int count = 0; <%%)C>l
String querySentence = "SELECT count(*) FROM Qk>U=]U
(`E`xb@E,=
user in class com.adt.po.User"; %,z;W-#gnY
Query query = getSession().createQuery 4%8den,|
?E+f<jol
(querySentence); u kZK*Y9P
count = ((Integer)query.iterate().next ]Q0bL
%xG<hNw/
()).intValue(); nh5=0{va|L
return count; _izjvg
} g] }!
bHx@
/* (non-Javadoc) tJ6Q7
J;n
* @see com.adt.dao.UserDAO#getUserByPage ~8mz.ZdY
hgW1g#
(org.flyware.util.page.Page) %`T}%B
*/ TIl 'Z7
publicList getUserByPage(Page page)throws ENr#3+m$;
#\}FQl6
HibernateException { Ug546Bz
String querySentence = "FROM user in class {5{VGAD&]>
na~ FT[3C
com.adt.po.User"; Me?I8:/
Query query = getSession().createQuery k[D,du')
jVN06,3z
(querySentence); #-f9>S9_
query.setFirstResult(page.getBeginIndex()) ZYY2pY 1
.setMaxResults(page.getEveryPage()); P*7G?
return query.list(); YZ8[h`z
} >K4Nn(~ys
0&I*)Zt9x
} Ly^bP>2i
/@1YlxKF
52Lp_M
%Gyn.9\
l=l$9H,
至此,一个完整的分页程序完成。前台的只需要调用 6s~B2t:Y
dm=?o
userManager.listUser(page)即可得到一个Page对象和结果集对象 ercXw7{
,<#Rk'y$
的综合体,而传入的参数page对象则可以由前台传入,如果用 ys`oHSf
3T0-RP*
webwork,甚至可以直接在配置文件中指定。 iEr?s-or
ilJ`_QN
下面给出一个webwork调用示例: g~.#.S ds
java代码: Haktr2I
r5nHYV&7
gYrB@W;2
/*Created on 2005-6-17*/ FNF `Z
package com.adt.action.user; N*&T)a
]ilLed
import java.util.List; wf]?:'}
]4[%Sv6]G
import org.apache.commons.logging.Log; 2#^g] o-N
import org.apache.commons.logging.LogFactory; `JiWS
import org.flyware.util.page.Page; Q
Kr/
^JMG'@x
import com.adt.bo.Result; |,oLZCNa
import com.adt.service.UserService; T!y 9v5
import com.opensymphony.xwork.Action; d^6-P
R_
H,GjPIG
/** 9d/-+j'
* @author Joa _L~ 3h
*/ x=7:D
publicclass ListUser implementsAction{ bsU$$;
Y %bb-|\W
privatestaticfinal Log logger = LogFactory.getLog %}zkmEY.e
yc3/5]E&
(ListUser.class); )}N:t:rry
.|go$}Fk
private UserService userService; p~8 O6h@J
JZxA:dg
l
private Page page; c,;VnZ
9wC
_^(1Qb[
privateList users; t'At9<ib
y6d!?M(0U
/* YzG?K0O%
* (non-Javadoc) 2[pOGc$
* 2>k*9kyp
* @see com.opensymphony.xwork.Action#execute() e_|<tYx><
*/ (T pnJq
publicString execute()throwsException{ v .C
Result result = userService.listUser(page); "PRHQW
page = result.getPage(); 8M,o)oH
users = result.getContent(); Q0jg(=9wP
return SUCCESS; ]nRf%Vi8g
} 57;0,k5Gy
M_%KhK
/** hLZfArq}
* @return Returns the page. A_U=`M=-
*/ XtZd%
#2},
public Page getPage(){ ibQ
xL3
return page; +kYp!00
} ]k]bLyz\J
g.`Ntsi$wI
/** "k @[7
7
* @return Returns the users. Pi?G:IF
*/ U7n#TPet
publicList getUsers(){ #>:S&R?2t
return users; :nb|WgEc
} EFVZAY"+!;
ETU-6qFtO
/** K{DmMi];I
* @param page !=,zy
* The page to set. ] WYub1
*/ >/4[OPB0R
publicvoid setPage(Page page){ #V/{DPz
this.page = page; 52o^]
} 0F- +)S?M[
PZJn/A1
/** T}Wbt=\M
* @param users u
e
* The users to set. dg#Pb@7a
*/ C|Gk}
publicvoid setUsers(List users){ VV$#<D<)
this.users = users; j?o6>j
} W>+`e]z
RiR],Sj
/** x!s=Nola
* @param userService QbHX.:C
* The userService to set. 9QHj$)?k,
*/ yZp/P %y
publicvoid setUserService(UserService userService){ MLTS<pW/
this.userService = userService; gS[B;+d
} ;g#nGs>
} 7w9'xY
tx<^PV2
hVB(*WA^D
,Il) t H
^}vf
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, ZEDvY=@a
q+8de_"]
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 AHuIA{AdUR
[+b8
!'|&
么只需要: 19O
java代码: -U$;\1--
hTEb?1CXU
[6g$;SicT
<?xml version="1.0"?> }8}`A\dgV
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork J^#g?RHN>m
\DE,
,
1.0//EN" "http://www.opensymphony.com/xwork/xwork- C"5P7F{
;?iu@h
1.0.dtd"> i qxMTH#!
1|G\&T
<xwork> nJv=kk1|o
T<Y*();Zo
<package name="user" extends="webwork-
2<8l&2}7]
s1[.L~;J
interceptors"> rt*>)GI]b
5o4KV?"
<!-- The default interceptor stack name b1'849i'y=
`IBNBJy
--> ->;2CcpHB
<default-interceptor-ref lcpiCZ
Z VdQ$
name="myDefaultWebStack"/> a"O;DYh
p]y.N)a
<action name="listUser" SfY 5Xgp
G,<d;:
class="com.adt.action.user.ListUser"> T3=h7a %=
<param [x,
`)Fk
-:r<sv$
name="page.everyPage">10</param> 0>-}c>
<result Ex]Ku
xuqG)HthRS
name="success">/user/user_list.jsp</result> w1zMY:9
</action> #M!{D
<{ v
%2
</package> b[:m[^
7p!f+\kM
</xwork> C`qV+pV
JURu>-i
l9j=;h
HWFTI /]
*(vh |
[h
B$%i]\<
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 hop|
xtai;
XGe;v~L
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 g#6R(
]FvGAG.*
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 "B +F6
/!>OWh*~
4IY|<
]3 GO_tL
?9eiT:2
我写的一个用于分页的类,用了泛型了,hoho zNo"P[J8
%{V7|Azt
java代码: Fo;J3<U)
yoe@]c=
RSB+Saf.8
package com.intokr.util; GJS(
wXnVQ-6H
import java.util.List; =tA;JB
iC! 6g|]X
/** 'ks .TS&
* 用于分页的类<br> 6q`)%"4k
* 可以用于传递查询的结果也可以用于传送查询的参数<br> 8n2;47 a
* <f.Eog
* @version 0.01 .dxELSV
* @author cheng >e-0A
*/ w9"~NK8xzM
public class Paginator<E> { ;{R;lF,
privateint count = 0; // 总记录数 jHHCJOHB8
privateint p = 1; // 页编号 O+<+yQl
privateint num = 20; // 每页的记录数 "8?Fl&=Q
privateList<E> results = null; // 结果 Dz2Z
(EXI~
}Cfl|t<5f
/** |-*50j l
* 结果总数 S{MB$JA
*/ U%BtBPL
publicint getCount(){ E|RC|Sz=u
return count; "+&pd!\
} GCr]x '
n?D/bX p
publicvoid setCount(int count){ ?5};ONjN
this.count = count; #J5_z#-Q;
} KMqGWO*
/f oI.S
/** D(<0tU^[
* 本结果所在的页码,从1开始 W)o*$cu
* >PQ?|Uk
* @return Returns the pageNo. &K