Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 aF*KY<w
?YE'J~0A6
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ;iT@41)7
v:\8
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 4/KGrY!ck
4<V%7z_.B
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 3y^PKIIrt
%Ms"LoK
。 X$*MxMNs
Pq\
`0/4_
分页支持类: L\0;)eJ#M
N>ncv
java代码: w>#{Nl7gz
]oT8H?%*Y
Dzd[<Qln
package com.javaeye.common.util; n/W@H Im#
[|iWLPO1&k
import java.util.List; +85#`{ D
y7CC5S?
publicclass PaginationSupport { 5k:SD7^b
CD^C}MB
publicfinalstaticint PAGESIZE = 30; YcQ$nZAU
\^o8qw'pt
privateint pageSize = PAGESIZE; LR:PSgy
$Lj~ge3#
privateList items; uqz HS>GM
rU6F$I=
privateint totalCount; Cws;6i*=@
s!k7Wwj
privateint[] indexes = newint[0]; G5WQTMzf&
d]A.=NAc
privateint startIndex = 0; PP*6nW8
u<L<o2
public PaginationSupport(List items, int Sg%h}]~
wnioIpRkh
totalCount){ { 6
#Qm7s-
setPageSize(PAGESIZE); -VZn`6%s
setTotalCount(totalCount); jY;T:C-T
setItems(items); Wd`*<+t]
setStartIndex(0); cNbH:r"Ay
} oW}nr<G{<
k8KRVXgx
public PaginationSupport(List items, int )Ehi8
LN z
totalCount, int startIndex){ su$IXI#R-&
setPageSize(PAGESIZE); .7K)'
setTotalCount(totalCount); j_I[k8z
setItems(items); In[rxT~K}Q
setStartIndex(startIndex); BiY-u/bH9a
} zA%YaekJ
mkE_ a>
public PaginationSupport(List items, int sKy3('5;
<OH{7>V
totalCount, int pageSize, int startIndex){ WC Tmf8f
setPageSize(pageSize); =Bg $OX
setTotalCount(totalCount); #B!|sXC
setItems(items); l4s*+H$vd?
setStartIndex(startIndex); jKh:}yl4
} D`|8Og
L@5sY0 M
publicList getItems(){ }SfS\b{|~
return items; A%[e<vj9
} reQr=OAez
-F. c<@*E
publicvoid setItems(List items){ J&2J6Eq
this.items = items; qX[{_$^Q
} Y/x>wNW
pV8_i7\
publicint getPageSize(){ 9^L{)t>
return pageSize; lRk_<A
} 3"BSP3/[l
~'V&[]nh8
publicvoid setPageSize(int pageSize){ 0OXl`V`w
this.pageSize = pageSize; A"e4w?
} +>&i]x(b
YdZ9##IU3
publicint getTotalCount(){ #<LJns\t
return totalCount; ?gsPHP US
} j.&Y'C7GOC
o%b6"_~%3
publicvoid setTotalCount(int totalCount){ /7 8zs-
if(totalCount > 0){ ;J@U){R
this.totalCount = totalCount; XS}-@5TI
int count = totalCount / 216`rQ}z
)x,/+R]{8l
pageSize; 2tb+3K1
if(totalCount % pageSize > 0) u`.3\Geh
count++; 4se6+oJe
indexes = newint[count]; E<ILZpP
for(int i = 0; i < count; i++){ r6eZ-V`4
indexes = pageSize * _1?nLx7n
w%?Zb[!&
i; 5tI#UBha
} zfD@/kU
}else{ &cWC&Ws"
this.totalCount = 0; GlHP`&;UH
} +/[L-&,
} x?UAj8z6
*rgF[
:
publicint[] getIndexes(){ y6dQ4Whv&
return indexes; iT;Ld $!{f
} 4VHWoN"U
VFrp7;z43
publicvoid setIndexes(int[] indexes){ VA>0Y
this.indexes = indexes; p,V%wGM
} k|czQ"vaI
)oALB vX
publicint getStartIndex(){ =]r2;014
return startIndex; =H`yzGt
} cL<,]%SkE
X
}`o9]y
publicvoid setStartIndex(int startIndex){ e^<'H
if(totalCount <= 0) 4ClSl#X#i
this.startIndex = 0; f}~=C2R1<!
elseif(startIndex >= totalCount) Q#X'.](1
this.startIndex = indexes p+pu_T;~
&mW7FR'(
[indexes.length - 1]; cyLl,OA
elseif(startIndex < 0) S0Ur{!9\#^
this.startIndex = 0; B^!-%_q
else{ -e_|^T"
this.startIndex = indexes QH,Fw$1
ym p
ik.'
[startIndex / pageSize]; .l hS
} g[R4/]K^$
} |ZM>UJ
aX~Jk >a0
publicint getNextIndex(){ 76o3Sge:
int nextIndex = getStartIndex() + 7|o!v);uR
k*u6'IKi.4
pageSize; a)4%sX*I
if(nextIndex >= totalCount) .EPv4[2%F8
return getStartIndex(); Qqi?DW1)-
else b9ud8wLE[
return nextIndex; Uqz.Q\A
} QI'-I\Co
)@p?4XsT4J
publicint getPreviousIndex(){ .R@s6}C`}=
int previousIndex = getStartIndex() - Q_Br{
`c
M KX+'p\w
pageSize; LzJ`@0RrX
if(previousIndex < 0) <$@I*xk[
return0; ,N_/J4Us
else wMw}3qX$j
return previousIndex; U {Knjo S
} o*artMkG
v
k=|TE
} "hQGk
cRMyYd J o
:
h(Z\D_
gkX7,J-0
抽象业务类 0Vrs bkS
java代码: Z^}[CQ&Am
{/(.Bpld
}a/z.&x]V
/** 'Hzc"<2Y\
* Created on 2005-7-12 6uv~.-T<l
*/ z(8G=C
package com.javaeye.common.business; piH0_7qr
&]Uo>Gb3!q
import java.io.Serializable; MD*dq
import java.util.List; m ?; ?I]`
,2rfN"o
import org.hibernate.Criteria; h1"|$
import org.hibernate.HibernateException; C=|8C70[%N
import org.hibernate.Session; { =\Fc`74
import org.hibernate.criterion.DetachedCriteria; B;F~6i
import org.hibernate.criterion.Projections; ahIDKvJ4
import ij|>hQC5i
w[D]\>QHa
org.springframework.orm.hibernate3.HibernateCallback; TqL+^:cq
import ZDAW>H<
wx[m-\
org.springframework.orm.hibernate3.support.HibernateDaoS ~#4FL<W
8MI8~
upport; Mo<q(_ZeRP
c_CVZR?
import com.javaeye.common.util.PaginationSupport; *Wvk~
Bu&9J(J1
public abstract class AbstractManager extends _si 5z
@tPr\F
HibernateDaoSupport { K3<A<&W_-
;BqCjS%`N
privateboolean cacheQueries = false; 4;W{#jk
M|j=J{r
privateString queryCacheRegion; k0O5c[j
%LzARTX
publicvoid setCacheQueries(boolean w~'}uh
}3 _b%{
cacheQueries){ -ycdg'v
this.cacheQueries = cacheQueries;
mhX66R
} WR`NISSp
J^ewG
publicvoid setQueryCacheRegion(String 7H?xp_D
4Ngp -
queryCacheRegion){ j}B86oX
this.queryCacheRegion = yci} #,nb
+}M3O]?4
queryCacheRegion; `'^o45
} \v6lcAL-
Z\U r F0
publicvoid save(finalObject entity){ T&MhSJf#
getHibernateTemplate().save(entity); p}h.2)PO
} @{q<"hT
\o/eF&
publicvoid persist(finalObject entity){ M2w'cdHk
getHibernateTemplate().save(entity); 9&uf
} Dw7Xy}I/
\>pm (gF
publicvoid update(finalObject entity){ QK#wsw
getHibernateTemplate().update(entity); ^9Cu?!xu0
} A7%/sMv
'Etq;^H
publicvoid delete(finalObject entity){ :{ZwzJ
getHibernateTemplate().delete(entity); Q!qD3<?5
} *Cf!p\7!
ppNMXbXR
publicObject load(finalClass entity, NN=^4Xpc:
c?EvrtND
finalSerializable id){ KK3iui
return getHibernateTemplate().load GF8wKx#J
Y I;iG[T,&
(entity, id); Hnk&2bY
} >;hAw!|#
i>,AnkI&
publicObject get(finalClass entity,
U-4F
~Ck OiWC0
finalSerializable id){ :>;F4gGVG
return getHibernateTemplate().get jLt3jN
LtX53c
(entity, id); e2NK7
} v\4<6Z:4
*9$SFe|&n:
publicList findAll(finalClass entity){ jq*`| m;Q
return getHibernateTemplate().find("from j}",+Hv
0"%dPKi
" + entity.getName()); ;aWk-
} r
*6S1bW
7+hF1eoI
publicList findByNamedQuery(finalString viUJ4Pn
TUC)S&bC
namedQuery){ YfB)TK\W9/
return getHibernateTemplate M @-:iP
u "jV#,,
().findByNamedQuery(namedQuery); {9}CU~R
} '!`\!=j-`
n`&D_AbQ
publicList findByNamedQuery(finalString query, RPgz"-
J](NCD
finalObject parameter){ @WS77d~S
return getHibernateTemplate 86 e13MF
;J TY#)Bh
().findByNamedQuery(query, parameter); e9RYk:O
} [V:~j1{3
$8UW^#Bpq
publicList findByNamedQuery(finalString query, $7DW-TA
"QNQ00[T`>
finalObject[] parameters){ w/ rQOHV{
return getHibernateTemplate bV&9>fC
bA#9'Qu^j
().findByNamedQuery(query, parameters); 2<I=xWwFA
} f%@~|:G:
=dDPQZEin
publicList find(finalString query){ `}#rcDK
return getHibernateTemplate().find lMGO4U[z
m","m
(query); ?l?l<`sTO
} =3-?$
5kTs7zJ^
publicList find(finalString query, finalObject Y06^M?}
{@)ZXg
parameter){ 15Mtlb
return getHibernateTemplate().find hFv{?v
ga%\n!S
(query, parameter); O8$~dzf,2
} w=WF$)ZU
6d6cZGS[:
public PaginationSupport findPageByCriteria )wM%Ul<s
Ld}?da Pj
(final DetachedCriteria detachedCriteria){ Fb]+h)on
return findPageByCriteria !P=Cv=
!9_(y~g{N
(detachedCriteria, PaginationSupport.PAGESIZE, 0); ftxL-7y%
} 4-x<^
ev=
b/:wpy+9Z
public PaginationSupport findPageByCriteria A5yVxSF
U _5`
(final DetachedCriteria detachedCriteria, finalint uW!XzX['
MmjZq
startIndex){ lxL.ztL
return findPageByCriteria ylZQwICk
>pfeP"[(3
(detachedCriteria, PaginationSupport.PAGESIZE, J@I>m N1\
F&czD;F
startIndex); :IS?si5|
} p lnH
+mVAmG@
public PaginationSupport findPageByCriteria ~?ezd0
)xV37]
(final DetachedCriteria detachedCriteria, finalint PO"lY'W.U
'l.tV7
pageSize, )dhR&@r*w
finalint startIndex){ w!20
return(PaginationSupport) 49QsT5b)
F*PhV|XU
getHibernateTemplate().execute(new HibernateCallback(){ -/JEKwc
publicObject doInHibernate (^}t
?lsK?>uU
(Session session)throws HibernateException { .u7}p#
Criteria criteria = xyGwYv>*KO
34u[#O{2
detachedCriteria.getExecutableCriteria(session); cr!W5+r
int totalCount = Jh
E C
iX+8!>Q
((Integer) criteria.setProjection(Projections.rowCount JKM(fX+
0AQ4:KV(Y
()).uniqueResult()).intValue(); "?3=FBp&
criteria.setProjection dRJ
](Gw
sq_>^z3T
(null); hI86WP9*
List items = F0U %m
}MRgNr'k
criteria.setFirstResult(startIndex).setMaxResults >6o <Q
%`&n ;K.c
(pageSize).list(); p<r<Y%
PaginationSupport ps = 7_1 Iadb
)-3~^Y#r_
new PaginationSupport(items, totalCount, pageSize, t`K9K"|k
f1_; da
startIndex);
pRobx
return ps; L K#A
} o7!A(Eu
}, true); 8IlUbj
} $?PI>9g!
?l9sj]^w
public List findAllByCriteria(final XZ
|L D#
:.+w'SEn4M
DetachedCriteria detachedCriteria){ {:gx*4}q8
return(List) getHibernateTemplate HqWWWCWal
Zmyq6.1q~
().execute(new HibernateCallback(){ kS-BB[T
publicObject doInHibernate I_ZJnu<
w"9h_;'C_
(Session session)throws HibernateException { Z5q%L!4G
Criteria criteria = ~JL
qh
k={D!4kKz
detachedCriteria.getExecutableCriteria(session); b\}a
return criteria.list(); caQ1SV^{9
} d%P2V>P
}, true); FSQB{9,H
} \|Af26
.z,-ThTH@\
public int getCountByCriteria(final ElW\;C:K*
L>14=Pr^(
DetachedCriteria detachedCriteria){ Z2]0brV
Integer count = (Integer) mKe6rEUs|
=T[P
getHibernateTemplate().execute(new HibernateCallback(){ daKZ*B|
publicObject doInHibernate gtuSJ+up
s=jmvvs_V}
(Session session)throws HibernateException { [}4zqY{
Criteria criteria = #g6 _)B=S
H2jypVs$2
detachedCriteria.getExecutableCriteria(session); A5Jadz~
return Dr.eos4 ~
;
pBLmm*F
criteria.setProjection(Projections.rowCount u;t<rEC2
1Gr^,Ry
()).uniqueResult(); Eg`~mE+a
} M$EF 8
}, true); UmVn: a
return count.intValue(); <9pI~\@w
} F7=9> ,
} vX }iA|`#
^`yhN
@sn:%/x _
"Y+VNS
`?$-T5Rr
W@AHE?s6g
用户在web层构造查询条件detachedCriteria,和可选的 4xW~@meNB
2`]c&k;]
startIndex,调用业务bean的相应findByCriteria方法,返回一个 %.$!VTO"
uY~mi9E
PaginationSupport的实例ps。 [s^pP2
/1LN\Eu
ps.getItems()得到已分页好的结果集 ]&]G
ps.getIndexes()得到分页索引的数组 @TALZk'%
ps.getTotalCount()得到总结果数 |2^mCL.r
ps.getStartIndex()当前分页索引 @M\JzV4 A[
ps.getNextIndex()下一页索引 C,W@C
ps.getPreviousIndex()上一页索引 c:K/0zY
zdJPMNHg
Nt8"6k_
\*CXXp`
wBpt
W2jA
ia\Gmh
%t&Lq }e
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 h:pgN,W}
PNAvT$0LaZ
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 rmw}Ui"
2Di~}* 9&
一下代码重构了。 bsu?Q'q
]B(}^N>WH
我把原本我的做法也提供出来供大家讨论吧: l#cVQ_^"
Kc]cJ`P4.
首先,为了实现分页查询,我封装了一个Page类: mdL T7
java代码: DH.`
|E K6txRb
RbUir185Y
/*Created on 2005-4-14*/ +DSbr5"VlB
package org.flyware.util.page; )q'dX+4=eL
wrJQkven-
/** ^kNVQJiZyG
* @author Joa =Jl\^u%H(x
* [UkcG9
*/ nycJZ}f:wP
publicclass Page { jF6Q:`k
mL1ZSX
o!
/** imply if the page has previous page */ 1R-0b{w[
privateboolean hasPrePage; 1W*Qc_5 v1
]Yt3@ug_f
/** imply if the page has next page */ g s1
privateboolean hasNextPage; |6-9vU!LK?
60~*$`
/** the number of every page */ /TbJCZ
privateint everyPage; bzpi7LKN
$]?pAqU\
/** the total page number */ *><j(uz!
privateint totalPage;
'*Y mYU
h(q4
B~
/** the number of current page */ BpA7
z /
privateint currentPage; KD#zsL)3
Qq{tX
/** the begin index of the records by the current wa[J\lW
N/-(~r[
query */ CPa+?__B
privateint beginIndex; gm]q<~eMW
?z)2\D
\Yp"D7:Qi
/** The default constructor */ R5MN;xG^
public Page(){ Usht\<{
o$bQ-_B`
} Y]R=z*i%
EO'+r[Y
/** construct the page by everyPage 9J%O$sF
* @param everyPage yT%<
t
* */ br0\O
public Page(int everyPage){ +
,]&&
this.everyPage = everyPage; q:>`|~MX
} DDIRJd<J
"c~``i\G
/** The whole constructor */ zhE4:g9v
public Page(boolean hasPrePage, boolean hasNextPage, Fc=F2M o?
D3 +|Os)
M&zB&Ia"'
int everyPage, int totalPage, 2:.$:wS
int currentPage, int beginIndex){ $m>( kd1
this.hasPrePage = hasPrePage; ]nV_K}!w
this.hasNextPage = hasNextPage; jMWTNZ
this.everyPage = everyPage; !K_<7iExI\
this.totalPage = totalPage; \Q`#E'?
this.currentPage = currentPage; LCRWC`%&
this.beginIndex = beginIndex; hBZh0xy
} :n<l0
~>]Ie~E: (
/** fX:G;vYn
* @return f3,Xb
]h
* Returns the beginIndex. *s1o?'e
*/ !N:w?zsp
publicint getBeginIndex(){ /jaO\t'q
return beginIndex; ?~^p:T
} "
d~M\Az
K~&3etQF
/** BR6HD7G
* @param beginIndex z,qNuv"W
* The beginIndex to set. :'H}b*VWx
*/ -K^(L#G
publicvoid setBeginIndex(int beginIndex){ muK)Yw[#N
this.beginIndex = beginIndex; ;(g"=9e
} oPAc6ObOV~
-uAGG?ZER
/** M+=q"#&
* @return ' z^v}~
* Returns the currentPage. ,=ju^_^sA
*/ _Axw$oYS
publicint getCurrentPage(){ %AgCE"!
return currentPage; 5=poe@1g
} `EP-Qlm
N:^4OnVR
/** 00W_XhJ
* @param currentPage <1V>0[[e
* The currentPage to set. zS\m8[+]
*/ ='/#G0W
publicvoid setCurrentPage(int currentPage){ }q/[\3
this.currentPage = currentPage; 5',b~Pp
} R;/LB^X]
up3mum
/** D1fUEHB}A8
* @return )A;jBfr
* Returns the everyPage. o5z&sRZ
*/ Xp|$z ~
publicint getEveryPage(){ DqH]F S?]
return everyPage; \iwUsv>SB
} wzI*QXV2s
d D^?%,a
/** 1kc{`oL
* @param everyPage n
u>6UjV
* The everyPage to set. {6*UtG
*/ n*=Tm
KQ
publicvoid setEveryPage(int everyPage){ RCGpZyl
this.everyPage = everyPage; ~bjT,i
} y3 S T"U
|R Qa.^.
/** .w~L0(
* @return 1 rmN)
* Returns the hasNextPage. 6:TA8w|
*/ p_sqw~)^%
publicboolean getHasNextPage(){ .O4=[wE!U
return hasNextPage; `? f sU
} TsRbIq[
w4&-9[@Y
/** ,S3uY6,
* @param hasNextPage wlX
K2D
* The hasNextPage to set. `\-mqe
*/ 28,HZaXhc
publicvoid setHasNextPage(boolean hasNextPage){ 5sMyH[5zY
this.hasNextPage = hasNextPage; hcD.-(-;)
} iEBxBsz_
fVBu?<=d
/** 6[1lK8o
* @return 0Szt^l 7
* Returns the hasPrePage. Fo|
rRI2
*/ k:E+]5
publicboolean getHasPrePage(){ Bk4|ik}
return hasPrePage; |fWR[\NU
} ^#j{9FpPs
2Y9@[
/** gG6BEsGa,
* @param hasPrePage BG@[m
* The hasPrePage to set. -Ly A
*/ xHwcP2 1
publicvoid setHasPrePage(boolean hasPrePage){ A `=.F
this.hasPrePage = hasPrePage; {$-\)K
} _k5-Wd5Ypw
}D#[yE,=\
/** q}7(w$&
* @return Returns the totalPage. !%yd'"6Dl
* ez *O'U
*/ cU=/X{&Om
publicint getTotalPage(){ (@u"
return totalPage; |G>Lud
} a`QKNrA2
m[*y9A1
/** UXV>#U?
* @param totalPage fxX4 !r
* The totalPage to set. +QFY.>KH
*/ Q\v^3u2;m`
publicvoid setTotalPage(int totalPage){ X1~ B
this.totalPage = totalPage; a{8g9a4
} _M}}H3
|/p2DU2
} /H[ !v:U
$P~Tt 4068
\wo'XF3:
EPwM+#|e-
fxk6 q$'
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 J"RmV@|
\rf2Os
个PageUtil,负责对Page对象进行构造: Dmv@ljwO
java代码: 0_-NE4SM/
%Nm69j-5%
qw%wyj7
/*Created on 2005-4-14*/ +q4AK<y-
package org.flyware.util.page; wpPCkfPyL
5U&?P
import org.apache.commons.logging.Log; &8wluOs/5
import org.apache.commons.logging.LogFactory; 3sq(FsT
J#& C&S 2
/** p^QB^HEV
* @author Joa d#G H4+C
* o8lwwM*
*/ -nrfu) G
publicclass PageUtil { e!~x-P5M`
}fKpih
privatestaticfinal Log logger = LogFactory.getLog 27KfT]=
a7Rg!%r
(PageUtil.class); UK xeN[fv
>T~duwS
/** b:}+l;e52
* Use the origin page to create a new page \a\ApD
* @param page JmK[7t
* @param totalRecords BPzlt
* @return -%x9^oQwY
*/ 14v,z;HXj
publicstatic Page createPage(Page page, int
=:-x;
(*2kM|
totalRecords){ 0<T/P+|
return createPage(page.getEveryPage(), wsNM'~(
Mw+8p}E
page.getCurrentPage(), totalRecords); -=D6[DjU<
} d4zqLD$A
^d2bl,1
/** T&`H )o
* the basic page utils not including exception cU'^
Ja?%
Lcyj,R
handler $VCWc#
* @param everyPage $w$4RQk3n
* @param currentPage C7[CfcPA
* @param totalRecords =-qv[;%&6
* @return page #I.Wmfz
*/ n7S~nk
publicstatic Page createPage(int everyPage, int 4^O'K;$leD
MzsDDP+h
currentPage, int totalRecords){ hVcV_
everyPage = getEveryPage(everyPage); u*$ 1e
currentPage = getCurrentPage(currentPage); C}{$'#DV2
int beginIndex = getBeginIndex(everyPage, 2x7%6'
B3^4,'
currentPage); 3;J)&(j0
int totalPage = getTotalPage(everyPage, {~ngI<
E|Lv_4lb=
totalRecords); %r*zd0*<n1
boolean hasNextPage = hasNextPage(currentPage, c|'hs
}~RH!Q1
totalPage); ,4wZ/r>
d
boolean hasPrePage = hasPrePage(currentPage); Dab1^H!KT
=K)au$BE|
returnnew Page(hasPrePage, hasNextPage, GUyc1{6
everyPage, totalPage, vK?{Z^J][
currentPage, 'J`%[,@V
`_;VD?")*l
beginIndex); f`jRLo*L
} Nz&J&\X)tD
yU(k;A-
privatestaticint getEveryPage(int everyPage){ 2Xm\; 7
return everyPage == 0 ? 10 : everyPage; 3' WS6B+
} `" E |
=kspHP<k
privatestaticint getCurrentPage(int currentPage){ =y/VrF.bV
return currentPage == 0 ? 1 : currentPage; Tl!}9/Q5E:
} sGCV um}
WBA0!
g98
privatestaticint getBeginIndex(int everyPage, int F:CqB|
5"[Qs|VjA6
currentPage){ %@{);5[
return(currentPage - 1) * everyPage; .TURS
} ,z?Re)qm
#n'tpp~O
privatestaticint getTotalPage(int everyPage, int \DE`tkV8
l#,WMu&
totalRecords){ v|XEC[F
int totalPage = 0; #isBE}sT{
* SG0-_S
if(totalRecords % everyPage == 0) 7ST[XLwt%}
totalPage = totalRecords / everyPage; Pv`^#BX'
else a"{tq Nc
totalPage = totalRecords / everyPage + 1 ; ?hS n)
m#'2
3
return totalPage; CW Y'q
} tF)aNtX4^
}Jgz#d
privatestaticboolean hasPrePage(int currentPage){ ]y,6
return currentPage == 1 ? false : true; :G|Jcl=r
} @Zs}8YhC
!m$OI:rr
privatestaticboolean hasNextPage(int currentPage, l|fOi A*K
/._wXH
int totalPage){ 7:1c5F~M
return currentPage == totalPage || totalPage == EY(@R2~#J
9z,?DBMvc
0 ? false : true; <dzE5]%\
} C,w$)x5kls
ztG_::QtG]
DB yRP-TH
} +>oVc\$
aT#R#7<Eg
5w`v
3o
!V.'~xj
S)GWr"m-
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。 f4zd(J
=@m|g )
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 Pb.-Z@
A8OV3h6]
做法如下: S*:b\{[f>
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ;""V s6
;h3uMUCml
的信息,和一个结果集List: nVoPTr
java代码:
_tN"<9v.
:JSOj@s
m5sgcxt/
/*Created on 2005-6-13*/ +GWeu0b(~
package com.adt.bo; -lyT8qZ:(
4.7ePbk[E
import java.util.List; S"w$#"EJA
Warz"n]iC
import org.flyware.util.page.Page; fAf sKO*
PKu+$
/** v[ru }/4
* @author Joa rZZueYuXO
*/ O'" &9
publicclass Result { |-I[{"6q$@
Y*0%lq({H
private Page page; r}9qK%C G.
`jJ5us
private List content; S
1|[}nYP
<?,o
{
/** *;O$=PE
* The default constructor ;*+jCL2F
*/ /+Xv(B
public Result(){ ?T70C9
super(); }7vX4{Yn
} A[Juv]X
p,@_A'
/** u
Y/Q]NT
* The constructor using fields &`<j!xlG
* 8(D>ws$
* @param page w@4q D
* @param content uA:|#mO
*/ iU{F\>
public Result(Page page, List content){ c0u!V+V%
this.page = page; f>5{SoM
this.content = content; $r9Sn
} H(!)]dO
8OZc:/
/** o8RagSIo8
* @return Returns the content. '>Y"s|
*/ vj^vzFb K
publicList getContent(){ ;&P%A<[`
return content; JMw1qPJQ
} r<Ll>R
xe|o(!(
/** d$kGYMT"
* @return Returns the page. s*:J=+D]G
*/ VLN=9
public Page getPage(){ 8\`]T%h
return page; (H<S&5[
} S?*v p=
v'S}&zmF]
/** ! SD?
* @param content >.SU=HG;
* The content to set. .ev'd&l.
*/ ^$24231^
public void setContent(List content){ '
V;cA$ $
this.content = content; H6x~mZu_:T
} @X"p"3V
a84^"GH7
/** `pE~M05
* @param page %.BbPR 7?h
* The page to set. a{QHv0goG
*/ %s%v|HDs
publicvoid setPage(Page page){ AIF?+i%H}
this.page = page; fEWS3`Yy
} M/ 0!B_(R
} P8Fq %k
EMmNlj6
y1(smZU
o';sHa'
)Rn}4)9!iT
2. 编写业务逻辑接口,并实现它(UserManager, 7:I`
~ @m
j{IAZs#@>
UserManagerImpl) gpe^G64c`
java代码: IR?ICXmtx
Y>{K2#k
RN'|./N
/*Created on 2005-7-15*/ /fWVgyW>6
package com.adt.service; k ;R*mg*K
Ti!j
import net.sf.hibernate.HibernateException; QSW62]=vV
p V(b>O
import org.flyware.util.page.Page; C+cSy'VIK!
@U_w:Q<9u
import com.adt.bo.Result; kV(}45i]s
M ZB0vdx
/** f[HhLAVGK`
* @author Joa }L{en
*/ ync2X{9D
publicinterface UserManager { =K =FzV'_~
0iinr:=u
public Result listUser(Page page)throws T/V8&'^i
gdRwh
HibernateException; } '. l'%
#qGfo)
} ;+g
p#&i`
:Oo(w%BD]
/-b)`%Q|Y
h )"PPI
@H"~/ m_o
java代码: b !J21cg<L
j~(rG^T
I&U?8
/*Created on 2005-7-15*/ KtU I(*$`
package com.adt.service.impl; YBN@{P$
_p\
import java.util.List; qgvg
MWj
L@2T
import net.sf.hibernate.HibernateException; }a,j1r_Hl&
5*xk8*
import org.flyware.util.page.Page; xI55pj*
import org.flyware.util.page.PageUtil; H`G[QC
DF-`nD
import com.adt.bo.Result; b{=2#J-
import com.adt.dao.UserDAO; 8 qt,sU
import com.adt.exception.ObjectNotFoundException; iv2did4
import com.adt.service.UserManager; x'{L %c>L
)C5<puh
/** m:59f9WXA
* @author Joa :D8V*F6P
*/ ='q:Io?T
publicclass UserManagerImpl implements UserManager { 2i;G3"\
<LIL{g0eX
private UserDAO userDAO; UJ1iXV[h"
hW$B;
/** n$g g$<
* @param userDAO The userDAO to set. DnS#
cs~
*/ aB;syl{
publicvoid setUserDAO(UserDAO userDAO){ Q>] iRx>MZ
this.userDAO = userDAO; {1;j1|CI
} .i>; ?(GH
dkt'~
/* (non-Javadoc) Mf
Dna>,Y
* @see com.adt.service.UserManager#listUser w,cfSF;=tC
.8S6;xnkC
(org.flyware.util.page.Page) Mdsn"Y V
*/ Jiyt,D*wX
public Result listUser(Page page)throws t8DySFT
Xi^3o
HibernateException, ObjectNotFoundException { {5QIQ
int totalRecords = userDAO.getUserCount(); IqJ7'X
if(totalRecords == 0) uIvy1h9m
throw new ObjectNotFoundException 0tv"tA;
z 0]K:YV_
("userNotExist"); 6e3s
|
page = PageUtil.createPage(page, totalRecords); >KmOTM<{
List users = userDAO.getUserByPage(page); 97lM*7h;
returnnew Result(page, users); 8Eyi`~cAiH
} T$5u+4>"
yQ-&+16^
} /_5I}{
`[p*qsp_
Fq>=0 )
R5c
Ya
47.c
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 @.;] $N&J
,)e&u1'
询,接下来编写UserDAO的代码: &Ed7|k]H
3. UserDAO 和 UserDAOImpl: fCdd,,,}
java代码: Kq
e,p{=
r!N)pt<g
HgPRz C
/*Created on 2005-7-15*/ kNP.0
package com.adt.dao;
|7XSC,"
j}7as&
import java.util.List; ||a
5)D
dqMt6b\}
import org.flyware.util.page.Page; pXf!8X&y
x%ju(B>
import net.sf.hibernate.HibernateException; }CnqJ@>C5
R("g ]
/** \>0%E{CR
* @author Joa wDswK "T
*/ T+ey>[
publicinterface UserDAO extends BaseDAO { ,ef"S
r
}'mVD^<+
publicList getUserByName(String name)throws WJbdsPs
NWWag}
HibernateException; c
Q:.V
-\6nT'P
publicint getUserCount()throws HibernateException; @RGVcfCG)
Y?W"@awE"\
publicList getUserByPage(Page page)throws PPSf8-MLW
.|[ZEXq
HibernateException; EN/>f=%
@ c,KK~{
} eSo/1D
[,[;'::=o4
}6ObQa43
0`.3`Mk
F4'g}yOLd
java代码: v'nM=
]H<5]({F
&$F4/2|b%
/*Created on 2005-7-15*/ `##qf@M
package com.adt.dao.impl; iU3)4(R
T&Z%=L_Q
import java.util.List; ,RIGV[u
b*Ny
import org.flyware.util.page.Page;
$0>>Z
GWo^hIfJ
import net.sf.hibernate.HibernateException; sf )ojq6s
import net.sf.hibernate.Query; eAKK uML
R|aA6} /I
import com.adt.dao.UserDAO; y57]q#k
H }w"4s
/** ReE-I/n8f
* @author Joa '{=dEEi
*/ 5N
"fD{v{
public class UserDAOImpl extends BaseDAOHibernateImpl XOgl>1O
V^fSrW]
implements UserDAO { pwo5Ij,~q
?z3c$}
/* (non-Javadoc) -;pZC}Nd3
* @see com.adt.dao.UserDAO#getUserByName a)J3=Z-
#v!(uuq,
(java.lang.String) EOJ k7
*/ "{>I5<:t
publicList getUserByName(String name)throws %"tLs%"7=P
.2?txOKh
HibernateException { k[lYdk
String querySentence = "FROM user in class c4QegN
d~+8ui{-U
com.adt.po.User WHERE user.name=:name"; 8m,PsUp7
Query query = getSession().createQuery Y@x }b{3
HDqPqrWm
(querySentence); T \%{zz_(
query.setParameter("name", name); C"l_78
return query.list(); "q@OMf
} lrSdFJ%
{TT@Mkz_QC
/* (non-Javadoc) (2J_Y*N~>
* @see com.adt.dao.UserDAO#getUserCount() n';"c;Ye)
*/ -L e:%q2
publicint getUserCount()throws HibernateException { FlJ(V
int count = 0; t}m6];
String querySentence = "SELECT count(*) FROM ~5Wr
|qg%{
'Gwa[ |6i
user in class com.adt.po.User"; wn*<.s
Query query = getSession().createQuery 0l-m:6
ghvF%-."1
(querySentence); m NkS!(L6
count = ((Integer)query.iterate().next L B`=+FD
}G^Bc4@b
()).intValue(); 0CXh|AU
return count; XE8~R5
} L~e\uP
2q}M1-^
/* (non-Javadoc) _4qP0LCa
* @see com.adt.dao.UserDAO#getUserByPage |lH~nU.*
A*l(0`aWq
(org.flyware.util.page.Page) v_Om3i9$E
*/ c\GJfsVk
publicList getUserByPage(Page page)throws K"'W4bO#7
&8!*u3
HibernateException { c%1<O!c
String querySentence = "FROM user in class +N0V8T%~z.
g1U
com.adt.po.User"; `P1jg$(eA
Query query = getSession().createQuery 2yqm$i9C
NJJsg^'
(querySentence); >XzCHtEP
query.setFirstResult(page.getBeginIndex()) v4]7"7GuW
.setMaxResults(page.getEveryPage()); Qx,?v|Xg
return query.list(); V0hC[Ilr
} "0Xa?z8"
Bi?.w5
} cU}j
Whu
?DP]#9 /4
;{b 1'
bA]/p%rZ8
:@LFNcWE
至此,一个完整的分页程序完成。前台的只需要调用 I"awvUP]a[
C D#:*
userManager.listUser(page)即可得到一个Page对象和结果集对象 Y9F78=Q
SI_{%~k*B
的综合体,而传入的参数page对象则可以由前台传入,如果用 M$O}roOa
$<^4G
webwork,甚至可以直接在配置文件中指定。 ]'Y
vI!r
0gNwC~IA8
下面给出一个webwork调用示例: ;)ffGg>
java代码: K{[yS B
dRg1I=|{_
,aI 6P-
/*Created on 2005-6-17*/ #;. tVo I
package com.adt.action.user; uS :3Yo
W-mi1l^H{
import java.util.List; ]p3hq1u3&
U85t !U
import org.apache.commons.logging.Log; NJ8QI(^"
import org.apache.commons.logging.LogFactory; 2^ 'X
import org.flyware.util.page.Page; ;OW`(jC
?_9cFo59:
import com.adt.bo.Result; |
>xUgpQi
import com.adt.service.UserService; [~$Ji&Dd
import com.opensymphony.xwork.Action; >W2Z]V
G
hH0-g{-
/** e*gCc7zz
* @author Joa hg7`jE&2
*/ d!)
&@k
publicclass ListUser implementsAction{ ,sPsL9]$
Zyqh
privatestaticfinal Log logger = LogFactory.getLog MtOAA
fd >t9.
(ListUser.class); k1y&'3%
/$zYSP)YT
private UserService userService; b6!?K!imT
<Q)6N!Tp^
private Page page; hNXP-s
e"en
ma\_
privateList users; -05zcIVo
oD_'8G}
/* eN]0]9JO
* (non-Javadoc) Qg
* #p~tkQ:'1
* @see com.opensymphony.xwork.Action#execute() >*%ySlZbs
*/ JBQ,rX_Hw
publicString execute()throwsException{ mj :8ZZ
Result result = userService.listUser(page); b\~rL,7(
page = result.getPage(); cw#p!mOi~
users = result.getContent(); 7V?]Qif~
return SUCCESS; \2i4]V
} jTk !wm=
w#_xV
=
/** 3$+|nP:U
* @return Returns the page. MO)N0{.b
*/ o?uTL>Zin
public Page getPage(){ R:YX{Tq
return page; !]qwRB$5
} Bt|S!tEy
z<_{m4I;
/** !pl<
* @return Returns the users. reLYtv
*/ }_}C ^
publicList getUsers(){ >L#&L?#
return users; M$A"<5
} 1fwCQM
e$QX?y .
/** Sj{z
* @param page 0[}"b(O{
* The page to set. Md'd=Y_0
*/ 7QL>f5Q
publicvoid setPage(Page page){ <jU[&~p
this.page = page; ch,<4E/c[R
} c:"*MM RC
l){l*~5zl2
/** 7~TE=t
* @param users mJ0nyjX^
* The users to set. |mV*HdqU
*/ OtJYr1:y_
publicvoid setUsers(List users){ pgT{#[=>
this.users = users; k7)H%31;
} R{)Sv| +`
HB`u@9le
/** c ;`
* @param userService l/;OC
* The userService to set. [(}f3W &
*/ 6grJoim|
publicvoid setUserService(UserService userService){ ":?>6'*1
this.userService = userService; @P+k7"f
} Y[Us"K`
} [~?LOH
("o<D{A
Y>Q9?>}Q
qQ%zSJ?
ORlz1&hW
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, laqKP+G
|{cdXbr
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 'R8VCj
i%>]$*
么只需要: /lDW5;d
java代码: wIuwq>
sxJKu
f]q3E[?/
<?xml version="1.0"?> $ t_s7
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork s@
m
A\
3WS`,}
1.0//EN" "http://www.opensymphony.com/xwork/xwork- i}ypEp
j#y_#
1.0.dtd"> z^I"{eT8
~|@ aV:k
<xwork> gt6*x=RCrQ
\ntmD?kA
<package name="user" extends="webwork- )ruC_)
C ,z7f"
interceptors"> qO[6?q=c:
}Y[Z`w
<!-- The default interceptor stack name '(Uyju=
zMt "ST.
--> g"(
vl-Uw
<default-interceptor-ref J]nb;4w
e V^@kI4
name="myDefaultWebStack"/> O[y.3>l[s
E*>tFw&[
<action name="listUser" D<5)i)J"
,%mTKOs
class="com.adt.action.user.ListUser"> RfDIwkpp
<param JT&CJ&#[h
:1eI"])(
name="page.everyPage">10</param> 3SVI|A5(d
<result O\pqZ`E=s
*aS|4M-
name="success">/user/user_list.jsp</result> |~hSK
</action> ST)l0c+Y>
|uV1S^!A
</package> EonZvT-D=
k!t5>kPSQ
</xwork> +cM; d4
&1893#V
D4G*K*z,w4
[yL%+I
e<YC=67n)
+|r;t
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 lYv :
fo&q/;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。 !0c7nzjm
.\X/o!xC
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 Crh5^?
~ygiKsD6b
Hx2UDHF
y.JAtsxD
aoz+g,1
//
我写的一个用于分页的类,用了泛型了,hoho ~ YO')
*pw:oTO
java代码: rIo`n2
HI#}M|4n
6g29!F`y
package com.intokr.util; ./jkY7
k
m LPQ5`_
import java.util.List; ~xGWL%og
HcUivC
/** 8|{:N>7
* 用于分页的类<br> X}0NeG^'O
* 可以用于传递查询的结果也可以用于传送查询的参数<br> @jN!j*Y H
* |;6FhDW+'
* @version 0.01 ?0hk~8c
* @author cheng 5|NM]8^^0[
*/ l Vo](#W
public class Paginator<E> { LPb43
privateint count = 0; // 总记录数 FT/H~|Z>
privateint p = 1; // 页编号 r.xGvo{iY
privateint num = 20; // 每页的记录数 Vm_y,;/(-R
privateList<E> results = null; // 结果 c~ l$_A
fW!~*Q
/** .
Uv7{(
* 结果总数 (k6=o';y
*/ /],:sS7
publicint getCount(){ -
4' yp
return count; G~a;q+7v'$
} Hlp!6\gukp
Otj=vGr0
publicvoid setCount(int count){ >*,Zc
this.count = count; ;H_yNrwA
} :m_0WT
6S])IA&VJ
/** 5ap}(bO
* 本结果所在的页码,从1开始 o B_c6]K
* 3%{XJV
* @return Returns the pageNo. ipjl[
*/ LT!.M m
publicint getP(){ kGc;j8>."
return p; K_ Y0;!W
} 2U2=ja9:Y
?'P8H^K6u
/** xE;4#+_I
* if(p<=0) p=1 Of7j~kdh83
* 7n,nODbJ
* @param p lEQ63)Z
*/ zu(/c
publicvoid setP(int p){ Ec8Y}C,{7<
if(p <= 0) 1m|Oi%i4
p = 1; 0fxA*]h
this.p = p;
?Vbe
} 9Vxsv*OR,
yrR<F5xge
/** "@Ra>qb
* 每页记录数量 Ik>sd@X*|
*/ q-/A_5>!;f
publicint getNum(){ tQ5gmj
return num; 0gm+R3;k^
} 1& YcCN\k
8'Xpx+v
/** & oZI.Qeo
* if(num<1) num=1 {(o\G"\<XY
*/ R)WvU4+U
publicvoid setNum(int num){ ~)tIO<$U
if(num < 1) Pw1V1v&>q
num = 1; $ n`<,;^l
this.num = num; DvF`KHsy
} .r[DqC
szF[LRb
/** %.pX!jL
* 获得总页数 (=CV")tF
*/ *^=`HE89S
publicint getPageNum(){ llhJ,wD
return(count - 1) / num + 1; zbddn4bW9
} 3xsC"c>
Y{1IRP?S
/** =9i:R!,W
* 获得本页的开始编号,为 (p-1)*num+1 p !AQ
*/ 2!~j(_TA
publicint getStart(){ 2etcSU(y>
return(p - 1) * num + 1; &1F)/$,v
} _{_LTy%[
nFzhj%Pt;
/** OC#o JwC
* @return Returns the results. k^ B'W{
*/
4sSQ
nK
publicList<E> getResults(){ g4=}].
return results; 0jrcXN~
} #i7!
m qPWCFP
public void setResults(List<E> results){ 7{D+\i
this.results = results; o83HR[
} i'L7t!f}o
M)Yu^
public String toString(){ 3_J9SwtN
StringBuilder buff = new StringBuilder |m"2B]"@
2xni! *T+
(); IA&((\YC
buff.append("{"); }{ pNasAU
buff.append("count:").append(count); A*n '"+_
buff.append(",p:").append(p); r*>XkM& M
buff.append(",nump:").append(num); y{?
6U>_
buff.append(",results:").append hDl& K E
NjdAfgA
(results); CmJI"
buff.append("}"); G-Sw`HHo
return buff.toString(); \hc}xy
0
} 5ii`!y
yh]#V"W3
} X3!btxa%t
4L^KR_h/
"h_n/}r=