Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 wW)&Px
n
IUBps0.T\
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 wx?{|
} k%\
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 v!v0,?b*
B}xo|:f!zj
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 {Z{NH:^
qh'f,#dI}
。 H ]N/Y{
m3v*,~
分页支持类: >p+gx,N
4 d 1Y\
java代码: F|ML$
Q`wA"mw6k
C?c -V,
package com.javaeye.common.util; p?gLW/n
MBTt'6M
import java.util.List; SO jDtZ
HjY-b*B
publicclass PaginationSupport { 7g<`wLAH
{XUfxNDf
publicfinalstaticint PAGESIZE = 30; J?=Ob?+
_
pQ2)M8 gf
privateint pageSize = PAGESIZE; b42pLbpe'E
,IvnNnl2
privateList items; B7jlJqV
|&pz,"(
privateint totalCount; QbKYB
rp[oH=&
privateint[] indexes = newint[0]; UDi3dH=
rM?Dp2
privateint startIndex = 0; ,/?V+3l
aFm]?75
public PaginationSupport(List items, int d4eC Bqx
es(LE/`e
totalCount){ n^(yW
setPageSize(PAGESIZE); gm8Tm$fY
setTotalCount(totalCount); $.]t1e7s
setItems(items); ,,j=RG_
setStartIndex(0); D/6@bcCSY
} m_U6"\n 5
DlkKQ
public PaginationSupport(List items, int .aH?H]^
}Knq9cf
totalCount, int startIndex){ (uxQBy
setPageSize(PAGESIZE); =y(YMWGS
setTotalCount(totalCount); !'t2
setItems(items); <"Cwy0V kp
setStartIndex(startIndex); pnw4QQ9
} S^"e5n2
EG8R*Cm,}
public PaginationSupport(List items, int GSb)|mj
=FJ9wiL
totalCount, int pageSize, int startIndex){ s6hWq&C
setPageSize(pageSize); cz~FWk
setTotalCount(totalCount); !?M_%fNE
setItems(items); *R6eykp
setStartIndex(startIndex); X@4d~6k?
} uR@Wv^
Zdg{{|mm
publicList getItems(){ :
MmXH&yR
return items; C>;8`6_!gU
} p. ~jo
#i=^WN<V
publicvoid setItems(List items){ $I]x &cF
this.items = items; 8GZjIW*0oq
} bh"v{V`=0
.W.U:C1
publicint getPageSize(){ 67:<X(u+!
return pageSize; !Jp.3,\?~
} #UN{
J6{
2EcYO$R!
publicvoid setPageSize(int pageSize){ +VCo=oA
this.pageSize = pageSize; aJ_Eh(cF
} n#'',4f
)H,<i{80c
publicint getTotalCount(){ M!DoR6
return totalCount; nhhJUN?8
} !VTS
$nJ4
s;f u
publicvoid setTotalCount(int totalCount){ 5j01Mx
A
if(totalCount > 0){ |MrH@v7S
this.totalCount = totalCount; Ntrn("!
int count = totalCount / LZ]pyoi
hQxe0Pdt
pageSize; z ate%y
if(totalCount % pageSize > 0) zO]dQ$r\Z
count++; Q&a<9e&
indexes = newint[count]; d~$t{46
for(int i = 0; i < count; i++){ F5q1VEe
indexes = pageSize * OHvzK8
?0&>?-?
i; | N,nt@~
} kYa'
] m
}else{ HliY
this.totalCount = 0; =gyK*F(RK
} /7)G"qG~F~
} 7+-}8&syu
m:7bynT{
publicint[] getIndexes(){ 6FFv+{2^@
return indexes; oh~Dbu=%
} iW$i%`>
XArLL5_L
publicvoid setIndexes(int[] indexes){ G ~\$Oq8
this.indexes = indexes; \Rt
} 41D[[Gh
tqf-,BLh
publicint getStartIndex(){ NVPYv#uK
return startIndex; y>18)8
} (_<n0
/qze
publicvoid setStartIndex(int startIndex){ rt;>pQ9,
if(totalCount <= 0) (ajX;/
this.startIndex = 0; /bk} J:QRg
elseif(startIndex >= totalCount) >R-$JrU.=
this.startIndex = indexes t!N>0]:mo
\hc9Rk
[indexes.length - 1]; Wm_-T]#_
elseif(startIndex < 0) ^i7a2<
z
this.startIndex = 0; `Yve
else{ 4D$E
this.startIndex = indexes P=z':4,M}
Y" |U$
[startIndex / pageSize]; w$HC!
} <[~M|OL9q,
} IrM3Uh
kS!*kk*a
publicint getNextIndex(){ `-2`UGB-
int nextIndex = getStartIndex() + zg"ZXZ
akwVU\RP
pageSize; ArMe[t0$
if(nextIndex >= totalCount) z [{%.kA
return getStartIndex(); @@&;gWr;
else ^PszZ10T
return nextIndex; Hc !_o`[{l
} h|Qh/jCX
)[.URp&
publicint getPreviousIndex(){ |zlwPi.
int previousIndex = getStartIndex() - 9r}}m0
b5C #xxIO
pageSize; $]86w8?-N
if(previousIndex < 0) ?~8V;Qn
return0; tO$M[P=b
else >MLqOUr#
return previousIndex; ~Q\[b%>J
} 8a1{x(\z.
1' s^W
} S8t9Ms:
k
KDk^)zv%!
0't)fnI#
xRmB?kM3]5
抽象业务类 EA72%Y9F
java代码: Jr
zU-g
r v>6k:(
:PJjy6,1
/** Fx 2&ji6u
* Created on 2005-7-12 3f
x!\
*/ IYPI5qCR
package com.javaeye.common.business; 'UCL?$
.v'8G)6g
import java.io.Serializable; PeZ=ONY5
import java.util.List; >EG;2]M&
K+H82$
#
import org.hibernate.Criteria; `. Z".
import org.hibernate.HibernateException; i=rW{0c%
import org.hibernate.Session; 0jq#,p=l;
import org.hibernate.criterion.DetachedCriteria; -g9f3Be
import org.hibernate.criterion.Projections; i[swOYz]X
import S]+}Zyg
M_DkjuR
org.springframework.orm.hibernate3.HibernateCallback; 54-x 14")
import Gl(,%~F9i
?g2K&
org.springframework.orm.hibernate3.support.HibernateDaoS +=v|kd
A2 rRYzN;
upport; B _ >|Mo/
mJ HX
import com.javaeye.common.util.PaginationSupport; ]b)(=-;>
B Xp3u|t
public abstract class AbstractManager extends oz--gA:g
6AY%onY
HibernateDaoSupport { L'(^[vR(
D!CGbP(
privateboolean cacheQueries = false; OXo-(HLE
@g{
"
E6
privateString queryCacheRegion; uM$=v]e^4
.x&>H
publicvoid setCacheQueries(boolean X9>ujgK
wP'`!O[W
cacheQueries){ `*B8IT)
this.cacheQueries = cacheQueries; sz5@=
} ! JN@4
XT\;2etVL
publicvoid setQueryCacheRegion(String |?8wyP
Oc1ZIIkh\
queryCacheRegion){ BC^WPr
this.queryCacheRegion = xxYFWvi
1E(pJu'K
queryCacheRegion; G.;<?W
} 6_7d1.wv9
Ek:u[Uw\
publicvoid save(finalObject entity){ se-}d.PwL
getHibernateTemplate().save(entity); 6%>0g^`)9Y
} x:(e:I8x(
gDH x+"?
publicvoid persist(finalObject entity){ *|'k
getHibernateTemplate().save(entity); 9%8T09I!
} W c nYD)
YV9%^ZaN7
publicvoid update(finalObject entity){ }v?{npEOt+
getHibernateTemplate().update(entity); h6#
} iJcl0)|
rW6LMkt72
publicvoid delete(finalObject entity){ Y\lBPp0{\v
getHibernateTemplate().delete(entity); =1D*K%
} 7RO=X%0A
NEvt71k
publicObject load(finalClass entity, }w$/x<Q[
$O[ut.
finalSerializable id){ (%bfNs|
return getHibernateTemplate().load ][.1b@)qV
3 Xy>kG}
(entity, id); @{j-B
IRZ0
} ?r/7:
aw~OvnX E
publicObject get(finalClass entity, Z@>>ZS1Do
fK[9<"PC0
finalSerializable id){ kG{(Qi
return getHibernateTemplate().get kb>9;-%^JK
E:7vm@+
(entity, id); g
wk\[I`;
}
*J6qL! ["
V[%r5!83H
publicList findAll(finalClass entity){ 0pu'K)Rb
return getHibernateTemplate().find("from dK=BH=S2?X
pz(clTOD:
" + entity.getName()); ?C_%"!GR
} 6rk/74gI,a
KxvT}"k
publicList findByNamedQuery(finalString +_+_`q>]
ym:JtI69
namedQuery){ 9F3`hJZRy>
return getHibernateTemplate r`lgK2r\
sbgRl%
().findByNamedQuery(namedQuery); ;qvZ *
} b{(:'.
Re=bJ|wo
publicList findByNamedQuery(finalString query, CnO$xE|{
xx%WIY:}
finalObject parameter){ r+>9O
return getHibernateTemplate S_^ "$j
3p7*UVR"
().findByNamedQuery(query, parameter); thOCzGJ$
} 0DN:{dJz
luV%_[F
publicList findByNamedQuery(finalString query, `toSU>:
kG%<5QH
finalObject[] parameters){ 4*'NpqC(_
return getHibernateTemplate H~
(I
)p&xpB(
().findByNamedQuery(query, parameters); ;DGp7f#9
} CnAh Ef)b
z8A`BVqI
publicList find(finalString query){ |>VHV} 4)<
return getHibernateTemplate().find v%_sCg
])e6\)
(query); #*w$JH
} g-6!+>w*>e
)Y)7p//
publicList find(finalString query, finalObject 9gjx!t>`H
C}45ZI4
parameter){ ^E>}A
return getHibernateTemplate().find _w)0r}{
%R(j|a9z
(query, parameter); d`^j\b>5(
} x<imMJ
^ 3Vjmv
public PaginationSupport findPageByCriteria OS,-dG(
1298&C@
(final DetachedCriteria detachedCriteria){ ; <3w ,r
return findPageByCriteria -^C;WFh8)
yl|+D]
(detachedCriteria, PaginationSupport.PAGESIZE, 0); x}72jJe`
} L{aT"Of{X
tw^V?4[Miu
public PaginationSupport findPageByCriteria ;b(/PH!O
^]OD+ v
(final DetachedCriteria detachedCriteria, finalint I9B B<~4o
AlGD .K
startIndex){ a ipvG
return findPageByCriteria Ro?yCy:L'
uPb9j;Q?
(detachedCriteria, PaginationSupport.PAGESIZE, S tn[M|
=T;%R^@
startIndex); ZO:{9vt=/
} %x L3=4\
JWM/np6
public PaginationSupport findPageByCriteria )6Z)z;n]aW
Xig%Q~oMp
(final DetachedCriteria detachedCriteria, finalint >KC*xa"
dA)7d77
pageSize, *F2ob pU
finalint startIndex){ 9v0f4Pbxm
return(PaginationSupport) UI |D?z<
/TS>I8V!
getHibernateTemplate().execute(new HibernateCallback(){ bMf+/n
publicObject doInHibernate R~)c(jj5
k:R9wo
(Session session)throws HibernateException { LKztGfy
Criteria criteria = Q-BciBh$
W>'R<IY4#N
detachedCriteria.getExecutableCriteria(session); R>#T{<<L
int totalCount = t4h5R
QR<IHE{~8
((Integer) criteria.setProjection(Projections.rowCount l{vi{9n)
^25$=0
()).uniqueResult()).intValue(); 6SW:'u|90
criteria.setProjection v:<u0B-)$
(~,Q-w"
(null); naW}[y*y;
List items = T3Qa[>+\
.#EmE'IP*
criteria.setFirstResult(startIndex).setMaxResults z&9vKF
;%hlh)k$
(pageSize).list(); yAXw?z!`O
PaginationSupport ps = bZ:w_z[3=
Bu*ge~
new PaginationSupport(items, totalCount, pageSize, !dStl:B
/k(0}g=\
startIndex); .,<-lMC+
return ps; ~~b[X\1
} o1-Zh!*a*
}, true); @R(6w{h9
} YM/^-[k3
-E?h^J&U
public List findAllByCriteria(final [gQ*y~N
Ga"$_DyM
DetachedCriteria detachedCriteria){ '72ZLdi}-
return(List) getHibernateTemplate , z<\ Z!+=
0:Ak4L6k
().execute(new HibernateCallback(){ aZ@Ke$jD
publicObject doInHibernate I(
G8cK
> & \QLo[5
(Session session)throws HibernateException { G}AfCd4
Criteria criteria = ^+Ec}+ Q
LKFL2|af
detachedCriteria.getExecutableCriteria(session); x$ ?{)EY
return criteria.list(); J$v0
} wYOSaGyZ0I
}, true); [D^KM|I%+
} (KK9/k
7P.C~,+D%P
public int getCountByCriteria(final YSs9BF:a
lX;2~iW{/
DetachedCriteria detachedCriteria){ Nq"/:3@4
Integer count = (Integer) xW#r)aN]p
2_R'Kl![
getHibernateTemplate().execute(new HibernateCallback(){ *R0Ae 4
publicObject doInHibernate 8 U B?X
=VH, i/@
(Session session)throws HibernateException { 9Psy$
Criteria criteria = m+s^K{k}
$
GL$
iA
detachedCriteria.getExecutableCriteria(session); KaZ$!JfT
return m("!
M~1
bH~ue5q
criteria.setProjection(Projections.rowCount 7fgA)dU:K
0Zs}y\J`
()).uniqueResult(); uF+if`?
} ry/AF
}, true); O)kC[e4
return count.intValue(); CZS{^6Ye
} R]0awV1b
} >u4%s7v
1t
WKH
6OkN(tL&.
W8'cAY
[ft#zxCJ
hCQzD2
用户在web层构造查询条件detachedCriteria,和可选的 D ?1$I0 =
>t<FG2
startIndex,调用业务bean的相应findByCriteria方法,返回一个 ?a+tL'D[
zZ3,e L
PaginationSupport的实例ps。 eva-?+n\q
)Fe-C
ps.getItems()得到已分页好的结果集 #(mm6dj
ps.getIndexes()得到分页索引的数组 G9TK)Nz
ps.getTotalCount()得到总结果数 R%Gh4y\nF
ps.getStartIndex()当前分页索引 3)^-A4~E
ps.getNextIndex()下一页索引 /d ?)
ps.getPreviousIndex()上一页索引 (30{:o&^
kL 6f^MoL
N|EH`eu^i
-ve{O-;
u.YPb@
g4cmYg3
*z!!zRh3x
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^a4 y+!
//2G5F ;
,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 -x=abyD
3@kiUbq7Eu
一下代码重构了。 6UXa
5t
(Hb
i+IHV
我把原本我的做法也提供出来供大家讨论吧: 8zS't2
u
AdxCP\S&
首先,为了实现分页查询,我封装了一个Page类: !([Q1r{u
java代码: br*L|s\P\9
JhRXfIK>{
<7fF9X
/*Created on 2005-4-14*/ ]1>U@oK
package org.flyware.util.page; :A%uXgK<k
*lRP ZN
/** |#q 5#@,
* @author Joa J)vP<.3:
* -g(&5._,ZW
*/ uh*b[`e
publicclass Page { 2T3v^%%j
{|c
<8
/** imply if the page has previous page */ |v#N
privateboolean hasPrePage; Adp:O"-H1o
3U9]&7^
/** imply if the page has next page */ ^B8%Re%
privateboolean hasNextPage; fo9O+e s
] S<y,d-
/** the number of every page */ "z)dz,&T
privateint everyPage; s,XKl5'+8e
p1
>
D
/** the total page number */ rs2G{a
privateint totalPage; 'L4@|c~x
t<mT=(zt*
/** the number of current page */ TkXD#%nFY
privateint currentPage; ye=*m
vU0j!XqE
/** the begin index of the records by the current rK)aR
,R]hNjs-{
query */ *jM~VTXwt
privateint beginIndex; Z?
u\
6C@,&2<yK
*ci,;-*C
/** The default constructor */ ;S5*n:d
public Page(){ o ?@,f/"5
y33+^
} $BKGPGmh
NKf][!bi
/** construct the page by everyPage +U_> Bo
* @param everyPage <cm,U)j2
* */ Sd/?xyF1(
public Page(int everyPage){ T;K,.a8bU
this.everyPage = everyPage; yo]!Zn
} ,DsqKXSU
gp'9Pf;\[
/** The whole constructor */ k?ubr)[)
public Page(boolean hasPrePage, boolean hasNextPage, ?n<b:oO
I:l<t*
2 Pn
int everyPage, int totalPage, /T&z
:st0
int currentPage, int beginIndex){ TD:NL4dm
this.hasPrePage = hasPrePage; |;3Ru vX?+
this.hasNextPage = hasNextPage; ={,\6a|]:
this.everyPage = everyPage; t"Ok-!c|
this.totalPage = totalPage; `_Iy8rv:P
this.currentPage = currentPage; _|qJ)gD[
this.beginIndex = beginIndex; \x?q!(;G2
} I@IZ1
/J,r
by; %k/
/** \ cmt'b
* @return B@g 0QgA
* Returns the beginIndex. G;:n*_QXE
*/ 1M+o7HO.mG
publicint getBeginIndex(){ epM;u
return beginIndex; /.{4
KW5
} oe,I vnt
N"Y)
/** =>nrU8x
* @param beginIndex ??eSGQ|
* The beginIndex to set. ]G.ttfC
*/ :ad
publicvoid setBeginIndex(int beginIndex){ +k|t[N
this.beginIndex = beginIndex; JW[y
} _Kdqa%L
!
_)s<E9t2N
/** s&:LY"[`
* @return [iVCorU
* Returns the currentPage. pleLdGq
*/ ;Q"xXT`;:
publicint getCurrentPage(){
s;V~dxAiv
return currentPage; (
HCB\!g
} {(;dHF%{
4FSA:]o-
/** Ibt~e4f
* @param currentPage a+A^njk
* The currentPage to set. jo 0
d#
*/ r}kQ<SRx
publicvoid setCurrentPage(int currentPage){ NAd|n+[d
this.currentPage = currentPage; S o>P)d$8+
} 7<{g+Q~7*
H",w$$eF
/** %Jy0?W N
* @return O.61-rp
* Returns the everyPage. ]7<}EG
*/ &+V6mH9m@
publicint getEveryPage(){
4C@ .X[r
return everyPage; e$HN/O
} q@K8,=/.#
k?r-%oJ7
/** nx{_^sK
* @param everyPage *12,MO>go
* The everyPage to set. #E35%7*
*/ lmmB =F
publicvoid setEveryPage(int everyPage){ tQ!p<Q=
$)
this.everyPage = everyPage; b(^g v
} #rZF4>c
-+vA9,pI
/** W(jXOgs+_
* @return +/!kL0[v
* Returns the hasNextPage. +; /]'
*/ \:>GF-Z(
publicboolean getHasNextPage(){ poJ7q (
return hasNextPage; Bw5zh1ALC;
} h)S223[
XLwmXi
/** 50MdZ;R-3
* @param hasNextPage z1wJ-l
* The hasNextPage to set. QuG=am?l`
*/ 5/U|oZM"
publicvoid setHasNextPage(boolean hasNextPage){ M#<U=Ha
this.hasNextPage = hasNextPage; <'s_3AC
} 8?p40x$m%
"S8JHHx
/** k^A17Nf`2
* @return 6T3uv,2
* Returns the hasPrePage. gz{~\0y
*/ | %E\?-TK
publicboolean getHasPrePage(){ -1\*}m%1e
return hasPrePage; : ?K}.Kb
} SePPI.n
ryhme\%l;f
/** ;%-f>'KhI7
* @param hasPrePage }^T7S2_Qy
* The hasPrePage to set. B 4s^X`?z
*/ $raxf80A
publicvoid setHasPrePage(boolean hasPrePage){ *g0} pD;r
this.hasPrePage = hasPrePage; $U3|.4
} 9\2<#,R1q
Gk"o/]Sf
/** &G#LQl
* @return Returns the totalPage. T6T3:DG_B
* 6??o(ziK$
*/ Cxn<#Kf\-<
publicint getTotalPage(){ q_0So}
return totalPage; YH_mWN\Wu
} \0}!qG![AA
{VBn@^'s
/** y r4j
* @param totalPage .9":Ljs(L
* The totalPage to set.
dv?ael^
*/ {zTo[i
publicvoid setTotalPage(int totalPage){ ;m/h?Y~
this.totalPage = totalPage; :5Y
yI.T
} GM1z@i\5
IJWUNKqo=
} 4*j6~
.f1
pQQN8Y~^Y
|2i=oX(r|
0_!')+
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 cRR[ci34k
W0zRV9"P
个PageUtil,负责对Page对象进行构造: uX.^zg]}%
java代码: cst}/8e
J^!2F}:
pKxsK^O5[
/*Created on 2005-4-14*/ IE)$.%q;)
package org.flyware.util.page; n\-nBrVSf
U(d K
import org.apache.commons.logging.Log; ?L%BD7
import org.apache.commons.logging.LogFactory; ^{Vt
#8Bs15aV
/** :\!D 6\o6
* @author Joa `l#|][B)g$
* e;|:W A
*/ A"SF^p
publicclass PageUtil { J?oI%r7^
t2L}
privatestaticfinal Log logger = LogFactory.getLog ~CtLSyB
>)Udb//
(PageUtil.class); 6Kvo Ho
wjq;9%eXk
/** Fjs:rZ#{
* Use the origin page to create a new page Li'>pQ+
* @param page Z<yLu'48)A
* @param totalRecords vz$_Fgsc.
* @return {^5LolCCH
*/ Wz8MV -D
publicstatic Page createPage(Page page, int #Nv^F
kFRl+,bi~
totalRecords){ gwA+%]
return createPage(page.getEveryPage(), KT4h3D`,
}Wk^7[Y
page.getCurrentPage(), totalRecords); qG6?k}\\
} "jUM}@q5
|;(95
/** {Vw\#/,
* the basic page utils not including exception 6>yfm4o
~nVO%IxM4J
handler |Ix{JP"Lk
* @param everyPage Lhts4D/V7
* @param currentPage rIh"MQvi[
* @param totalRecords s|`Z V^R
* @return page #`HY"-7m_
*/ FI(iqSJ6
publicstatic Page createPage(int everyPage, int y6hb-:
#1
qxQuXF>:#
currentPage, int totalRecords){ <Jf[N=
everyPage = getEveryPage(everyPage); |3bCq(ZR\P
currentPage = getCurrentPage(currentPage); s3/iG37K
int beginIndex = getBeginIndex(everyPage, *=2sXH1j
Uhw:XV@m
currentPage); f`gs/R
int totalPage = getTotalPage(everyPage, qk{+Y
/q^\g4J
totalRecords); m8T< x>
boolean hasNextPage = hasNextPage(currentPage, n9 %&HDl4
b2tUJ2p
totalPage); *QGyF`Go{
boolean hasPrePage = hasPrePage(currentPage); HM]mOmL90N
R PB%6z$
returnnew Page(hasPrePage, hasNextPage, t:O"t
G
everyPage, totalPage, KLBX2H2^0
currentPage, (
kKQs")
^.pd'
beginIndex); Wik8V 0(
} 6IPQ}/l
xXRlQ|84
privatestaticint getEveryPage(int everyPage){ Z1y=L$t8
return everyPage == 0 ? 10 : everyPage; .N>Th/K8
} vTl7x
W\pO`FL
privatestaticint getCurrentPage(int currentPage){ m<e_Z~ ^G
return currentPage == 0 ? 1 : currentPage; ~PtIq.BY
} @2;/-,4O
Tb[1\
privatestaticint getBeginIndex(int everyPage, int z[sP/{~z
k9_c<TSzu
currentPage){ Ncr*F^J4
return(currentPage - 1) * everyPage; YAsE,M+
} fe4Ki
TF%MO\!
privatestaticint getTotalPage(int everyPage, int ;{Nc9d
|[W7&@hF
totalRecords){ ccY! OSae
int totalPage = 0;
UOa
n
:pCv!g2
if(totalRecords % everyPage == 0) P#l"`C
/
totalPage = totalRecords / everyPage; (3Dz'X
else o()No_.8H
totalPage = totalRecords / everyPage + 1 ; d=DQS>Nz
)>]@@Trx
return totalPage; J=t@2
} SMn(c
'Z8=y[l
privatestaticboolean hasPrePage(int currentPage){ #8/pYQ;
return currentPage == 1 ? false : true; ~wFiq)v(
} 7t3ps
DLH|y%"
privatestaticboolean hasNextPage(int currentPage, vACJE
\(&UDG$
int totalPage){ :[J'B4>9
return currentPage == totalPage || totalPage == mv{bX|.
G -V~6
0 ? false : true; va[r~
} 928uGo5
".7\>8A#a
Pk{%2\%&2
} d#CAP9n;'
&e\UlM22
X.GK5Phd
uZml.#@4
phi9/tO\u
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。 z'9U.v'M)
+`f3_Xd
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 <lgX=wx L
vLs*}+f
做法如下: c->.eL%
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 (b8ZADI*
:pdl2#5H^
的信息,和一个结果集List: 85_Qb2<'r
java代码: (3? W)i
n.7-$1
&&ZX<wOM
/*Created on 2005-6-13*/ ~7>D>!!
package com.adt.bo; O_ d[{e=5`
lw43|_'G-t
import java.util.List; c<ORmg6
lSG]{
import org.flyware.util.page.Page; a];1)zVA6
Ku?1QDhrF*
/** rcz9\@M
* @author Joa vMzBp#MT
*/ i :|e#$x
publicclass Result { _>E=.$
@y2cC6+'t
private Page page; oc"7|YG
\DcO.`L
private List content; J,*+Ak
~
hrW2#v
/** 8 .t3`FGH
* The default constructor %J8uVD.2
*/ Ip|=NQL>
public Result(){ k_`h (R
super(); U&W/Nj
} snYyxi
[nf5<
/** L:\>)6]Ls
* The constructor using fields oFKTBH:I
* g&rz*)|/
* @param page NwN3T]W
* @param content PsM8J
*/ 3qkPe_<I
public Result(Page page, List content){ Z~]G+(
this.page = page; 'fYF1gR4
this.content = content; ,W BKN)%u
} PlR$s
ue*o>iohB
/**
H 3so&_
* @return Returns the content. $;rvKco)%
*/ W[:CCCDL
publicList getContent(){ `<-/e%8
return content; M<r]a{Yv
} Gkm{b[
W~FU!C?]
/** Nw '$r
* @return Returns the page. owx0J,,G
*/ mFmxEv
public Page getPage(){ tL M@o|:
return page; gwbV$[.X
} B'I_i$g4w
(duR1Dz
/** [Z^26/5a
* @param content 7Vuf4Z5
* The content to set. ~gaWZQXyu
*/ nrR2U`
public void setContent(List content){ 6mqp`x`
this.content = content; QjKh#sU&
} urg^>n4V]
Dq-[b+bm
/** aeDhC#h
* @param page .{-X1tJ7
* The page to set. WmkCV+thA
*/ J:@yG1VIp
publicvoid setPage(Page page){ %2\6.c=c
this.page = page; b94+GLU8b
} |I;]fH,+
} 4K
]*bF44
$>T(31)c
&eb8k2S
s>)?MB*vb
h; 6G~D
2. 编写业务逻辑接口,并实现它(UserManager, `I8ep=VZ
vSR5F9
UserManagerImpl) mkq246<D~
java代码: ' g d=\gV
UOyM=#ipY
J%lrXm(l{
/*Created on 2005-7-15*/ 51-'*Y
package com.adt.service; }0sLeGJ!
|;\pAZ2
import net.sf.hibernate.HibernateException; y&/bp<Z
MnlD87x@X
import org.flyware.util.page.Page; b~2LD3"3
ZYt1V"2VJ
import com.adt.bo.Result; WD1>{TSn
hcM9Sx"!
/** B4* uS (
* @author Joa !ST7@D
*/ {9*
l
publicinterface UserManager { T-h[$fxR_
jrpki<D
public Result listUser(Page page)throws I>q!co9n
H^dw=kS
HibernateException; J #5V>7G
m6'9Id-:L
} _2{2Xb
\Rs9B .
qMoo#UX
-3 Sb%V\
5gkQ6&m
java代码: d|8-#.gV
^"~r/@l
;GKL[tI"
/*Created on 2005-7-15*/ oF a,IA
package com.adt.service.impl; 1M b[S{
i'.D=o
import java.util.List; XMz*}B6GQ
?XeaoD/
import net.sf.hibernate.HibernateException; B@S~v+Gr
|bhv7(_
import org.flyware.util.page.Page; *>2e4j]
import org.flyware.util.page.PageUtil; {jv+ JL"5
ohs`[U=%~
import com.adt.bo.Result; B`||4*
import com.adt.dao.UserDAO; ox_DEg7l
import com.adt.exception.ObjectNotFoundException; R"l6|9tmP
import com.adt.service.UserManager; B_D0yhh
zeq")A
/** IVy<>xpt
* @author Joa oW(EV4J"
*/ `$XB_o%@
publicclass UserManagerImpl implements UserManager { yo(MJ^=d
$xK\$kw\
private UserDAO userDAO; _s<s14+od
@eutp`xoT\
/** lr[T+nQ
* @param userDAO The userDAO to set. mnBTZ/ZjS
*/ }%AfZ2g;h
publicvoid setUserDAO(UserDAO userDAO){ Qv
g_|~n
this.userDAO = userDAO; |ICn/r~
} >&ZlCE
`%^w-'
/* (non-Javadoc) C#8A|
* @see com.adt.service.UserManager#listUser )\PX1 198
IuA4eDr^Y%
(org.flyware.util.page.Page) f*ABIm
*/ mU
public Result listUser(Page page)throws 3ZI:EZ5
"shX~zd5
HibernateException, ObjectNotFoundException { WnOvU<Z
<
int totalRecords = userDAO.getUserCount(); 'Z:wEt!
if(totalRecords == 0) KFRf5^ %
throw new ObjectNotFoundException J"@X>n
';!-a]N
("userNotExist"); }p-/R'
page = PageUtil.createPage(page, totalRecords); 54B`T/>R:E
List users = userDAO.getUserByPage(page); ZJ~0o2xZ'
returnnew Result(page, users); .z=%3p8+
} u c}tTmB|
~H:=p
} U&=pKbTe
Rkp
+}@Y_
_n!>*A!
Kv9FqrDj
~:PM_o*6
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 oO`a {n-
4)>UTMF
询,接下来编写UserDAO的代码: %Ofw"W
3. UserDAO 和 UserDAOImpl: 3aBE[
java代码: @'5*jXd
w<zzS:PF*
wjZ Q.T!
/*Created on 2005-7-15*/ Gy;Fe=
package com.adt.dao; zGNW5S9G
GU9G5S.
import java.util.List; u!HX`~q+A
(+0(A777M
import org.flyware.util.page.Page; ^*+M9e9Z
z@o6[g/*Q
import net.sf.hibernate.HibernateException; (C1~>7L
VbMud]40F
/** P-$ ,
* @author Joa SS24@:"{
*/ ^^*L;b>I
publicinterface UserDAO extends BaseDAO { i(.V`G=
b:r8r}49
publicList getUserByName(String name)throws e@;'# t
xf8[&?
HibernateException; $E[M[1j
S:Jg#1rww-
publicint getUserCount()throws HibernateException; ]=ZPSLuEm%
'h7x@[|
publicList getUserByPage(Page page)throws if*~cPnN
/er{sKVX<
HibernateException; Q[aF"5h%
yPe9KN_
} 6Vncr}
G<k.d"<
mPqKk
:-<30LS$
N`$F>E,T%
java代码: C[hNngb7R
jUl_ToX
JiO8EIM
/*Created on 2005-7-15*/ <;'{Tj-"
package com.adt.dao.impl; wq,&0P-v
7cWeB5e?O
import java.util.List; sZxTsUW
e=p_qhBt
import org.flyware.util.page.Page; 6rWq
hIaI
N6p0`
import net.sf.hibernate.HibernateException; )V+/@ 4
import net.sf.hibernate.Query; I<,~>'cq.
{T,}]oX
import com.adt.dao.UserDAO; K7.ayM 0
3-6MGL9
/** "L`BuAB
* @author Joa {O).!
*/ 2L[!~h2
public class UserDAOImpl extends BaseDAOHibernateImpl 2<h~:
L
gR
gB=
C{
implements UserDAO { D5({&.X[-
8z7eL>)
/* (non-Javadoc) -sdzA6dp
* @see com.adt.dao.UserDAO#getUserByName Gd`7Tf)'
`8#xO{B1
(java.lang.String) -5]lHw}
*/ g.blDOmlc
publicList getUserByName(String name)throws KHx;r@{<
O"kb*//
HibernateException { :is2 &-|x
String querySentence = "FROM user in class |uz\XK
` ~^ My~f
com.adt.po.User WHERE user.name=:name"; J %B/(v`
Query query = getSession().createQuery (x@J@ GP*
TuPD5-wB&
(querySentence); F|/6;&*?M
query.setParameter("name", name); i `p1e5$
return query.list(); 7lAJ
0
} W"pHR sf
W/u(9
/* (non-Javadoc) Nu3IYS5&
* @see com.adt.dao.UserDAO#getUserCount() T-GvPl9ZJw
*/ cTn(Tv9s
publicint getUserCount()throws HibernateException { VAjl?\}6
int count = 0; {q+gm1iC
String querySentence = "SELECT count(*) FROM AS:k&t
f<$*,P
user in class com.adt.po.User"; ( xzruI5P
Query query = getSession().createQuery oOLA&N-A~
Zn40NKYc
(querySentence); t2.jg?`k
count = ((Integer)query.iterate().next X(17ESQ/Y
\6.dGKK
()).intValue(); ,'t&L]
return count; (fr=[m$`
} -^t.eZ*|
d2US~.;>l
/* (non-Javadoc) '@WBq!p
* @see com.adt.dao.UserDAO#getUserByPage 8 $H\b &u
$!!y v'K
(org.flyware.util.page.Page) 9!_LsQ\)
*/ UY,u-E"
publicList getUserByPage(Page page)throws bA$ElKT
23K#9!3
HibernateException { fhRu-
String querySentence = "FROM user in class (E 8jkc
:RZ'_5P[If
com.adt.po.User"; "\rO}(gC;`
Query query = getSession().createQuery hH-!3S2'
59:kL<;S-
(querySentence); "R-j
query.setFirstResult(page.getBeginIndex()) @"98u$5
.setMaxResults(page.getEveryPage()); [;
$:Lr
return query.list(); I7SFGO
} OEzSItAI/[
xO%yjG=
} `WxGU
N>sT@ >
)
UUtSme
X|g5tnsj`
qC& xuu|
至此,一个完整的分页程序完成。前台的只需要调用 4DP<)KX
OI:=>Bk
userManager.listUser(page)即可得到一个Page对象和结果集对象 0$Zh4Y
FEopNDy@y
的综合体,而传入的参数page对象则可以由前台传入,如果用 NU{eoqaT
0pB'^Q{
webwork,甚至可以直接在配置文件中指定。 :
4lR`%
3BLHd<
下面给出一个webwork调用示例: t4~?m{
java代码: 'Cz]p~oF
eYjF"Aq
"]'W^Fg
/*Created on 2005-6-17*/ 6 !fq658
package com.adt.action.user; $Op:-aW&
f4dHOH
import java.util.List; prIJjy-F
nSZp,?^
import org.apache.commons.logging.Log; Kuk@x.~0m
import org.apache.commons.logging.LogFactory; yTe25l{QaF
import org.flyware.util.page.Page; fHI@'
'0
=M4wP3V/
import com.adt.bo.Result; K&dc< 4DC
import com.adt.service.UserService; ,y/m5-D!
import com.opensymphony.xwork.Action; &@2`_%QtA
@Y(7n/*
/** _$HC NFdh
* @author Joa xs"\c7pC
*/ $SniQ
publicclass ListUser implementsAction{ @}+B%R
LA6Ik_-F
privatestaticfinal Log logger = LogFactory.getLog ,s@S`KS0
chE}`I?
(ListUser.class); Nii5},
Ur""&@
private UserService userService; :N
xksL^
,>TDxI;
private Page page; 9~iDL|0'~
5:EE%(g9
privateList users; 0d`lugf
aKRnj!4z
/* #X5Tt ;
* (non-Javadoc) N$ 2Iz
* vDc&m
* @see com.opensymphony.xwork.Action#execute() [{ A5BE -
*/ IY2f$YV
publicString execute()throwsException{ 1gYvp9Ma
Result result = userService.listUser(page); :ZM=P3QZ
page = result.getPage(); @Hp=xC9V
users = result.getContent(); +J}h
return SUCCESS; wG22ffaki
} oOQ0f |MGp
|l?*' =
/** k9&pX8#
* @return Returns the page. mT1Q7ta*P
*/ n{c-3w.uD
public Page getPage(){ |B),N f|a
return page; b&pL}o?/k
} b3-+*5L
)L,Nh~
/** l~*d0E-$
* @return Returns the users. Y3'dV)
*/ oYeFOw`
publicList getUsers(){ lJ4/bL2I/
return users; MPsm)jqX
} jSvo-
"fd'~e$S#
/** 7{=+Va5
* @param page ^"$~&\+x5
* The page to set. Psjk
7\
*/ tZD^<Q7}\
publicvoid setPage(Page page){ Lez]{%+.`[
this.page = page; 1|3vwgRhs
} Mgu=cm)
|c,'0V,"cH
/** k )fLJ9R
* @param users #}'sknvM}
* The users to set. x^UAtKSy
*/ HR?a93
publicvoid setUsers(List users){ T\T>\&nY+|
this.users = users; 7I {rhA
} CH=k=)() ]
7{
QjE
/** L0xh?B
* @param userService -$y/*'
* The userService to set. O'W[/\A56M
*/ -/6Ms%O
publicvoid setUserService(UserService userService){ 5|oi*b
this.userService = userService; yrrP#F
} Y2y =
P
} ]i'gU(+;`
I%ZSh]On
"eKM<S
BH?fFe&J:`
K%>3ev=y.s
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, p{rzP,Pb&
*3!ixDX[r
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 4=hz4(5a
YR68'Sft[
么只需要: to'O;f">n
java代码: 7C^W <SUo
A)o%\j
+}!FP3KgT
<?xml version="1.0"?> AaJnRtBS~
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork xy<)zKp
\F),SL
1.0//EN" "http://www.opensymphony.com/xwork/xwork- Cv1CRmqq%
_VAX~Y]
1.0.dtd"> ltG|#(
vtf`+q
<xwork> &0@AM_b
?rububDT{
<package name="user" extends="webwork- nA XWbavY
@?<1~/sfL
interceptors"> mF]8
~C ;gEE-
<!-- The default interceptor stack name EcmyY,w
1cPjgBxv#
--> iJ~e8l0CA
<default-interceptor-ref YH$whJ`W0
YU%U
name="myDefaultWebStack"/> +K*_=gHF.
{FNq&)#`
<action name="listUser" r*4@S~;
[5jXYqD=vj
class="com.adt.action.user.ListUser"> $t42?Z=N&z
<param eop7=!`-~~
C2Af$7c
name="page.everyPage">10</param> cP (is!
<result X0gWTs
`}&}2k
name="success">/user/user_list.jsp</result> LDq(WPI1#
</action> nM&UdKf3
)u(Dq u\t
</package> bmGtYv
GxcW^{;
</xwork> 8AVG pL
:l?/]K
5Lm<3:7Q+
3r,^is
@
Yzj
\I`g[nT|
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 e't1.%w
.2:S0=xt<
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 3k?|-js
XYsU)(;j
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 ]h_V5rdX@
]u@`XVEJ
>qjV(_?F-
[i)G:8U
t:.ZvA3
我写的一个用于分页的类,用了泛型了,hoho Z }Z]["q
*f( e`3E
java代码: }=JuC+#~n
-axV;+"b
?513A>U
package com.intokr.util; 9$:+5f,%a
nfzKUJY
import java.util.List; DANndXQLH
07tSXl5!
/** b_j8g{/9
* 用于分页的类<br> t+Rt*yjO
* 可以用于传递查询的结果也可以用于传送查询的参数<br> dsUY[X-<6
* n"c3C)
* @version 0.01 &26H
* @author cheng I &I
q
*/ fE/|U|5L[
public class Paginator<E> { JPfE`NZ
privateint count = 0; // 总记录数 TZ+2S93c
privateint p = 1; // 页编号 `h|>;u
privateint num = 20; // 每页的记录数 1$G'Kg/
privateList<E> results = null; // 结果 >On"BP# U
Ks-aJ+}
/** v&*}O
* 结果总数 nH^RQ'19
*/ F|t_&$Is?
publicint getCount(){ d9sqO9Ud8
return count; t.E3Fh!o
} bZsg7[: C
z@n779 i
publicvoid setCount(int count){ !u=,b fyH
this.count = count; =3?"s(9
} =c(3EI'w
Kp_^ 2V?
/** 2DbM48\E
* 本结果所在的页码,从1开始 +4%:q~C
* vs~lyM/
* @return Returns the pageNo. y()Si\9v
*/ E)7ODRVbl
publicint getP(){ Co#_Cyxg=9
return p; \9t6#8
} /i)1BaF
k|c=O6GO
/** %[C-KQH
* if(p<=0) p=1 3V`.<
* _z3YB
* @param p `Gp!Y
*/ edy6WzxBcm
publicvoid setP(int p){ oPA
[vY
if(p <= 0) fCxF3m(O
p = 1; *PVv=SU
this.p = p; T{%'"mm;
} d(-$ {
c
|6.1uRF E2
/** :'LG%E:b
* 每页记录数量 %d\|a~p:
*/ H\Jpw
publicint getNum(){ I^z$0
return num; ?hQ,'M2
} rX<gcntv
.5~W3v
<
/** Z/ypWoV(
* if(num<1) num=1 _("&jfn
*/ ?w[M{
publicvoid setNum(int num){ YQ+Kl[ec
if(num < 1) 8>|@O<2\
num = 1; =_L
this.num = num; 8/y~3~A{D
} }w)`)N
I2wT]L UV
/** 'Na/AcRdg
* 获得总页数 .{|AHW&0<
*/ !cWnQRIt_F
publicint getPageNum(){ j>0~"A
return(count - 1) / num + 1; 9#;UQ.qA
} Ay Obaa5
3[jk}2R';p
/** ^:RDu q
* 获得本页的开始编号,为 (p-1)*num+1 Nh[{B{k
*/ [}OL@num
publicint getStart(){ *ppb4R;CW
return(p - 1) * num + 1; j;k(AM<
} 92k}ON
7BX%z$_)A
/** e]+ [lq\p@
* @return Returns the results. c[Mz#BWG
*/ (Rc0 l;
publicList<E> getResults(){ U "qO&;m
return results; -0)So
} G"BoD 5m
):_x
public void setResults(List<E> results){ d%istFL)
this.results = results; L^`oJ9k!
} 995^[c1o6
,K'}<dm|x
public String toString(){ Lu~e^Ul
StringBuilder buff = new StringBuilder e<p_u)m
S %"7`xl
(); )pVxp]EI
buff.append("{"); iK"j@1|
buff.append("count:").append(count); A/U tf0{3"
buff.append(",p:").append(p); n]B)\D+V^
buff.append(",nump:").append(num); sv^;nOAc
buff.append(",results:").append T_}\
vR?L/G^.
(results); Z6b3gV
buff.append("}"); X
|f'e@
return buff.toString(); .~5cNu'#m
} (!';
Oed&B
} g(:y_EpmLH
B%Yb+M&K
a<V=C