Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 q:>^ "P{
4:3rc7_
1
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Z.L?1V8Q1
foF19_2 ,
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!62/df
%1
KbS
[
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 ?)Nj c&G
djQv[Vc{
。 kEeo5XN
e;bYaM4UX
分页支持类: %Kh4m7
8rZ!ia!
java代码: CF!Sa 6
<E;pgw!
seFGJfN\?f
package com.javaeye.common.util; =-cwXo{Q.O
72W,FU~OD
import java.util.List; I7+9~5p
~8 H_u
publicclass PaginationSupport { sML=5=otx
,ea^,H6
publicfinalstaticint PAGESIZE = 30; MfF~8
#$~ba%t9%
privateint pageSize = PAGESIZE; _i_Q?w`
->z54 T
privateList items; -Ue$T{;RoH
\mM<\-'p
privateint totalCount; |rw%FM{F
N(6|yZ<J3M
privateint[] indexes = newint[0]; /gcEw!JS
z@|dzvjl
Q
privateint startIndex = 0; SEwku}
2Q7R6*<N:
public PaginationSupport(List items, int MvLs%GE%
mpC`Yk
totalCount){ Ok5<TZ6t4k
setPageSize(PAGESIZE);
@4d)R
setTotalCount(totalCount); -hcS]~F
setItems(items); ] G.%Ty
setStartIndex(0); p?[Tm*r
} (GnuWc\p
`J<*9dq%
public PaginationSupport(List items, int +[@z(N-h
j| Wv7
totalCount, int startIndex){ 5S
Xn?
setPageSize(PAGESIZE); K`&oC8p
setTotalCount(totalCount); N/YWb y=H
setItems(items); 6h?gs"[j
setStartIndex(startIndex); v`J*ixZ7t
} J2q,7wI#
Mj-vgn&/
public PaginationSupport(List items, int ,H}_%}10
5IOFSy`
totalCount, int pageSize, int startIndex){ ~0$NJrUy
setPageSize(pageSize); -\ZcOXpMx=
setTotalCount(totalCount); C`=p+2I]
setItems(items); r;9 r!$d
setStartIndex(startIndex); 7*Qk`*Ii
} +h^jC9,m~{
mE O\r|A
publicList getItems(){ wS+V]`b
return items; <H3ezv1M
} q/3ziVd7p
TlAR.cV
publicvoid setItems(List items){ R2etB*k6[
this.items = items; k 4/D8(OXw
} 0tISXu-
d\MLOXnLq;
publicint getPageSize(){ "xcX'F^
return pageSize;
N#V.1<Y
} `.x$7!zLC
.Xm(D>>k
publicvoid setPageSize(int pageSize){ !f>d_RG
this.pageSize = pageSize; Y^Nuz/
} ]3ONFa
}7fZ[J3
publicint getTotalCount(){ '[$)bPMHl
return totalCount; 7*j
(*
} gM>t0)mGK
L!/\8-&$P
publicvoid setTotalCount(int totalCount){ ERwHLA
if(totalCount > 0){ V^y^
;0I}[
this.totalCount = totalCount; ')a(.f
int count = totalCount / s,bERN7'yO
T +5X0 Nv
pageSize; `k(yZtb
if(totalCount % pageSize > 0) s &Dg8$
count++; }nt*
[:%
indexes = newint[count]; wIkN9
f
for(int i = 0; i < count; i++){ &<zd.~N"
indexes = pageSize * gh`m*@
`&0Wv0D0
i; G;>
_<22
} *"9><lJ-!
}else{ 6cqP2!~
this.totalCount = 0; w6`9fX6{h
} 5tQ1fJze
} aKU*j9A?;Z
RMO,ZVq
publicint[] getIndexes(){ ]# t6Jwk
return indexes; `[o)<<}
} 4'W '}o|{
Sxjub&=
publicvoid setIndexes(int[] indexes){ l4T7'U>`
this.indexes = indexes; FZreP.2)!
} /TS=7J#
OY[e.N
t&
publicint getStartIndex(){ r&-m=Kk$
return startIndex; 9a'-Y
} Uax+dl
Bq/:Nd[y
publicvoid setStartIndex(int startIndex){ 7+./zN
if(totalCount <= 0) Vcd.mE(t%
this.startIndex = 0; 3+>G#W~
elseif(startIndex >= totalCount) hF2IW{=!
this.startIndex = indexes dEBcfya
2VW}9O
[indexes.length - 1]; .CP&bJP%
elseif(startIndex < 0) s
{^yj
this.startIndex = 0; Zmbfq8K
else{ dr4Z5mw"E
this.startIndex = indexes 0$r^C6}f
FP[!BUOf"
[startIndex / pageSize]; k
X {0y
} \OlmF<~
} ?UM*Xah
keRE==(D
publicint getNextIndex(){ 5SCKP<rb
int nextIndex = getStartIndex() + 04r$>#E
L(GjZAP
pageSize; `3p~m,
if(nextIndex >= totalCount) c8Z wr]DF
return getStartIndex(); vb9OonE2
else 1+?^0%AC
return nextIndex; hsu{ey p
} 54zlnM$
q7u'_R,;
publicint getPreviousIndex(){ UMX@7a,[3
int previousIndex = getStartIndex() - Z{'i F
tTd\|
pageSize; X.`~>`8
if(previousIndex < 0) !3T&4t
return0; fM^[7;]7e
else #^+DL]*l
return previousIndex; R$zH]
} 6q
2_WX
q -8t'7
} 3Hf0MAt
iR"N13
;c$ J=h]
G:g69=x y
抽象业务类 O|_h_I-2
java代码: `~eUee3b.~
QeF3qXI
FVhU^
/** N&@}/wzZ
* Created on 2005-7-12 gv5*!eI
*/ U*.0XNKp{
package com.javaeye.common.business;
}-~l!
J90v!p-
import java.io.Serializable; YJ$1N!rG
import java.util.List; m,fAeln
LdJYE;k Ju
import org.hibernate.Criteria; ! VjFW5'{
import org.hibernate.HibernateException; Sp@-p9#
import org.hibernate.Session; BT}&Y6
import org.hibernate.criterion.DetachedCriteria; eYx Kp!f
import org.hibernate.criterion.Projections; tBpC: SG
import EqI(|bFwy
=-p$jXVW%
org.springframework.orm.hibernate3.HibernateCallback; 7g_]mG[6
import P;4w*((} ~
w&ak"GgV
org.springframework.orm.hibernate3.support.HibernateDaoS O*#*%RL|
b+Br=Fv"T
upport; `p+Zz"/
Y))NK'B5
import com.javaeye.common.util.PaginationSupport; ^j7azn
Yup3^E
w&
public abstract class AbstractManager extends r&FDEBh
Yw0[[N<SW
HibernateDaoSupport { bJs9X/E
@B}aN@!/
privateboolean cacheQueries = false; _YRE (YZ/
43=,yz2Ef
privateString queryCacheRegion; $ MC)}l
5atYOep
publicvoid setCacheQueries(boolean 8_N]e'WUh
F:a ILx
cacheQueries){ u{L!n$D7
this.cacheQueries = cacheQueries; <_Q1k>
} d^`?ed\1
}V\N16f
publicvoid setQueryCacheRegion(String m^qBxA
H=
X|h)
queryCacheRegion){ zP<pEI
this.queryCacheRegion = <I;2{*QI2
ZRYEqSm
queryCacheRegion; !F?XLekTi
} }\C-}
Q
%iw3oh&Fkm
publicvoid save(finalObject entity){ 9?k_y ZV
getHibernateTemplate().save(entity); }u1O#L}F5
} Vx-7\NB
^aW
Z!gi
publicvoid persist(finalObject entity){ t45Z@hmcW
getHibernateTemplate().save(entity); yq$,,#XDD=
} tor!Dl@Mo
^b
%0B
publicvoid update(finalObject entity){ /7
Cn(s5 o
getHibernateTemplate().update(entity); H*r>Y
} Ps<d('=
B/n[m@O
publicvoid delete(finalObject entity){ V dn&c
getHibernateTemplate().delete(entity); IH"6? 9nd
} Nv"EV;$
.aflsUD
publicObject load(finalClass entity, yxc=Z0~1
=Qn ;_+Ct
finalSerializable id){ $.bBFWk
return getHibernateTemplate().load 9H%X2#:fH
&y#r;L<9
(entity, id); VJS8)oI~
} +$Rt+S BD
I"`M@ %
publicObject get(finalClass entity, 9VbOQ {8
{`w;39$+
finalSerializable id){ t2"FXTAq
return getHibernateTemplate().get vI@%Fg+D
wiBVuj#
(entity, id); Ot`VR&}
} qcT'nZ:
,#8e_3Z$
publicList findAll(finalClass entity){ 3*@5S]]
return getHibernateTemplate().find("from ^urDoB:
bAx?&$
" + entity.getName()); `HBf&Z
} }RP@!=
d \35a4l
publicList findByNamedQuery(finalString !Xph_SQ!B=
dc rSz4E|>
namedQuery){ plZ>03(6Q
return getHibernateTemplate CJ++?hB]X
ki)#d'
}
().findByNamedQuery(namedQuery); w[ ~#av9
} uDZT_c'Y
Rx+p.
publicList findByNamedQuery(finalString query, k]I0o)+O.
RH|XxH*
finalObject parameter){ [2Ud]l:6E
return getHibernateTemplate ;{[.Zu
y.Z?LCd<
().findByNamedQuery(query, parameter); <Z/x,-^*<
} r4#o+qE
Ggb5K8D*
publicList findByNamedQuery(finalString query, yR\btx|e5~
zi3\63D3eO
finalObject[] parameters){ 2J;kSh1,L
return getHibernateTemplate M^]cM(swK5
J.|+ID+
().findByNamedQuery(query, parameters); @|tL8?
} 9tqF8pb7v
PV=5UyjW
publicList find(finalString query){ tq|hPd<C
return getHibernateTemplate().find @i*|s~15
7!N2-6GV
(query); mtjh`
} %Ijj=wW
f1(+
bE%
publicList find(finalString query, finalObject #KiRfx4G
}3L@J8:D"
parameter){ A\.GV1
return getHibernateTemplate().find 'Un" rts
L{`JRu
(query, parameter); E)fglYWs2
} a 7,C>%I
AoI/n4T^
public PaginationSupport findPageByCriteria g"> {9YE
# m *J&
(final DetachedCriteria detachedCriteria){ Kc^;vT>3
return findPageByCriteria *C:|X b<9
+PuPO9jKO@
(detachedCriteria, PaginationSupport.PAGESIZE, 0); c7FRI0X
} :EA\)@^$R
TU
1I} ,
public PaginationSupport findPageByCriteria *v3]}g[<
`{xNXH]@
(final DetachedCriteria detachedCriteria, finalint +o51x'Ld*
uF3qD|I\
startIndex){ IyLx0[:U
return findPageByCriteria @$+ecaVW
UCClWr
(detachedCriteria, PaginationSupport.PAGESIZE, ,9o"43D:a|
yT,.z 0
startIndex); ok4@N @
} fwRZ5`v<
I}vmU^Y>
public PaginationSupport findPageByCriteria 9,r rQQD_
x3"#POp
(final DetachedCriteria detachedCriteria, finalint |1>*;\o-
c*@E_}C#
pageSize, g'm+/pU)w)
finalint startIndex){ [n$BRk|
return(PaginationSupport) }I2@%tt?
byfJy^8G
getHibernateTemplate().execute(new HibernateCallback(){ M%0C_=zg
publicObject doInHibernate y7i*s^ys{
KPj\-g'A
(Session session)throws HibernateException { =HlQ36;*
Criteria criteria = 7fba-7-P
;hjwD
detachedCriteria.getExecutableCriteria(session); CtS l
int totalCount = e;[F\ov%
L-k@-)98
((Integer) criteria.setProjection(Projections.rowCount ynhmMy%
dp*u9z~NA
()).uniqueResult()).intValue(); N
D2L_!g:(
criteria.setProjection H?X|(r|+
Oal3rb
(null); k|H:
List items = 9c6gkt9eB
D'Y-6W3
criteria.setFirstResult(startIndex).setMaxResults |YY_^C`"-
]f({`&K5
(pageSize).list(); UaB @
PaginationSupport ps = iB& 4>+N+
j_.5r&w
new PaginationSupport(items, totalCount, pageSize, t8+X%-r
hs$GN]
startIndex); 0PrLuejz
return ps; t?'!$6
} Oz%>/zw[h
}, true); X'qU*Eo
} jmFz51
ftF@Wq1f
public List findAllByCriteria(final /
:n#`o=;
^*Yh@4\{JH
DetachedCriteria detachedCriteria){ ^kB8F"X
return(List) getHibernateTemplate $H9%J
7G>dTO
().execute(new HibernateCallback(){ Q{5kxw1ZF
publicObject doInHibernate 3skC$mpJHw
20nP/e
(Session session)throws HibernateException { <
RH UH)I
Criteria criteria = 57&b:0`p
S-|)QGxV6
detachedCriteria.getExecutableCriteria(session); VeQg-#&I
return criteria.list(); 3 C<L
} 1BpiV-]=
}, true); [CXrSST")E
} ?3.b{Cq{-
j?x>_#tIY
public int getCountByCriteria(final ]33>m|?@
?}U(3
DetachedCriteria detachedCriteria){ v63"^%LX
Integer count = (Integer) U5.LDv;
<y NM%P<Oy
getHibernateTemplate().execute(new HibernateCallback(){ V13N}]
publicObject doInHibernate 70Wgg ty
5MtLT#C3r
(Session session)throws HibernateException { 5jgR4a*_v
Criteria criteria = #nPQ!NB/
K#=*9S
detachedCriteria.getExecutableCriteria(session); PC-"gi=h
return +2&@x=xy
I
,z3xU
criteria.setProjection(Projections.rowCount
`yH<E+
ne_TIwf w-
()).uniqueResult(); t~#zMUfac
} mSb#Nn6W
}, true); sWc*5Rt
return count.intValue(); \Yc'~2n
} 0,89H4
} V#S9H!hm$
E(8*
pI
m;GbLncA
8)10o,#L
rFj-kojg
vPTM
用户在web层构造查询条件detachedCriteria,和可选的 lY?QQ01D
Ne[7gxpu
startIndex,调用业务bean的相应findByCriteria方法,返回一个 < v@9#c
q$B>|y U
PaginationSupport的实例ps。 EkjN{$*
'z%o16F)L
ps.getItems()得到已分页好的结果集 <YhB8W9 P
ps.getIndexes()得到分页索引的数组 ZL&g_jC
ps.getTotalCount()得到总结果数 W;!}#o|%s
ps.getStartIndex()当前分页索引 %R}.#,Suo
ps.getNextIndex()下一页索引 HoRg^Ai?\
ps.getPreviousIndex()上一页索引 )quM4=u'
A|X">,A
H?&Mbw
d
3 I@}my1
O06"bi5Y
,P70Jb
lTV'J?8!-a
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 CkoLTY
2Q/4bJpd
,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 mUdOX7$c>
0"\H^
一下代码重构了。 @M_oH:GV
4GY[7^
我把原本我的做法也提供出来供大家讨论吧: Rld!,t
y)W@{@{kl
首先,为了实现分页查询,我封装了一个Page类: %'s>QF]'
java代码: -y8`yHb_
=E.t`x=
]%wVHC
/*Created on 2005-4-14*/ N`L0Vd
package org.flyware.util.page; V9{]OV%
Z\ja
/** ebUBrxZX
* @author Joa :7!0OVQla\
* Z7hgA-t
*/ 7b;I+q
publicclass Page { $m].8?
HUv/ ~^<
/** imply if the page has previous page */ C9n?@D;S
privateboolean hasPrePage; }%'?p<^M
hRrn$BdLX
/** imply if the page has next page */ XINu=N(g
privateboolean hasNextPage; ZjQ
|Wx
s'E2P[:
/** the number of every page */ ND>r#(_\
privateint everyPage; LYz.Ci}
lyy W
/** the total page number */ QgU8s'e
privateint totalPage; \eT5flC
bzuEfFaL
/** the number of current page */ ]|zp0d=&o
privateint currentPage; QxVq^H
G
MX?
/** the begin index of the records by the current &eCa0s?mI
)4<__|52"1
query */ W&&;:Fr
privateint beginIndex; vd
0ljA
HkUWehVm
pgI^4h
/** The default constructor */ Lvq>v0|
public Page(){ GT }F9F~
6@{(;~r
} LcSX *MC
[y'f|XN
/** construct the page by everyPage 723bkJw
V
* @param everyPage g*e
* */ K;>9ZZtl
public Page(int everyPage){ k.vBj~xU
this.everyPage = everyPage; 9F)z4
} /%}*Xh
u09:Z{tL;@
/** The whole constructor */ -0$55pa/@:
public Page(boolean hasPrePage, boolean hasNextPage, >VP=MbN
`\gnl'
E*V`":efS
int everyPage, int totalPage, s.N7qO^:E
int currentPage, int beginIndex){ K1r#8Q!t
this.hasPrePage = hasPrePage; 8S mCpg
this.hasNextPage = hasNextPage; Y^8C)p9r
this.everyPage = everyPage; K?B{rE Lp
this.totalPage = totalPage; b\vKJ2
this.currentPage = currentPage; )vjh~ybZ
this.beginIndex = beginIndex; ;V*R*R
} }XV+gyG=@
#(#Wv?r6
/** 4e~A1-
* @return #A1Z'y0
* Returns the beginIndex. ko.(pb@+
*/ R?~Yp?B^
publicint getBeginIndex(){ )0"wB
return beginIndex; ,2j&ko1
} ?Z Rs\+{vG
Rzbj
/** s>;v!^N?u
* @param beginIndex "?ucO4d
* The beginIndex to set. !;i`PPRwk
*/ Ox&P}P0f
publicvoid setBeginIndex(int beginIndex){ 8+a4>8[M
this.beginIndex = beginIndex; s \;" X
} \`oT#|0
xO^:_8=&:
/** 5p<ItU$pnL
* @return qq) rd
* Returns the currentPage. y#Fv+`YDl
*/ k7?N ?7w
publicint getCurrentPage(){ }.3nthgz
return currentPage; 1|kvPo#
} ;1`fC@rI
#!aN{nK0
/** {1V($aBl
* @param currentPage "= 6_V?&w
* The currentPage to set. :3XA!o&.T3
*/ @&%'4j&+
publicvoid setCurrentPage(int currentPage){ '(f&P=[b
this.currentPage = currentPage; <3xyjX'NE
} x_|UPF
4}_j`d/8|
/** uw[<5
* @return *5vV6][
* Returns the everyPage. _LMM,!f
*/ LR.Hh
publicint getEveryPage(){ t]y
D-3'l&
return everyPage; ]h>_\9qO
} %\D)u8}
-yE/f2PgQ
/** QrB@cK]
* @param everyPage LJk@Vy <?
* The everyPage to set. S4^vpY
DeN
*/ mL{B!Q
publicvoid setEveryPage(int everyPage){ #w,Dwy
this.everyPage = everyPage; 7ePqmB<.
} 0vEoGgY0*:
vy0X_DPCr
/** p<TpK )
* @return ?]Pmxp
H}
* Returns the hasNextPage. CN#+U,NZV
*/ lsNrAA%m
publicboolean getHasNextPage(){ ;3d"wW]}7K
return hasNextPage; ]l1\? I
} a:"Uh**
^* J2'X38I
/** S0~2{G"v
* @param hasNextPage =NnNN'}
* The hasNextPage to set. m@"QDMHk.
*/ #JgH}|&a$
publicvoid setHasNextPage(boolean hasNextPage){ W%T>SpFl
this.hasNextPage = hasNextPage; OK{quM5
} tSVc|j
h\5OrD@L
/** k5D%y3|9
* @return (@%gS[]
* Returns the hasPrePage. (d(hR0HKE
*/ AvdXEY(-
publicboolean getHasPrePage(){ 7![,Q~Fy
return hasPrePage; M,/mE~
} 3&u&x(
\@8+U;d
/** z.GMqW%B
* @param hasPrePage K8>zF/# +
* The hasPrePage to set. BybW)+~
*/ IPgt|if^
publicvoid setHasPrePage(boolean hasPrePage){ .QA }u ,EN
this.hasPrePage = hasPrePage;
tNGp\~
} |?qquD 4=
62 O.?Ij
/** 7B!xT2{T
* @return Returns the totalPage. k"NVV$;
* DE%KW:Hug
*/ ~-EOjX(X'E
publicint getTotalPage(){ K[ (NTp$E
return totalPage; 9cf:pXMi
} @!`Xl*l
}dp=?AFg
/** 2.% .Z_k)
* @param totalPage ^C_#<m_k
* The totalPage to set. M[6:p2u
*/ {$R' WXVs
publicvoid setTotalPage(int totalPage){ IB[)TZ2m
this.totalPage = totalPage; i'9vL:3
} RLbKD>
m=}B,']O
} p?B=1vn-2
2Ou[u#H
>sWp?
'yL%3h
_@
Ag&0wN+jTM
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 t^6dzrF
QA<Jr5Ys
个PageUtil,负责对Page对象进行构造: GM3f-\/
java代码: Zn
''_fjh
~kZ G{
W7 Cc
/*Created on 2005-4-14*/ Zy o[(`y
package org.flyware.util.page; ~xD={9BL
VO$
iNK
import org.apache.commons.logging.Log; b]x4o#t
import org.apache.commons.logging.LogFactory; W0l,cOOZJ
WN01h=1J_
/** %KmiH
;U
* @author Joa "br,/Dk>MX
* pL{U `5S
*/ |962G1.
publicclass PageUtil { ]`kmjn
!Cr(Pe]
privatestaticfinal Log logger = LogFactory.getLog DV _2P$tT|
.u4
W /
(PageUtil.class); ig/%zA*Bo
.Yf:[`Q6g
/** VxVE
* Use the origin page to create a new page Jh
]i]7r
* @param page #)C[5?{SNq
* @param totalRecords ||;hciO
* @return D|Q#gcWp o
*/ ,6om\9.E@
publicstatic Page createPage(Page page, int 3wC' r
@}@Z8$G^
totalRecords){ O*0l+mop
return createPage(page.getEveryPage(), YhDtUt}?
8=gjY\Dp
page.getCurrentPage(), totalRecords); sOU1n
} !"\80LP
J[4mLU
/** i70wrW#k
* the basic page utils not including exception ]=>F.GE
.
koYHq
handler 4scNSeW
* @param everyPage i[?Vin
* @param currentPage >AcrG]
* @param totalRecords ^-,xE>3o
* @return page y#q?A,C@n
*/ 4<k9?)~(J
publicstatic Page createPage(int everyPage, int /+@p7FqlE
}Q=!Y>Tc
currentPage, int totalRecords){ dvt9u9Vg=
everyPage = getEveryPage(everyPage); T3k#VNH
currentPage = getCurrentPage(currentPage); vvKEv/pN7
int beginIndex = getBeginIndex(everyPage, Y?(r3E^x
iZM+JqfU|D
currentPage); _Em.
int totalPage = getTotalPage(everyPage, {=F/C,-
QNpqdwu%h
totalRecords); S/4^ d &Gr
boolean hasNextPage = hasNextPage(currentPage, %?p1d!
~v6OsH%vx
totalPage); =Ur}~w&H8
boolean hasPrePage = hasPrePage(currentPage); aB7+Tb
][?G/*k
returnnew Page(hasPrePage, hasNextPage, Ry%Mej:
everyPage, totalPage, .6`9H 1
currentPage, @wE5S6! B\
Mf&{7%
beginIndex); ug+io mZ
} kPF9Z "l
X@K-^8
privatestaticint getEveryPage(int everyPage){ wtH?
[>S;)
return everyPage == 0 ? 10 : everyPage; J6L K
} sB c
(gr
f"qga/
privatestaticint getCurrentPage(int currentPage){ 6WU(%
return currentPage == 0 ? 1 : currentPage; SVO 3821
} 8]M_z:F7F
"a8j"lPJ
privatestaticint getBeginIndex(int everyPage, int r=X}%~_8X
qoj$]
currentPage){ (`sH3&Kl
return(currentPage - 1) * everyPage; "CUty"R8
} 1n:8s'\
?<(m
5Al7
privatestaticint getTotalPage(int everyPage, int [^U#Qj)hL
d5D$&5Ec
totalRecords){ 6P5Ih
int totalPage = 0; ?34 e-
iVy7elT;R
if(totalRecords % everyPage == 0) V`bi&1?6\
totalPage = totalRecords / everyPage; 5A
sP5
else ,!7 H]4Qx
totalPage = totalRecords / everyPage + 1 ; n#wI@W>%+
@@8J6*y
return totalPage; #m{UrTC
} |aT| l^2R@
UG'9*(*
privatestaticboolean hasPrePage(int currentPage){ #ZYVc|sT+
return currentPage == 1 ? false : true; 5ZMR,SZhC
} G|(
]bvJ?
j}~86JO+Cw
privatestaticboolean hasNextPage(int currentPage, $+>M{fg?
WC.t_"@
int totalPage){ o[cV1G
return currentPage == totalPage || totalPage == LAd\ Tvms
,0hA'cp
0 ? false : true; <-,gAk)u
} q.2ykL
3>R#zJf
%=/)
} ($}`R
xj1@
Vzwc}k*Y
Fl1;;F
?)`L$Vr=
5lm<%
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。 d"6&AJ5a
c2e
tc8
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 ?zQA
K9OYri^TQ
做法如下: M
$Es%
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 .8P.)%
JvT"bZk(o
的信息,和一个结果集List: }(1JaG
java代码: 2U; t(,dn'
m<0&~rg
WV #%PJ
/*Created on 2005-6-13*/ v7DE
package com.adt.bo; wyQzM6:,yX
OujCb^Rm
import java.util.List; 'rr^2d]`ST
4*'pl.rb>
import org.flyware.util.page.Page; IaT$6\>
sfOHarww
/** D;_ MPN[
* @author Joa 8'f4 Od ?
*/ IiZ&Pr
publicclass Result { I+dbZBX
FKT1fv[H
private Page page; ui@2s;1t
N9vP7
private List content; tPGJ<30
\l.-eu'O
/** vh*U]3@
* The default constructor 4qYUoCR&
*/ U
)l,'y2
public Result(){ k5C@>J
super(); ~Q>_uw}g#
} .F(i/)vaq|
^1L>l9F
/** MHsc+gQiz
* The constructor using fields TH$N5w%
* E[bd@[N
8
* @param page ! ykx^z
* @param content 9$|Gfyv
*/ ]- 4QNc=
public Result(Page page, List content){
NsJ(`zk:
this.page = page; a(v>Q*zNP
this.content = content; !}r%
u."
} NN1$'"@NL
6+KHQFb&N
/** R#DwF,
* @return Returns the content. I=.z+#Y
*/ 8G5m{XTS(
publicList getContent(){ hDp6YV,q
return content; N~NQ6:R[
} =@8H"&y`
hQDTS>U
/** r?*NhLG;
* @return Returns the page. [g Z"a*
*/ l+g9 5mjP
public Page getPage(){ pTyi!:g3W
return page; 3Bx:Ntx<
} !ZI7&r`u;
;x8k[p~2
/** Wxbq)Z[V
* @param content &2=dNREJ}1
* The content to set. K.z64/H:
*/ ]Wq?H-B{
public void setContent(List content){ \;mH(-
this.content = content; !k/Pv\j/R
} Kbb78S30
P b]3&!a
/** e4z1`YLsG
* @param page +5&wOgx
* The page to set. Myq5b`z
*/ o, !T2&}
publicvoid setPage(Page page){ eU N"w,@y
this.page = page; C$@yG)Pj
} p!<$vE
} {M?vBgR\B
.^m>AKC0cX
q=DN
{a:
h'$9C
&09U@uc$
2. 编写业务逻辑接口,并实现它(UserManager, lZrVY+D
n9\]S7]52
UserManagerImpl) ]wWPXx[>/
java代码: WwUv5GZTW
C{q :_M;
v,\R,{0
/*Created on 2005-7-15*/ D^-7JbE]
package com.adt.service; Kmdlf,[3d
RJON90,J
import net.sf.hibernate.HibernateException; cn-
nj]
vYU;_R
import org.flyware.util.page.Page; VT.;:Q
TcGoSj<Z
import com.adt.bo.Result; s9>(Jzcf9
\J6hI\/4^
/** H-xFiF
* @author Joa A;O~#Chvd
*/ iK IOh('G
publicinterface UserManager { 03iv3/{H
Zxb_K
public Result listUser(Page page)throws fI7j):h;
|P.6<
HibernateException; \6 93kQ
ee/&/Gt
} W},b{NT
ejO}t:}P
zP;cTF(C
R i'L
$DP&a1'g
java代码: Na\WZSu'"
atW'
Go&D[#
/*Created on 2005-7-15*/ ~-83Q5/[
package com.adt.service.impl; //&j<vus
N7s'6(`=X
import java.util.List; x+@&(NMP5
`+/H^
import net.sf.hibernate.HibernateException; wO>L#"X^v
:SsUdIX;P
import org.flyware.util.page.Page; 7E @+
import org.flyware.util.page.PageUtil; 4A3nO<oMF
}I!hOD>]O
import com.adt.bo.Result; P N*JR
import com.adt.dao.UserDAO; olW|$?
import com.adt.exception.ObjectNotFoundException; 6ITLGA
import com.adt.service.UserManager; *E~VKx1
5eA8niq#
/** u<n`x6gL
* @author Joa Do]*JO)(
*/ fN
"tA
publicclass UserManagerImpl implements UserManager { P &)1Rka
-OYDe@Wb]
private UserDAO userDAO; =5sF"L;b
gs
W0
/** YUdxG/~'
* @param userDAO The userDAO to set. NA.1QQ;e
*/ vwr74A.g0
publicvoid setUserDAO(UserDAO userDAO){ {@u<3 s
this.userDAO = userDAO; XIWm>IQ[)
} o."rxd
sK 2
e&
/* (non-Javadoc) 9%IlW
* @see com.adt.service.UserManager#listUser Q#Y k?Kv~
WM)F0@"
(org.flyware.util.page.Page) #2tCV't
*/ ZE`lr+_Y
public Result listUser(Page page)throws XTDE53Js&
60Z]M+8y8
HibernateException, ObjectNotFoundException { ?Mp1~{8
int totalRecords = userDAO.getUserCount(); <g9"Cr`
if(totalRecords == 0) 8)VgS&B~
throw new ObjectNotFoundException c[ht`!P
6TH!vuQ1(
("userNotExist"); .]|Zf!>}s
page = PageUtil.createPage(page, totalRecords); 4q$H
List users = userDAO.getUserByPage(page); C#w]4 $/
returnnew Result(page, users); ofW+_DKB?l
} &)pK%SAM
fB+b}aoV
} M3zDtN
|8)Xc=Hz
I|/'Ds:
Be}$I_95\P
8#` 6M5
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 E:nt)Ef,
oH2!5;A|
询,接下来编写UserDAO的代码: gZT)pP
3. UserDAO 和 UserDAOImpl: =raA?Bp3;(
java代码: 9B)(>~q
@gSkROCdC)
{[(pWd%J
/*Created on 2005-7-15*/ X;!D};;M
package com.adt.dao; X-B8MoG|
nB5Am^bP
import java.util.List; H0*5_OJ!i
x"(9II*
import org.flyware.util.page.Page; T ^JuZG
^t[HoFRa
import net.sf.hibernate.HibernateException; +dkS/b
?G?gy2
/** !6w{(Rc(C
* @author Joa Gowp
<9 F
*/ a-n4:QT
publicinterface UserDAO extends BaseDAO { iS@\ =CK
|)W!jC&k
publicList getUserByName(String name)throws Ak~4|w-
Oe1 t\
HibernateException; tL0`Rvl
["3df>!f
publicint getUserCount()throws HibernateException; @<_`2eW'/R
=z:U~D
publicList getUserByPage(Page page)throws
P
,K\
H:a|x#"
HibernateException; J fcMca
xfSG~csoz
} /'y5SlE[J
i=v]:TOu
FoPginZ]J
J?P]EQU
j.3o W
java代码: ,2 WH/"
m%QqmTH
#1$}S=8*f
/*Created on 2005-7-15*/ r9ke,7?
package com.adt.dao.impl; 6kvV
X9~m8c){z
import java.util.List; wVi%oSfM
:G'xi2bs
import org.flyware.util.page.Page; ~"ONAX
bdV3v`
import net.sf.hibernate.HibernateException; t ,qul4y}
import net.sf.hibernate.Query; ui'F'"tPz
LD+f'^>>Z
import com.adt.dao.UserDAO; gZ(O)uzv
'=} Y2?(
/** Ohl} X 1
* @author Joa NcL
=zo<
*/ lVeH+"M?
public class UserDAOImpl extends BaseDAOHibernateImpl ~SVQ;U)-
/aUFc '5
implements UserDAO { Z|^MGyn
*kaJ*Ti-/
/* (non-Javadoc) %OI4a5V*l
* @see com.adt.dao.UserDAO#getUserByName BV9 *s
qtSs)n
(java.lang.String) xaXV^ZM3
*/ MWq$AK]
publicList getUserByName(String name)throws Vdvx"s[`m
w)S; J,Hv
HibernateException { jXEGSn
String querySentence = "FROM user in class I$N7pobh
k]I*:'178
com.adt.po.User WHERE user.name=:name"; sT<{SmBF
Query query = getSession().createQuery E_[ONm=,
8wiA
(querySentence); fkW(Dt,
query.setParameter("name", name); B5Va%?Wg?H
return query.list(); MM_py!=>7
} *d
l"wH&
I=YCQ VvA
/* (non-Javadoc) "d?f:x3v^
* @see com.adt.dao.UserDAO#getUserCount() /{N))
*/ `F,zenk=
publicint getUserCount()throws HibernateException { ez0 \bym
int count = 0; >=!AL,:
String querySentence = "SELECT count(*) FROM ?;8M^a/
6=>7M
b$
user in class com.adt.po.User"; k.Zll,s
Query query = getSession().createQuery ?"@ET9
}%{=].)L
(querySentence); Y}/jR6hK
count = ((Integer)query.iterate().next >5i ?JUZ
+-HE'4mo
()).intValue(); Cnur"?w@o
return count; 3#9M2O\T
} , ;'SVe%
ct\<;I(H
/* (non-Javadoc) 0=m&^Jpp
* @see com.adt.dao.UserDAO#getUserByPage fI[dhd6
A*Q[k 9B
(org.flyware.util.page.Page) r"]Oe$[#
*/ z1vni'%J
publicList getUserByPage(Page page)throws 4? {*(
-~'kP /E^
HibernateException { a97Csxf;7
String querySentence = "FROM user in class ^@ UjQ9[>
pSrsp r
com.adt.po.User"; h]C2 8=N
Query query = getSession().createQuery 7Jc<.Z"/Gd
W}k[slqZA
(querySentence); ~\bHfiIDy
query.setFirstResult(page.getBeginIndex()) Fhi5LhWe+.
.setMaxResults(page.getEveryPage()); *'^:S#=
return query.list(); 7S2c|U4IM
} N K"%DU<
[Ye5Y?
} ~D!ESe*=
8XkIk7
F25<+1kr
sVD([`Nmc
j}RM.C\7
至此,一个完整的分页程序完成。前台的只需要调用 akrCs&Kka5
tD^a5qPh
userManager.listUser(page)即可得到一个Page对象和结果集对象 ^HoJ.oC/
5|m9:Hv[#
的综合体,而传入的参数page对象则可以由前台传入,如果用 J]]\&MtaO
%9YA^ri
webwork,甚至可以直接在配置文件中指定。 (lWKy9eTy`
1 ?]J;9p
下面给出一个webwork调用示例: 2_Jb9:/X
java代码: DD6 'M
U4
A xR\ned
&u4Ve8#
/*Created on 2005-6-17*/ z{V8@q/
package com.adt.action.user; PE7t_iSV
>!G5]?taa
import java.util.List; E$&;]a
2E([#Pzb
import org.apache.commons.logging.Log; HqDa2q4
import org.apache.commons.logging.LogFactory; (T2<!&0 @
import org.flyware.util.page.Page; dff#{
:9O|l)N)W=
import com.adt.bo.Result; |>[X<>m
import com.adt.service.UserService; ~{Ua92zV9
import com.opensymphony.xwork.Action; (77Dif0)'
X?_v+'G
/** P ]_Vz
* @author Joa L`JY4JM"
*/ ;lk f+,;
publicclass ListUser implementsAction{ h?3f5G*&H
t.u{.P\Md\
privatestaticfinal Log logger = LogFactory.getLog x6~Fb~aP
# m_\1&g
(ListUser.class); X~#@rg!"
`;T?9n
private UserService userService; td`wNy\
*ig5Q(b*N
private Page page; ur`V{9g
9cbB[c_.
privateList users; ~JT lPU'
H|'$dO)W
/* i|[S5QXCh
* (non-Javadoc) fV v$K&
* ?~]>H A:
* @see com.opensymphony.xwork.Action#execute() }"g@E-]N
*/ dfXV1B5
publicString execute()throwsException{ q
w"e0q% )
Result result = userService.listUser(page); G+;g:_E=
page = result.getPage(); @D2`*C9
users = result.getContent(); <,#rtVO$
return SUCCESS; -1#e^9Ve\
} yW'BrTw
%{c2lyw
/** N_|YOw6
* @return Returns the page. EsS!07fAM:
*/ rjt O`Mt`
public Page getPage(){ PwRNBb}6
return page; M~#5/eRX
} x%ZiE5#
pvI&-D #}
/** WodF -bE
* @return Returns the users. )vxVg*.Ee
*/ 30e(4@!4vW
publicList getUsers(){ s;~J2h[
return users; !Q\X)C
} ye9QTK6$,
Pau&4h0
/** F&-5&'6G+
* @param page %_cg|yy
* The page to set. CA'hvXb.
*/ ZD
iW72&Q
publicvoid setPage(Page page){ `7+tPbjs
this.page = page; CAcOWwDm
} sz){uOI
q|m#IVc
/** us(sZG
* @param users u~j'NOv
* The users to set. FC|y'j 0
*/ `=WzG"
publicvoid setUsers(List users){ ^2P;CAjj-
this.users = users; k)o7COx
} `V$cz88b
ZhxfI?i)l
/** =rE`ib
* @param userService $=QNGC2+
* The userService to set. jCdZ}M($
*/
9QO!vx
publicvoid setUserService(UserService userService){ a?f5(qW3
this.userService = userService; e/ppZ>
} 5k_Mj*{6
} Z.Lx^h+U
WcQZFtW
#<^/yoH7C6
uugzIV)
M}{n6T6B
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, y$"~^8"z
C: TuC5Sr
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 jp\JwE
oQKcGUZ
么只需要: 9e|{z9z[l
java代码: 7zi^{]
s7X~OF(#
K[Ws/yc^a
<?xml version="1.0"?> M<hs_8_*
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork bDcWb2lqs
JRcuw'8+q
1.0//EN" "http://www.opensymphony.com/xwork/xwork- Fb$5&~d
?.|wfBI
1.0.dtd"> :$u{
8=b{'s^^F
<xwork> A@lhm`Aa
ACMpm~C8Gu
<package name="user" extends="webwork- 8O}A/*1FJ
-+Awm{X_@
interceptors"> j/; @P
pU\xzL D
<!-- The default interceptor stack name zS>:7eG
}*{\)7g
--> UeC%Wa<[
<default-interceptor-ref P+D|_3j
C'xU=OnA8
name="myDefaultWebStack"/> jn#N7%{Mk
G> 5=`
<action name="listUser" z.\[Va$@l
'+GVozc6c"
class="com.adt.action.user.ListUser"> <y b=!
<param *=KexOa9
'44nk(hM69
name="page.everyPage">10</param> tS*^}e*
<result cnjj)
c
t8wz'[z
name="success">/user/user_list.jsp</result> RF\1.HJG
</action> oVxV,oH(
tkUW)ScJ
</package> y}H*p
Y+Q,4s
</xwork> ~,3v<A[5Vi
a#~Z5>{
y("0Xve
n?KS]ar>
M<|~MR
1\7"I-
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 \!4ghev3
?yd(er<_f
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 9_CA5?y$:
4<K ,w{I
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 LMhY"/hAXa
#uDBF
emDvy2uA#
x4 A TK
yz&q2
我写的一个用于分页的类,用了泛型了,hoho IQ27FV|3
QP-<$P;~
java代码: -EX3'
[*'
=.=.
\K
\]d*h]Hms
package com.intokr.util; b~jvmcr
Rcm(Y7
import java.util.List; h-v&I>
|jCE9Ve#
/** 2w.9Q
(Sn
* 用于分页的类<br> y^+[eT&