Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 K<kl2#
o{^`Y
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 DUh\x>^
"/mtuU3rt
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 CPMGsW^
%**f`L%jN
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 y?$DDD
DP ? dC`
。 d#ir=+o{h
Z>rY9VvWD
分页支持类: mayJwBfU
v,KKn\X
java代码: -=ZL(r
1
f9D e!"*&
pCIzpEsRs
package com.javaeye.common.util; ,erw(7}'.
?"B]"%M&
import java.util.List; 9j,g&G.K
,WT>"9+
publicclass PaginationSupport { U ZM #O
FcDS*ZEk!
publicfinalstaticint PAGESIZE = 30; Yd^@Ei9
;a:H-iC
privateint pageSize = PAGESIZE; hx;f/EPx
$<}c[Nm
privateList items; -3 I3 X
ks'>?Dw
privateint totalCount; NTg@UT<
\CbJU
privateint[] indexes = newint[0]; HgI!q<)
ZO0 Ee1/
privateint startIndex = 0; S{@}ECla
}U_
'7_JT
public PaginationSupport(List items, int k+3qX'fd
"}4%v Zz
totalCount){ ]MbPivM
setPageSize(PAGESIZE); E~'mxx~i
setTotalCount(totalCount); e[S`Dm"i)'
setItems(items); :+rGBkw1m
setStartIndex(0); wp[Ug2;G
} z6>@9+V-&
>DqF>w.1
public PaginationSupport(List items, int G0cG%sIl
-N *L1Zj
totalCount, int startIndex){ { _rfhz
setPageSize(PAGESIZE); FL0uY0K
setTotalCount(totalCount); M `xiC
setItems(items); x&}]8S)
setStartIndex(startIndex); ; *
[:~5Wc
} NkE0S`Xf
gEA SYIQ
public PaginationSupport(List items, int eim +oms
U$rMZk
totalCount, int pageSize, int startIndex){ bS.w<V
Ew
setPageSize(pageSize);
Ucj?$=
setTotalCount(totalCount); DL]tg[w{
setItems(items); zM0NRERi
setStartIndex(startIndex); &4#Zi.]
} D28`?B9(
Mf}M/Fh
publicList getItems(){ 0}{xH
return items; M>Q]{/V7T
} "L~(%Nx3
L74Mz]v
publicvoid setItems(List items){ ;"3B,Yj
this.items = items; |s| }u`(@9
} 'sNZFB#
2[E wN!IZ
publicint getPageSize(){ _n&Nw7d2
M
return pageSize; ,Q`qnn&
} .
,7bGY 1$
:Pud%}'
publicvoid setPageSize(int pageSize){ O&`.R|v
this.pageSize = pageSize; Onmmcem
} xO$P
C,
n*4`Tduu^
publicint getTotalCount(){ }=](p-] 5
return totalCount; l~s7Ae
} ;r\(p|e
&7mW9]
publicvoid setTotalCount(int totalCount){ 3Mjj'5KH!
if(totalCount > 0){ x+5k
<Xi}
this.totalCount = totalCount; Pz_Oe,{.I
int count = totalCount / }Nj97R
RrrK*Fk8=
pageSize; 4Aes#{R3v
if(totalCount % pageSize > 0) pE]?x$5U
count++; Oft arD
indexes = newint[count]; `bI)<B
for(int i = 0; i < count; i++){ 5FKBv
e@
indexes = pageSize * 'vV$]/wBF
+YY8h>hj
i; pcS+o
} j F"YTr6
}else{ 0*%&>
this.totalCount = 0; shC;hR&;
} ^ZeJ[t&!#
} *O$CaAr\s
^>&k]T`
publicint[] getIndexes(){ MhEw
_{?
return indexes; bUy,5gk-
} k_|^ kdWJ
8OhDjWVJ
publicvoid setIndexes(int[] indexes){ u0)7i.!M
this.indexes = indexes; l.)}t)my}
} M(q'%XL^
b;mSQ4+
publicint getStartIndex(){ 5`[n8mU
return startIndex; Ng><n}
} Wc3kO'J
R2etB*k6[
publicvoid setStartIndex(int startIndex){ @J{m@ji{
if(totalCount <= 0) WH ?}~u9
this.startIndex = 0; 2Y}?P+:%>
elseif(startIndex >= totalCount) 5Dp#u
this.startIndex = indexes -aRU]kIf
<9ig?{'
[indexes.length - 1]; t$2_xX
elseif(startIndex < 0) "gd=J_Yw
this.startIndex = 0; QY/hI`
else{ u$%t)2+$4
this.startIndex = indexes o:Qv
JcB
ZnFi<@UB)
[startIndex / pageSize]; &<zd.~N"
} )%rg?lI
} ,1'4o3
a`Gx=8
publicint getNextIndex(){ JvYPC
int nextIndex = getStartIndex() + f>BWG`
-(#I3h;I
pageSize; :^UFiUzrE
if(nextIndex >= totalCount) HW&%T7
a
return getStartIndex(); Li*eGlId
else _%'},Xd.z
return nextIndex; 9a'-Y
} L
lqM c
G!4(BGx&
publicint getPreviousIndex(){ B?VhIP e
int previousIndex = getStartIndex() - <2C7<7{7
q&C""!h^
pageSize; nRd)++
if(previousIndex < 0) zByT$P-
return0; t|t#vcB
else CJ}5T]WZ
return previousIndex; ^
9!!;)
} 04r$>#E
4k./(f2+
} bINvqv0v
o`q_wdy?
ul ER1\W
!Wy[).ZAf
抽象业务类 OKvPL=~
java代码: wlEo"BA
F`9ZH.
\0H's{uek
/** 't9hXzAfW
* Created on 2005-7-12 W!"}E%zx
*/ eU N"w,@y
package com.javaeye.common.business; o)[2@fRC(
~~6^Sh60g
import java.io.Serializable; en:4H
import java.util.List; _"#!e{N|
?l $Nf@-
import org.hibernate.Criteria; E gDQ+(
-
import org.hibernate.HibernateException; WwUv5GZTW
import org.hibernate.Session; ^_%kE%I
import org.hibernate.criterion.DetachedCriteria; @j4U^"_QB
import org.hibernate.criterion.Projections; _C+b]r/E
import !Y:0c#MPH
bQZ*r{g
org.springframework.orm.hibernate3.HibernateCallback; xGG,2W+z
import |K^"3`SJ
>Z;jY*
org.springframework.orm.hibernate3.support.HibernateDaoS 1 `7<2w
d|*"IFe
upport; CY&
hIh~S@
d.2mT?`#
import com.javaeye.common.util.PaginationSupport; zP;cTF(C
~6I)|^Z
public abstract class AbstractManager extends 7lo|dg80
D>!6,m2
HibernateDaoSupport { Jy
aag-
: ~ A%#
privateboolean cacheQueries = false; P\&! ]
er.CDKD%L
privateString queryCacheRegion; tdF9NFMD
_NcYI
publicvoid setCacheQueries(boolean _7D _72
c=6Q%S
cacheQueries){ fN
"tA
this.cacheQueries = cacheQueries; R <"6ojn
} e62Dx#IY
>l+EJ3W
publicvoid setQueryCacheRegion(String ]}UgS+g>$
CZEW-PIhj
queryCacheRegion){ =q"eU=9
this.queryCacheRegion = Cj*-[EL<
[Lp,Hqi5
queryCacheRegion; vLO&Lpv
} CWO=0_>2
j4R 4H;
publicvoid save(finalObject entity){ >bUj*#<
getHibernateTemplate().save(entity); |7^^*UzSK:
} F.)!3YE
]=!P(z|
publicvoid persist(finalObject entity){ p$k\m|t
getHibernateTemplate().save(entity); &)pK%SAM
} M"_FrIO
1>r ,vD&
publicvoid update(finalObject entity){ f'6|OsVQ
getHibernateTemplate().update(entity); jvzBh-!
} 1zktU.SZ
4UAvw
publicvoid delete(finalObject entity){ Yn9j-`
getHibernateTemplate().delete(entity); Bfd-:`Jk
} )h^NR3N
\O7J=6fn
publicObject load(finalClass entity, M@p"yq
5A&y]5-Q`
finalSerializable id){ JLb6C52
return getHibernateTemplate().load 7?)/>lx\>$
NfE.N&vI_c
(entity, id); yoqa@ V
} CQODXB^
eFTX6XB:i
publicObject get(finalClass entity, ^t'3rft
,f:
jioY
finalSerializable id){ g$j6n{Yl
return getHibernateTemplate().get LNQSb4
R#4^s
(entity, id); U '[?9/T
} 'nK~'PZ,
.9LL+d
publicList findAll(finalClass entity){ C4$/?,K(
return getHibernateTemplate().find("from w 7tC|^#G
OR+A_:c.D
" + entity.getName()); ~hURs;Sb
} !v!N>f4S$
T{*^_
publicList findByNamedQuery(finalString Rq7p29w
Nm8w/Q5D`
namedQuery){ =8{*@>CX
return getHibernateTemplate jeDlH6X'
QJ];L7Hbo
().findByNamedQuery(namedQuery); Goj4`Hc
} <<3+g"enno
W._G0b4}
publicList findByNamedQuery(finalString query, +0pW/4x
Bt>}LLBS2
finalObject parameter){ Wp*sPZ
return getHibernateTemplate a'[)9:
a@|.;#FF
().findByNamedQuery(query, parameter); -
8syjKTg
} Mn"/#tXL-
~eo^`4O{{
publicList findByNamedQuery(finalString query, umDtp\
hU,$|_WDy
finalObject[] parameters){ + x_wYv
return getHibernateTemplate [:i sZG*
ug6r]0]
().findByNamedQuery(query, parameters); $T*KaX\{B
} 3%NE/lw1
v_-ls"l
publicList find(finalString query){ ZA.fa0n
return getHibernateTemplate().find Za\RM[Z!I
TczXHT}G
(query); n.;3X
} I2*oTUSik
Xr2J:1pgg
publicList find(finalString query, finalObject X'2Gi
tG 7+7Z=
parameter){ &^ceOV0+
return getHibernateTemplate().find "4[<]pq
B_@7IbB
(query, parameter); t/LgHb:)
} J_/05(48
u.&|CF-
public PaginationSupport findPageByCriteria H_x35|"
79&Mc,69
(final DetachedCriteria detachedCriteria){ KxvT}"k
return findPageByCriteria 8`*(lKiL
y
jb.6
(detachedCriteria, PaginationSupport.PAGESIZE, 0); sbgRl%
} 4>(?R[:p)
*rWE.4=&
public PaginationSupport findPageByCriteria ~_K
Kl^Yq
(final DetachedCriteria detachedCriteria, finalint 9,,1\0-T*
H`fkds
startIndex){ RgEUTpX
return findPageByCriteria \HR QSfGt
l.C{Ar
(detachedCriteria, PaginationSupport.PAGESIZE, /+'@}u
|
])e6\)
startIndex); :5;[Rg5
2
} S!rUdxO
?
[=P
public PaginationSupport findPageByCriteria SJw0y[IL6(
k/Cr ^J"
(final DetachedCriteria detachedCriteria, finalint >5 Ce/P'R
N#|c2n+
pageSize, ZWYwVAo
finalint startIndex){ 9;.dNdg>
return(PaginationSupport) hd+JKh!u
5FzG_ w
getHibernateTemplate().execute(new HibernateCallback(){ nQ8EV>j2
publicObject doInHibernate )5&Wt@7Kj`
6?2/b`k
(Session session)throws HibernateException { =$fxK
Criteria criteria = K&Zdk (l)
jt?R
a1Z
detachedCriteria.getExecutableCriteria(session); =n%?oLg^
int totalCount = ]kc]YO7i%R
%N>@( .
((Integer) criteria.setProjection(Projections.rowCount sd
Z=3)
`4XfT.9GT
()).uniqueResult()).intValue(); "x&H*"
criteria.setProjection |qfnbi-\
M,|o 2'
(null); ;sb0,2YyP
List items = R0 {+Xd
+HUI1@ql
criteria.setFirstResult(startIndex).setMaxResults nbhx2@Teqe
CEt_wKzf
(pageSize).list(); RDk{;VED{
PaginationSupport ps = M`AbH19
fH}`
new PaginationSupport(items, totalCount, pageSize, /9W-;l{=z
7-bU9{5
startIndex); ^h=;]vxO
return ps; Kq{9:G
} j @sd x)1+
}, true); #2|sS|0 <
} ^25$=0
6SW:'u|90
public List findAllByCriteria(final v:<u0B-)$
H?M8j] R-)
DetachedCriteria detachedCriteria){ znX2W0V
return(List) getHibernateTemplate ExV>s* y
TC"mP!1
().execute(new HibernateCallback(){ bQEQHqY5
publicObject doInHibernate ]@>bz
KYd2=P6
(Session session)throws HibernateException { <c^m|v
Criteria criteria = ZN',=&;n'
l\jf]BHX'
detachedCriteria.getExecutableCriteria(session); N^CD4l
return criteria.list(); "P'W@
} Jc:*X4-'
}, true); tb^3-ZUb
} A1>R8Zuhy
:W 8DgL>l
public int getCountByCriteria(final d|w%F=
r4D6g>)h1q
DetachedCriteria detachedCriteria){
&-s!ko4z
Integer count = (Integer) kT!FC0E{
r68'DJ&m3
getHibernateTemplate().execute(new HibernateCallback(){ ?:~Y%4;
publicObject doInHibernate \HV%579
+mYD
DlvI
(Session session)throws HibernateException { zf4@:GM`
Criteria criteria = sq\oatMw[
r8}GiP0|
detachedCriteria.getExecutableCriteria(session); @ $4(!80-
return aKhI|%5kA
a<rk'4,8a
criteria.setProjection(Projections.rowCount $:t;WXc.<
hd8:| _
()).uniqueResult(); K.dgQ-vn
} G<Z|NT
}, true); hF.9\X]
return count.intValue(); PGOi#x
} P}KyT?X:
} 9=&LMjTQ
h7wm xa;
LTm2B_+
$7T3wv9
~ubGx
}2|>Y[v2j
用户在web层构造查询条件detachedCriteria,和可选的 C;y3?+6P$
3<AZ,gF1
startIndex,调用业务bean的相应findByCriteria方法,返回一个 CZS{^6Ye
ez"Xb 7
PaginationSupport的实例ps。 S=n,unn#t
A_muuOIcI
ps.getItems()得到已分页好的结果集 `u3to{
ps.getIndexes()得到分页索引的数组 YrS%Yvhj0
ps.getTotalCount()得到总结果数 7xb z)FI
ps.getStartIndex()当前分页索引 tq8B)<(]
ps.getNextIndex()下一页索引 x24
ps.getPreviousIndex()上一页索引 $o?Wum
.#2YJ~
#Wey)DI
?a+tL'D[
zZ3,e L
eva-?+n\q
6'3@/.
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 uHkL$}C
G9TK)Nz
,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 >?ZH[A
^,]'Ut
一下代码重构了。 iov55jT~l@
E5w.wx
我把原本我的做法也提供出来供大家讨论吧: .cdm@_Ls
+R@5e+auQ.
首先,为了实现分页查询,我封装了一个Page类: dq%7A=-
java代码: NkoyEa/^[
8n["/5,
?vFtv}@\
/*Created on 2005-4-14*/ <{h\Msx%
package org.flyware.util.page; ky&wv+7
#=)!\
/** O{\%{XrW
* @author Joa ?op;#/Q(
* 1CR\!?
*/ #^yOW^
publicclass Page {
9
]W4o"
-6u#:pVpU
/** imply if the page has previous page */ L=WB'*N
privateboolean hasPrePage; GcYT<pwN6
LQrm/)4bF5
/** imply if the page has next page */ ,HM~Zs
privateboolean hasNextPage; tug\X
|]9Z#lv+I
/** the number of every page */ S0<m><|kl
privateint everyPage; Z w&_Wt
_C97G&
/** the total page number */ fCxF3m(O
privateint totalPage; $"&U%3
@)YQiE$
/** the number of current page */ #Qp.O@e
privateint currentPage; H\Jpw
Ut
xe
/** the begin index of the records by the current .4NQ2k1io
MjHjL~Tg
query */ axW4cS ?
privateint beginIndex; 1#3 Qa{i
`b{.K,
0w_2E
/** The default constructor */ E0i_sB~T
public Page(){ >xt*( j&}
T'*.LpNP,
} mP)<;gm,
_l?5GLl_F$
/** construct the page by everyPage k*4?fr
* @param everyPage m,u?
^W
* */ R$cO`L*s
public Page(int everyPage){ omV.Qb'NS
this.everyPage = everyPage; >NwrJSx
} MjI}fs<
EMH?z2iGd
/** The whole constructor */ w9}I*Nra
public Page(boolean hasPrePage, boolean hasNextPage, |k'I?:'
$`'^&o;&f
Iw"?%k\U
int everyPage, int totalPage, T^GdN_qF
int currentPage, int beginIndex){ q_f
v1U3
this.hasPrePage = hasPrePage; e_ 6
i896
this.hasNextPage = hasNextPage; @fpxGMy&
this.everyPage = everyPage; ,ASY
&J5)7
this.totalPage = totalPage; &V( LeSI
this.currentPage = currentPage; i=2+1;K
this.beginIndex = beginIndex; gr=ke #
} Dz)bP{iq"
I{cn ,,8
/** }qz58]fyx
* @return 5<w0*~Zd~
* Returns the beginIndex. xs &vgel>
*/ dm$:xE":
publicint getBeginIndex(){ *8XGo
return beginIndex; y+:<
} GW
$iK@
F"23>3
/** vJq`l3&
* @param beginIndex TU. h
* The beginIndex to set. fQx 4/4j
*/ <1jiU%!w
publicvoid setBeginIndex(int beginIndex){ h V8A<VT
this.beginIndex = beginIndex; &P{%C5?{
} *`jEg=)
'ZDa *9nkF
/** BLJ-'8G
* @return Bv=Z*"Fv
* Returns the currentPage. n6uobo-
*/ 3]VTQl{P
publicint getCurrentPage(){ d7G'+B 1
return currentPage; :!A@B.E
} i([A8C_A
v^E5'M[A
/** lp]O8^][&
* @param currentPage 7I.[1V`
* The currentPage to set. ?4~lA
L1
*/ L |H{;r'
publicvoid setCurrentPage(int currentPage){ 7PvuKAv?k
this.currentPage = currentPage; g{ a0,B/j
} 0s4j>
G37_
`C
/** <St`"H
* @return !kz\
{
* Returns the everyPage. UmJg-~
*/ C'$U1%:
j
publicint getEveryPage(){ N!va12
return everyPage; oyd{}$71d
} Fq3;7Cq=hD
RcE%?2lD
/** NSkI2>+P
* @param everyPage >pYgF=J
* The everyPage to set. BxG;vS3>*e
*/ O|/tRkDMP{
publicvoid setEveryPage(int everyPage){ D;E&;vP6%
this.everyPage = everyPage; cP
Y^Bf5)
} _1Eyqh`oh
5Tu.2.)N
/** $200?[
* @return
g$97"d'
* Returns the hasNextPage. B?4\IXek
*/ x{- caOH
publicboolean getHasNextPage(){ *SW,pHYnLb
return hasNextPage; i>~?XVU
} A4^+p0@
rx"zqm9 }u
/** MoA{ /{
* @param hasNextPage 7MfT~v
* The hasNextPage to set. : ?V;
*/ s6$3[9Vh&9
publicvoid setHasNextPage(boolean hasNextPage){ gM*s/,;O"
this.hasNextPage = hasNextPage; `4=b|N+b"
} @K/Ia!Lw
:U9R
1^}A
/** 3%} Ma,
* @return \x!>5Z
Y
* Returns the hasPrePage. ,jn?s^X6Dj
*/ vv+km +
publicboolean getHasPrePage(){ W RF.[R"
return hasPrePage; K4:
$=
} =~&VdPZ
9UV9h_.x
/** 6hO-H&r++
* @param hasPrePage O5zE {#
* The hasPrePage to set. uAUp5XP|Z
*/ Q=WySIF.
publicvoid setHasPrePage(boolean hasPrePage){ {=67XrWN1
this.hasPrePage = hasPrePage; PQ$sOK|/
} /3 B
$(
:Bu2,EL*O
/** <FI-zca
* @return Returns the totalPage. '6y}ZE[
* zOgTQs"ZH
*/ 9d[5{"2j
publicint getTotalPage(){ #n0Y6Pr
return totalPage; 29CINC
} UhA"nt0
} :=Tm]S
/** s, k
* @param totalPage |EJD3&
* The totalPage to set. ]jo1{IcI
*/ 0"pAN[=K@
publicvoid setTotalPage(int totalPage){ N$U$5;r~`
this.totalPage = totalPage;
@fl-3q
} JPoN&BTCj
>LOjV0K/
} 75XJL;W #
'EbWFMjy
9N@W\DT
3Z5D)zuc
W+UfGk}A
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 ^(vs.U^U<
Nl^;A><u
个PageUtil,负责对Page对象进行构造: n>ULRgiT:o
java代码: t&H?\)!4
ok!L.ac
v|uAzM{73
/*Created on 2005-4-14*/ #$18*?tLv|
package org.flyware.util.page; (7*%K&x
-w9pwB
import org.apache.commons.logging.Log; 9^oKtkoDZ
import org.apache.commons.logging.LogFactory; R=gb'
OGK}EI
/** WI-&x
'
* @author Joa f .Q\Z'S^
* zHA!%>%'
*/ %zG;Q@
publicclass PageUtil { F*IzQ(#HW
gbF+WE
privatestaticfinal Log logger = LogFactory.getLog 0z1ifg&
"W6uV!
(PageUtil.class); O_`VV*
\k .{-nh
/** K"|l@Q[
* Use the origin page to create a new page eD,.~Y#?=
* @param page wPQH(~k:
* @param totalRecords EMY/~bQW
* @return &S~zNl^m
*/ zQcL|(N
publicstatic Page createPage(Page page, int iW$_zgN
e>6y%v;
totalRecords){ E{XH?_xo
return createPage(page.getEveryPage(), uaT!(Y6
kVkU)hqR
page.getCurrentPage(), totalRecords); 6n,i0W
} mWoAO@}Y
x-$&g*<
/** PQy4{0 _
* the basic page utils not including exception [4YTDEv%
YmL06<Mh
handler /5S30 |K
* @param everyPage r(:5kC8K
* @param currentPage ]OM"ZG/^
* @param totalRecords =$u!
59_dE
* @return page 8[a=OP
*/ ]] !VK
publicstatic Page createPage(int everyPage, int y&6FybIz
F0GxH?
currentPage, int totalRecords){ PRx8I
.
everyPage = getEveryPage(everyPage); ,vr? 2k
currentPage = getCurrentPage(currentPage); PY{
G [
int beginIndex = getBeginIndex(everyPage, "H7dft/
BBaQ}{F8>2
currentPage); urbp#G/>
int totalPage = getTotalPage(everyPage,
CuFSeRe
V[RF</2T
totalRecords); =b%MXT
boolean hasNextPage = hasNextPage(currentPage, ZT'`hK_up
O8+7g+J=!
totalPage); B;M?,<%FRU
boolean hasPrePage = hasPrePage(currentPage); WYH Q?
r)lEofX,g+
returnnew Page(hasPrePage, hasNextPage, aT{_0m$G10
everyPage, totalPage, ]s]vZ
currentPage, {
d=^}-^
!<j'Ea
beginIndex); @'w"R/,n-@
} _>5(iDW0
,`|3KE9
privatestaticint getEveryPage(int everyPage){ Dl<bnx;0
return everyPage == 0 ? 10 : everyPage; {Bk[rCl
} xR-%L
{ME2ImD
privatestaticint getCurrentPage(int currentPage){ m!gz3u]rN
return currentPage == 0 ? 1 : currentPage; fFMlDg[];
} o15-ZzE-
x/NfZ5e0X
privatestaticint getBeginIndex(int everyPage, int <Q3oT
|v`AA?@{8
currentPage){ i@C].X
return(currentPage - 1) * everyPage; US+Q~GTA
} z#zI1Am(O
Ye\rB\-
privatestaticint getTotalPage(int everyPage, int ?[VM6- &
?L5zC+c!
totalRecords){ %d1,a$*3}
int totalPage = 0; J; 3{3
rDD:7*z
if(totalRecords % everyPage == 0) 7yG#Z)VE
totalPage = totalRecords / everyPage; h2)yq:87
else }v@dL3{f
totalPage = totalRecords / everyPage + 1 ; Z EXc%-M
S(o#K|)>
return totalPage; S$f9m
} gcii9vz
`
ynmWW^dg
privatestaticboolean hasPrePage(int currentPage){ #=D) j
return currentPage == 1 ? false : true; nxY\|@
} GSY(
G[B=>Cy
privatestaticboolean hasNextPage(int currentPage, 8/DS:uM
F;>V>" edl
int totalPage){ TIx|L
return currentPage == totalPage || totalPage == CWf /H)~
.0p0_f=
0 ? false : true; R]Vt Y7}i,
} AG3>V+k{Lv
Gn22<C/
E0BMv/r8b
} Q;MT"=RW
g-qP;vy@"q
_G_Cj{w
iF*:d
sI43@[
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 rjl`&POqc
i}b${no
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 O7u(}$D
L
Z<U6<{b
做法如下: C#QpQg2
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 {Z{75}
-_ I_W&
的信息,和一个结果集List: ;1#H62Z*
java代码: T}
`x-
<
|e,05aM
M\C"5%2Mu
/*Created on 2005-6-13*/ :WC2Ax7$2
package com.adt.bo; ai}mOyJs
M-\Y"]sW
import java.util.List; D@C-5rmq
PxF<\pu&
import org.flyware.util.page.Page; TPVVck-T8
"BD~xP(
/** |\w=u6jX
* @author Joa r[1i*b$
*/ ;sfb 4x4
publicclass Result { JROM_>mC
Gb"r|(!
private Page page; k-Q%.o
NIh:DbE
private List content; WegtyO
UYFwS/ RW}
/** K )[]fm
* The default constructor m_hN*v
Py
*/ ktI/3Mb@
public Result(){ 2#o>Z4 r{
super(); `))\}C@k
} BeCWa>54i
dG@"!!,
/** U QE qX
* The constructor using fields El<]b7
* Z:ni$7<.
* @param page 'iy*^A `Y
* @param content Pa(^}n|
*/ ]'5;|xc9$/
public Result(Page page, List content){ (E/lIou
this.page = page; 9Kg21-?
this.content = content; [qdRUV'
} A"`foI$0
&GNxo$CG
/** jxiC
Kx,G
* @return Returns the content. ~CtL9m3tO
*/ MWI4Y@1bS
publicList getContent(){ =81@o,1w
return content; 1h>yu3O
} 3VI4X
A;5n:Sd
/** uqM yoIc
* @return Returns the page. ex+\nD>t4
*/ Ad:TYpLD
public Page getPage(){ p>vn7;s2#
return page; 7Q7-vx
} j>]nK~[ka
/D5`
/** ;2@BO-3K
* @param content o HMo>*?
* The content to set. 0E?jW7yr
*/ C|d\3S\(
public void setContent(List content){ 48jVRo
this.content = content; ET _W-
} {n/uh0>f*
W3D c r@Dy
/** H~GQ;PhRx
* @param page u\LiSGePN
* The page to set. u)3 $~m~
*/ @o#!EfZyE
publicvoid setPage(Page page){ @+'-ADX
this.page = page; `(v='$6}
} wj[\B*$?
} AtU v71D:
y;t6sM@
B;R.# ^@/
+j(d| L\
1BAgtd$3
2. 编写业务逻辑接口,并实现它(UserManager, %STliJ
}Ow>dV?
UserManagerImpl) /"
${$b{
java代码: ~/ 8M 3k/
D\@m6=L
N;A@'
tu8
/*Created on 2005-7-15*/ qOSg!aft{Q
package com.adt.service; Ma'_e=+A
TMs,j!w?I
import net.sf.hibernate.HibernateException; <&&SX;
2<`.#zIds
import org.flyware.util.page.Page; WVmq% ,7
UA4J>1 i
import com.adt.bo.Result; d"5oD@JG:
({-GOw46
/** Sr&515
* @author Joa ] GHt"
*/ Xg=x7\V
publicinterface UserManager { p.
R2gl1m
#l4)HV
public Result listUser(Page page)throws *[r!
Yly@ww9t|
HibernateException; %.<H=!$
_bzqd"
31I
} p}|.ZkyN
"]m+z)lWd
EyI}{6~F
bn(`O1r[(
DNR~_3Aq
java代码: /^$UhX9v
j,t#B"hOnp
-*~CV:2iq-
/*Created on 2005-7-15*/ ?9HhG?_x
package com.adt.service.impl; J0
k
SFb{o<0 =
import java.util.List; osOVg0Gyj
OFGsjYLw
import net.sf.hibernate.HibernateException; >Jw6l0z
Tzt ,/e
import org.flyware.util.page.Page; 2>]a)
import org.flyware.util.page.PageUtil; Gy,u^lkk:
xr qv@/kJ
import com.adt.bo.Result; $s4Wkq
import com.adt.dao.UserDAO; &m {kHM
import com.adt.exception.ObjectNotFoundException; tM,%^){p$
import com.adt.service.UserManager; hKNY+S})g
3IR
^
/** !mRx$
%ul
* @author Joa KQld YA|m
*/ ckjrk
publicclass UserManagerImpl implements UserManager { 1[E#vdbT
li]
6Pj,
private UserDAO userDAO; tu>{
nRb^<cZf
/** ?\/qeGW6G
* @param userDAO The userDAO to set. G~wF nl%
*/ RA],lNs
publicvoid setUserDAO(UserDAO userDAO){ ++}\v9Er
this.userDAO = userDAO; ~P-*}q2J
} IN7<@OS7
dQgk.k
/* (non-Javadoc) m7=1%6FN3
* @see com.adt.service.UserManager#listUser #hL*rbpT
02JoA+
(org.flyware.util.page.Page) /%n`V
*/ J^m<*
public Result listUser(Page page)throws C;Ic
D);'pKl
HibernateException, ObjectNotFoundException { ~%#mK:+
int totalRecords = userDAO.getUserCount(); yg;_.4TpIO
if(totalRecords == 0) ?@R")$
throw new ObjectNotFoundException "Vd_CO
=l942p
("userNotExist"); R^MiP|?ZH
page = PageUtil.createPage(page, totalRecords); Ep ~wWQh
List users = userDAO.getUserByPage(page); ~VTs:h
returnnew Result(page, users); gJ3c;
} -DO&