Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Zh~Lm
O3w_vm'
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 l"pz
)$eE
(h@yA8>n
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 >y06s{[
@#ho(_U8
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 EBL,E:_)
p`l[cVQ<
。
VjB`~
D'sboOY
分页支持类: Cp~3Jm3
IIt^e#s&
java代码: (.XDf3
tm36Lw
!K^Z5A_;
package com.javaeye.common.util; s*~jvL
w<F;&';@h
import java.util.List; LOb'<R\p
U37?P7i's
publicclass PaginationSupport { hC 4X Y
}$k`[ivBx(
publicfinalstaticint PAGESIZE = 30; eze(>0\f
fe9& V2Uu
privateint pageSize = PAGESIZE; luz%FY:
[|;Zxb:
privateList items; ':R3._tw\
k\thEEVP0*
privateint totalCount; 8$jT#\_
`@.s!L(V
privateint[] indexes = newint[0]; +@7x45;D
&F*QYz[
privateint startIndex = 0; 1PTu3o&3
~
GT\RAj[
public PaginationSupport(List items, int qxcBj
Y /ac}q
totalCount){ 7pI\`*7b
setPageSize(PAGESIZE); F+y`4>x
setTotalCount(totalCount); -x%`Wv@L
setItems(items); ;
# ?0#):-
setStartIndex(0); ESf7b `tS
} zQj%ds:
I&NpN~AU
public PaginationSupport(List items, int IweK!,:>dN
$Ex 9
totalCount, int startIndex){ zf;[nz
setPageSize(PAGESIZE); ONe!'a0
setTotalCount(totalCount); `0G.Y
setItems(items); [Fj#7VZK
setStartIndex(startIndex); pA,EUh|H
} uj1E*
98m
e}4^N1'd/
public PaginationSupport(List items, int .5CELtR
#M9D"
<pn}
totalCount, int pageSize, int startIndex){ #m$% S%s
setPageSize(pageSize); K,,@',
setTotalCount(totalCount); ,JBw$C
setItems(items); Am?Hkh2
setStartIndex(startIndex); #IrP"j^
} lnC Wu@{
|tJ%:`DGw
publicList getItems(){ #`L}.
return items; &eS70hq
} 6'*Uo:]
|>}0? '/]
publicvoid setItems(List items){ WKJL<
D ]:
this.items = items; }nY^T&?`
} f]A6Mx6
ST8/
;S#c
publicint getPageSize(){ `"b7y(M
return pageSize; ]j$p _s>
} "PScM9) \
F*].
publicvoid setPageSize(int pageSize){ 4Hpu EV8Q
this.pageSize = pageSize; utl=O
} GGL4<P7
wfTv<WG,.E
publicint getTotalCount(){ ?uX6X'-
return totalCount; U9[A(
} ec[[OIO
/\$|D&e
publicvoid setTotalCount(int totalCount){ KeHE\Fq^V
if(totalCount > 0){ KB *#t
this.totalCount = totalCount; xPJJ
!mY
int count = totalCount /
nK'8Mo
%+B-Z/1}
pageSize; r~fl=2>yQ
if(totalCount % pageSize > 0) 9}0Jc(B/x
count++; "/Q(UV<d
indexes = newint[count]; mS&\m#s<
for(int i = 0; i < count; i++){ UpseU8Wo
indexes = pageSize * FRQ("6(
jLS]^|
i; {ro!OuA
} 7`<? fO
}else{ X6*y/KGN
this.totalCount = 0; &r5%WRzpYT
} mL5f_Fb+
} wR+`("2{r
>upUY(3&
publicint[] getIndexes(){ RkP|_Bf8)
return indexes; $5CY<,f
} 9x^
/kAB
m:Cx~
publicvoid setIndexes(int[] indexes){
'L59\y8H
this.indexes = indexes; @%G"i:HZ&
} ]JPPL4wAT
uWtS83i
publicint getStartIndex(){ 2pNJWYW"
return startIndex; "_@+/Iy.
} _"bvT?|
$<%
nt
publicvoid setStartIndex(int startIndex){ -t'oW*kdL
if(totalCount <= 0) vk+%#w
this.startIndex = 0; ZjW| qb
elseif(startIndex >= totalCount) !enz05VW6.
this.startIndex = indexes EjE`S_i=
XTaWd0Y
[indexes.length - 1]; RW[<e
elseif(startIndex < 0) \0T*msYQ
this.startIndex = 0; Xt*%"7yTp
else{ f /i,Zw
this.startIndex = indexes f>[;|r@K
JP@m%Yj
[startIndex / pageSize]; X&oy.Roo
} -vfu0XI~
} f_2^PF>?
5nqdY*
publicint getNextIndex(){ PlRs-% d
int nextIndex = getStartIndex() + Sz@?%PnU|
j=% -b]
pageSize; %_O>Hy|p
if(nextIndex >= totalCount) }M@Jrq+7
return getStartIndex(); HwMsP$`q
else }4]x"DfIg
return nextIndex; 'wV26Dm
} V="f)'S$
*LdH/C.LIf
publicint getPreviousIndex(){ \#7%%>p=O'
int previousIndex = getStartIndex() - Riuv@i^6K
6;XpLivP7
pageSize; MJpTr5Vs
if(previousIndex < 0) ,,wx197XeD
return0; c;}n=7,>:L
else `|?$; )
return previousIndex; @7 HBXP
} \JC(pn
:Zo2@8@7
} 5MU@g*gj,C
*<QL[qyV
9sU,.T
&n kGdHX/a
抽象业务类 2_v+q
java代码: H1i4_T
%-po6Vf
3zF7V:XH
/**
C)}LV
* Created on 2005-7-12 g7f%(W2dd
*/ D|'Z c&
package com.javaeye.common.business; jt?%03iuk
"E!p1
import java.io.Serializable; "fd=(&
M*l
import java.util.List; ui0(#2'h%
@5GP;3T
import org.hibernate.Criteria; t1s@Ub5);I
import org.hibernate.HibernateException; %t.IxMY
import org.hibernate.Session; 6.=1k
import org.hibernate.criterion.DetachedCriteria; vGp@YABM
import org.hibernate.criterion.Projections; tzJtd
import =H?5fT^
_tJURk%
org.springframework.orm.hibernate3.HibernateCallback; qqred>K
import qZ1PC>
d0E5 ;3tQ
org.springframework.orm.hibernate3.support.HibernateDaoS ED&KJnquWJ
W\Y
4%y}
upport; q`zR 6
wb"t:(>&
import com.javaeye.common.util.PaginationSupport; 30`H
Xv@
n :kxG
public abstract class AbstractManager extends ~36XJ
uoc-qmm
HibernateDaoSupport { e}w!]
fltcdA
privateboolean cacheQueries = false; u)>*U'bM
I@v.Hqg+7
privateString queryCacheRegion; vB4qJ{f
5X|aa>/
publicvoid setCacheQueries(boolean |<icx8hbr
vtjG&0GSK
cacheQueries){ ,kuOaaV7K
this.cacheQueries = cacheQueries; (XWs4R.mkb
} (I
g
*iJ%2
:PkSX*E[q
publicvoid setQueryCacheRegion(String T5G+^XDA
m':m`,c!
queryCacheRegion){ -8e tH&
this.queryCacheRegion = hV>Ey^Ty
^E*C~;^S
queryCacheRegion; )A;<'{t #L
} f89<o#bm7h
36UWoo
publicvoid save(finalObject entity){ Yb/^Qk59
getHibernateTemplate().save(entity); ^>uGbhBp
} ^T>.04";x
?id^v 7d
publicvoid persist(finalObject entity){ ]TN}`]
getHibernateTemplate().save(entity); Q&{5.}L
} {'C74s
cn{l
%6K
publicvoid update(finalObject entity){ Gl9 a5b
getHibernateTemplate().update(entity); "$9ZkADO
} .<hv&t
l>q.BG
publicvoid delete(finalObject entity){ :g_ +{4
getHibernateTemplate().delete(entity); d^>s e'ya
} roQIP%h!
a)b@en;v
publicObject load(finalClass entity, <{j9|mt
A(5?
ci
finalSerializable id){ > xw+2<
return getHibernateTemplate().load vi|ASA{V
=wc[r?7
(entity, id); Hq8.O/Y"=
} G9Ezm*I;:
ST.W{:X
publicObject get(finalClass entity, qxh\umm+2
b2H6}s"=w
finalSerializable id){ ' 'N@ <|
return getHibernateTemplate().get j+seJg<_
)qe o`4+y
(entity, id); ;rbn/6
} @,.H)\a4
dno*Usx5d0
publicList findAll(finalClass entity){ ,B><la87
return getHibernateTemplate().find("from Ho|n\7$
uqH;1T;s
" + entity.getName()); un=)k;oh
} o,I642R~
L}+!<Ug
publicList findByNamedQuery(finalString j>zVC;Sj*
S/aPYrk>6
namedQuery){ l.!
~t1i
return getHibernateTemplate 9X~^w_cdk
2(|V1]6D?
().findByNamedQuery(namedQuery); I+SL0
} ;2}Gqh )Yr
2"T&Fp<
publicList findByNamedQuery(finalString query, FSk:J~Z;
X:5*LB\/v
finalObject parameter){ f5v|}gMAX
return getHibernateTemplate *']RYu?X
@ck2j3J/
().findByNamedQuery(query, parameter); 6dp~19T^
} j!/(9*\
Qzv_|U
publicList findByNamedQuery(finalString query, +Oa1FvoEA
e2Dj%=`EU
finalObject[] parameters){ 2UquN0
return getHibernateTemplate B HYEd}M
2o;M:+KQ)
().findByNamedQuery(query, parameters); +tF,E^
} .^,vK7
_{aVm&^kA
publicList find(finalString query){ M
5h U.3.L
return getHibernateTemplate().find >v{m^|QqB
Qt$Q/<8U
(query); ;I0/zeM%
} ?{'Q}%
CpXv?uU
publicList find(finalString query, finalObject mB\|<2
U?>cm`DBP
parameter){ O%I'
return getHibernateTemplate().find *`W82V
ZmDr$iU~
(query, parameter); f!yxS?j3
} !p2&$s"N.
n8Fi?/
public PaginationSupport findPageByCriteria (g\'Zw5bk
0IK']C
(final DetachedCriteria detachedCriteria){ +?p ;,Z%5
return findPageByCriteria ZO~N|s6B^
{*m?t 7
(detachedCriteria, PaginationSupport.PAGESIZE, 0); K+Qg=vGY
} %-dGK)?
mon(A|$|j
public PaginationSupport findPageByCriteria 8b/yT4f
(|-/S0AV
(final DetachedCriteria detachedCriteria, finalint q$K~BgFzpZ
|v+b?@
startIndex){ $f%_ 4 =
return findPageByCriteria =uH`EkY:
bCsQWsj^NW
(detachedCriteria, PaginationSupport.PAGESIZE, s`{O-
uf6{M_jXZ
startIndex); [T|~Kh%#
} .Qaqkb-Ty
7@`(DU`z
public PaginationSupport findPageByCriteria ^t*BWJxPC
%$08*bAtB7
(final DetachedCriteria detachedCriteria, finalint b4Z#]o
BB-`=X~:m
pageSize, Qk6FK]buV
finalint startIndex){ x>K em$z
return(PaginationSupport) ~I'hiV^-
D_{J:Hb
getHibernateTemplate().execute(new HibernateCallback(){ `CV a`%
publicObject doInHibernate ,[x'S>N
{974m` 5
(Session session)throws HibernateException { ~ rRIWfhb
Criteria criteria = q+z,{K
#Rs7Ieu+
detachedCriteria.getExecutableCriteria(session); OG.`\G|
int totalCount = +um;
eL7
-Fb/GZt|
((Integer) criteria.setProjection(Projections.rowCount y ^YrGz.
S7V;sR"V2
()).uniqueResult()).intValue(); tY7u\Y;^
criteria.setProjection 49CMRO,T
sx9N8T3n
(null); jN[Z mJz'
List items = nQ mkDPjU
*I~F7Z]|
criteria.setFirstResult(startIndex).setMaxResults e='3gzz
a*=e 3nS
(pageSize).list(); ,}NG@JID
PaginationSupport ps = k;%}%"EVZ
sbRg=k&Ns
new PaginationSupport(items, totalCount, pageSize, =zsXa=<
Ws=J)2q
startIndex); Z/64E^
return ps; Yz,*Q<t
} *yB!^O
}, true); ,[A} 86
} JO
_a+Yl
5~qr+la
public List findAllByCriteria(final 3vy5JTCz~
j"f]pzg&
DetachedCriteria detachedCriteria){ )%Y$FLB
return(List) getHibernateTemplate XOxm<3gXn
UZ
y
().execute(new HibernateCallback(){ NoMEe<
publicObject doInHibernate /q]WV^H
$jm'uDvm
(Session session)throws HibernateException { A/'G.H
Criteria criteria = Dhq7qz
0-=QQOART\
detachedCriteria.getExecutableCriteria(session); 2WKA] l;
return criteria.list(); Tux~4W
} R^D~ic
N
}, true); !OiP<8 ,H
} FrB19
Rq;R{a
public int getCountByCriteria(final p.zU9rID
&fW;;>
DetachedCriteria detachedCriteria){ -QRKDp
Integer count = (Integer) &We'omq
J?%Z7&/M>
getHibernateTemplate().execute(new HibernateCallback(){ w=OT^d 9n
publicObject doInHibernate wTOB'
\"n&|_SZ\
(Session session)throws HibernateException { ^E5Xpza
Criteria criteria = k%hif8y
/H\ZCIu/7
detachedCriteria.getExecutableCriteria(session); o'W &gkb9
return @#sQ7eMoy
keX0br7u_
criteria.setProjection(Projections.rowCount ~,ac{%8x
%e3lb<sv6
()).uniqueResult(); +^`c"qJo
} 3?2;z+cz*u
}, true); Q}G
return count.intValue(); b+hZ<U/
} :V`q;g
} w^dB1Y7c(W
x*(pr5k
P4s:wuJ^
64[j:t=N
7pkc*@t
n`CmbM@@
用户在web层构造查询条件detachedCriteria,和可选的 D`Fl*Wc4H
sjztT<{Q^-
startIndex,调用业务bean的相应findByCriteria方法,返回一个 t@b';Cuv
#*?a"
PaginationSupport的实例ps。
~B/|#o2
)5bhyzSZI
ps.getItems()得到已分页好的结果集 R\6#J0&Y-
ps.getIndexes()得到分页索引的数组 .0Cpqn,[
ps.getTotalCount()得到总结果数 <TDgv%eg0
ps.getStartIndex()当前分页索引 ?eeE [F
ps.getNextIndex()下一页索引 -Ndd6O[ a5
ps.getPreviousIndex()上一页索引 {R&F_51)V
e-x{7
,OG sx
!G,Ru~j5:
nAg|m,gA
ZcIwyh(`
W)o-aX!P
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 )0!hw|0|
_bFX(~37z?
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 S__+S7]Nr
^-rb&kW@:
一下代码重构了。 <.~j:GbsE
3xbA]u;gp
我把原本我的做法也提供出来供大家讨论吧: E+csK*A7
. [*6W.X
首先,为了实现分页查询,我封装了一个Page类: i
yMIP~N,$
java代码: ."cC^og
ig3uY#
KK/~W
/*Created on 2005-4-14*/ _epi[zf@
package org.flyware.util.page; -SZ^;t
q^k6.5*"
/** ;
*r5 d+]
* @author Joa !=Cd1
$<
* J$@3,=L6V
*/ -&%#R_RV
publicclass Page { {'EQ%H$q
a'W-& j
/** imply if the page has previous page */ -g_PJ.Hk
privateboolean hasPrePage; C {gYrz)
Vtr0=-m&
/** imply if the page has next page */ LBbk]I
privateboolean hasNextPage; x_AG=5OJX,
ps^Z)x`GV
/** the number of every page */ sYgpK92
privateint everyPage; D<C ZhYJ
LQ373
j-
/** the total page number */ ~O&3OL:L
privateint totalPage; E*i <P
^DM^HSm
/** the number of current page */ #|xK>;
privateint currentPage; nu|;(ly
%Gh!h4Pv
/** the begin index of the records by the current utfD$8UI
_.yBX\tf[
query */ =X]$J@j
privateint beginIndex; |?i-y3N
pd/{yX M
q>?uB4>^
/** The default constructor */ 7P|GKN~
public Page(){ zHeqV
Z<;am
} BbnY9"
~;9B\fE`
/** construct the page by everyPage H<Ed"-n$I<
* @param everyPage k[&+Iy
* */ ]|@RWzA
public Page(int everyPage){ ;gP@d`s
this.everyPage = everyPage; XN'x`%!*3#
} 9YwK1[G6/
-[^aWNqyJ
/** The whole constructor */ o!dTB,Molr
public Page(boolean hasPrePage, boolean hasNextPage, 3mIVNT@S9
T&j_7Q\;vI
9Qst5n\Z
int everyPage, int totalPage, Kp!sn,:
int currentPage, int beginIndex){ UPfH~H[1)
this.hasPrePage = hasPrePage; +W
x/zo
this.hasNextPage = hasNextPage; g#2Q1t,~U
this.everyPage = everyPage; 049E#[<Q"
this.totalPage = totalPage; \,+act"v
this.currentPage = currentPage; Dh*Uv,
this.beginIndex = beginIndex; tl !o;`W
} y_;LTCj?
_
)b:F=4j
/** 4en[!*
* @return ]hJ#%1
* Returns the beginIndex. NnRR"'
*/ )`, Bt
publicint getBeginIndex(){ ou0(C`
return beginIndex; +vY8HQ|v
} ]X ,f
2WE_NEpJI
/** \=P+]9
* @param beginIndex ]k-<[Z;I,
* The beginIndex to set. 1Y'9|+y+
*/ (&npr96f
publicvoid setBeginIndex(int beginIndex){ ""|vhgP
this.beginIndex = beginIndex; &!x!j,nT
} *fQ$s
IV]s!
/** E Z15
* @return ]2`PS<a2
* Returns the currentPage. 87.b7 b.
*/ {9S=:
publicint getCurrentPage(){ Lnc
_)RF
return currentPage; F@~zVu3'
} 6p|*H?|It
T:p,!?kc7
/** ,HO~NqmB4
* @param currentPage =87.6Ai
* The currentPage to set. -rb]<FrL^
*/ sN]O]qYXJ
publicvoid setCurrentPage(int currentPage){ >AX&PMb`
this.currentPage = currentPage; _BHR ?I[w
} bKRz=$P?
65X$k]x
/** jODx&dVr
* @return tXDO@YH3S
* Returns the everyPage. E2+x?Sc+
*/ ^@5#jS2
publicint getEveryPage(){ 8FYcUvxfT
return everyPage; 8VxjC1v+
} r\-Mj\$-
KjFNb;mM
/** 2mg4*Ys
* @param everyPage U>PF#@ C/
* The everyPage to set. vs]#?3+
*/ _1TSt%L
publicvoid setEveryPage(int everyPage){ kqxX!
this.everyPage = everyPage; 4Y2l]86
} 4Qh\3UL~
-b'93_ZTu:
/** >U?HXu/TJr
* @return P4@<`Eb
* Returns the hasNextPage. Z:7X=t=
*/ YaI8hj@}
publicboolean getHasNextPage(){ Ry2rQM`
return hasNextPage; #!!Ea'3Iq
} jLRUWg
|O =Fz3)
/** v,qK=]ty
* @param hasNextPage DY<Br;
* The hasNextPage to set. Huzw>
*/ Q%:#xG5AmE
publicvoid setHasNextPage(boolean hasNextPage){ T"ors]eI
this.hasNextPage = hasNextPage; Twi:BI`.
} lW}"6@0,
2O}UVp>
/** $C@v
* @return 1xAZ0X#
* Returns the hasPrePage. *tkbC2D
*/ 'oNY4.[
publicboolean getHasPrePage(){ rBG8.E36J
return hasPrePage; "uK`!{
} N]qX^RSb
$42%H#
/** =73""ry
* @param hasPrePage nu|paA
* The hasPrePage to set. 57W4E{A
*/ mqPV
Eo
publicvoid setHasPrePage(boolean hasPrePage){ e}e|??'(\
this.hasPrePage = hasPrePage; E07g^y"}i
} g_{hB5N](7
Ewg5s?2|
/** A#t#c*
* @return Returns the totalPage. e+J|se4L5
* cu&tdg^q
*/
--Dd'
publicint getTotalPage(){ jn[%@zD }
return totalPage; O{WJi;l
} tu(k"'aJ
4'L%Wz[6
/** Z[+H$ =$%
* @param totalPage eyPh^c]?`8
* The totalPage to set. gHCk;dmq81
*/ oB$7m4xO\
publicvoid setTotalPage(int totalPage){ -?)` OHc^
this.totalPage = totalPage; r2,AZ+4FP
} Sg$14B
!B36+W+
} ]u~6fknm
6uWzv~!*D
-8F~Tffx
}*0OLUFFJ
Sw!/IPO
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 hN%
h.;s
D#lx&J.s
个PageUtil,负责对Page对象进行构造: Nc4e,>$]&
java代码: ?FC6NEu}8
=l%"Om*A
5|zISK%zHS
/*Created on 2005-4-14*/ u[25U;xo
package org.flyware.util.page; {-X8MisI
P=ARttT`(
import org.apache.commons.logging.Log; %DJxUuh
import org.apache.commons.logging.LogFactory; \ dpsyc
40VdT|n$$
/** tg%U2+.q
* @author Joa Y>eypfK"
* B5%N@g$`j
*/ )2c[]d/a4
publicclass PageUtil { Mk-C'
"+^d.13+]
privatestaticfinal Log logger = LogFactory.getLog JvFU7`4@
adEcIvN$
(PageUtil.class); 0Me*X
3\Y}{(O |
/**
%trtP
* Use the origin page to create a new page TRQX#))B
* @param page lZ^UAFF
* @param totalRecords Rb_HD
* @return \qPgQsy4
*/ ?kvc`7>
publicstatic Page createPage(Page page, int ?cQ
lW F=bz0
totalRecords){ gHS;RF9
return createPage(page.getEveryPage(), I<Vh
Eo,
(^h47kY
page.getCurrentPage(), totalRecords); B@wQ[
} ;D5B$ @W>
J('p'SlI
/** r{m"E^K,
* the basic page utils not including exception 8e_ITqV%
=A,32&;@N
handler V0p@wG3
* @param everyPage Q^qG=
* @param currentPage a^+b(&;k
* @param totalRecords #N-NI+qX
* @return page VK9I#
*/ E|2klA^+*
publicstatic Page createPage(int everyPage, int l\l\T<wa,
*GsrG*OM*D
currentPage, int totalRecords){ XK:KWqW
everyPage = getEveryPage(everyPage); @nN+F,phx
currentPage = getCurrentPage(currentPage); h 9V9.'
int beginIndex = getBeginIndex(everyPage, a.F6!?
/wIev1Z!Y
currentPage); )4[{+OJa
int totalPage = getTotalPage(everyPage, [MM11K
h~$Q\WCm#
totalRecords); @vf{_g<
boolean hasNextPage = hasNextPage(currentPage, lyzMKla"
GiBq1U-Q
totalPage); Z@j$i\,`
boolean hasPrePage = hasPrePage(currentPage); E&k{ubcT
6ju+#]T
returnnew Page(hasPrePage, hasNextPage, r\+AeCyb"p
everyPage, totalPage, "HR
&Rf k
currentPage, 8;3T65KY
7M:0%n$
beginIndex); \$J!B&i
} VHsNz WI
%^RlE@l9
privatestaticint getEveryPage(int everyPage){ r ]1|I6:&)
return everyPage == 0 ? 10 : everyPage; g<~[k?~J
} Tr}@fa
Fs:l"5~>1
privatestaticint getCurrentPage(int currentPage){ Jrlc%,pZ
return currentPage == 0 ? 1 : currentPage; BY:
cSqAW
} whP>'9t.w
(E)/' sEb
privatestaticint getBeginIndex(int everyPage, int Xmy(pV!PF
]4@z.1Mr
currentPage){ Dbr(Wg
return(currentPage - 1) * everyPage; st36xS
} /IVw}:G
fw^mjD
privatestaticint getTotalPage(int everyPage, int FK!9to>
#m9V)1"wB
totalRecords){ #'z\[^vp
int totalPage = 0; WPyd ^Y<
ee&QZVL>
if(totalRecords % everyPage == 0) KM(U-<<R
totalPage = totalRecords / everyPage; 5}e-~-
else lqPRUkin
totalPage = totalRecords / everyPage + 1 ; 9&}qie,
2q# t/oN3T
return totalPage; Q>}I@eyJ
} ~I/7{B|yX
Bd m<<<
privatestaticboolean hasPrePage(int currentPage){ />\.zuAr&
return currentPage == 1 ? false : true; J.":oD
} 6"
3!9JC
^~MHxF5d
privatestaticboolean hasNextPage(int currentPage, (FMG W
(
/S9Mu
)1Y
int totalPage){ > ^3xBI:Q
return currentPage == totalPage || totalPage == =fBJQK2sk
@6.1EK0
0 ? false : true; UR-e'Z&]
} u
` 9Eh;
D4[5}NYU
~C=`yj
} 8%7H
F:
n<yV]i$
TO[5h Y\
wSIt"g,%
4$.UVW\
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。 ) !ZA.sx
z[qM2
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 hFa\x5I5
@]*z!>1
做法如下: /]]\jj#^
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 1;L!g*!E
#=t:xEz
的信息,和一个结果集List: iG!MIt*
java代码: 7+T\
r~nrP=-%
$.kIB+K
/*Created on 2005-6-13*/ T:cSv
@G
package com.adt.bo; >E"FoZM=
|#5JI#,vX
import java.util.List; ]2zx}D4f
v}[KVwse
import org.flyware.util.page.Page; xNxIqq<k
%XG X(
/** @b!fs
* @author Joa ?\hXJih
*/ B5B'H3@
publicclass Result { &;9<a^td
/q='~t
private Page page; 6mdJ
=b#
Mw'd<{
private List content; "@`mPe/
,\}V.:THF
/** ;5y4v
* The default constructor "cJ5Fd:*
*/ Vzbl*Zmx
public Result(){ `p1`Sxz?
super(); HdWghxz?)
} =#%e'\)a
aKCCFHq t!
/** WlZ[9,:p1
* The constructor using fields ^r;}6
* o}WbW }&
* @param page 3L>V-RPi M
* @param content aeUm,'Y$
*/ N@)4H2_u \
public Result(Page page, List content){ Hg(\EEe
this.page = page; ]iLfe&f
this.content = content; Iobo5B
} @gX@mT"
wK#UFOp
/** 8n~@Rj5
* @return Returns the content. (2qo9j"j/Y
*/ HTx7._b
publicList getContent(){ o]Vx6
return content; W97Ka}Y
} >+oQxml6nI
9@D,ZSi
/** RFA5vCG
* @return Returns the page. k_}ICKzw1
*/ NJl|/(]v
public Page getPage(){ :^iR&`2~
return page; sOJ"~p
} -QS_bQG%
,rX!V=Z5
/** <Bu*: O
* @param content ol`]6"Sc
* The content to set. ^Gs!" Y
*/ kf5921(P
public void setContent(List content){ ;ejC:3yO
this.content = content; ZTS*E,U%
} Ti' GSL
:l9C7o
/** 4dfe5\
* @param page QG9 2^
* The page to set. @~gz-l^$
*/ C5sV-UMR
publicvoid setPage(Page page){ )SDGj;j+
this.page = page; tO~H/0
} M6?Q w=
} @RaMO#
wp*;F#: G
VCc4nn#
_'j>xK
#lVVSrF,-
2. 编写业务逻辑接口,并实现它(UserManager, ,hOJe=u46
7?hCt
UserManagerImpl) ?on3z
java代码: b$gDFNa
S%%>&^5
CB|z{(&N
/*Created on 2005-7-15*/ FP9ZOo og
package com.adt.service; ]i$CE|~
J::SFu=
import net.sf.hibernate.HibernateException; q(uu;l[
QT-rb~
import org.flyware.util.page.Page; N+}yw4lb
3rR(>}:[V
import com.adt.bo.Result; 2,_BO6
!d
n!tC z<v
/** 9U;) [R Mb
* @author Joa )(!vd!p5
*/ hR{Fn L
publicinterface UserManager { }:hdAZ+z
u-k*[!JU
public Result listUser(Page page)throws R6AZIN:
mfx'Yw*{
HibernateException; O>k. sO
<
DTr0u}m
} i,bFe&7J
'x6Mqv1W
"ht2X
w
7x1jpQ-
zxsnrn;|
java代码: \<z{@
Bq$bxuhV
cc^V~-ph
/*Created on 2005-7-15*/ OK2wxf
package com.adt.service.impl; e| kYu[^
v1)jZ.:
import java.util.List; :W'1Q2
^rxXAc[
import net.sf.hibernate.HibernateException; LL,~&5{
@7BH`b$)!
import org.flyware.util.page.Page; bTn-Pg){
import org.flyware.util.page.PageUtil; v4S|&m
'rCwPsI&4
import com.adt.bo.Result; dB1bf2'b#
import com.adt.dao.UserDAO; K):)bL(B
import com.adt.exception.ObjectNotFoundException; 7tt&/k?Q
import com.adt.service.UserManager; #D}NT*w/
H ($=k-+5
/** ~i(*.Z)
\
* @author Joa isDr|g$S
*/ sjzZl*GSy
publicclass UserManagerImpl implements UserManager { kU#$
8taaBM`:
private UserDAO userDAO; OY@/18D<>
f:HRrKf9
/** zfxxPL'
* @param userDAO The userDAO to set. KD#ip3
*/ \GPWC}V\s
publicvoid setUserDAO(UserDAO userDAO){ m$$U%=r>@
this.userDAO = userDAO; naAZR*(A
} 2j_L
jY'7
{cG&l:-r
/* (non-Javadoc) 5qFqH
* @see com.adt.service.UserManager#listUser >+G=|2
Z?^AX&F
(org.flyware.util.page.Page) b2:CFtH5
*/ 7,
O_'T &
public Result listUser(Page page)throws Z/2#h<zj
6t@3
a?
HibernateException, ObjectNotFoundException { Xf Y]qQP
int totalRecords = userDAO.getUserCount(); E7 7Au;TL
if(totalRecords == 0) G2e m>W_n
throw new ObjectNotFoundException "\e9Y<
XLOk + Fn
("userNotExist"); 3:76x
page = PageUtil.createPage(page, totalRecords); ThFI=K
List users = userDAO.getUserByPage(page); R2r0'Yx
returnnew Result(page, users); q`qbaX\J3
} =NlAGzv!w
RJSNniYr7
} /dtFB5Z"w
a}=)b#T`
B?Pu0
_|s
EpPKo
M(5l Su
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 =o9
%)
g.z/%LpK
询,接下来编写UserDAO的代码: i5:fn@&
3. UserDAO 和 UserDAOImpl: k2O==IG]6
java代码:
1vQ*Br
ZfIQ Fh>
g9
g
&]
/*Created on 2005-7-15*/ j1>1vD-`T
package com.adt.dao; T}U`?s`)
zi<C5E`
import java.util.List; XFH7jHnL+U
,Y}HP3
import org.flyware.util.page.Page; .,feRK>3
Vbz$dpT
import net.sf.hibernate.HibernateException; *n}{)Ef
>a]{q^0
/** X$J
* @author Joa d+z8^$z"
*/ OCF=)#}qd
publicinterface UserDAO extends BaseDAO { a^|mF#
z
0urQA_JC
publicList getUserByName(String name)throws fF<~2MiKw
i]YH"t8GY
HibernateException; ^|OxlfS
j].XVn,
publicint getUserCount()throws HibernateException; VYik#n>|Gp
PYW~x@]k%,
publicList getUserByPage(Page page)throws {QJJw}!#
td{$c6
HibernateException; [&"`2n
SmC91XO
} kOeW,:&65
EtKy?]i
rr9N(AoxW
bm`x
U H
`=
java代码: }zj_Pp
?3"lI,!0
rVkRU5
/*Created on 2005-7-15*/ sF f@>
package com.adt.dao.impl; lg~Gkd6
-PoW56
import java.util.List; _-^a8F>/19
qgDd^0
import org.flyware.util.page.Page; Jro)
8FU8E2zo
import net.sf.hibernate.HibernateException; }cEcoi<v!
import net.sf.hibernate.Query; 9K~X}]u
PA&Ev0`+
import com.adt.dao.UserDAO; 1H{JT
op
Jf9a<[CcV
/** ={B%qq
* @author Joa 9J$N5
*/ lE'2\kxI?
public class UserDAOImpl extends BaseDAOHibernateImpl k_/*>lIZY
'de&9\
implements UserDAO { K>N\U@@8i
0EKi?vP@y7
/* (non-Javadoc) k`_sKr]9
* @see com.adt.dao.UserDAO#getUserByName 2.qEy6
-QN1=G4
(java.lang.String) kq8.SvIb
*/ gwm!Pw j
publicList getUserByName(String name)throws X0.k Q
F}wy7s2i
HibernateException { Z8%?ej`8
String querySentence = "FROM user in class pE,2pT2>
E{k$4
com.adt.po.User WHERE user.name=:name"; 9$$dSN\&
Query query = getSession().createQuery ]{s0/(EA
TD!--l*gL
(querySentence); SYkwM6
query.setParameter("name", name); s'b 4Me
return query.list(); Y 3h`uLQ
} _(l?gj
L7;8:^ v
/* (non-Javadoc) m}hEi
* @see com.adt.dao.UserDAO#getUserCount() ^CO{86V
*/ c#(Hh{0
publicint getUserCount()throws HibernateException { J2adG+=
int count = 0; \|&KD
String querySentence = "SELECT count(*) FROM N?`V;`[
-M5vh~Tp
user in class com.adt.po.User"; dhv?36uE
Query query = getSession().createQuery HCfme<'
%D1 |0v8}
(querySentence); Swa0TiT(
count = ((Integer)query.iterate().next Ql"kJ_F!br
)0+6^[Tqq
()).intValue(); 0Q?)?8_
return count; FkE)~g
} p>_Qns7W
& 6'Rc#\P
/* (non-Javadoc) }C4wED.
* @see com.adt.dao.UserDAO#getUserByPage ~I6N6T Z
ZP{<f~;
(org.flyware.util.page.Page) +`,;tz=?
*/ `>)[UG!:|
publicList getUserByPage(Page page)throws 2Pow-o*r
)G#mC0?PV
HibernateException { /|q.q
String querySentence = "FROM user in class ysapvQN_6
`6$|d,m5
com.adt.po.User"; )Zf1%h~0r
Query query = getSession().createQuery 0vX4v)-^u
xt_:R~/[
(querySentence); aD]!
eP/)
query.setFirstResult(page.getBeginIndex()) wg%g(FO
.setMaxResults(page.getEveryPage()); &hEn3u
return query.list(); &S,_Z/BS;
} 0vETg'r
vjjVZ
} FFa =/XB"
m8@&-,T
!iO2yp
$Nd,6w*`
?iZ2sRWR6
至此,一个完整的分页程序完成。前台的只需要调用 mG"xo^1_H
%UAF~2]g
userManager.listUser(page)即可得到一个Page对象和结果集对象 m _cRK}>
28k=@k^q
的综合体,而传入的参数page对象则可以由前台传入,如果用 CP~mKmMV
&&nbdu
webwork,甚至可以直接在配置文件中指定。 Ve2{;`t
jp_|pC'
下面给出一个webwork调用示例: =Ox}WrU~
java代码: sUF9_W5z
>H^#!eaqw
e2f+Fv
9
/*Created on 2005-6-17*/ {`QA.he.
package com.adt.action.user; W1 k]P.
)adV`V%=>
import java.util.List; `^52IkM)
AtewC
Yo
import org.apache.commons.logging.Log; D|)a7_
import org.apache.commons.logging.LogFactory; NMe{1RM
import org.flyware.util.page.Page; %xN${4)6
v\GVy[Qyv
import com.adt.bo.Result; H4s~=iB
import com.adt.service.UserService; gVrQAcJj
import com.opensymphony.xwork.Action; J$Z=`=]t+
2]1u0-M5L
/** zcKQD )]
* @author Joa Q_U.J0
*/ Dn6U8s&
publicclass ListUser implementsAction{ hTa(^
o:D,,MkSw
privatestaticfinal Log logger = LogFactory.getLog %Yj%0
J91[w?,
(ListUser.class); ,Cb3R|L8
12a`,~
private UserService userService; yL*]_
s'h;a5Q1'Q
private Page page; =hkYQq`Q
'`3#FCg
privateList users; @@)2 12
C,An\lsT
/* 5?lc%,-&
* (non-Javadoc) )P$|9<_q7x
* < cvh1~>(
* @see com.opensymphony.xwork.Action#execute() ?3=G'Ip5n
*/ EHk\Q\
publicString execute()throwsException{ sU"%,Q5
Result result = userService.listUser(page); X*QS/\
page = result.getPage(); ovdJ[bO
users = result.getContent(); hbJ>GSoZ,
return SUCCESS; z5kAf~A
} h q)1YO
>#w;67he2
/** ZEAUoC1E1
* @return Returns the page. JVYH b 60Z
*/ ;f=m+QXU
public Page getPage(){ <eoie6@3
return page; |^6{3a
} EU$.{C_O(
s
V_(9@b
/** E5w;75,
* @return Returns the users. %GHGd'KO&
*/ 2;8m0+tl
publicList getUsers(){ !y= R)k
return users; -QrC>3xZR
} V)j[`,M:
-L1785pB85
/** T3X'73M
* @param page +(W1x
C0
* The page to set. wDJ`#"5p{
*/ ']r8q %
publicvoid setPage(Page page){ pk :P;\
this.page = page; WMSJU/-P
} JZ:@iI5>+
Ao\xse{E
/** CkT(\6B-
* @param users JE=t
e(a
* The users to set. X\AH^I6S
*/ (N7uaZ?Z
publicvoid setUsers(List users){ V!W.P
this.users = users; Zh=arlk
} 2
T!Tiu
c0oHE8@
/** TSlB.pw%v
* @param userService #Wk=y?sn
* The userService to set. e-nA>v
*/ @^P^-B
publicvoid setUserService(UserService userService){ CKYg!\g(:
this.userService = userService; +0'F@l
} fw%`[(hK
} CSO'``16
p+VU:%.t
.ZpOYhk
i%hCV o
WsI`!ez;D
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, !@xO]Jwv
Vy\Vpp
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 -V2\s
N3%X>*'
么只需要: 2 !s&|lI
java代码: %rzPh<>e
"Ms;sdjg}&
W>K^55'
<?xml version="1.0"?> XKoY!Y\
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork rUiYR]mV
Lc*>sOm9
1.0//EN" "http://www.opensymphony.com/xwork/xwork- <ql,@*Y
kT%wt1T4
1.0.dtd"> v}G^+-?
g'8Y5x[
<xwork> w;z7vN~/O
at: li
<package name="user" extends="webwork- 3S^0%"fY
#z\ub5um
interceptors"> D|]BFu)F
H_+n_r*
<!-- The default interceptor stack name dftBD
s]arNaaA
--> RB 5SK#z
<default-interceptor-ref v pI9TG
Dw-d`8*
name="myDefaultWebStack"/> vgz`+Zj*S
"y1Iu
<action name="listUser" YR%iZ"`*+O
+r:g }iR
class="com.adt.action.user.ListUser"> $v^hzC
<param -@orIwA&
%TB(E<p`
name="page.everyPage">10</param> I6>J.6luF9
<result RK3 yq$
__=H"UhWv
name="success">/user/user_list.jsp</result> 79\wjR!T
</action> _P>YG<*"kQ
#[93$)Gd!
</package> IGlR,tw_/
z _!ut
</xwork> B`*,L\LZ*
| f#wbw
8nz({Mb9Z
U{U"%XdO
} M#e\neii
,g*!NK_:5t
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 S@qp_!
&V"oJ}M/a
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 !X>u.}?g
V Z(/g"9
注:上面的<param>的配置,还需要webwork和Spring整合的配合。
bGRt
qQ@| Cj
9U8M|W|d
S,Y|;p<+^
c}(WniR-"
我写的一个用于分页的类,用了泛型了,hoho *@U{[J
K,b
M9>}
java代码: 3DU1c?M:
Ndmt$(b
Fn4v/)*H
package com.intokr.util; 2*#|t: (c
f5jl$H.
import java.util.List; =L6#=7hcl
Gp"GTPT{
/** ?J}Q&p.
* 用于分页的类<br> $( hT{C,K
* 可以用于传递查询的结果也可以用于传送查询的参数<br> $] 6u#5
* @MW@mP)#
* @version 0.01 +-9vrEB
* @author cheng g=*jKSZ
*/ 5&]5*;Bv J
public class Paginator<E> { mH*ldf;J;=
privateint count = 0; // 总记录数 %,>z`D,Hg
privateint p = 1; // 页编号 D6 B-#u!M
privateint num = 20; // 每页的记录数 @^{Hq6_`
privateList<E> results = null; // 结果 2
$>DX\h
Z\&f"z?L
/** sD|l}f
* 结果总数 4S_ -9&z
*/ Xn7G2Yp
publicint getCount(){ C2
N+X (
return count; c9(3z0!F?
} ]
V
D
+v~xgUs
publicvoid setCount(int count){ i"{O~[
this.count = count; 6j#JhcS+
} d2\!tJm
Ni$'#
W?t
/** Epzg|L1)
* 本结果所在的页码,从1开始 f?3-C8hU
* N Ob`)qb
* @return Returns the pageNo. "oP^2|${
*/ _O9V"DM
publicint getP(){ rb*|0ST
return p; te_2"Z
} `lf_wB+I
-,bFGTvYQ
/** tC[ZWL
* if(p<=0) p=1 X.]I4O&_
* H]TdW;ZbZ
* @param p /l$x}
*/ BK$y>=
`
publicvoid setP(int p){ 'Zx5+rM${}
if(p <= 0) ofvR0yV
p = 1; UwN Vvo
this.p = p; `L1,JE`
q
} P_bB{~$4
z8kO)'
/** 3%WB?kc
* 每页记录数量 ]5%0EE64
*/ 3JazQU
publicint getNum(){ #3uv^m LGa
return num; (vXr2Z<l
} Sp`l>BL
FO{=^I5YA
/** 1 ZdB6U0
* if(num<1) num=1 %6K7uvTq
*/ t)SZ2G1r
publicvoid setNum(int num){ |IxHtg3>6{
if(num < 1) 1gI7$y+?
num = 1; -I< >Ab
this.num = num; Vk5Z[w a
} C@M-_Ud>Q
8%rD/b6`
/** hpdI5
* 获得总页数 K_Y-N!h
*/ E)b$;'
publicint getPageNum(){ R2bq hSlF
return(count - 1) / num + 1; bM W|:rn
} F.s$Y+c!6
2.qPMqH
/** H MOIUd
* 获得本页的开始编号,为 (p-1)*num+1 dSI"yz
*/ zzmC[,u}
publicint getStart(){ _,3ljf?WQM
return(p - 1) * num + 1; h>Kx
} 1"
'3/MFQ8
HU0.)tD
/** #G9
W65 f
* @return Returns the results. sz7*x{E
*/ d0J/"<
publicList<E> getResults(){ !j~wAdHk
return results; L!f~Am:#
} vHaM yA-
Bfb~<rs[
public void setResults(List<E> results){ jkeerU6
this.results = results; X$};K\I
} pn" !wqg
j
cd<'\;
public String toString(){ j?T'N:Qd
StringBuilder buff = new StringBuilder iUkUo x
5(;Y&?k
(); Ou[K7-m%&
buff.append("{"); p.8 bX
buff.append("count:").append(count); 79DNNj~
buff.append(",p:").append(p); ixTjXl2g
buff.append(",nump:").append(num); jCd]ENl+_
buff.append(",results:").append DYX{v`>f^
.ARYCTyG
(results); F`=p/IAJK
buff.append("}"); 0d2P
return buff.toString(); (3e.q'
} 4:MvC^X~z
Jb,54uN
} .G/Rh92
vG |!d+
z']6C9m}