Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 \::<]
Af pB=3
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 0.4c|-n
&Y;z[+(P
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 r in#lu&N
&]iX>m.
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 o
/AEp)8
qiV#T+\
。 7Q7z6p/\v
ZY-W~p1:G
分页支持类: ,~w)~fMb8
x3xBl_t
java代码: s
de|t
O:"gJ4D
;]34l."85
package com.javaeye.common.util; &ok2Xw
a*o#,T5A
import java.util.List; }@_F( B
Ouc=4'$-
publicclass PaginationSupport { K]yCt~A$
J~9l+?
publicfinalstaticint PAGESIZE = 30; yf(VwU,
x
m7Nm!Z7
privateint pageSize = PAGESIZE; W]{mEB
J'`,];su
privateList items; j4$XAq~W
*aT3L#0(
privateint totalCount; ";AM3
PXz,[<ET?#
privateint[] indexes = newint[0]; hJ 4]GA'
6":=p:PT.
privateint startIndex = 0; r 'wam]1Z
]fg?)z-Z
public PaginationSupport(List items, int [H$rdh[+
*[t@j*al
totalCount){ # kl?ww U
setPageSize(PAGESIZE); 'kPc`)\
setTotalCount(totalCount); {]]qd!,
setItems(items); \^orl9
setStartIndex(0); DfgqB3U[
} ^5x\cR
A6YkoYgC
public PaginationSupport(List items, int q|0Lu
2uu"0Rm%
totalCount, int startIndex){ %:yJ/&-Q,Z
setPageSize(PAGESIZE); (Vnv"= (
setTotalCount(totalCount); ^noKk6Aaa
setItems(items); V6)\;c
setStartIndex(startIndex); avrf]raM|
} */fmy|#
O$ui:<]dS
public PaginationSupport(List items, int `?{i dg
_PZGns,u
totalCount, int pageSize, int startIndex){ *oqQ=#\
setPageSize(pageSize); m~mw1r
setTotalCount(totalCount); ,r!_4|\
setItems(items); $e1==@
R
setStartIndex(startIndex); @eu4W^W
} 6a51bj!f
|{udd~oE&
publicList getItems(){ gZF-zhnC
return items; GZ(
W64
} 8%q:lI
CqOvVv
publicvoid setItems(List items){ ^=Q/H
this.items = items; B%QvFxZz
} :^]rjy/|+
'M+iw:R__
publicint getPageSize(){ 2&7:JM~#
return pageSize; "u:5
} kBg,U 8|S
pLi_)(#z_
publicvoid setPageSize(int pageSize){ #e:cB' f
this.pageSize = pageSize; b:VCr ^vp
} KfD=3h=
9bd $mp
publicint getTotalCount(){ UPQ?vh2F2
return totalCount; wxU@M1w}
} hF|N81T
l0N~mes
publicvoid setTotalCount(int totalCount){ HE#IJB6BS?
if(totalCount > 0){ 2ZW
{
this.totalCount = totalCount; 706-QE^
int count = totalCount / Dz4e.tvN
tGv5pe*r
pageSize; Tl>D=Vnhh
if(totalCount % pageSize > 0) 3BHPD;U
count++; 0<Q['l4Ar
indexes = newint[count]; }}L :6^
for(int i = 0; i < count; i++){ If[4]-dq
indexes = pageSize * 8>Az<EF^=#
P]w5`aBM
i; "X<vgM^:
} X}x"+#\<@
}else{ Ud@D%?A7
this.totalCount = 0; %<c2jvn+k
} mX2i^.zH
} &[QvMh
3fA.DK[4[
publicint[] getIndexes(){ `F-<P%k
return indexes; eW%Cef
} J?9K|4
)
g:&YSjO>G
publicvoid setIndexes(int[] indexes){ g{0a]'ph
this.indexes = indexes; ,=!_7'm
} >G`Uc&=
ZYf0FC=-
publicint getStartIndex(){ Mkc
return startIndex; rD^ b{]E3
} 84(NylZ
R|4a9G
publicvoid setStartIndex(int startIndex){ /Wos{}Z0
if(totalCount <= 0) 5,Rxc=
this.startIndex = 0; NL`}rj
elseif(startIndex >= totalCount) 8x":7 yV&
this.startIndex = indexes D XFU~J*
qaE>])
[indexes.length - 1]; ,6N|?<26O
elseif(startIndex < 0) .T;:6/??1
this.startIndex = 0; $#2zxpr,
else{ o_=t9\:
this.startIndex = indexes /qf(5Bm
|AD"}8
[startIndex / pageSize]; vlW521
} rf@Cz%xDD
} C1/qiSHsh
Y
1v9sMN,
publicint getNextIndex(){ jd>ug=~x
int nextIndex = getStartIndex() + oW[];r
">zK1t5=
pageSize; Tnd)4}2p
if(nextIndex >= totalCount) 2H\}N^;f
return getStartIndex(); *GUQz
else X8m@xFW}
return nextIndex; K9z 1'k QH
} 6b!F7kyg
tNk.|}
publicint getPreviousIndex(){ GhlbYa
int previousIndex = getStartIndex() - 0Ncx':]5
|j2b=0Rpk
pageSize; 'BUix!k0<
if(previousIndex < 0) (%N=7?
return0;
p"l GR&b
else MZ$x(Vcj
return previousIndex; st4WjX_Q
} R%%Uw %`
/J@<e{&t~
} Vv|%;5(
<I
5F@pe'
ICvl;Q
!!KA9mP
抽象业务类 ?ZF~U
java代码: {e35O(Y
\}Hi\k+h':
>_3P6-L>
/** FGRdA^`
* Created on 2005-7-12 H^TU?vz}
<
*/ %2q0lFdcM
package com.javaeye.common.business; 5u5-:#sLy
=\ek;d0Tqb
import java.io.Serializable; ScCp88KpFI
import java.util.List; 6y0CEly>3#
4LY$;J;2
import org.hibernate.Criteria; ;xXD2{q
import org.hibernate.HibernateException; ":I@>t{H*
import org.hibernate.Session; P*
Z1Rs_
import org.hibernate.criterion.DetachedCriteria; JKjVrx>
@
import org.hibernate.criterion.Projections; *#y9 Pve
import f*%Y]XL;%
TWU[/>K
org.springframework.orm.hibernate3.HibernateCallback; $*\GZ$y>
import /s~(? =qYH
@r130eLh
org.springframework.orm.hibernate3.support.HibernateDaoS c'!+]'Lr
|XrGf2P9u
upport; ow<z @^ 3'
q2{Aq[
import com.javaeye.common.util.PaginationSupport; h 2QJQ|7a
N9S?c
public abstract class AbstractManager extends Jx+e_k$gHO
E*"-U!?)l2
HibernateDaoSupport { cVYPPal
}+/F?_I=
%
privateboolean cacheQueries = false; R9q9cBi3
y 1I(^<qO=
privateString queryCacheRegion; 8
*Y(wqH
HKXtS>7d
publicvoid setCacheQueries(boolean Z@ dS,M*
hY(q@_s
cacheQueries){ #qcF2&a%
this.cacheQueries = cacheQueries; c,,(s{1
} -s_=4U,
zcE`.)y
publicvoid setQueryCacheRegion(String p|`[8uY?
K%@#a}kRb
queryCacheRegion){ Ib}~Q@?2
this.queryCacheRegion = IM(=j
D:56>%y@
queryCacheRegion; _(_U=
} Q2LAXTF]y
xXQW|#X\
publicvoid save(finalObject entity){ gw^X -
getHibernateTemplate().save(entity); E%&E<<nhZ
} rvUJK,oE
)VM'^sV?
publicvoid persist(finalObject entity){ FdE9k\E#/)
getHibernateTemplate().save(entity); G0mvrc-(
} lxh}N,
D>6vI
publicvoid update(finalObject entity){ *7`amF-
getHibernateTemplate().update(entity); "t>WM
} +'`I]K>
Yw6d-5=:
publicvoid delete(finalObject entity){ W5U;{5
getHibernateTemplate().delete(entity); !#TM%w
} k:0nj!^4w>
J,_IHzO~Z
publicObject load(finalClass entity, @"vTz8oY@
q6T>y%|FZ
finalSerializable id){ Pm=i(TBS/
return getHibernateTemplate().load q+1SU6x'm
0N`'a?x
(entity, id); cHw-;
} M1,1J-h
s g6e%
5
publicObject get(finalClass entity, o#frNT}
omZ
bn
finalSerializable id){ Uv|^k8(
return getHibernateTemplate().get E>L_$J -A-
pcO{%]?p
(entity, id); MngfXm
} r.10b]b
[W--%=Ou
publicList findAll(finalClass entity){ `XK+Y
return getHibernateTemplate().find("from be(p13&od
rCn"{.rI
" + entity.getName()); Y6ORI
} M^?=!!US^
8
huB<^
publicList findByNamedQuery(finalString v>'mW
gH[lpRu|7
namedQuery){ 39Zs
return getHibernateTemplate >vk?wY^f
:qxd
s>Xm
().findByNamedQuery(namedQuery); 'k!V!wcD^y
} tOVYA\]
5imqZw
publicList findByNamedQuery(finalString query, ghVxcK
aj6{
finalObject parameter){ od`:w[2\
return getHibernateTemplate z!
DD'8r>
j.vBld
().findByNamedQuery(query, parameter); ;h#nal>w@S
} I.L8A|nZ
}ej-Lu,b3
publicList findByNamedQuery(finalString query, *+>R^\uT
5c+7c@.
finalObject[] parameters){ t.]c44RY
return getHibernateTemplate !Z`xwk"!
-"X}
)N2
().findByNamedQuery(query, parameters); Rss=ihlM
} ^J7g)j3
VkDFR
[k_
publicList find(finalString query){ d){Al(/
return getHibernateTemplate().find *N?y <U
; J40t14u
(query); a&~]77)
} )`gE-udR
$C ?G7Vs
publicList find(finalString query, finalObject bmu<V1[W
,';+A{aV
parameter){ bcy(
?(
return getHibernateTemplate().find C@q&0\HN
Mb[4G>-v=
(query, parameter); PdD|3B&
} ^"\.,Y
`<kV)d%xEF
public PaginationSupport findPageByCriteria MB]Y|Vee
WX9pJ9d
(final DetachedCriteria detachedCriteria){ )bPF@'rF2
return findPageByCriteria DU:
sQS4
d8T,33>T
(detachedCriteria, PaginationSupport.PAGESIZE, 0); Le':b2o
} B\a#Vtyut
L7&|
public PaginationSupport findPageByCriteria L~~Dj:%uq
iWNTI
(final DetachedCriteria detachedCriteria, finalint )QiHe}
C},$(2>0+
startIndex){ `L<)9*
return findPageByCriteria Lu?)Rya
bUi@4S
(detachedCriteria, PaginationSupport.PAGESIZE, -?Aa RwZ,
kg_f;uk+
startIndex); DLrG-C33
} 6lc/_&0
&Jw4^ob
public PaginationSupport findPageByCriteria lt&30nf=
AFcA5:ja
(final DetachedCriteria detachedCriteria, finalint >
AV
R3b
jn;b{*Lf
pageSize, ]\:FFg_O6t
finalint startIndex){ {\HE'C/?
return(PaginationSupport) ,As78^E{
!%2aw0Yv
getHibernateTemplate().execute(new HibernateCallback(){ +6*
.lRA
publicObject doInHibernate AH(O"v`
b!'
bu
(Session session)throws HibernateException { :4D#hOI
Criteria criteria = 7l})`>
k
7#R&
OQ
detachedCriteria.getExecutableCriteria(session); S-:7P.#Q
int totalCount = 7TQh'j
S hM}w/4
((Integer) criteria.setProjection(Projections.rowCount ;,h*s,i
IBzHXa>75
()).uniqueResult()).intValue(); =9;jVaEMJL
criteria.setProjection 9h6xl i
Pk; 9\0k7
(null); K,IPVjS
List items = p3eJFg$
r_Rjjo
criteria.setFirstResult(startIndex).setMaxResults uGQCW\!"4
ka&-tGg
(pageSize).list(); uXNf)?MpA
PaginationSupport ps = VM3H&$d(h
Vy:ER
new PaginationSupport(items, totalCount, pageSize, NB&u^8b
NW9k.D%
startIndex); e-os0F
return ps; 1*x4T%RF$
} ~QsQ7SAs
}, true); ::vw1Es
} +G_6Ek4
B!le=V,@,
public List findAllByCriteria(final =P+S]<O
vAJfMUlP
DetachedCriteria detachedCriteria){ z~oGd,
return(List) getHibernateTemplate Ac.z6]p
EVj48
().execute(new HibernateCallback(){ uBks#Y*3$
publicObject doInHibernate <][|,9mw
R^F99L
(Session session)throws HibernateException { %;zWS/JhL
Criteria criteria = 7q|(ZZa
M{7EFTy!y
detachedCriteria.getExecutableCriteria(session); _pNUI{De
return criteria.list(); "7)F";_(^
} ryx<^q
}, true); @ec QVk
} r\[HR ^`
)M]4p6Y
public int getCountByCriteria(final BsB}noN}
?XGZp?6
DetachedCriteria detachedCriteria){ ;:9 x.IkxC
Integer count = (Integer) xsFW F*HPs
(cYc03"
getHibernateTemplate().execute(new HibernateCallback(){ !T0IMI
publicObject doInHibernate -JZl?hY(
ZrA\a#z"<
(Session session)throws HibernateException { hBE}?J>
Criteria criteria = <UQ:1W8>B
%1HW
) 7
detachedCriteria.getExecutableCriteria(session); xm YA/wt8
return cp?`\P
mc(&'U8R0I
criteria.setProjection(Projections.rowCount YQN=.Wtc
\lR~!6:
()).uniqueResult(); =WEfo;
} -"a+<(Y
}, true); &,&+/Sr11
return count.intValue(); @R2|=ox
} \hM6 ykY-
} H[,.nH_>+
>M:5yk@
4g1u9Sc0
K)Db3JIIk
CaBTqo
ooZ7HTP|
用户在web层构造查询条件detachedCriteria,和可选的 v,|;uc+
t41cl
startIndex,调用业务bean的相应findByCriteria方法,返回一个 Gs?W7}<$
jQ`"Op 3
PaginationSupport的实例ps。 %q*U[vv
nLtP^
1~9H
ps.getItems()得到已分页好的结果集 cR5<.$aY
ps.getIndexes()得到分页索引的数组 KUyua~tF
ps.getTotalCount()得到总结果数 ~+lC%R
ps.getStartIndex()当前分页索引 e-}PJ%!,T
ps.getNextIndex()下一页索引 aYj3a;EmU
ps.getPreviousIndex()上一页索引 //+UQgl6
,XA;S5FE
Pm?6]] 7
,+X8?9v
c~RIl5j
>M1/m=a
Pucf0 #
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 *q0N$}k
ldX]A#d.
,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 OC>" +
Jx>P%>+<j
一下代码重构了。 <m(nZ'Zqz2
r\3In-(AT
我把原本我的做法也提供出来供大家讨论吧: huTJ
a2
<aHK{*'3
首先,为了实现分页查询,我封装了一个Page类: 2hu6
java代码: zWY6D4
@W @L%<
g{J3Ba
/*Created on 2005-4-14*/ 9M7P]$^
package org.flyware.util.page; T]vD ,I+
'[-/Xa['
/** ttw@nv%
@
* @author Joa _?r+SRFn
* ;:!LAe
*/ 2hpx%H
publicclass Page { u\E.H5u27
16Xwtn72
/** imply if the page has previous page */ ]Pd*w`R
privateboolean hasPrePage; U50X`J
df:,5@CJ8
/** imply if the page has next page */ FFQF0.@EBi
privateboolean hasNextPage; 2)8lJXM$L
Sc0ZT/Lm
/** the number of every page */ MYx*W7X
privateint everyPage; F@I_sGCcb
Va 5U`0
/** the total page number */ uVO9r-O8p
privateint totalPage; JV/,QWar
~T-.k
7t
/** the number of current page */ ji8Rd"S
privateint currentPage; f/c}XCH_h
|(V%(_s
/** the begin index of the records by the current Ml3F\ fAW
^4fkZh
query */ >'T%=50YH
privateint beginIndex; ;I7Z*'5!
GS,pl9#V_
vn_avYwiy
/** The default constructor */ ~J2Q0Jv
public Page(){ 9qW,I|G
X%-4x
} wd]Yjr#%Ii
t!=S[
/** construct the page by everyPage <7&b|f$CL
* @param everyPage k@Tt,.];
* */ cnc$^[c
public Page(int everyPage){ 0PfFli`2;
this.everyPage = everyPage; @<PL
} 4Oy
c D
_YJw F1e+M
/** The whole constructor */ NWpRzh8$u
public Page(boolean hasPrePage, boolean hasNextPage, fU}w81oe
#X8[g _d/
TXa XJIp
int everyPage, int totalPage, 4|e#b(!
int currentPage, int beginIndex){ Ov|j{}=L=9
this.hasPrePage = hasPrePage; b?^n'0
this.hasNextPage = hasNextPage; w#1dO~
this.everyPage = everyPage; t}tKm
this.totalPage = totalPage; 4Klfnki
this.currentPage = currentPage; QXz!1o+"
this.beginIndex = beginIndex; S&Sf}uK
} zXD@M{
4[ra
/** S'O0'5U@
* @return JU@$(
* Returns the beginIndex. + ND9###
*/ yR!>80$j
publicint getBeginIndex(){ NLpD,q{
return beginIndex; G#V22Wca8
} L$xRn/\
-Gpj^aBU
/** Dk-L4FS
* @param beginIndex c`.:"i"k3
* The beginIndex to set. h$&XQq0T
*/ }rE|\p>
publicvoid setBeginIndex(int beginIndex){ )yP>}ME
this.beginIndex = beginIndex; o7+/v70D
} _~kcr5
fz&}N`n
/** ;x#>J +QlG
* @return A-io-P7qyj
* Returns the currentPage. MH?B.2
*/ r Lh
h
publicint getCurrentPage(){ =<05PB
return currentPage; _:L*{=N
} K)?^b|D
~c^-DAgB
/** rYJ))@
* @param currentPage R}>Do=hAO
* The currentPage to set. B`F82_O
*/ yjq
)}y,tF
publicvoid setCurrentPage(int currentPage){ D'h2 DP!
this.currentPage = currentPage; >DRs(~|V#
} .{-yveE
M9K).P=
/** ~30Wb9eL
* @return I/aAx.q
* Returns the everyPage. h 3&:"*A2
*/ rieQ&Jt"
publicint getEveryPage(){ ?N
ga
return everyPage; aK{\8L3]
} mSfhl(<L
+joE
/** ECScx02
* @param everyPage !iVFzG
@m
* The everyPage to set. v~\ 45eEA
*/ ([Aq
publicvoid setEveryPage(int everyPage){ ry
?2 o!
this.everyPage = everyPage; :RsPGj6
} cPcV[6)5K9
Yg[IEy
/** S nHAY<
* @return l5[xJH
* Returns the hasNextPage. ".%LBs~$
*/ ;ZJ,l)BNO
publicboolean getHasNextPage(){
x]oQl^F
return hasNextPage; Q*.FUV&;
} /aG>we
`5Btg.
&
/** (weokP!
* @param hasNextPage F9\Ot^~
* The hasNextPage to set. \z9?rvT:
*/ X{}#hyYk"
publicvoid setHasNextPage(boolean hasNextPage){ 4E>(Y98
this.hasNextPage = hasNextPage; _,FoXf7
} }i&dZTBGW
dSVu_*y
/** k~f+L O
* @return j9}0jC2Tb
* Returns the hasPrePage. NE3wui1 V
*/ p*,P%tX
publicboolean getHasPrePage(){ $>=Nb~t!/
return hasPrePage; 0 '7s
} wW8
6rB
Jche79B
/** o%%x'uC
* @param hasPrePage =h::VB}Lv
* The hasPrePage to set. Oq,.Kz
*/ s jI[Vq
publicvoid setHasPrePage(boolean hasPrePage){ /K) b0QX
this.hasPrePage = hasPrePage; yZp:hs#
} VaSNFl1_M
oks=|'&
/** Qz+d[%Q}x
* @return Returns the totalPage. jF{gDK
* &&1Y"dFs
*/ -]\E}Ti
publicint getTotalPage(){ df6Ν4L
return totalPage; xzl4v=7
} Czr4
-#2
MLBg_<
/** kA%OF*%|6
* @param totalPage >J3ja>Gw/
* The totalPage to set. +?Jk@lE<
*/ =jIT"rk
publicvoid setTotalPage(int totalPage){ o:8S$F`O@
this.totalPage = totalPage; xdfvme[
} X/-KkC
Cw[Od"B\?U
} #A/J^Ko
tH,K\v`f
~,!hE&LE~
yp{F8V 8
UD<^r]'x
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 v?D
kDnta
W(a'^
#xe
个PageUtil,负责对Page对象进行构造: 62)lf2$1
java代码: QP5:M!O<)
xrVZxK:!
S~rVRC"<xo
/*Created on 2005-4-14*/ aC yb-P
package org.flyware.util.page; .;Utkf'I
7lDaok
import org.apache.commons.logging.Log; )SL@>Cij
import org.apache.commons.logging.LogFactory; _RaVnMJKX4
tw4am.o1]
/** ONN{4&7@<
* @author Joa |g\. 5IM#W
* #~URLN
*/ ro&Y7m
publicclass PageUtil { 9hR:y.
K~Au?\{
privatestaticfinal Log logger = LogFactory.getLog r,.95@
[> &+*c
(PageUtil.class); ?X_0Iy}1
)_b@~fC
/** L2>?m`wp
* Use the origin page to create a new page VIz{}_~'s
* @param page y>7VxX0xi
* @param totalRecords <Xs@ \
* @return bOxjm`B<
*/ W_BAb+$aF
publicstatic Page createPage(Page page, int (#-=y~%
/[|}rqX(
totalRecords){ <[3lV)~t
return createPage(page.getEveryPage(), &Qq/Xi,bZ
TFJ{fLG
page.getCurrentPage(), totalRecords); oj^5G
]_<
} KSgQ:_u4}
X[~f:E[1J
/** *]:G7SW{
* the basic page utils not including exception +A'q#~yILa
Jl}!CE@-
handler |,a%z-l
* @param everyPage LTYuxZ
* @param currentPage
il IV}8
* @param totalRecords !QQ<Ai!E
* @return page k\Z;Cmh>
*/ neB.Wu~WH
publicstatic Page createPage(int everyPage, int +2V%'{:
\}u7T[R=`
currentPage, int totalRecords){ Owh*KY:
everyPage = getEveryPage(everyPage); igRDt{}
currentPage = getCurrentPage(currentPage); ^i`3cCFB<
int beginIndex = getBeginIndex(everyPage, r\l3_t
e<L 9k}c
currentPage); w~Tq|kU[
int totalPage = getTotalPage(everyPage, ZM-/n>
VRd:2uDS
totalRecords); 2w x[D
boolean hasNextPage = hasNextPage(currentPage, ~b>nCP8q
;Z!~A"~$>
totalPage);
'{j\0
boolean hasPrePage = hasPrePage(currentPage); ui.QYAYaV
]s*[Lib
returnnew Page(hasPrePage, hasNextPage, Bt*&L[&57
everyPage, totalPage, uFrJ:l+
currentPage, A{i][1N
U9@t?j_#X{
beginIndex); Lem\UD$D`
} (:&&;]sI
X|-v0 f
privatestaticint getEveryPage(int everyPage){ (5Z8zNH`3
return everyPage == 0 ? 10 : everyPage; 8g#
c%eZ
} S<y>Y
I5TQ>WJbf
privatestaticint getCurrentPage(int currentPage){ u:AfHZ
return currentPage == 0 ? 1 : currentPage; .fLiX x
} vy{rwZ$
x%IXwP0
privatestaticint getBeginIndex(int everyPage, int 5A2Y'ms,/
0,1L e$)6
currentPage){ -+
]T77r
return(currentPage - 1) * everyPage; jlRl2 #"
} Qb6QXjN
Q
(6ohrM>Q
privatestaticint getTotalPage(int everyPage, int
8(vC jL
Q>}eIQ Y
totalRecords){ (opROsFh
int totalPage = 0; ~J:$gu~`
-(/2_&"
if(totalRecords % everyPage == 0) Z%Tq1O
totalPage = totalRecords / everyPage; a!c/5)v(
else eEW roF
totalPage = totalRecords / everyPage + 1 ; r%g
<hT 8
E(aX4^]g
return totalPage; =1{H
Sf
} 7X9+Qj;
$I)Tk`=
privatestaticboolean hasPrePage(int currentPage){ V!pq,!C$v
return currentPage == 1 ? false : true; %Lh-aP{[e
} Vr&el
I<D&,LFH*w
privatestaticboolean hasNextPage(int currentPage, i$`|Y*
vKU]80T
int totalPage){ dp"<KcP_
return currentPage == totalPage || totalPage == _SMT.lG
}"%!(rx
0 ? false : true; di]$dl|Wi
} rt5oRf:wY
Kf:2%_DB
RJtixuvh@
} 8F O1`%8Oe
$Q`yNEc
-,K*~z.l
,GdxUld
6T^N!3p_
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 oJlN.Q#u&
a-T*'F
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 O tXw/
=,&u_>Dp
做法如下: G]L0eV
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ) >>u|#@z
92P,:2`a
的信息,和一个结果集List: 3n.+_ jQ>s
java代码: th.M.jas
k1^V?O
S`pF7[%rp
/*Created on 2005-6-13*/ !6XvvTs/<
package com.adt.bo; t Y:G54d=_
hrJ$%U
import java.util.List; +L`V[;
B8bvp:Ho|
import org.flyware.util.page.Page; iyA*JCD
4/*]`
/** Ep^B,;~
* @author Joa Kwy1SyU
*/ W9
n^T+2
publicclass Result { ~fyF&+ibp'
#@nZ4=/z
private Page page; Mq+viU&
C!$Xv&"r
private List content; S[-.tvI;Q
7,pje j
/** a='IT 5
* The default constructor z{_mEE49
*/ UlK/x"JDv
public Result(){ Nhjle@J<
super(); C$KaT3I
} N+*(Y5TU
G[|3^O>P
/** !d:tIu{)
* The constructor using fields /'-:=0a
* ::4"wU3t
* @param page K&j'c
* @param content z`\#$
*/ bcq@N
public Result(Page page, List content){ -(6eVI
this.page = page; .[edln
this.content = content; pO\S#GnX
} o&CghF
b cC\
/** l9]o\JFXk
* @return Returns the content.
*Zc9yZl2
*/ j FgZ}Xp
publicList getContent(){ cNdu.c[@
return content; }=Hf?';m
} V^j3y`K
y' 2<qj
/** '"Bex`
* @return Returns the page. V%i<;C
*/ Zkw J.SuU
public Page getPage(){ B#J{ F
return page; $`E4m8fX
} V78Mq:7d
x*:n4FZ7b
/** P1dN32H
o
* @param content !?yxh/>lM
* The content to set. gBMta+<fE~
*/ 7^c2e*S
public void setContent(List content){ kJ/+IGV^v
this.content = content; A$/KP\0Y2
} ]a8eDy
g* %bzfk=|
/** Y3D3.T6Q
* @param page J =b*
* The page to set. rU],J!LF
*/ )m|C8[ u
publicvoid setPage(Page page){ O\%j56Bf
this.page = page; X
d!Cp
} Gj6<s./
} Lt>?y&CcQ
mG
X\wta
P<8LAc$T
yxqTm%?y
HS7R lU^
2. 编写业务逻辑接口,并实现它(UserManager, MY&<)|v\
F/)f,sZF
UserManagerImpl) c qv.dC
java代码: L%f-L.9`u
P;jlHZ 9?O
y*_K=}pk
/*Created on 2005-7-15*/ RTA%hCr!
package com.adt.service; C:Vv!u
yj>){NcX
import net.sf.hibernate.HibernateException; P1$f}K}
M\I_{Q?_
import org.flyware.util.page.Page; fH&zR#T7U4
'wa g |-
import com.adt.bo.Result; *<w3" iq
o.v2z~V
/** /({P1ti:C
* @author Joa dZF8R
*/ 'HCnB]1
publicinterface UserManager { ^<!Ia
#&k8TY
public Result listUser(Page page)throws V_jiOT!
+5#x6[
HibernateException; !TGr .R
/=bSt
} cY{I:MA+h@
Q^nG0<q+
jn~!V!++
" l.!Ed
f7.m=lbe
java代码: P7'M],!9w
'\@WN]
hUBF/4s\
/*Created on 2005-7-15*/ _'&k#Q
package com.adt.service.impl; 2,+d|1(4o
70{RDj6{
import java.util.List; @#A!w;bz
T=.-Cl1A
import net.sf.hibernate.HibernateException; QJQJR/g
D_Guc8*
import org.flyware.util.page.Page; >cTjA):
import org.flyware.util.page.PageUtil; R^uc%onP
\`
&ej{
import com.adt.bo.Result; Bf/|{@
import com.adt.dao.UserDAO; gUspGsfr
import com.adt.exception.ObjectNotFoundException; N_0pO<<cs
import com.adt.service.UserManager; :fhB*SYK
*aI~W^N3
/** 3XnE y
+
* @author Joa # 9V'';:
*/ RTZ:U@
publicclass UserManagerImpl implements UserManager { Q~8y4=|#CY
hc"6u\>
private UserDAO userDAO; <M=';h^w2
GZ
<nXU>
/** W|0My0y
* @param userDAO The userDAO to set. sSNCosb
*/ ) ,yH= 6
publicvoid setUserDAO(UserDAO userDAO){ vABXXB
this.userDAO = userDAO; =Aj"j-r&{
} % oR>Uo
M= atls
/* (non-Javadoc) u"\=^F
* @see com.adt.service.UserManager#listUser Xty#vI
|J\,F.{'
(org.flyware.util.page.Page) G#|Hu;C6"
*/ ]?M)NRk%S
public Result listUser(Page page)throws .5]{M\aA
4'` C1 a
HibernateException, ObjectNotFoundException { X'jr|s^s
int totalRecords = userDAO.getUserCount(); {-J:4*`
if(totalRecords == 0) ,b4g.CV
throw new ObjectNotFoundException ?@>;/@
*CzCUu:%t
("userNotExist"); ;HP#bx
page = PageUtil.createPage(page, totalRecords); 2p+C%"n>
List users = userDAO.getUserByPage(page); ^B|YO8.v
returnnew Result(page, users); >r=6A
} 1!d)PK>1$
VJ*\pM@no
} $3]b>v
t GC2
^a#~
Tn /Ut}]O
22|"K**3J|
r
3|4gG
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 'd+:D'
I=o'+>az
询,接下来编写UserDAO的代码: jx'2N~$
3. UserDAO 和 UserDAOImpl: V'C-'Ythwf
java代码: QE3ryD
x_k S
g
<$Z tik1
/*Created on 2005-7-15*/ &lq^dFP&Su
package com.adt.dao; +
LS3T^
_=?2 3
import java.util.List; z|Ap\[GS
EQ/^&
import org.flyware.util.page.Page; %6Rn4J^^
`/0u{[
import net.sf.hibernate.HibernateException; W-ez[raY
`On3/gU|
/** P,U$ %C!
* @author Joa d-h"JZ9
*/ UP]1(S?
publicinterface UserDAO extends BaseDAO { /,LfA2^_j{
o(zTNk5d
publicList getUserByName(String name)throws =!<^^6LZ
.$P|^Zx,
HibernateException; b[yE~EQxr
`\ R{5TU
publicint getUserCount()throws HibernateException; KxX[S.C
!VFem~'d
publicList getUserByPage(Page page)throws aiJnfU]W
bs
BZE
HibernateException; Li]k7w?H
O2% ` 2h
} =q5@,wN^
G0pBR]_5z$
x~z_,':
x2@,9OUx
$
o"
L;j
java代码: SHwRX?
B|
yjFe'
WcU@~05b
/*Created on 2005-7-15*/ QkL@JF]Re
package com.adt.dao.impl; @iRO7 6m
HitAc8
import java.util.List; 4#7Umj
9qre|AA
import org.flyware.util.page.Page; v&r=-}z2!
u1N1n;#
import net.sf.hibernate.HibernateException; ^aHh{BQ%
import net.sf.hibernate.Query; GQ[pG{_+
p/3BD&6
import com.adt.dao.UserDAO; [Y$V\h=V
d/lffNS=
/** R:f7LRF/\
* @author Joa -%H%m`wD
*/ [IMQIX
public class UserDAOImpl extends BaseDAOHibernateImpl :/i~y $t
r@yD8 D \
implements UserDAO { ami09JHy
Dkw*Je#6PX
/* (non-Javadoc) Z\' wm'
* @see com.adt.dao.UserDAO#getUserByName PtqGX=u
8 URj1 W
(java.lang.String) Fg4@On[,i
*/ .it2NS
publicList getUserByName(String name)throws x9~[HuJ
4w;~4#ZPp
HibernateException { lLMPw}r<
String querySentence = "FROM user in class lJ&y&N<O
]-a{IWVN
com.adt.po.User WHERE user.name=:name"; FT(iX`YQ
Query query = getSession().createQuery ZV(
w
l&Q!mU}
(querySentence); wV:C<Mg7q
query.setParameter("name", name); jtCZfFD?
return query.list(); `kPc!I7Y
} ;`X~ k|7K
YZ**;"<G
/* (non-Javadoc) u7#z^r
* @see com.adt.dao.UserDAO#getUserCount() 3~<}bee5|q
*/ i.M2E$b|
publicint getUserCount()throws HibernateException { G0/>8_Q>Nr
int count = 0; akCIa'>t
String querySentence = "SELECT count(*) FROM (u9Zk~)F
:XYy7xz<
user in class com.adt.po.User"; JGgxAd{L
Query query = getSession().createQuery fI]b zv;
qtY
m!g
(querySentence); \8>oJR 6
count = ((Integer)query.iterate().next 6c &Y
Yf=FeH7"
()).intValue(); h)@InYwu7
return count; J=9 #mOcg"
} n`.#59-Hx
s i?HkJv5
/* (non-Javadoc) W>/UBN3
* @see com.adt.dao.UserDAO#getUserByPage o\goE^,aeR
8(Fu
(org.flyware.util.page.Page) f'_M0x
*/ L=g_@b
publicList getUserByPage(Page page)throws ^/a*.cu
m|1n
x
HibernateException { ?ZX!7^7
String querySentence = "FROM user in class Up|f=@=
c3W
BALdh
com.adt.po.User"; CC#C
Query query = getSession().createQuery kc Y,vl
PUCx]5
(querySentence); ~K`1
query.setFirstResult(page.getBeginIndex()) bjzx!OCpV
.setMaxResults(page.getEveryPage()); Bm}iU~(Z`
return query.list(); nh0&'hA
} agT7=hX].
j3 P$@<
} eM }W6vIn
8[R1A
m8AAp1=
]EN&S Wh
$20s]ywS
至此,一个完整的分页程序完成。前台的只需要调用 ~-<:+9m
EY$?^iS
userManager.listUser(page)即可得到一个Page对象和结果集对象 DY.58IHg1
l{Er+)a
的综合体,而传入的参数page对象则可以由前台传入,如果用 u E.^w;~2=
_Wma\(3$
webwork,甚至可以直接在配置文件中指定。 +>#e=nH
M5O'=\+,F
下面给出一个webwork调用示例: }"4roJ
java代码: oIxH 3T
x8/us
h[Mdr
/*Created on 2005-6-17*/ =fWdk\Wv
package com.adt.action.user; vi|Zit
|_nC6;
import java.util.List; +nQ!4
<T4(H[9B
import org.apache.commons.logging.Log; a.,i.2
import org.apache.commons.logging.LogFactory; G=cNzr9
import org.flyware.util.page.Page; OoM_q/oI
c[:Wf<%|
import com.adt.bo.Result; t:T?7-XIE
import com.adt.service.UserService; Nb1J ~v
import com.opensymphony.xwork.Action; oyW00]ka
&^+3errO
/** u`6/I#q`
* @author Joa
i6 L
*/ F`srE6H
publicclass ListUser implementsAction{ EneAX&SG
q,@+^aZ
privatestaticfinal Log logger = LogFactory.getLog @\PpA9ebg%
qpTm
(ListUser.class); W_m!@T"@H
MS{{R+&
private UserService userService; 74]a/'4
@d)LRw.I
private Page page; ohsH 2]C
.YC;zn^
privateList users; d$[8w/5Of
ETm]o
/* D$hQyhz'
* (non-Javadoc) bpp*
* u~}%1
* @see com.opensymphony.xwork.Action#execute() _:%U_U
*/ !0Nf9
publicString execute()throwsException{ Mj'lASI
Result result = userService.listUser(page); HamEIL-l.
page = result.getPage(); 4#h?Wga
users = result.getContent(); T.2ZBG~|[
return SUCCESS; SSQT ;>
} Bk@WW#b
{82rne`[
/** UE;Bb*<
* @return Returns the page. w+Vk3c5uI)
*/ EzpwGNfz }
public Page getPage(){ !qaDn.9
return page; {+\'bIV[
} Fx5ZwT
t
4|F#gK5E
/** 8f-:d]
* @return Returns the users. ;dOs0/UM&
*/ Mciq-c)
publicList getUsers(){ Y}/c
N\
return users; gVA; `<
} =)*JbwQ
.+vd6Uc5a
/** XNlhu^jh
* @param page C fSl
54
* The page to set. n}:t<
*/ AsAFUuI
publicvoid setPage(Page page){ n.Vtc-yZU
this.page = page; "*bk{)dz}
} bP03G=`6w
lC2?sD$
/** P}l#VJWp
* @param users _uJVuCc
* The users to set. >HIt}Zh
*/ r`[B@
publicvoid setUsers(List users){ 0\wi am-
this.users = users; L;Vq j]_
} L~
2q1
ngLJ@TP-
/** gLx/w\l6
* @param userService !EM#m@kZ{
* The userService to set. 8T7f[?
*/ Gh=<0WaF=
publicvoid setUserService(UserService userService){ ?} X}#
this.userService = userService; ^Xa*lR 3
} O%VA)<
} _k|g@"
0 {,h.:
V&R$8tpz
.HCaXFW
R=Ymo.zs6
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, 5v3RVaqZ
O8[k_0@
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 wibwyzo
wI>h%y-%!
么只需要: Ge0Lb+<G
java代码: =1/q)b,p)
zv@bI~3~
K9*IA@xL
<?xml version="1.0"?> u{P~zyx
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork #!L%J<MX
fa yKM
1.0//EN" "http://www.opensymphony.com/xwork/xwork- [G=:?J,P
5y}BCY2=/
1.0.dtd"> AI~9m-,mE
jiq2 x\\!
<xwork> 7$#rNYa,z
3t*# !^$
<package name="user" extends="webwork- %i3{TL
h(|;\ ~
interceptors"> wB2}uk7
=+4 _j
<!-- The default interceptor stack name Hh@2 m\HA
egWx9xX
--> o"\{OX
<default-interceptor-ref p>&S7M/9
i3d y
name="myDefaultWebStack"/> sNf
+ lga0
@sdS0pC
<action name="listUser" 19) !$Hl
V pH|R
class="com.adt.action.user.ListUser"> dxntGH< O
<param EZ `}*Yrd
V $>"f(
name="page.everyPage">10</param> ([tG y
<result D Kq-C%
? osfL
name="success">/user/user_list.jsp</result> %b9fW
</action> ]xYa yN!n
&8afl"_~
</package> s_v}=C^
@'Q%Jc(
</xwork> RJLFj
A-;^~I
^F&A6{9f/h
d9|T=R
ve~C`2=;
8lpzSJP4k
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 /0l-mfRr
^H-QYuz:T0
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。 Qj:{p5H'
2$3kKY6$e
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 ]Cr]Pvab{
jQkUNPHu
}I)z7l.
pKnIQa[c
l:x_j\
我写的一个用于分页的类,用了泛型了,hoho LjCykk
<0>[c<{V<
java代码: UFL0 K
c<>y!^g
1MpX] j8C#
package com.intokr.util; RRNH0-D1l
cT I,1U
import java.util.List; @| P3
P.!;Uf}32
/** [{?;c+[
* 用于分页的类<br> T*8_FR <
* 可以用于传递查询的结果也可以用于传送查询的参数<br> J(^
>?d'
* 69rwX"^
* @version 0.01 F46O!xb%
* @author cheng v23TL
*/ 7pd$?=__I
public class Paginator<E> { {aT92-D3
privateint count = 0; // 总记录数 jKYm /}d
privateint p = 1; // 页编号 BjN{@aEO
privateint num = 20; // 每页的记录数 6Z$b?A3zM
privateList<E> results = null; // 结果 V.U|OQouT
y6bjJ}
/** Ty.drM
* 结果总数 }\U0[x#q
*/ uO6c3|Zjs
publicint getCount(){ pL%4= ]m
return count; x)d2G6x
} |KTpK(6p
nwhm[AaNs
publicvoid setCount(int count){ D)h["z|F
this.count = count; 8dlInms
} aK!xRnY
+B](5 z4
/** qq/_yt
* 本结果所在的页码,从1开始 jzQ9zy_
* ^971<B(v
* @return Returns the pageNo.
KzIt
*/ G;Us-IRZ
publicint getP(){ 1O|RIv7F[/
return p; n|J.)E.
} |b,zw^!e['
Dxz5NW4
/** Gi;9 S
* if(p<=0) p=1 RsR] T]4
* py}.00it
* @param p 0@:Y>qVa
*/ .HQVj 'g
publicvoid setP(int p){ 38<~R
if(p <= 0) t]gq+ c Lo
p = 1; G[y&`Qc)G
this.p = p; ]<Z&=0i# 9
} S[ws0Y60
*1R##9\jU7
/** ~>.awu+o|
* 每页记录数量 {V{0^T-
*/ ,o4r,.3[s
publicint getNum(){ S$Qr@5
return num; 4RlnnXY
} SIj6.RK
iZsau2K
/** #/\pUK~km
* if(num<1) num=1 |+>%o.M&i
*/ m9v"v:Pw
publicvoid setNum(int num){ X
S6]C{
if(num < 1) 6JUav."`~
num = 1; ;G iI'M
this.num = num; jq7vOr-_g
} (N&k}CO]W
/QV [N
/** u Eu6f
* 获得总页数 n$nne6|O
*/ TJeou#=/
publicint getPageNum(){ H9.oVF^~
return(count - 1) / num + 1; S(@*3]!q
} _G_ &Me0
kyp U&F
/** tn(f rccy
* 获得本页的开始编号,为 (p-1)*num+1 GZxglU,3T
*/ ;a#}fX
publicint getStart(){ "US"`a2
return(p - 1) * num + 1; e5]&1^+
} u>JqFw1
p,3go[9X:R
/** Z5"!0B^ j
* @return Returns the results. ~)WfJ
*/ #L|JkBia
publicList<E> getResults(){
O6M}W_
return results; ~e,f )?
} >DSNKU+j
qz-#LZFTR
public void setResults(List<E> results){ &':UlzG
this.results = results; /zChdjz
} 4SX3c:>
MR^umLM88
public String toString(){ N]3-L`t
StringBuilder buff = new StringBuilder o06A=4I
'vqj5YTj
(); Qi(e`(,'
buff.append("{"); ?,A}E|jZ
buff.append("count:").append(count); kKFuTem_3
buff.append(",p:").append(p); )Tyky%P+iI
buff.append(",nump:").append(num); bCJ<=X,g`K
buff.append(",results:").append X}n&`y{/
1]a*Oer}
(results); k)<~nc-
buff.append("}"); 5`OK-
return buff.toString(); ;EE{~
} hY4)W
n.;5P {V1
} "@UU[o
(ffOu#RQ3
9RCB$Ka6X