Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 hWDgMmo7
b8QW^Z
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ]kKf4SJZFU
}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 d(fgv
TcRnjsY$
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 ")Bf^DV
ydlH6 >
。 Up/1c:<J
)rj.WK.
分页支持类: `cZG&R
.# M5L
java代码: 9Z#37)
o AQ92~b
KAUYE^
package com.javaeye.common.util; ~=#jO0dE|
Ro%S_!
import java.util.List; uj8]\MY
hefV0)4K
publicclass PaginationSupport { (EohxLl !p
;1eu8N8
publicfinalstaticint PAGESIZE = 30; f \4Qp
S
- 7JDE>
privateint pageSize = PAGESIZE; JWxPH5L
$_)f|\s
privateList items; _q8s 7H
V7^?jy&&
privateint totalCount; W>@+H"pZ
7s[ ATu
privateint[] indexes = newint[0]; NT8%{>F`
gW*ee
privateint startIndex = 0; U&B~GJT+
J(l6(+8
public PaginationSupport(List items, int 2y<d@z:K
z?7s'2w&{
totalCount){ zV2c`he%z
setPageSize(PAGESIZE); [NKWudq
setTotalCount(totalCount); C g&1
setItems(items); i.fDH57
setStartIndex(0); 33u7
} NgH%
=jG3wf*
public PaginationSupport(List items, int Kfj*#)SZ
2_Pe/
totalCount, int startIndex){ i!Ne<Q
setPageSize(PAGESIZE); (+Uo;)~!YC
setTotalCount(totalCount); TbXZU$[c
setItems(items); GZ4{<QG
setStartIndex(startIndex); cb
UVeh7Q
} r@n%
gjs-j{*
public PaginationSupport(List items, int 7,O^c+
-><_J4
totalCount, int pageSize, int startIndex){ S)[2\Z{**T
setPageSize(pageSize); U'#{v7u
setTotalCount(totalCount); w{UU(
setItems(items); &V2G<gm0
setStartIndex(startIndex); OPjscc5
} z&-`<uV~
_c #P
publicList getItems(){ rhUZ9Fdv
return items; }Rf }
iG
} _wqFKj
}M9'N%PU
publicvoid setItems(List items){ ~ 01]VA
this.items = items; P089Mh9
} hpw;w}m
SE/@ li
publicint getPageSize(){ v'iQLUgI
return pageSize; JUXK}0d%eN
} 2<J82(4j
F'h[g.\}
publicvoid setPageSize(int pageSize){ ,$G89jSM
this.pageSize = pageSize;
\(A>~D8Fo
} -BjB>Vt
$MR{3-
publicint getTotalCount(){ #G\)ZheG
return totalCount; ,qr)}s-
} RZz] .Nx
?Dfgyz
publicvoid setTotalCount(int totalCount){ 8m6L\Z&
if(totalCount > 0){ I015)vFc
this.totalCount = totalCount; !WIL|\jbh
int count = totalCount / hxtu^E/
~o8$/%Oeb/
pageSize; *F9uv)[kz
if(totalCount % pageSize > 0) lc'Jn$O@
count++; 6DExsB~@
indexes = newint[count]; fa!iQfr
for(int i = 0; i < count; i++){ 4sva%Up
indexes = pageSize * b.t]p
ukPV nk
i; 1 8&^k|
} T0Gu(c`1d
}else{ !u=[/>
this.totalCount = 0; LS \4y&J40
} yqAw7GaBN
} gFW1Nm_DJ
%RJW@~!
publicint[] getIndexes(){ ;1o"Oij
return indexes; <Siz5qQI4
} b _6j77
%f^TZ,q$
publicvoid setIndexes(int[] indexes){ .]jKuTC\<
this.indexes = indexes; %]:u ^\7
} .E@yB`AR
AMkjoy3+]
publicint getStartIndex(){ @F=4B0=
return startIndex; W"~G]a+
} rK`*v*
z
|t0mS$
publicvoid setStartIndex(int startIndex){ T}zOM%]]
if(totalCount <= 0) W;o\}irep
this.startIndex = 0; gjwp' GN
elseif(startIndex >= totalCount) .m4K ]^m
this.startIndex = indexes \BS^="AcpP
4w\')@`[jk
[indexes.length - 1]; J
\G8g,@
elseif(startIndex < 0) ni3^J5X W
this.startIndex = 0; Ye,E7A*L
else{ d*!,McBn
this.startIndex = indexes ]xFd_OHdb
sKNN ahGjh
[startIndex / pageSize]; \.}* s]6
} F*(<`V
} 7$/ O{GBJ
P,*R@N
publicint getNextIndex(){ F9Mv$g79
int nextIndex = getStartIndex() + &%FpNU9
0OlB;
pageSize; P=eL24j
if(nextIndex >= totalCount) 5z=;q!3
return getStartIndex(); obY5taOw
else 5B"j\TwQ
return nextIndex; O'_D*?
} 8Kv=Zp,?`
|2^cPnv?G&
publicint getPreviousIndex(){ U@i+XZc"S
int previousIndex = getStartIndex() - w+[r$+z!k
>/-<,,<\C
pageSize; M$|^?U>cm
if(previousIndex < 0) #lF8"@)a-$
return0; s,lrw~17
else ?7(`2=J
return previousIndex; St'3e<
} |wWBV{^
`a
} zQ5'q
U
Tw\_s
~6E
`6;`
~-|K5
抽象业务类 Bg Uf:PT
java代码: L`3 g5)V
Fvl_5 l
V*Ta[)E
/** 4|ML#aRz
* Created on 2005-7-12 ?:H4Xd7
*/ )7f;FWI
package com.javaeye.common.business; a9}7K/Y=d
I($0&Y\De
import java.io.Serializable; ckykRqk}
import java.util.List; $pr\"!|z
#Ie/|
import org.hibernate.Criteria; BE>^;` K
import org.hibernate.HibernateException; Kg4\:A7Sa.
import org.hibernate.Session; ' d' Dlg
import org.hibernate.criterion.DetachedCriteria; 0@7%
import org.hibernate.criterion.Projections; }M7{~ov#s
import v P;
{wA(%e3_
org.springframework.orm.hibernate3.HibernateCallback; EX@wenR
import gc,%A'OR^<
h9-^aB$8^
org.springframework.orm.hibernate3.support.HibernateDaoS 5 6w6=Is
NhG?@N
upport; 8vRQ_
-]n\|U<
import com.javaeye.common.util.PaginationSupport; t}6QU
^__';! e
public abstract class AbstractManager extends .6C9N{?Tqf
%'+}-w
HibernateDaoSupport { pUF$Nq>og
/;E{(%U)t
privateboolean cacheQueries = false; r`-=<@[
Wz{,N07Q#{
privateString queryCacheRegion; inQ1$
{+Zj}3o
publicvoid setCacheQueries(boolean ^`iqa-1
^jhc(ZW"
cacheQueries){ IE]? WW5
this.cacheQueries = cacheQueries; aNUU' [
} 94.|l
b,h@.s
publicvoid setQueryCacheRegion(String Y[sBVz'j5
\0j-p
queryCacheRegion){ h8XoF1wuw
this.queryCacheRegion = Dm{9;Abs%
uE &/:+
queryCacheRegion; \gCh'3
} ?*AhGza/
pGRk
publicvoid save(finalObject entity){ 5FMe &
getHibernateTemplate().save(entity); 2p %j@O
} _9f7@@b
mE"(d*fe'
publicvoid persist(finalObject entity){ *q-VY[2
getHibernateTemplate().save(entity); KOhK#t>H@0
} l~Hu#+O
%p;;aZG
publicvoid update(finalObject entity){ B%n|%g6K|h
getHibernateTemplate().update(entity); y0]"qB
} )ko[_OJj
7S/\;DF
publicvoid delete(finalObject entity){ {zIcEN$ ~
getHibernateTemplate().delete(entity); 7 I/a
} }v xRjO,
S'(IG m4
publicObject load(finalClass entity, j4wsDtmAU
V}h
<,E9
finalSerializable id){ ntxaFVD
return getHibernateTemplate().load XUVBD;"f!
bx%Ky0Z
(entity, id); 7Y.mp9,
} 3!op'X!
bjBXs;zr@\
publicObject get(finalClass entity, tISb' ^T
\E1CQP-
finalSerializable id){ f5z*AeI
return getHibernateTemplate().get 6!@p$ pm)a
Z|B`n
SzH
(entity, id); u
p zBd]
} q*!Vyk
/Yj; '\3
publicList findAll(finalClass entity){ JLGC'mbJ
return getHibernateTemplate().find("from P N(<=v&E
oXQI"?^+
" + entity.getName()); RF
[81/w]
} !jR 1!i
&8dj*!4H
publicList findByNamedQuery(finalString J u"/#@
~H4Tr[8a
namedQuery){ =)f.Yf|A*
return getHibernateTemplate 8CUl |I ~
%<>|cO
().findByNamedQuery(namedQuery); 4|hfzCjMI
} 2]5ux!Lqln
]4Q~x
publicList findByNamedQuery(finalString query, MFz6y":~
:n OCs
finalObject parameter){ ft$
'UJ%j
return getHibernateTemplate #.2} t0*]5
"d*-k R
().findByNamedQuery(query, parameter); BO>[\!=y
} 'DUYf5nF
|H%,>r`9S
publicList findByNamedQuery(finalString query, SpMHq_MLM
(/|f6_9!
finalObject[] parameters){ >Ft:&N9L{
return getHibernateTemplate BAy)P1
>L^2Z*
().findByNamedQuery(query, parameters); AQs_(LR
} ]eI|_O^u
ej[Y
`N
publicList find(finalString query){ |iVw7M:
return getHibernateTemplate().find +L
pMNnl6
9-.`~v
(query); 5r^u7k
} H6Kt^s<6xu
`<?((l%;R
publicList find(finalString query, finalObject F D.L{
4Z/]7Ie
parameter){ |Gt]V`4
return getHibernateTemplate().find 30QQnMH3
xKXD`-|W
(query, parameter); t.]e8=dE
} dLw,dg
{+ WI>3
public PaginationSupport findPageByCriteria 51puR8AG>
*KPNWY9!W
(final DetachedCriteria detachedCriteria){ << aAYkx<
return findPageByCriteria '.zr:l
Gx-tPW}
(detachedCriteria, PaginationSupport.PAGESIZE, 0); FD^s5>"Y+
} mg
*kB:p
%M-B"#OB7
public PaginationSupport findPageByCriteria ys9MV%*
Es+BV+x[.c
(final DetachedCriteria detachedCriteria, finalint M!iYj+nrP
(ChL$!x
startIndex){ r%II`
i
return findPageByCriteria CQ#%v%
5x}OrfDU
(detachedCriteria, PaginationSupport.PAGESIZE, vH vwH
Nk shJ2
startIndex); %|3NCyJ*7
} 6M@m`c
Zc*gRC
public PaginationSupport findPageByCriteria ^4tz*i
]|/\Sd
(final DetachedCriteria detachedCriteria, finalint !Baq4V?KN
/ Hexv#3
pageSize, u )KtvC!
finalint startIndex){ |79n
1;+\?
return(PaginationSupport) k&3'[&$I*,
' q{|p+
getHibernateTemplate().execute(new HibernateCallback(){ m>-(c=3
publicObject doInHibernate :_+Fe,h>|
} @jT-t]P
(Session session)throws HibernateException { z_en.
Criteria criteria = lof}isOz
& ^JY
detachedCriteria.getExecutableCriteria(session); Z sbE
int totalCount = ]}jY]
l
+X7+:QQ}
((Integer) criteria.setProjection(Projections.rowCount T\o!^|8
YGr^uTQb
()).uniqueResult()).intValue(); uM9RlI5
criteria.setProjection u6BLhyS
wQ/FJoB
(null); }\_[+@*EJ
List items = 1|%C66f^
}5sJd>u5^
criteria.setFirstResult(startIndex).setMaxResults UP |#WegO
HtGGcO'bqg
(pageSize).list(); R(F+Xgje
PaginationSupport ps = @d=4C{g%o
@@Vf"o+S
new PaginationSupport(items, totalCount, pageSize, ~<w9a]
}u8 D5Q<(
startIndex); GHo=)NTjy
return ps; ^DS+O>
} ;COZHj9b
}, true); R?$Nl
} q=h~zjQ?R
oyY0!w,Y
public List findAllByCriteria(final ~85Pgb<
Yet!qmZ
DetachedCriteria detachedCriteria){ QH_I<Y:n
return(List) getHibernateTemplate jaImO
p;m2RHYF
().execute(new HibernateCallback(){ }w8:`g'T0/
publicObject doInHibernate sz%'=J~!V
Mlr}v^"G
(Session session)throws HibernateException { zE\@x+k.
Criteria criteria = {9C+=v?
MPmsW&
detachedCriteria.getExecutableCriteria(session); >E`p@
e+
return criteria.list(); 2u|}gZts
} GwaU7[6
}, true); y!?l;xMS
} h_:|H8t;w
1V37%
D
public int getCountByCriteria(final V_"K
?H_'L4Wv
DetachedCriteria detachedCriteria){ A9HJWKO
Integer count = (Integer) 7I_lTu(
Y l1sAf/
getHibernateTemplate().execute(new HibernateCallback(){ s8]9OG3g
publicObject doInHibernate csF!*!tta
#7~M1/eH=t
(Session session)throws HibernateException { kM
T73OI>_
Criteria criteria = 2v6QUf
DIurFDQSS
detachedCriteria.getExecutableCriteria(session); ^?)o,djY&
return }$ZcC_
r&t)%R@q
criteria.setProjection(Projections.rowCount =?/RaK/
w
*n=NBkq%/!
()).uniqueResult(); 9V=bV=4:
} j7)Xm,wI8
}, true); n(#159pZ
return count.intValue(); yEe4{j$
} UldG0+1d
} /Ma"a
^
oG )JH)!
,S i23S\
$MEKt}S
t3)nG8>
)
j&.MT@
用户在web层构造查询条件detachedCriteria,和可选的 FaNH+LPe
)TBG-<wt
startIndex,调用业务bean的相应findByCriteria方法,返回一个 \e/'d~F
yjbqby7
PaginationSupport的实例ps。 4S]`S\w
{{?[b^
ps.getItems()得到已分页好的结果集 @,63%
ps.getIndexes()得到分页索引的数组 b1}P3W
ps.getTotalCount()得到总结果数 4#z@B1Jx
ps.getStartIndex()当前分页索引 ;@@1$mzK
ps.getNextIndex()下一页索引 IZ;%lV7t
ps.getPreviousIndex()上一页索引 rI5)w_E?
DM*mOT
I4Ys,n
j6~#_t[
]&3UF?
y#3mc#)k
?[\(i)]
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 =yfLqU
%jK-}0Tu
,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 c D+IMlT
Mlp[xk|
一下代码重构了。 ' [fo
VR>;{>~
我把原本我的做法也提供出来供大家讨论吧: $^Dx4:k<2
3+;}2x0-F
首先,为了实现分页查询,我封装了一个Page类: byYdX'd.
java代码: {@u;F2?
'Dq!o[2y
7B$iM,}.b
/*Created on 2005-4-14*/
?6!7fs,
package org.flyware.util.page; .pgTp X
)jK"\'cK
/** 38dXfl
* @author Joa fmvX;0O
* ? {Lp
*/ &Z_W*D
publicclass Page { W^W^5-'"D,
$up.<qzj
/** imply if the page has previous page */ 8Hf!@p6R+
privateboolean hasPrePage; xS` %3+|
bmEo5f~C!
/** imply if the page has next page */ {|%N
privateboolean hasNextPage; }Lx?RU+@=
J 21D/#v
/** the number of every page */ XQhBnam%
privateint everyPage; Yw=Ve 0
#5kQn>R
/** the total page number */ |2\6X's
privateint totalPage; [ds:LQq)/
a[:0<Ek
/** the number of current page */ n^|n6(EZ
privateint currentPage; =Uta5$\a)
~jb6
/** the begin index of the records by the current #]i*u1
3u7N/OQ(
query */ edqek jh
privateint beginIndex; 8kw`=wSH>
[Z484dS`_
s#ijpc>h
/** The default constructor */ 9cAb\5c|
public Page(){ ,
e{kC
]l>)Di#*o
} 8/f,B:by
^o]ZDc
/** construct the page by everyPage ,V3P.ni]
* @param everyPage %0}qMYS
* */ 1Fn+nDnO6
public Page(int everyPage){ NaSg K
this.everyPage = everyPage; f0fN1
} 'H2TwSbIXI
iIq='xwa9
/** The whole constructor */ mHo}, |
public Page(boolean hasPrePage, boolean hasNextPage, ^ad
p<?q4
g]R }w@nJ
M-u:8dPu
int everyPage, int totalPage, o+SD(KVn-
int currentPage, int beginIndex){ SIjdwr!+ZZ
this.hasPrePage = hasPrePage; 5C/W_H+9iK
this.hasNextPage = hasNextPage; w{Wz^=';
this.everyPage = everyPage; t5#IiPp
this.totalPage = totalPage; p5c^dC{
this.currentPage = currentPage; 8*3<Erv
this.beginIndex = beginIndex; ua*k{0[
} _e$15qW+
BEyg63=
/** U[=VW0
* @return nnX,_5s
* Returns the beginIndex. _rXTHo7P
*/ 1`N q
K
publicint getBeginIndex(){ k'X
v*U
return beginIndex; m(E-?VMHo
} s_-G`xT>{
1+RG@Cp
/** |ul25/B
B
* @param beginIndex 5BCXI8Ox9x
* The beginIndex to set. cj@Ygc)n
*/ ~U#afGH$
publicvoid setBeginIndex(int beginIndex){ '5.n28W>
this.beginIndex = beginIndex; "qUUH4mR`
} bB'iK4
s@K)RhTY
/** C3Q[L}X\
* @return *z;4.
OX
* Returns the currentPage. _Iy0-=G
*/ NARW3\
publicint getCurrentPage(){ y|U3
return currentPage; Tw"u{%t
} 9nlfb~F~P
Ro$'|}(+A
/** 4G0Er?D
* @param currentPage ~YKe:K+&z
* The currentPage to set. bsy\L|wd
*/ Lt0JUUa0
publicvoid setCurrentPage(int currentPage){ u
HqP b8
this.currentPage = currentPage; ~~k_A|&
} rvuskXdo
xal+buOiP
/** XRCiv
* @return %4Cs
c
* Returns the everyPage. c1M/:*?%
*/ L5!aLv#
publicint getEveryPage(){ R9nW5f
Nf
return everyPage; -hw^3Af
} }YWLXxb;
?Z=
%I$i
/** 7J,j
* @param everyPage I}Uj"m`>
* The everyPage to set. ED&>~~k)
*/ t7tX<|aN
publicvoid setEveryPage(int everyPage){ |u8IQR'B
this.everyPage = everyPage; 6gV-u~j [#
} p9Zi}!
z&[Rw<{Psb
/** dO}6zQ\
* @return Aq%TZ_m
* Returns the hasNextPage. __M(dN(^
*/ +<7~yZ[Z8
publicboolean getHasNextPage(){ u )PB@
return hasNextPage; #4iSQ$0
} ^JZ ]?iny
@ofivCc<%
/** .6aC2A]es
* @param hasNextPage n@ lf+
* The hasNextPage to set. .Nz2K[
*/ 6r{NW9y'
publicvoid setHasNextPage(boolean hasNextPage){ 42E]&=Cet
this.hasNextPage = hasNextPage; Aon3G
} P*Va<'{:{
LgXc}3
/** TeaP\a
* @return Q.X)QCp#r
* Returns the hasPrePage. b{JcV
*/ |`[0U
publicboolean getHasPrePage(){ 0w9)#e+JS
return hasPrePage; TELN4*
} <5(P4cm9
_ K["qm{X_
/** -J*BY2LU3f
* @param hasPrePage 69ZGdN
* The hasPrePage to set. NQ~keN
*/ 5e=9~].7
publicvoid setHasPrePage(boolean hasPrePage){ Hy=';Ccn}
this.hasPrePage = hasPrePage; 7pf]h$2
} -L&r2RF/
K}7E;O5m"
/** koDIxj'%X
* @return Returns the totalPage. x6Zhw9RV
* DCr&%)Ll
*/ jez=q
publicint getTotalPage(){ mh&wvT<:{
return totalPage; 6BK-(>c(6
} k?]`PUrV
h=h4`uA9
/** n4 A_vz
* @param totalPage shlMJa?
* The totalPage to set. vpnQ s#8O
*/ dC+WII`V
publicvoid setTotalPage(int totalPage){ 8h"Val|qP
this.totalPage = totalPage; U4;r.#qw,
} APY^A6^:j
QS(aA*D
} ;PM(q<@\
&[71~.Od
K|[p4*6
D>tex/Of3
,5}%_
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 @p`*MWU
fNR2(8;}
个PageUtil,负责对Page对象进行构造: q,S[[{("
java代码: -;]m4R)z
KA~eOEjM
LF6PKS
/*Created on 2005-4-14*/ CVUA7eG+
package org.flyware.util.page; ]mIcK
N,k PR
import org.apache.commons.logging.Log; xAJ
N(8?
import org.apache.commons.logging.LogFactory; 9~3;upWu!
v *'anw&Z
/** aia`mO]
* @author Joa /`6Y-8e2
* u NmbR8Mx
*/ Ub[SUeBGH
publicclass PageUtil { 7\(mn$
:c75*h`
privatestaticfinal Log logger = LogFactory.getLog rdj_3Utv
fv@mA --
(PageUtil.class); 3an9Rb V
YA+jLy6ZL
/** 9ZXkuP9vm
* Use the origin page to create a new page \vg(@)$q
* @param page ;IV
* @param totalRecords H(|n,c
* @return v9*ugu[K9
*/ 9t$#!2z
publicstatic Page createPage(Page page, int P}"=67$
hSAdD!
totalRecords){ 2Xw=kw u
return createPage(page.getEveryPage(), RBOb/.$
pg<m0g@W*;
page.getCurrentPage(), totalRecords); D;?cf+6$
} 0FN;^hP5|
tL#~U2K
/** _\"2Mdk`]
* the basic page utils not including exception _PPZ!r(
da[=d*I.
handler qStZW^lFeY
* @param everyPage :zA/~/Wo
* @param currentPage F#b^l}
* @param totalRecords $G\WW@*GE
* @return page g2RrBK,
*/ /$[9-G?
publicstatic Page createPage(int everyPage, int [|qV*3|?
;-0
d 2Z
currentPage, int totalRecords){ p]jkfsCjN
everyPage = getEveryPage(everyPage); SI)QX\is8
currentPage = getCurrentPage(currentPage); srbES6
int beginIndex = getBeginIndex(everyPage, hZZ
5S9i>B
currentPage); 7];AB;0"
int totalPage = getTotalPage(everyPage, 8n&Gn%DvX
!l6Ez_'
totalRecords); W(4Mvd
boolean hasNextPage = hasNextPage(currentPage, y
-6{>P/
k2 _i;v
totalPage); cePe0\\
boolean hasPrePage = hasPrePage(currentPage); d/&W[jJ
!k3 eUBF
returnnew Page(hasPrePage, hasNextPage, Wg5<@=x!G
everyPage, totalPage, {<}9r6k;f
currentPage, ?2(52?cJ
!+Fr U'^
beginIndex); WWEZTFL:j
} #}p@+rkg2
G+~f
privatestaticint getEveryPage(int everyPage){ tFEY8ut{
return everyPage == 0 ? 10 : everyPage; OH
>#f6`[
} Iwx~kvz\_(
wo+b":
privatestaticint getCurrentPage(int currentPage){ F G:t2ea
return currentPage == 0 ? 1 : currentPage; c80Ffq
} gf ?_tB0C
ROhhd.
privatestaticint getBeginIndex(int everyPage, int H 8x66}
c
8t
currentPage){ MvKr~
return(currentPage - 1) * everyPage; c4f3Dr'xw
} eF"k"Ckt'
y9Q#%a8V
privatestaticint getTotalPage(int everyPage, int NNxzZ!q!
<*Gd0 v%
totalRecords){ Z35(f0b
int totalPage = 0; yE#.Q<4
S[;d\Z]~
if(totalRecords % everyPage == 0) }`pxs
totalPage = totalRecords / everyPage; oh0*b h
else [.Rdq]w6
totalPage = totalRecords / everyPage + 1 ; yU"lJ>Eh}}
uXo uN$&
return totalPage; ge4Qa K
} <nk9IAH
2C
Fgit
privatestaticboolean hasPrePage(int currentPage){ V7"^.W*
return currentPage == 1 ? false : true; F{G.dXZZ<
} /UqIkc
4 KX\'K
privatestaticboolean hasNextPage(int currentPage, 4aiI&,
*e25!#o1
int totalPage){ qKD
Nw8>
return currentPage == totalPage || totalPage == 2EH0d6nt
Ya&\ b 6
0 ? false : true; ffQm"s:P
} :+_
eakQZ-Q
r3NdE~OAi
} "x0/i?pqa
=[:pm)
sOO_J!bblP
"-Yj~
'Rb
tcFb
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。 QuIZpP=
hb<cynY
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 $x*(D|\'<
?[=OQ/E
做法如下: X7rsO^}W
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 74=zLDDS
!C@+CZXLx
的信息,和一个结果集List: 050V-S>s
java代码: 9S|a!9J
[(2XL"4D
jN AS'JV
/*Created on 2005-6-13*/ 6~-,.{Y
package com.adt.bo; 5.LfN{gE)
+1]A$|qyW
import java.util.List; f28bBuv1?
f~R+Q/Gtz`
import org.flyware.util.page.Page; w! PguP
'!F'B:
/** bao"iv~z
* @author Joa FeNNzV=
*/ w$Z%RF'p
publicclass Result { "QvTn=
qP$)V3l
private Page page; CiV^bYi
^ib
=fLu
private List content; mqtYny'
c,:nWf
/** "Hk7s+%
* The default constructor SZUo RWx
*/ Jflm-Hhsf
public Result(){ J|w%n5Y
super(); 8O_yZ
~Z4
} Us.k,
Ae%AG@L
/** 26;Gt8
* The constructor using fields {rwT4]4
* F!fsW9
* @param page BV6B:=E0
* @param content $*:g~#bh
*/ N@Q_5t0bk
public Result(Page page, List content){ a 2[rY
this.page = page; >Q=Q%~
this.content = content; P;eXUF+jn
} m8V}E&6
lL&U
ioo}D
/** s!S_Bt):3
* @return Returns the content. DYoGtks(
*/ dQz#&&s-
publicList getContent(){ [FZq'E"87
return content; TPs
]n7]:
} "|Kag|(qB
m@UrFPZ
/** ^#XQ2UN
* @return Returns the page. pfs]pDjS:
*/ mGa :~x
public Page getPage(){ ExM VGe
return page; .K]Uk/W
} >?#zPweA
l&*=
.Zc7!
/** ^]D+H9Tl
* @param content ^wD`sj<Qg
* The content to set. ~(#iGc]7
*/ 7X)4ec9H\
public void setContent(List content){ ==BOW\
this.content = content; LpL$=9
} 8rjD1<
tyWDa$u,u
/** d0i|^
* @param page &KY!a0s
* The page to set. rP}[>
*/ i5=~tS
publicvoid setPage(Page page){ @t;726
this.page = page; \._|_+HiW
} DN iH" 0%
} -L<FVB
-$X4RS
h#c7v!g
)TEm1\
/::Y &&$f
2. 编写业务逻辑接口,并实现它(UserManager, 4U16'd
fZ&' _
UserManagerImpl) !iq|sXs
java代码: E*IP#:R
=ZO lE|4
]1pB7XL
/*Created on 2005-7-15*/ 1w,34*- }
package com.adt.service; AF8:bk,R
eco&!R[G
import net.sf.hibernate.HibernateException; [[pt~=0
K- $,:28
import org.flyware.util.page.Page; &YcOmI/MM
N:okt)q:%
import com.adt.bo.Result; cRuN;
zWv0y8[d
/** y=.bn!u}z
* @author Joa J .VZD
*/ O;5lF
publicinterface UserManager { ?;H}5>^8P
Pjn{3/*wi
public Result listUser(Page page)throws j@w1S[vt
:`Ep#[Wvo
HibernateException; d S'J @e=#
l^$'6q"
} $:\`E56\
5KDCmw
oH!O{pQK}
UG=]8YY!
|2%|=
java代码: <5,|h3]-#
]31=8+D
Y9>92#aME
/*Created on 2005-7-15*/ 'n
^,lXWB
package com.adt.service.impl; =*I|z+
8]exsnZ
import java.util.List; ,Si{]y
Z1:%AqxP
import net.sf.hibernate.HibernateException; p:K%-^
\gB~0@[\7
import org.flyware.util.page.Page; E1tCY.N{
import org.flyware.util.page.PageUtil; IVkB)9IW
K!.t}s.t
import com.adt.bo.Result; q*|Alrm
import com.adt.dao.UserDAO; EFljUT?&
import com.adt.exception.ObjectNotFoundException; K5|~iW'
import com.adt.service.UserManager; 1^2Q`~,g
<nN.$4~X
/** 5OtdB'UITd
* @author Joa oC*a;o
*/ #{{p4/:
publicclass UserManagerImpl implements UserManager { u '/)l}
Nh_\{
&r
private UserDAO userDAO; >*VvV/UU
]wdE
:k,D
/** y`j=(|DV
* @param userDAO The userDAO to set. vq^';<Wh.
*/ *i^$xjOa
publicvoid setUserDAO(UserDAO userDAO){ ]K*R[
this.userDAO = userDAO; gwQMy$
} iB"ji4[z
abm 3q!a-
/* (non-Javadoc) Um6}h@>
* @see com.adt.service.UserManager#listUser lZ.lf.{F
TH'8^w f
(org.flyware.util.page.Page) [A/2
M s
*/ RJzIzv99m
public Result listUser(Page page)throws kHylg{i{"
#IZh}*$
HibernateException, ObjectNotFoundException { r A(A$VR
int totalRecords = userDAO.getUserCount(); Zfcf?&><
if(totalRecords == 0) 2dkWzx
throw new ObjectNotFoundException 3
dJ362
!cYID \}S,
("userNotExist"); X,_K
)f
page = PageUtil.createPage(page, totalRecords); 0bM_EC
List users = userDAO.getUserByPage(page); %" 7UYLX
returnnew Result(page, users); NWvIwt{
} _<FUS'"
J sz=5`
} g:a[N%[C
W
h 9L!5
$b1>,d'oz
S-88m/"]s
qbfX(`nS
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 q%e'WM G~n
H~nX!sO
询,接下来编写UserDAO的代码: uJ
-$i
3. UserDAO 和 UserDAOImpl: 9N'fU),I
java代码: T+&fUhSy
t_w\k_
T
-43>?m/a
/*Created on 2005-7-15*/ B I)@n:p
package com.adt.dao; qvB{vU
|cY,@X,X6
import java.util.List; 8| =C/k
(w)%2vZ^
import org.flyware.util.page.Page; yzp#
r8:"\%"f>
import net.sf.hibernate.HibernateException; !zF07.(E
5l1R")0`t_
/** 7<!x:G?C
* @author Joa f^B'BioW(
*/ {qi#
publicinterface UserDAO extends BaseDAO { _7Y-gy#\a
=3QhGFd
publicList getUserByName(String name)throws (b//YyqN
>pLJ ,Z
HibernateException; )MF@'zRK
5%WAnh
publicint getUserCount()throws HibernateException; &d2L9kTk
}bca-|N
publicList getUserByPage(Page page)throws $Y_S`#c@i
QJ;dw8
HibernateException; 1g{}O^ul
C 8wGbU6`
} = NZgbl
f0sLe 3
G6zFQ\&f
^C~Ryw7
U@y)x+:
java代码: qzbW0AM[M
mz6]=]1w
#J&3Zds
/*Created on 2005-7-15*/ B2Y.1mXq
package com.adt.dao.impl; 'hU5]}=
^rO"U[To
import java.util.List; -o%? ]S
_MTZuhY
import org.flyware.util.page.Page; VtI`Qcjc
0H>gMXWE]
import net.sf.hibernate.HibernateException; $Bz};@
import net.sf.hibernate.Query; 4x[_lsj
rIcgf1v70
import com.adt.dao.UserDAO; yjL+1_"B
?SFQx\/
/** j
[lS.Lb
* @author Joa 06^/zr
*/ z6@8IszU
public class UserDAOImpl extends BaseDAOHibernateImpl [?I<$f"
HP]5"ziA
implements UserDAO { OS@uGp=
iZy>V$Aq
/* (non-Javadoc) NT5=%X]
* @see com.adt.dao.UserDAO#getUserByName I*.nwV<
:Q("
(java.lang.String) Ue9Y+'-x
*/ iKrk?B<
publicList getUserByName(String name)throws TYGI
f4z
SXqB<j$.;
HibernateException { /i>n1>~yn
String querySentence = "FROM user in class ;hDk gp
bpZA%{GS
com.adt.po.User WHERE user.name=:name"; uPl}NEwU|
Query query = getSession().createQuery f^1J_}cL
&Ril[siw
(querySentence); bl
a`B=r
query.setParameter("name", name); w6!97x
return query.list(); AH&RabH2
} uthW
AT &
AE~a=e\x
/* (non-Javadoc) i8e*9;4@
* @see com.adt.dao.UserDAO#getUserCount() T{Xd >
*/ P1rjF:x[*
publicint getUserCount()throws HibernateException { Pz0MafF|T
int count = 0; 2kVZlt'y
String querySentence = "SELECT count(*) FROM 8b'@_s!_
!38KHq^|&
user in class com.adt.po.User"; vO2WZ7E!
Query query = getSession().createQuery H%Gz"
cdL]s^z
(querySentence); /g+-{+sx
count = ((Integer)query.iterate().next U$gR}8\e
o|h=M/
()).intValue(); oFP8s[B
return count; ugTsI~aE
} E5rV}>(Y
fV>d_6Lf}
/* (non-Javadoc) oMg-.!6
* @see com.adt.dao.UserDAO#getUserByPage Gl'G;F$Y-
W/BPf{U
(org.flyware.util.page.Page) &^#iS<s1
*/ Fdhgm{Y2s
publicList getUserByPage(Page page)throws R`<2DC>h9
7BU7sQjs
HibernateException { ?H PAX
String querySentence = "FROM user in class q( ~rk
:5&D6
com.adt.po.User"; 37kFbR@x
Query query = getSession().createQuery li3,6{S#
46NuT]6/4
(querySentence); o+=wQ$"tP
query.setFirstResult(page.getBeginIndex()) 2mzn{S)nV
.setMaxResults(page.getEveryPage()); P05`DX}r,
return query.list(); -V{"Lzrfug
} 7d%x 7!E
IXtG
36O
} -)(=~|,Pq/
~|S0E:*.
(CIcM3|9C
Wr b[\
?-
y*^UGJC:
至此,一个完整的分页程序完成。前台的只需要调用 }#D=Rf?2\P
n?cC]k;P~
userManager.listUser(page)即可得到一个Page对象和结果集对象 CBf[$[e
%k4Qx5`?d
的综合体,而传入的参数page对象则可以由前台传入,如果用 sPZwA0%
nC,QvV
webwork,甚至可以直接在配置文件中指定。 Hj
r'C?[
=QVkY7
下面给出一个webwork调用示例: 6 :|;O
java代码: `$JvWN,kB
/5Qh*.(S
Qb?a[[3
/*Created on 2005-6-17*/ !gW`xVGv
package com.adt.action.user; \;N+PE
o+{,>t
import java.util.List; AA[1[
N8Rq7i3F?a
import org.apache.commons.logging.Log; *nU5PSs
import org.apache.commons.logging.LogFactory; 0yC~"u[N Y
import org.flyware.util.page.Page; `.pEI q^
a~jb%i_
import com.adt.bo.Result; mM&P&mz/D
import com.adt.service.UserService; :a/rwZ[r
import com.opensymphony.xwork.Action; &v .S_Ym
C5 ILVQ
/** 1z7+:~;l
* @author Joa ^
34Ng
*/ *:TwO=)
publicclass ListUser implementsAction{ 4!{lySW
;iX~3[]
privatestaticfinal Log logger = LogFactory.getLog r2\%/9uO
2fr%_GNu
(ListUser.class); h +B7BjA>G
Rw0|q
private UserService userService; <J+Oh\8tad
rd0Fd+t/
private Page page; vVo'f|fW
3?V'O6
privateList users; G@ot^n3
JR]elRR
/* 0=HB!{@
* (non-Javadoc) %HpPTjAW
* }:faHLYT
* @see com.opensymphony.xwork.Action#execute() N}U+K
*/ QxW+|Gt._
publicString execute()throwsException{ }O~D3z4l0
Result result = userService.listUser(page); q]: 72+
page = result.getPage();
sG#O s
users = result.getContent(); ?1\I/'E9
return SUCCESS; 3v_j*wy
} /Q@4HV
eG(YORkR
/** /~'C!so[v
* @return Returns the page. r~T!$Tb
*/ LAk
.f
public Page getPage(){ "W6cQsi
return page; ?9{^gW4|
} el5Pe{j'
^V; r
/** bgE]Wk0
* @return Returns the users. 5(CInl
*/ YG0/e#5
publicList getUsers(){ F>{bVPh
VA
return users; bTeuOpp
} geK;r0(f
!%R):^R8
/** Ld_u Me?Z
* @param page LI}e_=E
* The page to set. )2y [#Blo
*/ !U@ETo
publicvoid setPage(Page page){ NqF*hat
this.page = page; KtAEM;g
} *bpN!2
E7h@Y~bNhW
/** N:3=G`Ws
* @param users Pn^:cr|
* The users to set. [p'2#Et
*/ 51eZf JB
publicvoid setUsers(List users){ A*0X~6W
this.users = users; K3:z5j.X
} ]~
N.
Nk-xnTZ"
/** R-pON4D"*
* @param userService }*!L~B!
* The userService to set. />Zfx. Aj6
*/ C&0f8PnD
publicvoid setUserService(UserService userService){ r|}Pg}O
this.userService = userService; 7<70\6
} 5,XEN$^
} *.w6 =}
1 M!4hM
Q
f1SKOq
_s#J\!F
^-?^iWQG
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, (BH<\&yHE
n+=7u[AZi
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 ).,twf58
<k1muSe
么只需要: Yqh-U%"'
java代码: ES,JdImZ|
k"[AV2UW1
*fi`DiO
<?xml version="1.0"?> ,.{M1D6'R`
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork W="pu5q$5
rJf{YUZe
1.0//EN" "http://www.opensymphony.com/xwork/xwork- a++gwl
@)Vb?|3
1.0.dtd"> .&]3wB~
x!S}Y"
<xwork> FiReb3zR
A1B[5a*o!
<package name="user" extends="webwork- _\dC<K *>
L8.A|
interceptors"> :twp95{R1
aC9iNm8w
<!-- The default interceptor stack name !4^Lv{1QZ
Ye|gW=FUR
--> 0?FJ~pu
<default-interceptor-ref G@D8[
(oiQ5s^f
name="myDefaultWebStack"/> &VU^d3gv~
ok ,O/|E}?
<action name="listUser" }@$CS5w
>nehyo:#
class="com.adt.action.user.ListUser"> 5R.jhYAj
<param #%GBopv
kQ\l7xd
name="page.everyPage">10</param> o\tw)_ >
<result s!gVY!0
F_@`
<d!
name="success">/user/user_list.jsp</result> %eHr^j~w$
</action> LmsPS.It
Qj
[p/H$
</package> JUGq\b&m
0 "@J*e#
</xwork> QN#Lbsd
?zsRs?rc0
3:sc%IDP
}n^}%GB
8=f+`e
}3
~*/30V
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 yhK9rcJq6}
-=:tlH
n
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。 =dKk #*
#Sy~t{4
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 i%f
C`@
,,EG"Um6
U;ujN 8
!f!YMpN
]*$o qn=m
我写的一个用于分页的类,用了泛型了,hoho &% (1?\~u
WzdlrkD
java代码: Eos;7$u[
iH>JR[A
8PeVHpZ
package com.intokr.util; g-x;a0MQx
8j]QnH0&
import java.util.List; C2iOF /4
m=pH G
/** jtpk5 fJB
* 用于分页的类<br> ept:<!4
* 可以用于传递查询的结果也可以用于传送查询的参数<br> {9@E[bWp#
* DB jUHirK
* @version 0.01 Q[`2?j?
* @author cheng .Xxxz
Wyk
*/ "AWk
jdj
public class Paginator<E> { K;`*n7=IA
privateint count = 0; // 总记录数 1-4[w
*u>
privateint p = 1; // 页编号 _{B2z[G}
privateint num = 20; // 每页的记录数 v+C D{Tc
privateList<E> results = null; // 结果 ~d3BVKP5
L^s?EqLXS
/** 6QPbmO]z
* 结果总数 )OlYz!#?
*/ KJ-Q$
M
publicint getCount(){ 'r^'wv]
return count; v<0S@9~
} >Zf*u;/dW$
*:l$ud
publicvoid setCount(int count){ HW6Cz>WxOW
this.count = count; 8,CL>*A
} 0eCjK.
v!mP9c
j
/** phwq#AxQ
* 本结果所在的页码,从1开始 X5tV Xd
* Df1eHa5-7
* @return Returns the pageNo. zcEpywNP
*/ hB:+_[=Kj.
publicint getP(){ K^I$05idi
return p; )gR3S%Ju
} dt>!=<|k
Z%-uyT@a
/** 6|Rj
YX
* if(p<=0) p=1 w'5W L
* ?GZ?HK|
* @param p b DF_
*/ YWq{?'AaR
publicvoid setP(int p){ @zix%x
if(p <= 0) sg]g;U
p = 1; @[rlwwG,
this.p = p; [9p@uRE
} mL,{ZL ^
l4^8$@;s
/** ,6U=F#z
* 每页记录数量 hn/SS
*/ Qbj:^{`>(
publicint getNum(){ P6tJo{l8w
return num; I|mxyyf
} k"FY
&;G(G
NL ceBok
/** 0g@*N4
* if(num<1) num=1 RQn3y-N]
*/ )T^aJ-Uf
publicvoid setNum(int num){ 0ENqK2
if(num < 1) A kqGk5e
^
num = 1; afcyAzIB&
this.num = num; AqrK==0N
} TF,a`?c`
JnH5v(/
/** 6tM@I`l
* 获得总页数 .aIFm5N3?
*/ T~N877
publicint getPageNum(){ D
<Fl7QAb
return(count - 1) / num + 1; o\yqf:V8
} kZ
9n@($B
SR\$ fmo
/** Fg^zz*e
* 获得本页的开始编号,为 (p-1)*num+1 [
**F
*/ yj`xOncE}
publicint getStart(){ C_hIPMU=
return(p - 1) * num + 1; 3j$,x(ua9
} VzFzVeJ
dU"C=c(w\
/** _k
W:FB
* @return Returns the results. xJ|Z]m=d
*/ iwEHEi%
publicList<E> getResults(){ YpbJoHiSH
return results; `JG7Pl/ih
} yz=6 V%
]GHx<5Q:\
public void setResults(List<E> results){ i0&]Ig|;
this.results = results; [6Nzz]yy
} 3nkO+qQ
'P)[=+O?t
public String toString(){ CQ%yki
StringBuilder buff = new StringBuilder >qIZ
KTu&R6|
(); a<V* )
buff.append("{"); V -9z{
buff.append("count:").append(count); qS2]|7q?Tc
buff.append(",p:").append(p); xZ&S7G1