Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 l{?9R.L
bM_fuy55Op
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 }h/7M
Ap"%%D^{:
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 Q;y4yJ$wI
5>e<|@2
X
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 YsiH=x
dKXzFyW
。 J?t(TW6E
Iq19IbR8
分页支持类: F 3q<j$y
fpZHE=}r
java代码: A=ez,87
#ax% n
)eSQce7H
package com.javaeye.common.util; dci,[TEGu
?qHQ#0 @y]
import java.util.List; =<#++;!I
S}Z@g
publicclass PaginationSupport { 6v}q @z
T8*;?j*@
publicfinalstaticint PAGESIZE = 30; o9Mr7
i(e=
privateint pageSize = PAGESIZE; 4u0?[v[Hu
n^55G>"0|
privateList items;
{fEb>
j~+(#|
privateint totalCount; [*C~BM
|z@AvS[
privateint[] indexes = newint[0]; Y)(w&E>1
-!T24/l
privateint startIndex = 0; nnu#rtvZp}
6&LmR75C
public PaginationSupport(List items, int gd%Ho8,T
+g1+,?cU
totalCount){ >#T?]5Z'MF
setPageSize(PAGESIZE); (bNoe(<qU
setTotalCount(totalCount); \Q|,0`
setItems(items); 9 ,tk
setStartIndex(0); cuf]-C1_
} +uNMyVH
p?
VDBAx
public PaginationSupport(List items, int A 3q#,%
DV({! [EP
totalCount, int startIndex){ `4Z:qh+fJ
setPageSize(PAGESIZE); NVom6K
setTotalCount(totalCount); QR-pji
y
setItems(items); ?vik2RW
setStartIndex(startIndex); 5YI6$ZdQ
} AEFd,;GF
eAQ-r\h'2
public PaginationSupport(List items, int Z)3oiLmD
|hDN$By
totalCount, int pageSize, int startIndex){ 0x&L'&SpN
setPageSize(pageSize); ]gA2.,)}D
setTotalCount(totalCount); #c/K.?
setItems(items); BOdlz#&s
setStartIndex(startIndex); WkpHe
} )#? K2E
/
U~yYh
publicList getItems(){ p]s)Xys
return items; ]}&HvrOld
} .M[t5I'\
xA*6Z)Y
publicvoid setItems(List items){ AS4oz:B
this.items = items; )T
slI
} m("KLp8
9*!*n ~
publicint getPageSize(){ 5lwMc0{/3
return pageSize; 7~N4~KAUS
} 'w/S6j
Oq}7q!H
publicvoid setPageSize(int pageSize){ vMJ_n=Vf
this.pageSize = pageSize; XVKRT7U
} ;D(6Gy9~
.F _u/"**
publicint getTotalCount(){ NJ$Qm.S
return totalCount; f&Sovuuh
} #z*,-EV|
3^)c5kcI
publicvoid setTotalCount(int totalCount){ e+m(g
if(totalCount > 0){ 3Zp q#
this.totalCount = totalCount; \mt Y_O
int count = totalCount / NUtKT~V
O2lM;="
pageSize; \ZSq ZDq
if(totalCount % pageSize > 0) :"i2`y;u
count++; i8*(J-M
indexes = newint[count]; \2Q#'
for(int i = 0; i < count; i++){ R=iwp%c(
indexes = pageSize * ?2gXF0+~Y2
r. rzU
i; tp\d:4~R
} hfvC-f97L
}else{ au+:-Khm
this.totalCount = 0; ]%G#x
} [KW)z#`*
} zCS }i_ p
cw_B^f8^
publicint[] getIndexes(){ x%dVD
return indexes; eQfXUpk3@I
} T&<ee|t@{
LF:~&
m
publicvoid setIndexes(int[] indexes){ XHJ/211
this.indexes = indexes; 6jov8GIAt
} +mO/9m
M@pF[J/
publicint getStartIndex(){ "SC]G22
return startIndex; 7PO]\X^(zE
} <c,iu{:
jS#YqVuN
publicvoid setStartIndex(int startIndex){ bc& 5*?
if(totalCount <= 0) W:8{}Iu<
this.startIndex = 0; M~9IL\J^G
elseif(startIndex >= totalCount) ?'tFTh
this.startIndex = indexes zP$"6~.
NR^3
1&}It
[indexes.length - 1]; w[^lxq
elseif(startIndex < 0) po*r14f
this.startIndex = 0; B+c,3@)x
else{ ' 1dhdm8
this.startIndex = indexes c11;(
T7?z0DKi
[startIndex / pageSize]; 5m>f1`4JS
} t<^7s9r;I
} a\p`J 9Z@
vhU#<59a1
publicint getNextIndex(){ BGstf4v>A<
int nextIndex = getStartIndex() + /1+jQS
X9&>.?r
pageSize; YTfi g{a
if(nextIndex >= totalCount) [| C
return getStartIndex(); E7<l^/<2S+
else &~=d;llkT
return nextIndex; LO%OH
u}]
}
_akpW
3Z}KRsp3
publicint getPreviousIndex(){ "2"2qZ*h}
int previousIndex = getStartIndex() - w:~vfdJ
WjvgDNk
pageSize; 6x16?x
if(previousIndex < 0) x*:"G'zT
return0; Rf{YASPIw&
else
1<0Z@D~F
return previousIndex; ?:7$c
} OHH\sA
<CS,v)4,nH
} YgQb(umK
y@ c[S;
tR?)C=4,
{CgF{7`
抽象业务类 U6YQ*%mZ_
java代码: \.=,}sV2Z
L~Xzo
"~08<+
/** NU3s^ 8\(
* Created on 2005-7-12 Z..s /K{
*/ V$ "]f6
package com.javaeye.common.business; AaM~B`B
1f$1~5Z
import java.io.Serializable; X9YbTN
import java.util.List; jZ<f-Ff0
bZgFea_>i
import org.hibernate.Criteria; P#,g5
import org.hibernate.HibernateException; 80LN(0?x
import org.hibernate.Session; ca'c5*Fs
import org.hibernate.criterion.DetachedCriteria; o"qG'\x
import org.hibernate.criterion.Projections; aBKJd
import e8)8QmB{o
u X(#+
org.springframework.orm.hibernate3.HibernateCallback;
&/)To
import o4YF,c+>q
ii ^Nxnc=
org.springframework.orm.hibernate3.support.HibernateDaoS <t,lq
wf~n>e^e
upport; .h@bp1)l
l0%7u
import com.javaeye.common.util.PaginationSupport; x!fRT.,}
k.%FGn'fR
public abstract class AbstractManager extends ~01t_Xp qc
[4mIww%
HibernateDaoSupport { W"D>>]$|u
&M#}?@!C
privateboolean cacheQueries = false; oK2j PP
J+qcA}
privateString queryCacheRegion; Nbt.y 'd
]q|U0(q9
publicvoid setCacheQueries(boolean Htce<H-P
lh;;%@1DM
cacheQueries){ X1&c?T1 %[
this.cacheQueries = cacheQueries; t#nRa Pzp
} q =26($
U)_x(B3d/
publicvoid setQueryCacheRegion(String 3Zm;:v4y
88zK)k{
queryCacheRegion){ E> YE3-]
this.queryCacheRegion = Nkk+*(Z
%p^`,b}
queryCacheRegion; .:Zb~
} (l)r.Vj
KtaoU2s
publicvoid save(finalObject entity){ F7`[r9 $
getHibernateTemplate().save(entity); @.h;k4TD
} PLK;y
GO6uQ};
publicvoid persist(finalObject entity){ s 5F?m
getHibernateTemplate().save(entity); (5)DQ1LaF
} 9@YhAj
xepp."O
publicvoid update(finalObject entity){ ,veI'WHMB
getHibernateTemplate().update(entity); -K0!wrKC
} F>aaUj
P5Pb2|\*
publicvoid delete(finalObject entity){ Y58et9gRO
getHibernateTemplate().delete(entity); f}Uf*Bp
} v.>95|8
,UW!?}@
publicObject load(finalClass entity, xDn#=%~+x
le~p2l#e
finalSerializable id){ N[sJ5oF
return getHibernateTemplate().load R rp-SR?O
A7zL\U4
(entity, id); ] U.*KkQ
} 1m<8M[6u
JQA]O/|N
publicObject get(finalClass entity, 2h`Tn{&1/
--F6n/>
finalSerializable id){ ZP"Xn/L
return getHibernateTemplate().get qyR}|<F8*
bfKF6
(entity, id); =dY!-#yg!
} +y|Q7+
B5!|L)7>{p
publicList findAll(finalClass entity){ _i2k$Nr
return getHibernateTemplate().find("from @"/:Omh
RFLw)IWkL_
" + entity.getName()); ^8
cq
qu
} /vw$3,*z
e9rgJJ
publicList findByNamedQuery(finalString }k_'a^;C1
^NFL3v8
namedQuery){ {,e-;2q
return getHibernateTemplate VH<-||X/4
.c\iKc#
().findByNamedQuery(namedQuery); )^j62uv
} x]~&4fp
Tvd: P^C
publicList findByNamedQuery(finalString query, oGz5ZDa#
Z8\/Fb
finalObject parameter){ G)&S%R!i\N
return getHibernateTemplate 2X 0<-Y#'
";
mlQyP
().findByNamedQuery(query, parameter); F??gVa aj
} #? 7g_
?~tx@k$;Es
publicList findByNamedQuery(finalString query, y`J8hawp
6K5mMu#4
finalObject[] parameters){ qzii[Mf
return getHibernateTemplate 3?<LWrhV3
V6fJaZ
().findByNamedQuery(query, parameters); P$6Pe>3
} :dwP
3%
O[W
publicList find(finalString query){ Fq'Ds[wd5
return getHibernateTemplate().find {Hzj(c~S?
FA}y"I'W
(query); ;.3
{}.Y
} 9~4@AGL
QNGp+xUHJ9
publicList find(finalString query, finalObject E*d UJ.>
#S"s8wdD
parameter){ Ceew~n{
return getHibernateTemplate().find $ <Mf#.8%
%g~zEa-g
(query, parameter); lec3rv0)
} | *N;R+b
Te7xj8<
public PaginationSupport findPageByCriteria C(2kx4 n
_a zJ>
(final DetachedCriteria detachedCriteria){ }N"YlGY\Yn
return findPageByCriteria !JA//{?
`pfRY!
(detachedCriteria, PaginationSupport.PAGESIZE, 0); &A~hM[-
} hY|-l%2f
e;9x%kNs!
public PaginationSupport findPageByCriteria Mt&n|']`8
M# cJ&+rP
(final DetachedCriteria detachedCriteria, finalint gPIl:, d(
m[s$) -T
startIndex){ DC2[g9S>8@
return findPageByCriteria >FqU=Q
T%w5%{dqJ
(detachedCriteria, PaginationSupport.PAGESIZE, Y-~MkB
=-/sB>-C
startIndex); Hd_,`W@
} t)4]2z)$
=A(Az
public PaginationSupport findPageByCriteria XzPUll;ZU
<aY>fg d/1
(final DetachedCriteria detachedCriteria, finalint )oy+-1dE
y-mjfW`n
pageSize, >{>X.I~
finalint startIndex){ SZ~lCdWad
return(PaginationSupport) ;KT/;I
)C0d*T0i
getHibernateTemplate().execute(new HibernateCallback(){ J>1%*Tz
publicObject doInHibernate O"J"H2}S
x;A.Ll
(Session session)throws HibernateException { "%#CMCE|f
Criteria criteria = 5E
=!L
g
LR3>_t
detachedCriteria.getExecutableCriteria(session); RM>A9nv$\
int totalCount = vK$wc~
aev(CY,z
((Integer) criteria.setProjection(Projections.rowCount ]U,m
1
@ ?bY,
()).uniqueResult()).intValue(); =ba1::18
criteria.setProjection 5-UrHbpCZ#
kc<5wY_t
(null); lLLPvW[Q
List items = WG
+]
K?>sP%m)
criteria.setFirstResult(startIndex).setMaxResults 9(lcQuE9
RV%)~S@!R
(pageSize).list(); sW76RKX8
PaginationSupport ps = ?0+N
svtqX-Vj"
new PaginationSupport(items, totalCount, pageSize, ?%$~Bb _
yYdh+ x
startIndex); d
'\^S}
return ps; 0 gR_1~3
} S}qGf%
}, true); v
,zD52
} 15d'/f
-K/c~'%'*
public List findAllByCriteria(final f6 s .xQ
9U Hh#
DetachedCriteria detachedCriteria){ hx ^ l
return(List) getHibernateTemplate 0bOT&Z^
ua,!kyS
().execute(new HibernateCallback(){ #44}Snz
publicObject doInHibernate [}dPn61
tTT
:r),}$
(Session session)throws HibernateException { $GYy[8{:V
Criteria criteria = 1p=bpJC
`cPZsL
detachedCriteria.getExecutableCriteria(session); 8Yo;oHk7
return criteria.list(); S3&n?\CO:
} @U9`V&])F[
}, true); .@$A~/ YU
} 6W:FT Pt44
5..YC=_20
public int getCountByCriteria(final %!8w)1U
i`=%X{9
DetachedCriteria detachedCriteria){ 9+ |W;
Integer count = (Integer)
I]BhkJ
I=
a?z<
getHibernateTemplate().execute(new HibernateCallback(){ @mb' !r
publicObject doInHibernate t*`Sme]"B
eKf5orN
(Session session)throws HibernateException { u#NX`_
Criteria criteria = AuZISb%6
\i\>$'f*z
detachedCriteria.getExecutableCriteria(session); p3e=~{v*
return ^tIYr<I
4/OmgBo'
criteria.setProjection(Projections.rowCount tlB-s;
)TEod!]
()).uniqueResult(); >E3-/)Ti
} ppGWh
}, true); @FF80U4'
return count.intValue(); `qRyh}Ax"
} _-2ntO<E
} .9?GKD
ZD4aT1|Q7
x+b.9f4xJ
~y"OyO i&
'S*]JZ1
l gZ9*@d
用户在web层构造查询条件detachedCriteria,和可选的 *X^C+F
A5Q4wy`
startIndex,调用业务bean的相应findByCriteria方法,返回一个 x,|fblQz
trB-(B%5
PaginationSupport的实例ps。 HE>V\+
AL
|9X2AS Qu
ps.getItems()得到已分页好的结果集 `?SC.KT
ps.getIndexes()得到分页索引的数组 ~(B%E'
ps.getTotalCount()得到总结果数 "=LeHY=9
ps.getStartIndex()当前分页索引 KtArV
ps.getNextIndex()下一页索引 HZ1 nuA
ps.getPreviousIndex()上一页索引 MhJA8|B6|
5sNN:m
"c.-`1,t
|~&cTDd
hBVm;`
pl$wy}W-
$ wDSED -
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 |*M07Hc x
9e.$x%7j
,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 ^%tn$4@@Z.
%e)?Mem
一下代码重构了。 5\h 6'
yXqC
我把原本我的做法也提供出来供大家讨论吧: y Pg0:o-
;Sg,$`]
首先,为了实现分页查询,我封装了一个Page类: +ej5C:El_}
java代码: z?F`)}
?@kz`BY
I!SIy&=W
/*Created on 2005-4-14*/ xM@s`s|n
package org.flyware.util.page; ]9c{qm}y
Mpco8b-b
/** G~ LQM
* @author Joa @"wX#ot
* /a)^)
*/ LROrhO
publicclass Page { P1Eg%Y6
{u-J?(s}
/** imply if the page has previous page */ 6']G HDK
privateboolean hasPrePage; k'+y
Br.UN~q
/** imply if the page has next page */
V<?0(esgR
privateboolean hasNextPage; |WSpWsr,
RCoDdtMo
/** the number of every page */ h:sf?X[
privateint everyPage; Db;>MWt+e
'-Oh$hqCx|
/** the total page number */ |o*qZ}6
privateint totalPage; ovdaK"q2
dBS_N/
/** the number of current page */ k8@bQ"#b
privateint currentPage; xxr'g =
\RRSrPLd-
/** the begin index of the records by the current pp(?rE$S
.J8 gW
query */ 0AF,} &$
privateint beginIndex;
n_k`L(8*
A (p^Q
BPm")DMo
/** The default constructor */ ~wOMT
public Page(){ Zsmv{p
N9s.nu
} qk>SM|{
yeBfzKI{b
/** construct the page by everyPage XsDZ<j%x89
* @param everyPage Ts3!mjn
* */ 7oc Ng
public Page(int everyPage){ "]Uj _d
this.everyPage = everyPage; Bjj=UtI
} 2I& dTxIa
DY{v@
<3
/** The whole constructor */ G)c+GoK
public Page(boolean hasPrePage, boolean hasNextPage, <a&xhG}
aQf2}kD
lQ4^I^?m
int everyPage, int totalPage, _MuzD&^qE
int currentPage, int beginIndex){ uXvE>VpJG
this.hasPrePage = hasPrePage; +$xw0)|
this.hasNextPage = hasNextPage; 7i'clB9!
this.everyPage = everyPage; )s4:&!
this.totalPage = totalPage; N}<!k#d
E
this.currentPage = currentPage; ~4Mz:h^
this.beginIndex = beginIndex; g0 ;;+z
} U2tgBF?)A
r`.Bj0
/** j]`hy"
* @return ~D`R"vzw=
* Returns the beginIndex. uFhPNR2l
*/ jTZi<
Y:bB
publicint getBeginIndex(){ 9j5|o([J
return beginIndex; GoH.0eQ^
} q?)5yukeF
nh80"Ny5
/** j9GKz1
* @param beginIndex vu}U2 0@
* The beginIndex to set. !0UfX{.
*/ 1zw,;m n
publicvoid setBeginIndex(int beginIndex){ tFX<"cAvK
this.beginIndex = beginIndex; #3eI4KJ4+l
} E>gLUMG$
A7&/3C6{H
/** p!)tA
* @return vb]uO ' l
* Returns the currentPage. W(?J,8>
*/ 2"j&_$#l5X
publicint getCurrentPage(){ i,%N#
return currentPage; Pgq(yPC
} 2
e#"JZ=
l0qHoM,1Y[
/** rc7c$3# X
* @param currentPage =|dm#w_L"
* The currentPage to set. oHp"\Z&
*/ /v|b]Ji
publicvoid setCurrentPage(int currentPage){ lw?C:-m
this.currentPage = currentPage; %[ *+
} (~! @Uz5
7;C~>WlU
/** 3RxR'M1
* @return
fCnwDT
* Returns the everyPage. zV;NRf)
9.
*/ k`]76C7
publicint getEveryPage(){ Zy{hYHQ
return everyPage; _ouZd.
} | z_av
Ol<LL#<j4
/** 9&<c)sS&B
* @param everyPage B<h4ZK%
* The everyPage to set. (!0_s48f
*/ *UJB*r
publicvoid setEveryPage(int everyPage){ 45iO2W uur
this.everyPage = everyPage; n<HF]
} ) te_ <W
0}'/p N>
/** !U(KQ:j
* @return K|6}g7&X
* Returns the hasNextPage. xG Y!r"[
*/ f,LeJTX=
publicboolean getHasNextPage(){ AXi4{Q,
return hasNextPage; i.[k"(
} JHVndK4L
R$MR|
/** &hi][Pt
* @param hasNextPage IM[=]j.?
* The hasNextPage to set. V \FlKC
*/ f`\J%9U _O
publicvoid setHasNextPage(boolean hasNextPage){ mUR[;;l
this.hasNextPage = hasNextPage; ?duw0SZ
} glKPjL *
}g%&}`%'
/** 8^^ehaxy
* @return P9Eh,j0_
* Returns the hasPrePage. 3+:NX6Ewb*
*/ ~)X;z"y%b
publicboolean getHasPrePage(){ |8x_Av0
return hasPrePage; `ZP[-: `
} t*6C?zEAU
f^5sJ0;%
/** Y2N$&]O{
* @param hasPrePage 9c1q:>|
* The hasPrePage to set. #-R]HLW*
*/ N "eK9>
publicvoid setHasPrePage(boolean hasPrePage){ vt5>>rl
this.hasPrePage = hasPrePage;
!y!s/i&P%
} @cm[]]f'l
iU~d2R+
/** <8Z%'C6d
* @return Returns the totalPage. "/UPq6
* M$f_I +
*/ rfZg
publicint getTotalPage(){ ^BI&-bR@
return totalPage; 9+5F(pd(
} c]z^(:_>
Ml+f3#HP
/** 8-b~p
* @param totalPage 6G-XZko~a
* The totalPage to set. K+yi_n L
*/ p{SIGpbR&
publicvoid setTotalPage(int totalPage){ Esg:
this.totalPage = totalPage; 'Nx"_jQ
} $Df1t
+s [_
4
} =umF C[.W
Tilr%D(Q
i@<w"yNd_
(m.jC}J
y %Y P
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 DAEWa
Kui
e+@.n
个PageUtil,负责对Page对象进行构造: 7bJM
$
java代码: >S?7-2X
kaDn=
={YM
: R8+jO
/*Created on 2005-4-14*/ f9n4/(Cy
package org.flyware.util.page; )oS~ish
d{C8}U
import org.apache.commons.logging.Log; U2JxzHXZ
import org.apache.commons.logging.LogFactory; y>RqA*J
j{zVVT
/** ' 94HVag
* @author Joa T16B2|C"Y
* `X`|]mWj
*/ kYd=DY
publicclass PageUtil { rj5)b:c}
h 'is#X 6:
privatestaticfinal Log logger = LogFactory.getLog ^AUQsRA7PZ
#`"B
YFV[E
(PageUtil.class); ;:Kc{B.s
q93V'[)F
/** i{J[;rV9
* Use the origin page to create a new page >>=v`}
* @param page z_z'3d.r7
* @param totalRecords a1weTn*
* @return RZj06|r8
*/ <)@^TRS
publicstatic Page createPage(Page page, int _)#~D*3
D,uT#P
totalRecords){ y|wR)\
return createPage(page.getEveryPage(), ACgWT
&0-Pl.M
page.getCurrentPage(), totalRecords); qv/chD`C
} x/92],.Mz
9AQ2FD
/** Aq/wa6^%
* the basic page utils not including exception WS$~o*Z8
m(WVxVB
handler
Y
XxWu8
* @param everyPage Zt4 r_7
* @param currentPage HL!" U(_
* @param totalRecords D/WzYc2h]
* @return page @jD19=
*/ j7HOh|q
publicstatic Page createPage(int everyPage, int "QY~V{u5
jH4Wu`r;m
currentPage, int totalRecords){ 9p"';*{=
everyPage = getEveryPage(everyPage); m$q*
currentPage = getCurrentPage(currentPage); u #7AB>wi{
int beginIndex = getBeginIndex(everyPage, *P[N.5{
h^b=
currentPage); ]g9n#$|.
int totalPage = getTotalPage(everyPage, =iPQ\_ON@
u\UI6/
totalRecords); cuQ=bRIb
boolean hasNextPage = hasNextPage(currentPage, 6[>Z y)P
E__A1j*gd
totalPage); w;^7FuBaC
boolean hasPrePage = hasPrePage(currentPage); hM`*-+Zb
5{8,+
Z
returnnew Page(hasPrePage, hasNextPage, <NM Os"NB
everyPage, totalPage, UgLJV2M6
currentPage, mHC36ba
GJuU?h#:/{
beginIndex); ;V1e>?3
} )i>T\B
DZ|/#- k
privatestaticint getEveryPage(int everyPage){ 3bB%@^<
return everyPage == 0 ? 10 : everyPage; gH/k}M7tA#
} ;4]l P
(%;D&
~%o
privatestaticint getCurrentPage(int currentPage){ ]5J*UZ}
return currentPage == 0 ? 1 : currentPage; R
)e^H
} 885
,3AdA
22m'+3I~Y
privatestaticint getBeginIndex(int everyPage, int (fWQ?6[
y]f| U-f:~
currentPage){ ZbcpE~<a
return(currentPage - 1) * everyPage; cY*lsBo
} J7rfHhz
MT@Uu
privatestaticint getTotalPage(int everyPage, int SkA"MhX
'~'3x4Bo
totalRecords){ Ehf{Kl
int totalPage = 0; aD3Q-a[
5($
'@u
if(totalRecords % everyPage == 0) N
DV_/BI
totalPage = totalRecords / everyPage; S>p>$m,
Q
else DnPV
Tp(>
totalPage = totalRecords / everyPage + 1 ; cj/FqU"
nyB~C7zR
return totalPage; "A9 c]
} cb~m==G
\>-%OcYlM
privatestaticboolean hasPrePage(int currentPage){ U
z6XQskX
return currentPage == 1 ? false : true; mCx6$jz
} tMy@'nj
$eBE pN
privatestaticboolean hasNextPage(int currentPage, 7gQ~"Q
I^6zUVH
int totalPage){ Q}jl1dIq
return currentPage == totalPage || totalPage == /c 1FFkq|K
wA}+E)x/C
0 ? false : true; .oo>NS
} Fc<+N0M{
hYN b9^
ysiBru[u
} oMi"X"C:q
4%k_c79>
"2bCq]I0
,Z I"+v
}KHdlhD
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。 etH%E aF[
`#lNur\x
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 D?Q{&6p
z7J2O
做法如下: u-. _;
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 #`4ma:Pj
X;0DQnAI8j
的信息,和一个结果集List: I(Yyg,1Z
java代码: bmO[9
)G
RtR]9^:~
)y:~T\g
/*Created on 2005-6-13*/ OsR4oT
package com.adt.bo; fW4N+2
f z8eL:i:
import java.util.List; cf0Dq~G
o3l_&?^
import org.flyware.util.page.Page; Xu:Sh<:R
MLcc
/** 3l 0>
* @author Joa m>6,{g)
*/ pemb2HQ'4j
publicclass Result { S0Y$$r
u#Qd`@p
private Page page; BS;_l"?
b#^UP
private List content; ;,]T|>M
.~6p/fHX
/** DO$jX
4
* The default constructor |L4K#
*/ :-
ydsR/
public Result(){ ;Z"6ve4
super(); ]J C}il_b
} T0Q)}%L
?j8F5(HF?
/** B@l/'$G
* The constructor using fields ;%AK< RT
* xS`>[8?3<T
* @param page ,r{\aW@
* @param content /AP@Bhm
*/ F"3PP ~
public Result(Page page, List content){ oToUpkAI
this.page = page; j']m*aM1>
this.content = content;
`'5(4j
} (AdQ6eGM b
R;f!s/^)
/** cSBYC_LU
* @return Returns the content. n8[
sl]L
*/ +I7n6s\
publicList getContent(){ Y`3>i,S6\
return content; wbzAX
}
wEo/H
,&!Txyye
/** n9Z|69W6>
* @return Returns the page. ^e>`ob
*/ ]v3 9ag_hu
public Page getPage(){ vO"Sy{)Z>
return page; Z| Z447_
} !t6:uC7H
ZUb6d*B
/** E[>4b7{g:
* @param content `6b!W0$
-
* The content to set. }r6SV%]:
*/ HP2]b?C
public void setContent(List content){ #n7uw
this.content = content; =)(o(bfSKr
} UfSWdR)
j9sf~}D>
/** [:
X
* @param page *BT-@V.4
* The page to set. =usx' #rb
*/ 2![.Kbqa%
publicvoid setPage(Page page){ AW4N#gt8',
this.page = page; 'c\zWmAZ
} JB a:))lw
} Aq}]{gfQ1
_mKO4Atw
S,EXc^A7
it!8+hvq9*
zo&'2I
2. 编写业务逻辑接口,并实现它(UserManager, _H|x6X1-
|<P]yn
UserManagerImpl) `AeId/A4n
java代码: 0x'>}5`5
?ZDXT2b~~
pm,&