Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Q- cFtu-w
j8v8uZ;x
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 >8~.wXyoC
/ C:Y94B-z
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 u
1>2v
wT6"U$cV
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 pj\u9
L_
du<tGsy
。 [g7L&`f9
g;H=6JeG/
分页支持类: Lu?C-$a C
O*hDbM2QQw
java代码: S]}nm
%|s; C
}n]Ng]KM`
package com.javaeye.common.util; ;,hwZZA
iw3FA4{(
import java.util.List; >nJ\BPx
F~,Mw8
publicclass PaginationSupport { %R}qg6dL
A=$04<nP8!
publicfinalstaticint PAGESIZE = 30; W>${zVu
%^?fMeI|Y
privateint pageSize = PAGESIZE; Y@;CF
&C`Gg<
privateList items; E(*0jAvO[z
J?*1*h
privateint totalCount; DwM)r7<Ex
U\g/ 2dM
privateint[] indexes = newint[0]; F6|TP.VY_.
4GkWRu1
privateint startIndex = 0; C'>|J9~Gz
()Y~Q(5ji
public PaginationSupport(List items, int z 9vInf@M
3U<cWl@
totalCount){ e),q0%5
setPageSize(PAGESIZE); ahJ`T*)HY
setTotalCount(totalCount); J9\Cm!H
setItems(items); 2]z8:a
setStartIndex(0); X2#2C/6#u
} ,1y@Z 5wy
{kA0z2Fe
public PaginationSupport(List items, int Yk'XGr)
y`L>wq,KU
totalCount, int startIndex){ 8EZ$g<}
setPageSize(PAGESIZE);
|tKsgj
setTotalCount(totalCount); Xe3U`P7(
setItems(items); R4[N:~Z$|
setStartIndex(startIndex);
oI?3<M^
} S(k3 `;K
^%d\qd`
public PaginationSupport(List items, int YX!{P=Ua
n7zm>&
totalCount, int pageSize, int startIndex){ R"-mKT}
setPageSize(pageSize); ^PDJ0k/u1
setTotalCount(totalCount); |J1$=s
setItems(items);
vHgi<@u
setStartIndex(startIndex); >Rl"
} Lz
|?ek7Q
E@z<:pG{
publicList getItems(){ e2AX0(
return items; 5Y.)("1f}f
} 4R#chQ
5GI,o|[s6
publicvoid setItems(List items){ D@,6M#SK
this.items = items; BnX0G1|#
} S4Pxc
]!
(9tX5$e6N
publicint getPageSize(){ EGGWrl}1
return pageSize; ~IY%
} j5(Z_dm'
{dhXIs
publicvoid setPageSize(int pageSize){ _:ReN_0
this.pageSize = pageSize; -Fi`Z$
} Wvq27YK'
^-TE([ bW
publicint getTotalCount(){ o8 IL$:
return totalCount; WO7z
} )!3V/`I
M-$%Rzl_
publicvoid setTotalCount(int totalCount){ lXx=But
if(totalCount > 0){ ^6jV_QM#
this.totalCount = totalCount; ^4y,W]JUDt
int count = totalCount / 6,^>mNm
kVuUjP6(c
pageSize; fJ=0HNmX
if(totalCount % pageSize > 0) sSr&:BOsi
count++; $|zX|
indexes = newint[count]; d8DV[{^
for(int i = 0; i < count; i++){ f- K+]aZ)
indexes = pageSize * @#l `iK
w_ akn t T
i; 0 3L]
} %p Ynnfr
}else{ SU MrFd~
this.totalCount = 0; o5u3Fjz3
} ,dv+p&Tz2
} -{KQr1{5UM
CLxynZ\ ;
publicint[] getIndexes(){ Bm:98? [
return indexes; cF\;_0u
} I!ED?n
b}2ED9HG\
publicvoid setIndexes(int[] indexes){ HNb/-e ,"
this.indexes = indexes; S%$ }(
} ^8]NxV@l
z$&{:\hj
publicint getStartIndex(){ aKJwofD
return startIndex; L{#IT.
} %gInje
t DO=P
c
publicvoid setStartIndex(int startIndex){ <h!_>:2L
if(totalCount <= 0) =R^%(Py
this.startIndex = 0; aJSO4W)P
elseif(startIndex >= totalCount) 99]R$eT8
this.startIndex = indexes L s
G\OG
kAKK bmE
[indexes.length - 1]; d.[8c=$
elseif(startIndex < 0) #?RU;1)Cw
this.startIndex = 0; b\ X@gq
else{ ~]nRV *^
this.startIndex = indexes ;p.v]0]is
\|n-
O=}=2
[startIndex / pageSize]; gGR"Z]DBk
} *~2,/D
} XP`Nf)3{Yd
_Mi5g_
publicint getNextIndex(){ j9m_jv
int nextIndex = getStartIndex() + ~Q*%DRd&Z-
7( #:GD
pageSize; T*I{WW
if(nextIndex >= totalCount) ]q\b,)4
e
return getStartIndex(); ['b}QW@Fx
else Z/G
ev"p
return nextIndex; w3N[9w?1
} M
"ui0
ac
hz{`h
publicint getPreviousIndex(){ BfXgh'Z~
int previousIndex = getStartIndex() - K>
%Tq
CVDV)#JA
pageSize; x!hh"x
if(previousIndex < 0) _PPy44r2
return0; 2"COP>
else uY0lR:|
return previousIndex; T!uM+6|Y
} QER?i;-wb
H
h4WMZJG
} \h+AXs<j
JX<)EZ!F
&g#@3e1>
y$;/Vm_'
抽象业务类 []D&bYpv
java代码: t1]K<>g
md+nj{Ib
9/9j+5}+
/** '_<{p3M
* Created on 2005-7-12 sXqz+z$*
*/ YP
6`L
package com.javaeye.common.business; -<6\1J
} j<)L,
import java.io.Serializable; __uA}fZp
import java.util.List; j*d
yp
:{{F *FM;
import org.hibernate.Criteria; 97Lte5c6r
import org.hibernate.HibernateException; Cwr~HY
import org.hibernate.Session; ^0Zf,40
import org.hibernate.criterion.DetachedCriteria; N1}c9}
import org.hibernate.criterion.Projections; K~uXO
import !H#bJTXB
O3;u G.:1
org.springframework.orm.hibernate3.HibernateCallback; r`$OO,W
import ht|z<XJ
T=<@]$?
org.springframework.orm.hibernate3.support.HibernateDaoS '-QwssE
(XVw"m/ye
upport; M\vwI"
Cmu@4j&
import com.javaeye.common.util.PaginationSupport; MvuQz7M#d
% BVs47g
public abstract class AbstractManager extends ysJQb~2q
z__EYh
HibernateDaoSupport { 4Xgg%@C
FSP+?((
privateboolean cacheQueries = false; eP.wOl
w2Us!<x
privateString queryCacheRegion; &]V.S7LC#
Y1L[;)H n
publicvoid setCacheQueries(boolean Uq[>_"}
uyO/55;HO
cacheQueries){ +ndaLhj'
this.cacheQueries = cacheQueries; !]42^?GH
} Q}`0W[a
~
B|Du@^$
publicvoid setQueryCacheRegion(String fJ5iS
i3dkYevs?
queryCacheRegion){ <qtr
this.queryCacheRegion = Q`~jw>x
^pxX]G]
queryCacheRegion; 7X`l&7IXP
} ]99|KQ<s
u6?Q3
bvI
publicvoid save(finalObject entity){ XYjV.j\
getHibernateTemplate().save(entity); oxC[F*mD
} \4&fxe
u&^b~#T
publicvoid persist(finalObject entity){ UG'Q]S#!
getHibernateTemplate().save(entity); {mm)ay|M
} Bz^jw>1b
5:\},n+VE
publicvoid update(finalObject entity){ \<.+rqa!
getHibernateTemplate().update(entity); 63^O|y\W8
} >l]Xz*HE
8H;t_B
publicvoid delete(finalObject entity){ ?TM,Q
getHibernateTemplate().delete(entity); %!]@J[*1
} wHzEMwY_
3("_Z%
publicObject load(finalClass entity, f6EZ(
v
\"qY "V
finalSerializable id){ Olt`:;j-
return getHibernateTemplate().load ) dn(G@5
2 X.r%&!1M
(entity, id); oin$-i|Xp!
} 3Ko/{f
hM@
H A
publicObject get(finalClass entity, *e<[SZzYZ
//*fSF
finalSerializable id){ T{Gj+7bQ~
return getHibernateTemplate().get !_"@^?,q
DD7h^-x
(entity, id); $g@=Z"
} IW>T}@
|
;t'5},(FP
publicList findAll(finalClass entity){ 7zA'ri3w
return getHibernateTemplate().find("from 8R2QZXJb-
Jy^u?
" + entity.getName()); >5_2_Y$"
} "/)#O~
a<@1-j<
publicList findByNamedQuery(finalString ztnFhJ<a$
MPCBT!o4Z
namedQuery){ M:XSQ["6>V
return getHibernateTemplate }d&_q7L@@6
VE#Wb7
().findByNamedQuery(namedQuery); c(J!~7
} O#b6mKPt;t
O|\J}rm'
publicList findByNamedQuery(finalString query, zxMXXm;
^2+yHw
finalObject parameter){ p%#<D9S
return getHibernateTemplate
7_%"BVb"
{`J)j6;
().findByNamedQuery(query, parameter); ;P;-}u
} 7/!8e.M\
'r4/e-`pK
publicList findByNamedQuery(finalString query, ks"|}9\%<
S-Wz our,
finalObject[] parameters){ 0M*Z'n
+
return getHibernateTemplate rw: c
$RYa6"`
().findByNamedQuery(query, parameters); FR$:"
} W6f/T3
4S5,w(6N
publicList find(finalString query){ ao%NK<Lt
return getHibernateTemplate().find &wie]
Uhe=h&e2k@
(query); V}bjK8$$
} 4y)P>c
| 1E|hh@k
publicList find(finalString query, finalObject mlixIW2
?a8^1:
parameter){ }0eF~>Df
return getHibernateTemplate().find y6LWx:
lH-/L(h2
(query, parameter); i8`Vv7LF
} ?$vCW|f
B{|8#jqY
public PaginationSupport findPageByCriteria o1Ph~|s*8
l H#u
(final DetachedCriteria detachedCriteria){ |L-]fjBbF
return findPageByCriteria |*:'TKzNS
P=7zs;k
(detachedCriteria, PaginationSupport.PAGESIZE, 0); Gnf~u[T6
} %{ABaeb]
^X0P'l&D2
public PaginationSupport findPageByCriteria YwteZSbp6M
ZZk=E4aae
(final DetachedCriteria detachedCriteria, finalint >{N9kWY
Kh,V.+7k
startIndex){ J]v%q,"
return findPageByCriteria IzsphBI
}x@2]juJ
(detachedCriteria, PaginationSupport.PAGESIZE, u6T+Cg
Q?e*4ba
startIndex); QOjqQfmM;
} s@9vY\5[9
{ D^{[I
public PaginationSupport findPageByCriteria W"zab
Id'X*U7Q
(final DetachedCriteria detachedCriteria, finalint 8JM&(Q%#
5i>$]*o
pageSize, b@rVo;
finalint startIndex){ }'""(,2
return(PaginationSupport) -}=i 04^
Rec6c&5_
getHibernateTemplate().execute(new HibernateCallback(){ }vZ+A
publicObject doInHibernate ' qWALu
y&Mr=5:y
(Session session)throws HibernateException { W{%TlN
Criteria criteria = )\_:{ c
f%Ns[S~ r
detachedCriteria.getExecutableCriteria(session); n1JRDw"e$$
int totalCount = hn^<;av=
sp#p8@Cj
((Integer) criteria.setProjection(Projections.rowCount /]=C{)8
wp#'nO
()).uniqueResult()).intValue(); 9S-Z&2L
criteria.setProjection TatpXN\
>SML"+>
(null); TcIcS]w%
List items = ]DOX?qI
i
mX\TD0$d
criteria.setFirstResult(startIndex).setMaxResults ,RJtm%w
/a^1_q-bX
(pageSize).list(); fBalTk;G{U
PaginationSupport ps = z8QAo\_I(
WX=Jl<
new PaginationSupport(items, totalCount, pageSize, '$|[R98
*+-}P|S:
startIndex); &{>cZh}\
return ps; ~p1j`r;
} ]%|GmtqZs,
}, true); ~KW,kyXBnD
} Qj,]N@7
g6Q !8
public List findAllByCriteria(final 7N-w eX
:,Pn3xl
DetachedCriteria detachedCriteria){
f#?fxUH~
return(List) getHibernateTemplate h!&prYx
94+KdHAo^M
().execute(new HibernateCallback(){ wT `a3Ymm
publicObject doInHibernate Q7R~{5r>W
j<u@j+V
(Session session)throws HibernateException { vg
D77
Criteria criteria = j:k[90
Q?3Gk%T0[
detachedCriteria.getExecutableCriteria(session); Qk\A
c
return criteria.list(); \=uKHNP?#
} "ul {d(K3
}, true); t"k*PA
} -M[$Z y^
G]fRk^~
public int getCountByCriteria(final %F!1
#>%X_o-o23
DetachedCriteria detachedCriteria){ X=hYB}}nu
Integer count = (Integer) twP,cyR
Fb^:V4<T
getHibernateTemplate().execute(new HibernateCallback(){ WpF2)R}G=
publicObject doInHibernate pcYG~pZ9
IkBei&4F`
(Session session)throws HibernateException { Pm
lx8@D
Criteria criteria = nX(+s*Y+w
%;e/7`>Ma
detachedCriteria.getExecutableCriteria(session); )^4\,u\@
return T(e!_VY|m
3T"j)R_=l
criteria.setProjection(Projections.rowCount > `n,S
m\$\ 09
()).uniqueResult(); &m|wH4\
} AT9q3
}, true); T-5nB>)
return count.intValue(); uM_#
} P5
K' p5}#
} *tgnYa[l
|
\'rP_I>
0BH_'ZW
KcK>%%
VwOW=4`6
Svc|0Ad&
用户在web层构造查询条件detachedCriteria,和可选的 SILQ
c3:,Ab|
startIndex,调用业务bean的相应findByCriteria方法,返回一个 UVw~8o9s
ag*mG*Z
PaginationSupport的实例ps。 :cq9f2)
0TGLM#{
ps.getItems()得到已分页好的结果集 >S'17D
ps.getIndexes()得到分页索引的数组 +RnkJ* l
ps.getTotalCount()得到总结果数 6`v7c!7
ps.getStartIndex()当前分页索引 \RvvHty-V
ps.getNextIndex()下一页索引
"Qja1TQ
ps.getPreviousIndex()上一页索引 CAcS~ "
"\}@gV#r$A
xER\ZpA:,
rb1`UG"h$
*d"DA[(
e pU:
))&;}2{
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 m|=H#
0KGY\,ae:;
,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 (N&lHLy
.Fnwm}
一下代码重构了。 UEozAY
WHjUR0NZ
我把原本我的做法也提供出来供大家讨论吧: R}lsnX<
[P 06lIO
首先,为了实现分页查询,我封装了一个Page类: w9,iq@
java代码: 2 !At2P2
VUhbD
Xtp"QY
p
/*Created on 2005-4-14*/ uO=aaKG
package org.flyware.util.page; +"8,Mh
\ gLHi~
/** |b*?
qf
* @author Joa ^4,a 8`
* )hk
*/ tI7:5Cm
publicclass Page { G3rj`Sg^c
JaK}|
/** imply if the page has previous page */ ,t`Kv1
privateboolean hasPrePage; 0#ClWynjRO
Eh|]i;G%
/** imply if the page has next page */ G.(mp<-
privateboolean hasNextPage; |37
g ~
K91)qI;BD
/** the number of every page */ w9o^s5n
privateint everyPage; e _/b2"{
j{NNSi3
/** the total page number */ /Wy.>YC|
privateint totalPage; 'Er:a?88l
]R=,5kK3
/** the number of current page */ `;>= '"O!\
privateint currentPage; s1e:v+B]
RLSc+kDH_
/** the begin index of the records by the current BRk0CLr5
!OT-b>*w
query */ :dLAs@z
privateint beginIndex; cIp
D~0\
wlEdt1G
* 1Od-3
/** The default constructor */ uPRQU+
public Page(){ Ay
!G1;
*Mw_0Y
} CT1ja.\;
2AtLyN'.
/** construct the page by everyPage 6%fKuMpK(
* @param everyPage (4\d]*u5-c
* */ [-)r5Dsdq
public Page(int everyPage){ i} N8(B(
this.everyPage = everyPage; HO[wTB|D]
} '
4ER00
ET[kpL
/** The whole constructor */ <0S,Q+&
public Page(boolean hasPrePage, boolean hasNextPage, r\blyWi
i:Zm*+Gi
$2u 'N:o
int everyPage, int totalPage, WdnIp!
int currentPage, int beginIndex){ ZKXo-~=>
this.hasPrePage = hasPrePage; {'AWZ(
this.hasNextPage = hasNextPage; Dgx8\~(E'
this.everyPage = everyPage; J]q%gcM
this.totalPage = totalPage; 1c;6xc,ub
this.currentPage = currentPage; #'q<v"w
this.beginIndex = beginIndex; &[At`Nw71
} 1?| flK
0
s70r
/** 2hee./F`
* @return wN2QK6Oc
* Returns the beginIndex. O)Y?=G)
*/ gt/zpiKmV
publicint getBeginIndex(){ ;L,mBQB?0b
return beginIndex; fPrLM'
} [p2H=
MNg^]tpf
/** 8Th` ]tI
* @param beginIndex bO&7-Z~:=
* The beginIndex to set. uaOKv.%
*/ @c~)W8
publicvoid setBeginIndex(int beginIndex){ RGK8'i/X
this.beginIndex = beginIndex; Q6XRsFc
} a&k_=/X&
lt_']QqU
/** Q7g>4GZC
* @return 5bA)j!#)|X
* Returns the currentPage. ki{3IEOr}
*/ z.CywME<)t
publicint getCurrentPage(){ 5l,ZoB8
return currentPage; Fh*j#*oe
} wQ%mN[
Uz7^1.-g4
/** 0v]?6wX
* @param currentPage l$YC/bP
* The currentPage to set. VL[kJi
*/ e4G4GZH8
publicvoid setCurrentPage(int currentPage){ '*Almv {
this.currentPage = currentPage; YOrrkbJ(
} NBF MN%
de]z T^&C
/** ,&d@O>$E:
* @return {<5ybbhLV
* Returns the everyPage. R@wjccu
*/ 4pln5v=
publicint getEveryPage(){ Qjnd6uv{I
return everyPage; ;P;((2_X9
} Hk7q{`:N
zz^F
k&
/** 5P .qXA"D
* @param everyPage >j{z>
* The everyPage to set. 6&!&\
*/ &*s0\
8
publicvoid setEveryPage(int everyPage){ iL=
m{
this.everyPage = everyPage; [lk'xzE
} "7v-`i
k@ K7yK
/** 3b YCOqG
* @return ~Aq5XI%i
* Returns the hasNextPage. 720)VzT
*/ Pub0IIs
publicboolean getHasNextPage(){ 87WBM;$&s
return hasNextPage; m{7^EF
} yi^b)2G
'SYo_!
/**
[|~2X>
* @param hasNextPage 9z
I.pv+]
* The hasNextPage to set. `y+-H|%?
*/ WO6/X/#8b
publicvoid setHasNextPage(boolean hasNextPage){ Lw'9
this.hasNextPage = hasNextPage; bT6sb#"W
} )XfzLF7
HAYMX:%
/** Jjl%R[mI
* @return DOz\n|8S
* Returns the hasPrePage. &vovA} F
*/ [DHoGy,P
publicboolean getHasPrePage(){ p7ir*r/2
return hasPrePage; c>1RP5vx
} ZvGgmLN
UA~RK2k?
/** {"vkji>
* @param hasPrePage W-
$a
Y2
* The hasPrePage to set. 5/QRL\
*/ cE iu)2*e
publicvoid setHasPrePage(boolean hasPrePage){ SI_iI 71
this.hasPrePage = hasPrePage; v_S4hz6w\
} S?{/hy
.d?%;2*{q
/** Eh|.
* @return Returns the totalPage. K\^ 0_F K
* [~\PQYm'
*/ CU:o*;jP
publicint getTotalPage(){ dx,=Rd5'
return totalPage; &ff&Y.q~
} y[@\j9Hq
93IFcmO.H@
/** "7d-z<^n
* @param totalPage z^nvMTC
* The totalPage to set. NA$zd(
*/ 0lM{l?
publicvoid setTotalPage(int totalPage){ `Y40w#?uW
this.totalPage = totalPage; 0)m8)!gj
} LwuF0\
@mt0kV9
} \uG`|Dn
-xg2q
V\c
uE=$p)
m6
s7F/
]v G{kAnH
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 CnN9!~]"
U"f??y%)
个PageUtil,负责对Page对象进行构造: fQnwy!-\
java代码: sP'0Sl~NU
1\L[i];L8
(x;g/!:
/*Created on 2005-4-14*/ mgZf3?,)
package org.flyware.util.page; 1x~U*vbhQ
zVv04_:
import org.apache.commons.logging.Log; jy2IZ o
import org.apache.commons.logging.LogFactory; .7ayQp
/q\_&@
/** ~n!!jM:N
* @author Joa M!M!Ni
* =\,
qP
*/ :`vP}I ^
publicclass PageUtil { 6qo^2
>cL{Ya}Rz
privatestaticfinal Log logger = LogFactory.getLog DZ
^1s~
s]27l3)B
(PageUtil.class); HjWq[[Nz
=wi*Nd7L
/** *oI*-C
* Use the origin page to create a new page bVr*h2p
* @param page mT*{-n_Zs
* @param totalRecords 1U\$iy8}
* @return 1+y"i<3)
*/ Zt3}Z4d
publicstatic Page createPage(Page page, int ?lCd{14Mkh
-m 5}#P89
totalRecords){ *B)yy[8j+
return createPage(page.getEveryPage(), ;P?q2jI
FrTg4
page.getCurrentPage(), totalRecords); 0m9ZQ
O
} bzmr"/#D3
_'x8M
/** w8~K/>!f
* the basic page utils not including exception j%Y\A~DV
BRG|Asg(
handler Ek.&Sf$cd'
* @param everyPage B`#h{ )[
* @param currentPage $<)Yyi>6E
* @param totalRecords &[|VZ[
* @return page mjnUs-`W|
*/ HO|-@yOF^
publicstatic Page createPage(int everyPage, int xcCl
(M]+
I12KT~z<r
currentPage, int totalRecords){ {#Q\z>
everyPage = getEveryPage(everyPage); farDaS[\VY
currentPage = getCurrentPage(currentPage); ://U^sFL
int beginIndex = getBeginIndex(everyPage, +zOOdSFk.
zxZtz
currentPage); zz$q5[n
int totalPage = getTotalPage(everyPage, U!q[e`B
eQX`,9:5
totalRecords); ,35&G"JK5
boolean hasNextPage = hasNextPage(currentPage, @y~P&HUN
Yig0/"
totalPage); MXAEX2xmme
boolean hasPrePage = hasPrePage(currentPage); &w~Xa( uu
73NZ:h%=
returnnew Page(hasPrePage, hasNextPage, FY;+PY@I{
everyPage, totalPage, 3=4SGt5m
currentPage, 1|y$~R.H
<ZPZk'53<f
beginIndex); F#q&(
} Db03Nk>#
\ a-CN>
privatestaticint getEveryPage(int everyPage){ Fq,N
return everyPage == 0 ? 10 : everyPage; ddpl Pzm#
} m24v@?*
+GNWF%
zN
privatestaticint getCurrentPage(int currentPage){ $G?(OWI}l`
return currentPage == 0 ? 1 : currentPage; %|Hp Bs#'
} ML!9:vz
{/M\Q@j
privatestaticint getBeginIndex(int everyPage, int 7|D|4!i2Y
L-'k7?%(
currentPage){ qJs[i>P[W
return(currentPage - 1) * everyPage; p%RUHN3G[
} oFg'wAO.
}N3`gCy9eN
privatestaticint getTotalPage(int everyPage, int 'wQy]zm$
]
VG?+
totalRecords){ saK;[&I*
int totalPage = 0; (ppoW
;( KMGir
if(totalRecords % everyPage == 0) ]O{_O&w
totalPage = totalRecords / everyPage; NtZ6$o<Y
else ,Q2N[Jwd$
totalPage = totalRecords / everyPage + 1 ; w6,*9(;$Pk
6&!l'[hU
return totalPage; I"Q<n[g0'
} ua& @GXvZ
U}P,EP%p
privatestaticboolean hasPrePage(int currentPage){ ~w.2-D
return currentPage == 1 ? false : true; pzEABA
} ,nE&MeJ
ckwF|:e7*
privatestaticboolean hasNextPage(int currentPage, gL]'B!dGd
Ee?;i<u
int totalPage){ (:} <xxl
return currentPage == totalPage || totalPage == zHFTCL>"
Wvr+y!F
0 ? false : true; $pu3Ig$^
} 1mUTtYU
i,OKfXp
U)~#g'6:8
} 6VR18Y!y
t"YIq/08
d^aNR
Lv
Y+|PY?
~
0BC`iql5
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。 zzf7S%1I
swZpWC
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 5#u.pu
3X'WR]
做法如下: eY3=|RR
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 |!b9b(_j9
{})y^L
的信息,和一个结果集List: ZlM_m
>,o
java代码: u9>6|w+
T +\ B'"
,P{HE8.
/*Created on 2005-6-13*/ v72,h
package com.adt.bo; ?'+8[OHiF^
FW^.m?}|
import java.util.List; n0FYfqH
+ U5U.f%
import org.flyware.util.page.Page; h]}`@M"
3:" &Z6t#
/** GN%<"I.
* @author Joa MgnE-6_c
*/ w
a.f![
publicclass Result { |uQ[W17^N
~^7
private Page page; ((9YG
[tN` :}?
private List content; W"O-L
}bgo )<i
/** *. dKR
* The default constructor C38XQLC
*/ `(T!>QVW+g
public Result(){ 4
m$sJ
super(); SY8U"Qc;9
} R9E6uz.j
`t9.xB#Z
/** b6Xi
* The constructor using fields nk>8SW^
* q(1r<2
* @param page UC#"=Xd4
* @param content <[5#c*A
*/ u2,H ]-
public Result(Page page, List content){ E@]sq A
this.page = page; ]W|RtdF3.N
this.content = content; K Dz]wNf
} %%x0w^
r4S=I
/** k) 3s?
* @return Returns the content. #-dK0<:
*/ .r*#OUC
publicList getContent(){ >gGil|I
return content; j #es2;
} #rq?f
Bpas[2gYC
/**
I9Om#m
* @return Returns the page. @|]G0&gn&?
*/ l }+Cdy9>
public Page getPage(){ 5])8qb/F
return page; @dl<-
} mQnL<0_<f
PuU*vs3
/** Ir>2sTrm
* @param content z^9E;
* The content to set. VX&WlG`wa
*/ l"?]BC~
public void setContent(List content){ E6JV}`hSk
this.content = content; [nC4/V+-
} $&Ac5Zo%}
+qZc}
7rJF
/** k)Zn>
* @param page x36NL^
* The page to set. fYs?D+U;PF
*/ p&m
^IWD
publicvoid setPage(Page page){ _Z0\`kba+
this.page = page; b+_hI)T
} e
%&
} :=Nb=&lst
uh1S
7!^
a6P!Wzb
KDX$.$#
}*Dd/'2+1
2. 编写业务逻辑接口,并实现它(UserManager, c0SX]4}
G
n'Bmz
UserManagerImpl) +L n M\n
java代码: m.Twgin
%L28$c3p
4xp j<
/*Created on 2005-7-15*/ h9U+%=^O
package com.adt.service; H[Cj7{V
3 ^pYCK%
import net.sf.hibernate.HibernateException; :K:f^o]s
jB` 7T^bU
import org.flyware.util.page.Page; a&8l[xe1
XS3{R
import com.adt.bo.Result; 3m3
EXz
MHGj vSx
/** 2S'AIuIew
* @author Joa *J.c $1#h
*/ e7h\(`J0lj
publicinterface UserManager { H a90
TdNsyr}JG
public Result listUser(Page page)throws x{~_/;\p3
fHLFeSfH
HibernateException; aQxe)
A}gYcc85Z
} AVU7WU{
q$3HvZP
kGruo5A
h<GyplG
wXP_]-
java代码: /#@LRN<oCq
o}d2N/T
B%) zGTp6
/*Created on 2005-7-15*/ QXsfp
package com.adt.service.impl; +BU0 6lLD
B*32D8t`u
import java.util.List; j-j'ph K
RFhU#
import net.sf.hibernate.HibernateException; gYRqqV
MPqY?KF
import org.flyware.util.page.Page; m9%yR"g9
import org.flyware.util.page.PageUtil; sw[<VsxjR
4$..r4@
import com.adt.bo.Result; w4NZt|>5j;
import com.adt.dao.UserDAO; |&9tU
import com.adt.exception.ObjectNotFoundException; l.sm~/
import com.adt.service.UserManager; -6(h@F%E
5sG ]3z+1
/** ]aREQ?ma&z
* @author Joa *X%?3"WH8
*/ L,f^mX0<
publicclass UserManagerImpl implements UserManager { D`1I;Tb#
Ml'bZLwq
private UserDAO userDAO; loml.e=87
rve7YS'
/** jM{qRfOrg
* @param userDAO The userDAO to set. " vv$%^
*/ '\Qf,%%.
publicvoid setUserDAO(UserDAO userDAO){ @ysJt
this.userDAO = userDAO; X *_
SHt
} :8GlyN<E
E=$7ieW
/* (non-Javadoc) 8[vl3C
* @see com.adt.service.UserManager#listUser u!hqq^1
Bidqf7v
(org.flyware.util.page.Page) 6(\q< fx
*/ q]2}UuM|U
public Result listUser(Page page)throws Sr4dY`V*:z
Uyz;U34 oI
HibernateException, ObjectNotFoundException { _HSTiJVr
int totalRecords = userDAO.getUserCount(); ]|H]9mys98
if(totalRecords == 0) y.L|rRe@P
throw new ObjectNotFoundException Wh#os,U$
,| $|kO/
("userNotExist"); 40`9t Xn
page = PageUtil.createPage(page, totalRecords); l=Vowx.$2f
List users = userDAO.getUserByPage(page); nC-c8y
returnnew Result(page, users); dY/|/eOt<K
} %iHyt,0v2
#p11D=
@[
} u40b?
n.
oVKsic?
]9bh+
s@*,r@<
X; e`y:9
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 CUAg{]
KfJ c
询,接下来编写UserDAO的代码: 7vB9K _wCI
3. UserDAO 和 UserDAOImpl: |;xfe"]
java代码: (:tTx>V#
I^rZgp<'i
6)tB{:h&~0
/*Created on 2005-7-15*/ YzforM^F
package com.adt.dao; yHa:?u6
FCS5@l,'<
import java.util.List; U'f$YVc
wa-_O<
import org.flyware.util.page.Page; o3kt0NuF,
G_7ks]u-
import net.sf.hibernate.HibernateException; m-~V+JU;x
CDwFVR'_Af
/** F[Guy7?O
* @author Joa eSQzjR*
*/ EhmUX@k],
publicinterface UserDAO extends BaseDAO { s!nSE
F$"MFdc[
publicList getUserByName(String name)throws '<*CD_2t-
GN~[xXJU
HibernateException; 0jip::x
Q"l"p:n%n
publicint getUserCount()throws HibernateException; I_jM-/3b
mmpr]cT@'k
publicList getUserByPage(Page page)throws hIE%-gZ/
\N-|
iq
HibernateException; qr<-eJf
UH1S_:6
} &deZ
U{U:8==
RGx]DP$5G
.O@q5G
{7ZtOe
java代码: K%aPl~e
#w%a
m`+
mTI\,x%<OC
/*Created on 2005-7-15*/ $)kBz*C[
package com.adt.dao.impl; }
Y7W1$he
$9
&Q.Kpq>
import java.util.List; /:
\V wH
8VAYIxRv
import org.flyware.util.page.Page; 6B!j(R
6x (L&>F
import net.sf.hibernate.HibernateException; buxI-wv
import net.sf.hibernate.Query; %O4}i@Fe
rhzv^t
import com.adt.dao.UserDAO; _taHf %\4
`K@df<}%*,
/** d-#u/{jG)
* @author Joa #*7/05)
*/ FJwZo}<6E
public class UserDAOImpl extends BaseDAOHibernateImpl mV!
@oNCK
9wDBC~.
implements UserDAO { u]>>B>KOJ7
:<WQ;q
/* (non-Javadoc) I!soV0VU]
* @see com.adt.dao.UserDAO#getUserByName b[&,%Sm+6
yjM@/b
(java.lang.String) 08d_DCR
*/ "`$'tk[
publicList getUserByName(String name)throws 7/U<\(V!g
s&QBFyKtJ
HibernateException { Te U7W?M^
String querySentence = "FROM user in class zvK5Zxl
8KL_PwRX_f
com.adt.po.User WHERE user.name=:name"; +{=_|3(
Query query = getSession().createQuery =|WV^0=S'%
3A}nNHpN
(querySentence); j~,LoGuPh
query.setParameter("name", name); zb~MF_ &gE
return query.list(); Kt!IyIa;Ht
} #.<F5
5M\=+5wB
/* (non-Javadoc) A 4W
* @see com.adt.dao.UserDAO#getUserCount() !7"K>m<
*/ 5qtmb4R~
publicint getUserCount()throws HibernateException { EV?47\~
int count = 0; ZR01<V
String querySentence = "SELECT count(*) FROM R6WgA@Z|r
ah!O&ECh
user in class com.adt.po.User"; ]zwqG A
Query query = getSession().createQuery #()cG
k1$2a8ja
(querySentence); /Vm}+"BCS
count = ((Integer)query.iterate().next G=bP<XF
8HRPJSO~g
()).intValue(); pJ*#aH[ySP
return count; Oih2UrF
} AZ9\>U@hD
"aCb;2Rs
/* (non-Javadoc) CAo )v,f
* @see com.adt.dao.UserDAO#getUserByPage DP6{HR$L
J PzQBc5e
(org.flyware.util.page.Page) s
eZ<52f2
*/ *_).UAP.
publicList getUserByPage(Page page)throws ch,Zk )y:_
D`~{[cv)\
HibernateException { iP?ASqo{
String querySentence = "FROM user in class 5q_OuZ/6
-C'X4C+
com.adt.po.User"; c%LB|(@j{
Query query = getSession().createQuery g<T`F
4{pemqS*
(querySentence); <%3SI.
query.setFirstResult(page.getBeginIndex()) FG5c:Ep
.setMaxResults(page.getEveryPage()); HT,kx
return query.list(); h3d\MYO)B
} g=YiR/O1QN
#!d^3iB2
} R$;&O.
5M
YT(1
"{:
9X{nJ"
UK<DcM~n
L5 k>;|SA
至此,一个完整的分页程序完成。前台的只需要调用 (8-lDoW
0-~6}
r$
userManager.listUser(page)即可得到一个Page对象和结果集对象 o?O,nD
6
^B!?;\4IM
的综合体,而传入的参数page对象则可以由前台传入,如果用 C8W`Oly:]
AIxBZt7{b
webwork,甚至可以直接在配置文件中指定。 gUszMhHX
6[h$r/GXh"
下面给出一个webwork调用示例: f~" V
java代码: FvNSu"O~K1
v.LUK
wAOVH].
/*Created on 2005-6-17*/ nM.?Q}yO~
package com.adt.action.user; Nj-rZ%&
c.{&~
import java.util.List; h. (;GJO
cD`O+WA2K
import org.apache.commons.logging.Log; Gxa.<E^k
import org.apache.commons.logging.LogFactory; BfE-s<
import org.flyware.util.page.Page; nC!^,c
\;:@=9`
import com.adt.bo.Result; "`3^MvC
import com.adt.service.UserService;
pOI`,i}.
import com.opensymphony.xwork.Action; 6p=x gk-q
!4,xQ^
/** )(!Z90@
* @author Joa 7CL@iL Tq
*/ g&F<Uv#mZ
publicclass ListUser implementsAction{ A{Htpm ~
)>M@hIV5>
privatestaticfinal Log logger = LogFactory.getLog '-]BSU
qddT9U|8~
(ListUser.class); %V1T!<
(:HbtrI
private UserService userService; 8(/f!~
P ~
pbx
private Page page; 07"Oj9NlA
W]}V<S$
privateList users; o4 g
9PGR#!!F$
/* Cbg#Yz~/
* (non-Javadoc) B{UoNm@
* sAN:C{
* @see com.opensymphony.xwork.Action#execute() v?TJ!o
*/ g#%FY1xp
publicString execute()throwsException{ E,"btBg
Result result = userService.listUser(page); MirBJL
page = result.getPage(); 8Gg/M%wq9U
users = result.getContent(); G{Enh<V
return SUCCESS; DD$Pr&~=
} 27 TZ+?
y^46z(I
/** 3R:i*8C
* @return Returns the page. <.(/#=2
*/ =egi?Ne
public Page getPage(){ k\<Ln
w
return page; N b[o6AX
} ~rX6owBq
u\geD
/** 5_C#_=E
* @return Returns the users. 5t#]lg[06'
*/ GXlg%
publicList getUsers(){ MVd
3*
return users; :@Dos'0Px
} 'I>#0VRr
[_hhC
/** `DllW{l
* @param page ~tuFjj^
* The page to set. Z:$b)+2:\
*/ _O,ZeES
publicvoid setPage(Page page){ Jv.R?1;8i
this.page = page; UBHQzc+,
} GFa/9Bi
4^ 6L ])y
/** bCe-0!Q
* @param users xLK0~|_#!
* The users to set. W8h\ s {
*/ SfL`JNi)
publicvoid setUsers(List users){ 6MNA.{Jdd
this.users = users; l4reG:uYG
} Byj~\QMD|
-?1J+}?
/** iPO
S
* @param userService y+afUJT
* The userService to set. OT3;qT*fw
*/ M #&L@fg!
publicvoid setUserService(UserService userService){ c!^}!32j)
this.userService = userService; \o)4m[oF
} <1.mm_pw
} -%)
!XB
;O|63
dKTAc":-}
`2+e\%f/0
|6^ K
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, Z?'|9FM
N4jLbnA
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 1W<_5 j_
T@Z{KV"S
么只需要:
#de^~
java代码: 0w. _}Cz
{~I_rlo n
}3y\cv0ct
<?xml version="1.0"?> 8mLU ~P
|
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 4PM`hc
q#3X*!)
1.0//EN" "http://www.opensymphony.com/xwork/xwork- :?k=Yr
mJR
T+SZ
1.0.dtd"> @\}36y
}?kO<)d
<xwork> q:sR zX
Vp{2Z9]}
<package name="user" extends="webwork- "<a|Q ,!
%pQ o%<d
interceptors"> 2<@!m@
695ppiKU
<!-- The default interceptor stack name nW'x#0-
_ u2
--> S]/+n>
<default-interceptor-ref C~V$G}mM
m
kf{_!TK
name="myDefaultWebStack"/> PzDgl6C
c (8J
<action name="listUser" v ed
Qwzh
0M+tKFb
class="com.adt.action.user.ListUser"> ~"Ki2'j)^]
<param Fsj[J E
dwMwd@*j
name="page.everyPage">10</param> x's-UO"^
<result UdJV;T'rm
|h/2'zd^-
name="success">/user/user_list.jsp</result> :q1r2&ne
</action> $7d"9s\$"
$u"$mg7x
</package> ??V["o T
R,1 ,4XT
</xwork> ^0-=(JrC
pk1M.+
Tj9q(Vq
e*s{/a?,
\9QOrjiw
V1A3l{>L
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 -#x\ E%v.F
nTKfwIeg5
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。 =>*N W9c
)aSkUytg"
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 epyfggMT
|Wk
G='02
<-}\V!@E!
C ,hsr
vrbh+
我写的一个用于分页的类,用了泛型了,hoho e*H$c?7NL
Din)5CxFX
java代码: _AYF'o-Cm
'DQyB`V2y
pASVnXJZ
package com.intokr.util; 9 To6Rc;
"QS7?=>*F
import java.util.List; ||aU>Wj4
>,3
3Jx
/** xK3;/!\`
* 用于分页的类<br> 4PQWdPv;
* 可以用于传递查询的结果也可以用于传送查询的参数<br> 7!%"8Rl-
* f
lB2gr^
* @version 0.01 .SN]hLV5
* @author cheng !&[4T#c
*/ X2v'9 x
public class Paginator<E> { z?,5v`,t2
privateint count = 0; // 总记录数 <bI,y_<K
privateint p = 1; // 页编号 ? Q}{&J
privateint num = 20; // 每页的记录数 VIzZmd
privateList<E> results = null; // 结果 q?&&:.H"?5
&=bI3-
/** 2-84
* 结果总数 mX^RSg9 E}
*/ zn|}YovY+
publicint getCount(){ 5Y^YKV{
return count; )3sb2
#
} @4$E.q<0
+$5^+C\6A
publicvoid setCount(int count){ K<GCP2
this.count = count; W6Pg:Il7
} C.<4D1}P
bAp`lmFI
/** 6-"&jbvm
* 本结果所在的页码,从1开始 :xCobMs_/
* ny=iAZM>q
* @return Returns the pageNo. F1>,^qyG6
*/ ^ a:F*<D
publicint getP(){ x}d\%*B
return p; rej[G!
} t
,$)PV
#SueT"F
/** WM26-nR
* if(p<=0) p=1 A_%w(7o"
* k1J}9HNYR
* @param p 1 <+^$QL
*/ mLE`IKgd]
publicvoid setP(int p){ ] ?(=rm9u
if(p <= 0) }g?]B +0
p = 1; X6RM2
this.p = p;
t2iFd?
} nj
mE>2
7Y/_/t~Y
/** kWFR(J&R
* 每页记录数量 Lrq&k40y
*/ V
EzIWNV
publicint getNum(){ o;fQ,rP%
return num; ^-ZqS
} o/R-1\Dn
Wm 61
/** |UG)*t/
* if(num<1) num=1 T[~X~dqwn"
*/ [z\*Zg
publicvoid setNum(int num){ :[doYizk:
if(num < 1) lV8Mr6m
num = 1; N5^:2ag
this.num = num; Y2Bu,/9^
} I8y\D,
\GWC5R7Q0j
/** +\4=G@P.J
* 获得总页数 +Ji dP
*/ *L=CJg
publicint getPageNum(){ v&Kw
3!X#E
return(count - 1) / num + 1; eC?N>wHH
} /1*\*<cs
_N6GV$Q
/** ~&kV
* 获得本页的开始编号,为 (p-1)*num+1 TUG3#PSnm*
*/ Mtu8zm
publicint getStart(){ x)*[>d2yd
return(p - 1) * num + 1; rlD@O~P4
} Ch3##-
8QU`SoS9
/**
l}JVRU{
* @return Returns the results. ~0L>l J
*/ E%TvGe;#
publicList<E> getResults(){ ]#`bYh^y
return results; [{YV<kN
} %llG/]q#
l<5!R;?$
public void setResults(List<E> results){ j2+&B9(
this.results = results; )jg3`I@
} ,~v1NK*
\2Yh I0skW
public String toString(){ 95}"AIi
StringBuilder buff = new StringBuilder &A~ 1Q#4
a`}-^;}SW
(); Rzp-Q5@MY
buff.append("{"); 7r>^_ aW
buff.append("count:").append(count); Ex<loVIrP$
buff.append(",p:").append(p); I8m(p+Z=
buff.append(",nump:").append(num); /Mv'fich(
buff.append(",results:").append 1*Z}M%
.$Y[>9
(results); ^-DK<jZ^
buff.append("}"); 46b.= }
return buff.toString(); \>+gZc]an
} =Oy,SX
.*ZNZ|g_
} #C|iW@
p?Y1^/
3'8~H]<W