Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 P{Q=mEQ
'+j} >Q
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 jqr1V_3(
fDx9iHGv
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 E^U0f/5
m
v&Kqq!DE
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 S*AERm
Lg"C ]
。 e.c3nKXZ q
KR7@[
分页支持类: mo~*C
p }[zt#v
java代码: =_YG#yS
0ZQ' _g|%
ccd8O{G.M
package com.javaeye.common.util; 1:Si,d,wh
_G1gtu]
import java.util.List; nC{%quwh{
Zw
wqSyuGf
publicclass PaginationSupport { ^&g=u5
d0
wcDRH)AW.
publicfinalstaticint PAGESIZE = 30; {mB0rKVm
h$L"8#
privateint pageSize = PAGESIZE; RmZ]"
`
.xBu-?6s6
privateList items; a1Qv@p^._b
xeGb?DPu
privateint totalCount; \c^45<G2qA
V]90
privateint[] indexes = newint[0]; v9T_&
v@# b}N0n
privateint startIndex = 0; 3]?#he
h<~7"ONhV
public PaginationSupport(List items, int soCi[j$lH
[
Bl c^C{f
totalCount){ Rb3V^;i
setPageSize(PAGESIZE); )?wJF<[_#
setTotalCount(totalCount); ;2Q~0a|
setItems(items); vX ] Gf4,
setStartIndex(0); ytNO*XoR
} &HSq(te
vzmc}y G
public PaginationSupport(List items, int x`6<m!d`
]vuwkn+)
totalCount, int startIndex){ _ 84ut
setPageSize(PAGESIZE); XV^1tX>f{
setTotalCount(totalCount); Hty0qr3
setItems(items); A/`%/0e
setStartIndex(startIndex); %\i9p]=
} n@ G[
>ooZj9:'
public PaginationSupport(List items, int "n*~Mj Ny
+Jr|z\
totalCount, int pageSize, int startIndex){ p<:!)kt
setPageSize(pageSize); 3MRc4UlB
setTotalCount(totalCount); Y3O#Q)-j$
setItems(items); -kbg\,PW
setStartIndex(startIndex); [LRLJ_~g5
} M`S0u~#tI
'}Ri`
publicList getItems(){ bu51$s?B
return items; V\6]n2
} t]Xw{)T
2<}NB?f`N
publicvoid setItems(List items){ n9s iX
this.items = items; $ [yFsA6
} FN[{s
yeHDa+}
publicint getPageSize(){ VWO9=A*Y|
return pageSize; o: ;"w"G
} 0
Us5
Qqlup
publicvoid setPageSize(int pageSize){ ":_vK}5
this.pageSize = pageSize; 2=_gf
} f47M#UC
zhf.NCSt(
publicint getTotalCount(){ R"K#7{p9
return totalCount; GaSPJt
} c*@G_rb
QD%L0;j
publicvoid setTotalCount(int totalCount){ <^$<#Kd
if(totalCount > 0){ NB<A>baL*
this.totalCount = totalCount; 2+X\}s1vN
int count = totalCount / *E{2J:`
\_B[{e7z
pageSize; %RDI!e<e}
if(totalCount % pageSize > 0) Qca&E`~Q
count++; 7NJhRz`_
indexes = newint[count]; R+CM`4CD
for(int i = 0; i < count; i++){ O|w J)
indexes = pageSize * KIWe@e
%dY<=x#b
i; xNbPsoK
} yiO.z
}else{ F8apH{&t
this.totalCount = 0; 50={%R
} |DsnNk0c
} xt*u4%
~*wk6&|
publicint[] getIndexes(){ tToTxf~
return indexes; 7nuU^wc
} h*v8#\b$J_
&?(?vDFfZ
publicvoid setIndexes(int[] indexes){ +>PX&F
this.indexes = indexes; 6:~v4W!k
} o]opdw
gg8Uo G
publicint getStartIndex(){ 4]E3cAJ
return startIndex; qT^I?g"!
} Ng_!zrx04
)Eo)t>
publicvoid setStartIndex(int startIndex){ K>{T_) {
if(totalCount <= 0) 53[~bwD
this.startIndex = 0; YD7Oao4:o
elseif(startIndex >= totalCount) $ ,
u+4h
this.startIndex = indexes X*\J_
#{\%rWnCm
[indexes.length - 1]; JeE;V![
elseif(startIndex < 0) d N$Tf
this.startIndex = 0; R47\Y
else{ L+i(TM=
this.startIndex = indexes ?F3h)(}
G
nG>7f[v
[startIndex / pageSize]; qo|WXwP2
} aca=yDs2
} &Udb9
a0#J9O_
publicint getNextIndex(){ tdu$pC6
int nextIndex = getStartIndex() + p }~qf
% oo2/aF
pageSize; :*KHx|Q
if(nextIndex >= totalCount) L'kmNVvYN
return getStartIndex(); P ! _rEV
else ;&)-;l7M
return nextIndex; WILMH`
}
>=-(UA
hr)B[<9
publicint getPreviousIndex(){ aYSCw3C<
int previousIndex = getStartIndex() - v%iflCK
\:UIc*S
pageSize; ~W-PD
if(previousIndex < 0) Uw7h=UQh
return0; @
rc{SB
else %B.yW`,X
return previousIndex; HKUn`ng
} K9up:.{QQ
Qr{E[6
} @nCd
5f 5f0|ok
#%h-[/
#e$5d>j(
抽象业务类 *vwbgJG! *
java代码: 73\JwOn~
&eX!#nQ_.
|Ur"&
Z{
/** {fjdr
* Created on 2005-7-12 XY3v_5~/1F
*/ ZNvEW
package com.javaeye.common.business; "9Q40w\
=D<PVGo9
import java.io.Serializable; Rw0qcM\>|
import java.util.List; |3KLk ?2
Jh!I:;/
import org.hibernate.Criteria; )`(p9@,V
import org.hibernate.HibernateException; W~7A+=&
import org.hibernate.Session; LF& z
import org.hibernate.criterion.DetachedCriteria; @y\XR
import org.hibernate.criterion.Projections; ,1+y/{S
import )`O~f_pIC
#;2n;.a
org.springframework.orm.hibernate3.HibernateCallback; 8p:e##%
import |}di&y@-JI
MjC_ ( cs
org.springframework.orm.hibernate3.support.HibernateDaoS z)r=+ -
E;R n`oxk
upport; fUA uqfj[
I!Z_[M
import com.javaeye.common.util.PaginationSupport; lrIjJ
V
U ^5Kz-5.
public abstract class AbstractManager extends _ =VqrK7T
A"dR{8&0
HibernateDaoSupport { LoN< oj5
i\rDu^VQ
privateboolean cacheQueries = false; 1oWED*B
Ay0U=#XP
privateString queryCacheRegion; kr9*,E9cv
aGtf z)
publicvoid setCacheQueries(boolean ?FpWvyz|
a C\MJ9
cacheQueries){ ij( B,Y
this.cacheQueries = cacheQueries; 9Hb6nm
} tnN.:%mZ
1;Cyz)
publicvoid setQueryCacheRegion(String p;3O#n-_
I%j|D#qY:T
queryCacheRegion){ {YAJBIvHV
this.queryCacheRegion = deV
8
f=r<nb'H
queryCacheRegion; RbP6F*f
} ogHCt{'
lvBx\e;7P
publicvoid save(finalObject entity){ #mCL) [
getHibernateTemplate().save(entity); g4=pnK8
} NflD/q/ L
= C8 ?M
publicvoid persist(finalObject entity){ WrxP
getHibernateTemplate().save(entity); ,*&:2o_r
} O7-mT8o
:toh0oB[
publicvoid update(finalObject entity){ 1Z+8r
getHibernateTemplate().update(entity); #~2%)
} p6#g;$V$
mGJKvJF
publicvoid delete(finalObject entity){ 7vrl'^ 1
getHibernateTemplate().delete(entity); ff,pvk8N5
} jET{Le8i
bYpntV
publicObject load(finalClass entity, }Qn&^[[miL
mS$j?>m
finalSerializable id){ nYR#
return getHibernateTemplate().load :8=i kwQ
Ln')QN
(entity, id); Tc>
} eTI%^d|
)wam8k5
publicObject get(finalClass entity, XHK<AO^
`scR*]f1+
finalSerializable id){ /YW>*?"N
return getHibernateTemplate().get 7~^GA.92
(C-{B[Y
(entity, id); r3&G)g=u
} |[<_GQl
U@_dm/;0&
publicList findAll(finalClass entity){ EUD~CZhS"k
return getHibernateTemplate().find("from ,
pDnRRJ!
%p^wZtm
" + entity.getName()); 8=B|C'>
} M -cTRd-i
ww\CQ6/h
publicList findByNamedQuery(finalString l&OKBUG
[842&5Pd?
namedQuery){ h)ECf?r<
return getHibernateTemplate WejYy|
w28o}$b`
().findByNamedQuery(namedQuery); @=bLDTx;c)
} Q('r<v96
`5cKA;j>b
publicList findByNamedQuery(finalString query, &S{RGXj_
xu/cq9
finalObject parameter){ jaTh^L
return getHibernateTemplate ,&]S(|2%>t
3}TaF~
().findByNamedQuery(query, parameter); >Ea8G,
} ~
-4{B
:~b3^xhc^
publicList findByNamedQuery(finalString query, lGPUIoUo
Bn=by{i
finalObject[] parameters){ .0S~872
return getHibernateTemplate Uol|9F
B:b5UD
().findByNamedQuery(query, parameters); 2Nu=/tMN
} hm84Aq= f
tX9{hC^
publicList find(finalString query){ 1->dMm}G[
return getHibernateTemplate().find bU>U14ix<
*g:4e3Iy
(query); Fsmycr!R
} E
]A#Uy
>BR(Wd.
publicList find(finalString query, finalObject oX#Q<2z*
`slL%j^"
parameter){ Y l4^AR&
return getHibernateTemplate().find M>wYD\oeg
D"Bl:W'?j
(query, parameter); /7aBDc-v
} =e/9&993
-V-RP;">
public PaginationSupport findPageByCriteria [.O?Z=5a[V
YZL kL26[
(final DetachedCriteria detachedCriteria){ .f*4T4eR-
return findPageByCriteria _Zp}?b5Q
nF54tR[
(detachedCriteria, PaginationSupport.PAGESIZE, 0); |'.*K]Yp
} 1Ce@*XBU
yQ_B)b
public PaginationSupport findPageByCriteria H7z,j}l
)JDs\fUE
(final DetachedCriteria detachedCriteria, finalint 9A/\h3HrJ
Hbj,[$Jb
startIndex){ #X%~B'
return findPageByCriteria }6p@lla,%]
PXK7b2fE.
(detachedCriteria, PaginationSupport.PAGESIZE, 6_J$UBT
^Ew]uN>,
startIndex); 8UXjm_B^'
} oiF}?:7Q7
^ssK
public PaginationSupport findPageByCriteria lW+\j3?Z$
:}Xll#.,m
(final DetachedCriteria detachedCriteria, finalint j| v%)A
]mo-rhDsM
pageSize, j>*R]mr6
finalint startIndex){ ~x A-V4.
return(PaginationSupport) o9|nJ;
X^T:8npxt
getHibernateTemplate().execute(new HibernateCallback(){ (X $=Q6
publicObject doInHibernate %zA;+s$l
q
0$,*[PH
(Session session)throws HibernateException { 2QD3&Q9
Criteria criteria = 9i'jjN
;
o?-yI&T*
detachedCriteria.getExecutableCriteria(session); =[H;orMr
int totalCount = 6TQoqH8@U
UR%/MV
((Integer) criteria.setProjection(Projections.rowCount ?+_Gs;DGVE
txJr;
()).uniqueResult()).intValue(); 8e*,jH3
criteria.setProjection xAqb\|$^
w zYzug
(null); K0H'4' I
List items = %j:]^vqFA
I3=%h
criteria.setFirstResult(startIndex).setMaxResults ge,H-8'Z
kY&k-K\
(pageSize).list(); 'z0:Ccbj
PaginationSupport ps = H;?{BV
'{a/2
l
new PaginationSupport(items, totalCount, pageSize, )LdP5z-
%@wJ`F2a_
startIndex); )jU)_To
return ps; k&&2Tq
} `s"'r !
}, true); _4rFEYz$d
} '[U8}z3
{\S+#W\
public List findAllByCriteria(final m`v2: S}
#Vl 0.l3
DetachedCriteria detachedCriteria){ *}]Nf
return(List) getHibernateTemplate jq-p;-i
DQNnNsP:M-
().execute(new HibernateCallback(){ 3
*d"B tg
publicObject doInHibernate &%8'8,.
^$%S &W
(Session session)throws HibernateException { M9Cv
wMi
Criteria criteria = ZW-yP2
]=.\-K
detachedCriteria.getExecutableCriteria(session); ?i)f^O
return criteria.list(); l,R/Gl
} XxT#X3D/,"
}, true); 6FUw"|\u{
} E4gYemuN
*-+&[P]m
public int getCountByCriteria(final +1Vjw'P
CAWA3fcQp
DetachedCriteria detachedCriteria){ iocI:b<
Integer count = (Integer) 03xa'Of>
wmk
*h-
getHibernateTemplate().execute(new HibernateCallback(){ >NqYyW,%
publicObject doInHibernate Ot:CPm@
;KOLNi-B&
(Session session)throws HibernateException { RSr
%n1
Criteria criteria = I[=j&rK`
@|Fg,N<Y]
detachedCriteria.getExecutableCriteria(session); )!Jc3%(B
return 3 ,>0a
pwO>h>ik
criteria.setProjection(Projections.rowCount CEXyrs<
3b*cU}go
()).uniqueResult(); &Flglj~7l
} e8y;.D[2
}, true); ~hZ"2$(0
return count.intValue(); d{rQzia"mV
} w3#Wh|LQ-
} IN4=YrM^
s4G|_==
A:>01ZJ5S+
cmBB[pk\
^:K3vC[h;c
un shH <
用户在web层构造查询条件detachedCriteria,和可选的 FjK3
.>'
'Hc-~l>D
startIndex,调用业务bean的相应findByCriteria方法,返回一个 [r3 !\HI7x
- d8TD*^
PaginationSupport的实例ps。 5 elw~u
#?5 (o
ps.getItems()得到已分页好的结果集 LL] zT H0
ps.getIndexes()得到分页索引的数组 qgE 73.!`6
ps.getTotalCount()得到总结果数 wDcj,:h`
ps.getStartIndex()当前分页索引 vK 7^*qr;j
ps.getNextIndex()下一页索引 HqI t74+
ps.getPreviousIndex()上一页索引 $>*3/H
_Bj)r}~7#
`o<'
x.I
=2[7
E
EzDk}uKY0R
r9X?PA0f
Ae
mDJ8Y
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 JQ}$Aqk
dODt(J}%
,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 #@^t;)|
Q&MZN);.
一下代码重构了。 0*%Z's\M"
qi;f^9M%
我把原本我的做法也提供出来供大家讨论吧: OH;b"]
D0g ZC
首先,为了实现分页查询,我封装了一个Page类: ~}F{vm
java代码: =Qh\D
RD\
km)zMoE{c{
/*Created on 2005-4-14*/ zfI>qJ+Nqt
package org.flyware.util.page; `^bgUmJ~
D-8O+.@
/** %T X@I$Ba
* @author Joa g$HwxA9Gp/
* .}'qUPNR
*/ &F\?
publicclass Page { ZPiq-q
}xBc0gr
/** imply if the page has previous page */ }tsYJlh5
privateboolean hasPrePage; "[vu6 `m?
y|CP;:f;
/** imply if the page has next page */ EPS={w$'s
privateboolean hasNextPage; W.z;B<
lCAIK
/** the number of every page */ QF{4/y^j{
privateint everyPage; a-l;vDs
$"0M U
/** the total page number */ HOw-]JSP2
privateint totalPage; m0LTx\w!
Nndddk`
/** the number of current page */ j*F`"df
privateint currentPage; gT$Ju88
~7Ts_:E-
/** the begin index of the records by the current f>aEkh6u9
jZh';M8"
query */ R16'?,
privateint beginIndex; '6Ay&A3N]
>2~+.WePu
u`y><w4i
/** The default constructor */ J\d3N7_d
public Page(){ %FXfqF9
ObLly%|i
} .jS~By|r
an4GSL
/** construct the page by everyPage T?:glp[4I
* @param everyPage dYSr4pb
* */ zXv3:uRp.
public Page(int everyPage){ ._8KsuJG
this.everyPage = everyPage; qtiz a~u
} &07]LF$]
V6t,BJjS
/** The whole constructor */ , #U.j
public Page(boolean hasPrePage, boolean hasNextPage, vJ\pR~?
YhOlxON
rA2g&
int everyPage, int totalPage, GDu~d<R H
int currentPage, int beginIndex){ .mDM[e@'
this.hasPrePage = hasPrePage; SG-'R1
J
this.hasNextPage = hasNextPage; }
@K FB
this.everyPage = everyPage; vk*=4}:
this.totalPage = totalPage; o&`<+4
i
this.currentPage = currentPage; IX*idcxR
this.beginIndex = beginIndex; 2P/K
K
} ]xX$<@HR
OR}c)|1
/** y]J89
* @return K?s+ 3
* Returns the beginIndex. [%9noB
*/ .pfP7weQ
publicint getBeginIndex(){ LbaK={tR
return beginIndex; L3G \
} 7<%<Ff@^)O
wD68tG$
/** kGd<5vCs
* @param beginIndex :4MB]v[K
* The beginIndex to set. +n<k)E@>J
*/ D8>enum
publicvoid setBeginIndex(int beginIndex){ S,<EEtXQ
this.beginIndex = beginIndex; wY~&Q}U
} ;]gP@ h/
qduWzxB
/** OCZ[D{i9@
* @return 3}@_hS"^8
* Returns the currentPage. 5B&;uY
*/ a@\D$#2r
publicint getCurrentPage(){ ~er\~kp
return currentPage; hoQs
@[
} VH=S?_RY>
u0#}9UKQ
/** SB5&A_tr
* @param currentPage NPd%M
* The currentPage to set. AJSx%?h:6
*/ /9zE^YcT
publicvoid setCurrentPage(int currentPage){ x.3J[=z=>
this.currentPage = currentPage; $ &P>r
} lY{FSGp
TQ{Han!
/** wMdal:n^
* @return {}QB|IH`
* Returns the everyPage. s/7 A7![
*/ mcn 2Wt
publicint getEveryPage(){ *P 3V
return everyPage; /F4pb]U!*
} E\IlF 6
&Ch#-CUE/
/** `;l?12|X
* @param everyPage '0\@Mc U]
* The everyPage to set. E@-KGsdhK
*/ -0_d/'d
publicvoid setEveryPage(int everyPage){ >[Ye
this.everyPage = everyPage; >IX/<
{);M
} Zum0J{l
h
m8SA6Y\
/** RPIyO
* @return ZxlAk+<]
* Returns the hasNextPage. cwm_nQKk
*/ ]D@0|
publicboolean getHasNextPage(){ 0b/ WpP
return hasNextPage; ,(.MmP`
} H-3Eo#b#
=)E,8L
/** N? 5x9duK
* @param hasNextPage v3GwD00
* The hasNextPage to set. S a4W`
*/ u(OW gbA3
publicvoid setHasNextPage(boolean hasNextPage){ ?7M.o
this.hasNextPage = hasNextPage; f>s?4
} yA)(*PFz
v^ /Q 8Q
/** P7
PB t
* @return :> & fV
* Returns the hasPrePage. h Xb%;GL
*/ kPQtQh]y%
publicboolean getHasPrePage(){ L:(1ZS
return hasPrePage; 'S2bp4G
} xl"HotsX-x
? tfT8$
/** "+zCS|
* @param hasPrePage 7},)]da>,'
* The hasPrePage to set. >Bs#Xb_B]
*/ S}f?.7
publicvoid setHasPrePage(boolean hasPrePage){ (mtoA#X1:h
this.hasPrePage = hasPrePage; mKT>,M
} (;%|-{7e-
`)qVF,Z}
/** vsL[*OeI
* @return Returns the totalPage. lc_E!"1
* Kf 2jD4z}
*/ i/b'4o=8
publicint getTotalPage(){ @Kf_z5tm:
return totalPage; .XkMk|t8
}
t8+_/BXv
Fb/XC:AD
/** 66#"
* @param totalPage 6{,HiY
* The totalPage to set. +[J/Zw0{
*/ |v[ Rp=?]
publicvoid setTotalPage(int totalPage){ m%"uPv\
this.totalPage = totalPage; kD) $2I?
} #q3l!3\mW
M7>(hVEAW'
} JbO ~n
)%x
UZEI:k,dv
m^_6:Q0F!8
^E6d`2w-
mR8W]'gl.L
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 >K# ,cxY
n,~;x@=5
个PageUtil,负责对Page对象进行构造: "xAWG$b
java代码: Z+pom7A"E
\<vNVz7.D
'cNKjL;
/*Created on 2005-4-14*/ 9_fePS|Z4
package org.flyware.util.page; $|$e%
FuX 8v
import org.apache.commons.logging.Log; I
_i6-<c.Q
import org.apache.commons.logging.LogFactory; =e><z9hY
o{*ay$vA]
/** +Z!;P
Z6
* @author Joa *?yJkJ"
* F8e<}v&7R
*/ JaWv]@9*
publicclass PageUtil { 19(Dj&x
FFEfp.T1M
privatestaticfinal Log logger = LogFactory.getLog 7&O`p(j
$jI>[%
(PageUtil.class); JK#vkCkyM
7%OKH<i\2<
/** G6K
<
* Use the origin page to create a new page U-0#0} _
* @param page yBLUNIr
* @param totalRecords ^*R(!P^
* @return 5&CDHc7Oj
*/ t ]c{c#N/
publicstatic Page createPage(Page page, int ]%RNA:(F'
.Qt4&B
totalRecords){ )[&_scSa
return createPage(page.getEveryPage(), ,J mbqOV?!
?p[O%_Xf
page.getCurrentPage(), totalRecords); R*1kR|*_)
} 5 waw`F
vMSW$Bx ;
/** Oajv^H,Em
* the basic page utils not including exception L6
6-LMkH
A1cb"N^
handler __p_8P
* @param everyPage *! :QdWLq
* @param currentPage H L<s@kEZ
* @param totalRecords .g\6g~n
* @return page <c,~aq#W'
*/ MM{_Ur7Q
publicstatic Page createPage(int everyPage, int Cd#E"dY6
IGj`_a
currentPage, int totalRecords){ V7=SV:+1or
everyPage = getEveryPage(everyPage); ,<ya@Fi{
currentPage = getCurrentPage(currentPage); m.%`4L^`T
int beginIndex = getBeginIndex(everyPage, FQeYx-7
}dSFAKI2dM
currentPage); }GHxG9!z
int totalPage = getTotalPage(everyPage, i6no;}j
_JGs}aQ
totalRecords); !ZtSbOC '
boolean hasNextPage = hasNextPage(currentPage, z>vtEV))
Q]JX`HgPaU
totalPage); e`UQz$4!
boolean hasPrePage = hasPrePage(currentPage); <"&'>?8j
3"
Vd==oK~
returnnew Page(hasPrePage, hasNextPage, aSaAC7sFk
everyPage, totalPage, rjojG59U>
currentPage, B0mLI%B
L&w.j0fq
beginIndex); @Gjny BJ
} W=-|`
):6-
privatestaticint getEveryPage(int everyPage){ 18!VO4u\I
return everyPage == 0 ? 10 : everyPage; Z>A{i?#m
} !G=>ve
H/cTJ9zz
privatestaticint getCurrentPage(int currentPage){ $Tl<V/
return currentPage == 0 ? 1 : currentPage; jMpa?Jp 1
} DvT+`X?R
*v #/Y9}
privatestaticint getBeginIndex(int everyPage, int F&@ |M(
T |"`8mG
currentPage){ o)]FtL:mm
return(currentPage - 1) * everyPage; 3o8\/-*<
} aw$Y`6,S
INNAYQ
privatestaticint getTotalPage(int everyPage, int Lx+`<<_dJ
G%hO\EO
totalRecords){ 70iH0j)
int totalPage = 0; jUY+3"?
<f%/px%1
if(totalRecords % everyPage == 0) !$kR ;Q"/
totalPage = totalRecords / everyPage; W);W.:F
else oX|?:MS:
totalPage = totalRecords / everyPage + 1 ; 9O;vUy)
5H.Db
return totalPage; H-&3}
} sc xLB;
ZgF/;8!~V-
privatestaticboolean hasPrePage(int currentPage){ TA)LPBG
return currentPage == 1 ? false : true; 1xC`ZhjcD
} ^
KAG|r9
e[4V%h
privatestaticboolean hasNextPage(int currentPage, iG-N
&>=#w"skb6
int totalPage){ "L_-}BK
return currentPage == totalPage || totalPage == Kq7C0)23
lPS*-p#IZ
0 ? false : true; 8A/>JD3^
} [$:@X V(
zPBfiK_hV
oc;VIK)g]c
} 1f;or_f#k?
E\!n49
5&(3A|P2
k`@w(HhS
d$Em\*C
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 =c]a
{|W?
^srs$
w]
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 vzy!3Hiw
`]&*`9IK{
做法如下: V/&o]b
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 %yhI;M^
NDW8~lkL
的信息,和一个结果集List: `oPLl0
java代码: `vX4!@Tw
j@SYXKL~
j!CU
/*Created on 2005-6-13*/ {g@A>
package com.adt.bo; oek #^:pF
-fQX4'3R
import java.util.List; <4$YO-:E
%09*l%,;
import org.flyware.util.page.Page; pj@Yqg/
Q>[Ce3
/** oB}K[3uB:t
* @author Joa wO!%
q[
*/ D{W
SKn
publicclass Result { )^(P@D.L
#!1IP~
private Page page; :@;6
.xo_}Vw
private List content; F`3^wHw^
<L2GUX36#
/** ~K%k
0kT
* The default constructor 'DeW<Sa~
*/ t#{x?cF
public Result(){ 15JsmA*Q
super(); qkiJH T
} gu!](yEgl
q>P[n z%
/** W0U`Kt&~a
* The constructor using fields f!EOYowW
* bu_/R~&3{
* @param page J+0/ :00(
* @param content _~:j3=1&