Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 FHy76^h>e
dtM[E`PL
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 NQTnhiM7$
5`^o1nGO'
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 {mYP<NBT
[c K^+s)N
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 *#>F.#9
c"YXxAJ
。 I"L;L?\S
s}M= oe
分页支持类: $KV&\Q3\0
wn+FTqj
java代码: BJjx|VA+
ClW'W#*(Y
}6RT,O g
package com.javaeye.common.util; 8$P>wCK\l
-=$2p0"R
import java.util.List; <~Qi67I
u.|~
publicclass PaginationSupport { BWPP5X9
;uI~BV*3
publicfinalstaticint PAGESIZE = 30; uPyVF-i
BW[5o3
i
privateint pageSize = PAGESIZE; dFW=9ru+MQ
IxSV? k
privateList items; I d8wS!W`7
g1m-+a
privateint totalCount; 5vp|?-\h>
<zfe}0
privateint[] indexes = newint[0]; Qez SJ
io
0Vv9BL{
privateint startIndex = 0; AMlV%U#
uK*|2U6t
public PaginationSupport(List items, int ,4F,:w
I@7/jUO
totalCount){ M8W# io
setPageSize(PAGESIZE); wvc>0?t'
setTotalCount(totalCount); tiQ;#p7%
setItems(items); SBKeb|H8
setStartIndex(0); ))#'4
} ``4wX-y
\3Jq_9Xv
public PaginationSupport(List items, int s3t!<9[m
O&?.&h
totalCount, int startIndex){ D5]{2z}k
setPageSize(PAGESIZE); &~~s6
setTotalCount(totalCount); `7Ug/R<
setItems(items); 0Oxz3r%}r
setStartIndex(startIndex); vE\lp8j+
} q^Tis>*u6
KsdG(.I+ek
public PaginationSupport(List items, int ?C;JJ#Ho
F|eu<^"$ H
totalCount, int pageSize, int startIndex){ +uQB
rG
setPageSize(pageSize); *3Nn +T
setTotalCount(totalCount); 5{l1A(b
setItems(items); }=GM?,7b
setStartIndex(startIndex); F>Jg~ FD*
} T0|H9>M
gbGTG(:1S
publicList getItems(){ R{3CW^1
return items; d'zT:g
} U</+ .$b
b7$}JCn
publicvoid setItems(List items){ 4;<DJ.XlN=
this.items = items; MW@ DXbKVl
} Pz473d
'j79GC0
publicint getPageSize(){ YFx=b!/s
return pageSize;
KOSyh<&
} R;THA!
:kp0EiJ
publicvoid setPageSize(int pageSize){ =lrN'$z?%
this.pageSize = pageSize; i$O#%12l
} &%e"9v2`
ryEvmWYu
publicint getTotalCount(){ lG]GlgSs
return totalCount; (3fPt;U
} AQ}l%
bOXh|u_3i
publicvoid setTotalCount(int totalCount){ Y'_ D<Mp
if(totalCount > 0){ MVAc8d S
this.totalCount = totalCount; #NF+UJYJ&'
int count = totalCount / >sV Bj(f
eCL?mh K
pageSize;
rk|a'&
if(totalCount % pageSize > 0) \>[gl!B_Rr
count++; WguV{#=H
indexes = newint[count]; g
=\13#F
for(int i = 0; i < count; i++){ KgU[
indexes = pageSize * rxkBg0Z`a
j&}B<f _6J
i; ~[;{
} K!b>TICa:
}else{ SD I,M
this.totalCount = 0; nK:`e9ES
} 9oD#t~+F4
} #ZwY?T
x
~p!QSRu~,b
publicint[] getIndexes(){ "j;!_v>=f`
return indexes; B2"+Hwbk
} Oi#k:vq4
]=pWZ~A
publicvoid setIndexes(int[] indexes){ 2c*2\93>
this.indexes = indexes; %,E7vYjT%
} Ot"(uW4$[
N>T=L0`
publicint getStartIndex(){ X)FQ%(H<
return startIndex; '|+=B u
} kjfxjAS=m
vKV{
$|
publicvoid setStartIndex(int startIndex){ /3;=xZq
if(totalCount <= 0) ~l@%=/m
this.startIndex = 0; w7[0
elseif(startIndex >= totalCount) gGD]t;<u
this.startIndex = indexes @~Rk^/0
lHRK'?Q
[indexes.length - 1]; $M%}Oz3*
elseif(startIndex < 0) p@`4 Qz
this.startIndex = 0; |Yg}WHm
else{ 1W4H-/Re
this.startIndex = indexes Ez wF`3RjK
K T"h74@
[startIndex / pageSize]; 96k(XLR
} !WDn7j'A
} ">0 /8] l
g!z8oPT
publicint getNextIndex(){ 047*gn.b
int nextIndex = getStartIndex() + k0R,!F
O{O9}]6
pageSize; agGgJ@
if(nextIndex >= totalCount) ',<{X(#(
return getStartIndex(); Cf.WO %?P
else 4{uJ||!
return nextIndex; +lW+H12
} k$Nx6?8E
(p}9^Y
publicint getPreviousIndex(){ K4BTk!
int previousIndex = getStartIndex() - |2tSUOZ
h:eN>yW
pageSize; 9iiU,}M`j
if(previousIndex < 0) YeR7*[l
return0; 7 B4w.P,B
else 8kKRx
return previousIndex; )[F46?$vrk
} eU<]h>2
$,!dan<eA
} [j]}$fFe
:"h
Pg]'
K]lb8q}Z~
`K@5_db\
抽象业务类 Jc9@VxWY
java代码: >&4I.nA
T(t
<Ay?c
`"-`D!U?$
/** 4'7
v!I9
* Created on 2005-7-12 E0WrpGZ
*/ Rq~
>h99M
package com.javaeye.common.business; loAfFK>g
A@fshWrl%
import java.io.Serializable; 8tG/VE[
import java.util.List; T% jjs
'npT+p$V
import org.hibernate.Criteria; S0X.8Bq
import org.hibernate.HibernateException; Y:#kel<
import org.hibernate.Session; N
P0Hgd
import org.hibernate.criterion.DetachedCriteria; N69eIdl
import org.hibernate.criterion.Projections; Z:r$;`K/
import ,
.NG.Q4f
H@OrX
org.springframework.orm.hibernate3.HibernateCallback; K%.YNVHHC
import '/n%}=a=
HquB*=^xh
org.springframework.orm.hibernate3.support.HibernateDaoS $TH'"XK
nOL 25 Y:
upport; !Barc,kA
GwU>o:g"
import com.javaeye.common.util.PaginationSupport; V"D<)VVA
dcc%G7w
public abstract class AbstractManager extends 8M(|{~~3:
i32_ZB Z?y
HibernateDaoSupport { ,EGD8$RA]
g)|++?
privateboolean cacheQueries = false; GhfUCW%
o sgS?=8
privateString queryCacheRegion; JCU3\39}
O'yjB$j
publicvoid setCacheQueries(boolean J,77pf!B
+H m+#o
cacheQueries){ =-s20mdj
this.cacheQueries = cacheQueries; ,VcDvZ7
} Kr}M>hF+|
\i;~~;D
publicvoid setQueryCacheRegion(String po](6V
H2p XJ/XF
queryCacheRegion){ >cr_^(UW&
this.queryCacheRegion = Hr8$1I$=
i[BR(D&l_p
queryCacheRegion; +h vIJv ?
} -GkK[KCH
{-7yZ]OO$
publicvoid save(finalObject entity){ +qW w-8
getHibernateTemplate().save(entity); g:3'x/a1
} ]OCJ~Zw
j7HlvoZV
publicvoid persist(finalObject entity){ n4_:#L?
getHibernateTemplate().save(entity); <[B[
} SAxa7B/U2
8iH;GFNJ7'
publicvoid update(finalObject entity){ j?KB8oY`TP
getHibernateTemplate().update(entity); /5'<w(
} E<G@LT
R&|)y:bg|
publicvoid delete(finalObject entity){ s2v#evI`+
getHibernateTemplate().delete(entity); Kac j
} <B{VL8IA>
pZJQKTCG
publicObject load(finalClass entity, !}Ou|r4_
VOK$;s'9}
finalSerializable id){ 2WECQl=r
return getHibernateTemplate().load LsD9hb7
n; '~"AG)
(entity, id); _(kwD^x6O{
} =O:ek#Bp
wj5s5dH
publicObject get(finalClass entity, PdN\0B`
Tvw2py q
finalSerializable id){ F$y FR
return getHibernateTemplate().get ]fS~N9B
H_f2:Za
(entity, id); eV=sDx
} 1Kf
t?g
Y},GZ ^zqy
publicList findAll(finalClass entity){ 2u H\8A+'f
return getHibernateTemplate().find("from e6xjlaKb
SK}g(X7IWH
" + entity.getName()); Nl)jQ
} c(g^*8Pb
ef;="N
publicList findByNamedQuery(finalString k*6eZ 7
g
UAPjR
namedQuery){ "EkO>M/fr
return getHibernateTemplate ssbyvzQ
HZ4
^T7G
().findByNamedQuery(namedQuery); yf^gU*
} a2_IF,p*?
I2!HXMrp
publicList findByNamedQuery(finalString query, +NMSvu_?
oDI*\S>
finalObject parameter){ ?\VN`8Yb
return getHibernateTemplate 1Nu`@)D0
5)i0g
().findByNamedQuery(query, parameter); <$6E r
} zb)SlR
dg8\(G
publicList findByNamedQuery(finalString query, %b4(wn?n:B
6x8|v7cMH
finalObject[] parameters){ ,.F+x}
return getHibernateTemplate *heQ@ww
(W/UR9x)|d
().findByNamedQuery(query, parameters); ~ZN9 E-uL
} d>psqmQ
ee` =B
publicList find(finalString query){ hIr^"kVK
return getHibernateTemplate().find xF+x I6
x"De
9SB
(query); q8]k]:r
} 9DKB+K.1
ka[NYW{.
publicList find(finalString query, finalObject W4a20KM2
VH65=9z
parameter){ zH4#\d
return getHibernateTemplate().find A*;h}\n
(E[hl
(query, parameter); 2 G{KpM&
} 6nhB1Aei
(Cd`~*5
public PaginationSupport findPageByCriteria -3Hq 1
9Ua@-
(final DetachedCriteria detachedCriteria){ zf#&3K 'k
return findPageByCriteria ]0E- lD0J
')<$AMy1
(detachedCriteria, PaginationSupport.PAGESIZE, 0); &ayoTE^0,
} ,_O[;L
VvKH]>*
public PaginationSupport findPageByCriteria K)OlCpHc
uM#/
(final DetachedCriteria detachedCriteria, finalint V"73^
P]GGnT(!
startIndex){ { q<l]jn9
return findPageByCriteria Wd#6Y}:
qZG >FC37
(detachedCriteria, PaginationSupport.PAGESIZE, ?9A[;j|a0
L_|Y_=r."
startIndex); ~JiA
} B%/Pn
2
lhU# /}Z
public PaginationSupport findPageByCriteria ]gZjV
-d]z_
SP@
(final DetachedCriteria detachedCriteria, finalint uPPe"$
q[lqEc
pageSize, o hCPNm
finalint startIndex){ }{"\"Bn_
return(PaginationSupport) NR5A"_'
j06DP _9M
getHibernateTemplate().execute(new HibernateCallback(){ b;{C1aa>}
publicObject doInHibernate ` {p5SYj
gFH_^~7i8p
(Session session)throws HibernateException { PZ s
Criteria criteria = c=gUY~Rl
RfD$@q9
detachedCriteria.getExecutableCriteria(session); {)M4h?.2
int totalCount = 7~&Y"&
tj0vB]c
((Integer) criteria.setProjection(Projections.rowCount T>?~eYHXs
v|xlI4
()).uniqueResult()).intValue(); <|4j<U
criteria.setProjection gM8 eO-d
TJ<PT
(null); T]xGE
List items = Vswi /(
9fiZ5\
criteria.setFirstResult(startIndex).setMaxResults >h9U~#G=
:A$6Y*s\
(pageSize).list();
<j>@Fg#q
PaginationSupport ps = ">o/\sXeH
:/3`+&T^/
new PaginationSupport(items, totalCount, pageSize, 8P 8"dN[
u0,~pJvX
startIndex); Z#Fw 1
return ps; s-*XAnot
} 5FMKJ7sC9
}, true); kU /?#s
} ;#
{x_>M
>iCMjT]4
public List findAllByCriteria(final HOw hl
ns3k{l#
DetachedCriteria detachedCriteria){ }XUHP%
return(List) getHibernateTemplate (Cq-8**dY
#yqcUbJY0R
().execute(new HibernateCallback(){ L \$zr,=C
publicObject doInHibernate Zwcb5\Q
FR <wp
(Session session)throws HibernateException { sOJ~PRA
Criteria criteria = t!k 0n&P
9we=aX5
detachedCriteria.getExecutableCriteria(session); rEViw?^KT
return criteria.list(); Mf
*qr9*
} c]9OP9F
}, true); 1v Thb
}
D;5RcZ
s^U^n//
public int getCountByCriteria(final |oM6(px
{r"s.|n
DetachedCriteria detachedCriteria){ _w26iCnB{
Integer count = (Integer) _k}b
1~*_H_Q't
getHibernateTemplate().execute(new HibernateCallback(){ r}991O<
publicObject doInHibernate sqy5rug
RPrk]<<1
(Session session)throws HibernateException { pp:+SoyN
Criteria criteria = L+u_153
#y?z2!
detachedCriteria.getExecutableCriteria(session); "[%NXan
return ZpdM[\Q-
=}L[/ RL
criteria.setProjection(Projections.rowCount /; _"A)0
!>+
0/
()).uniqueResult(); e0qa~5
} HG^8&uh]
}, true); hk=+t&Y<H
return count.intValue(); D&'".N,}
} [:o#d`^
} ~5|a9HV:
^mGT ZxO
_V;J7Vz
wjl?@K
Kb}N!<Z*
4b#YpK$7U
用户在web层构造查询条件detachedCriteria,和可选的 }A#FGH+
Y8d%L;b[D
startIndex,调用业务bean的相应findByCriteria方法,返回一个 YONg1.^!(
JmBYD[h,
PaginationSupport的实例ps。 *)w
8fq
J:>TV.TP
ps.getItems()得到已分页好的结果集 T7,tJk,(
ps.getIndexes()得到分页索引的数组 j_{gk"2:d`
ps.getTotalCount()得到总结果数 5pDxFs=v
ps.getStartIndex()当前分页索引 4uv }6&R
ps.getNextIndex()下一页索引 &O'yhAP] j
ps.getPreviousIndex()上一页索引 7fVVU+y
l})uYae/
Y8P
GY!&H"%
_x lgsa
A_g'9
-uh/W=Q1R
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 bXJE 2N
BG|Kw)z*KM
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 CzK
X}
rF5<x3
一下代码重构了。 UeVF@rw
6"wY;E
我把原本我的做法也提供出来供大家讨论吧: 0}ZuF.
41:Z8YL(
首先,为了实现分页查询,我封装了一个Page类: 8-m"] o3
java代码: eBP
N[V
isaT0__8
:ortyCB:H
/*Created on 2005-4-14*/ (cMrEuv
package org.flyware.util.page; U9@q"v-
wU=(_S,c
/** J3$ihH.
* @author Joa Ji7A9Hk
* ;[|x5o/<
*/ gcz1*3)
publicclass Page { j;'NJ~NZ$
~v5tx
/** imply if the page has previous page */ gh~C.>W}q+
privateboolean hasPrePage; lr|-_snx2
0
xXAhv-)O
/** imply if the page has next page */ j\ )Qn2r
privateboolean hasNextPage; -?GYW81Q
R%ddB D\?
/** the number of every page */ ($3QjH_@
privateint everyPage; |GMK@Q'0:
l@^RbF['
/** the total page number */ 2Gj&7A3b
privateint totalPage; gDA hl
yXkgGY5
/** the number of current page */ X`22Hf4ct
privateint currentPage; k<St:X%.O
5$y<nMP
/** the begin index of the records by the current !|}>Y
`W-:@?PmQx
query */ HezCRtxRcc
privateint beginIndex; |~>8]3. Y
Hj5b.fB
5Po.&eS
/** The default constructor */ ZGS=;jM
public Page(){ \zKVgywR
tV<Au
} t!PFosFp
1e&`m~5K+
/** construct the page by everyPage h[ tOY
* @param everyPage 8`im4.~#%
* */ No[>1]ds
public Page(int everyPage){ *:_.cbo
this.everyPage = everyPage; ]-0
&[@I4@
} [H"Ods~_`
79i>@u%
/** The whole constructor */ O ~"^\]\
public Page(boolean hasPrePage, boolean hasNextPage, 9zX\ioT
7qs[t7-h?
,,i;6q_f
int everyPage, int totalPage, WjA)0HL(
int currentPage, int beginIndex){ b]J_R"}
this.hasPrePage = hasPrePage; (5atU |8r
this.hasNextPage = hasNextPage; NE/3aU
this.everyPage = everyPage; ]ao]?=q C
this.totalPage = totalPage; \ii^F?+b
this.currentPage = currentPage; x*_c'\F|
this.beginIndex = beginIndex; )EO$JwQ
} 4YdmG.CU
JNZKzyJ9K
/** R^K<u#>K
* @return aZmSCi:&'
* Returns the beginIndex. 2Qn%p[#n
*/ `B^?Za,xN
publicint getBeginIndex(){ 8(ZQD+U(9F
return beginIndex; tv?~LJYN
} ??k^Rw+0R
oW-luC+
/** ($ae n
* @param beginIndex zRu}lJ1#W$
* The beginIndex to set. b7=]"|c$@
*/ P$qIB[Xi
publicvoid setBeginIndex(int beginIndex){
vH`u
this.beginIndex = beginIndex; 'a4xi0**I
} F n6>n04v
R(Z2DEt</
/** SA}]ZK P
* @return MF=@PE][
* Returns the currentPage. $rf5\_G,96
*/ =_TCtH
publicint getCurrentPage(){ ;zs4>>^>
return currentPage; u dH7Q&"
} Vj`9j. 5
+]B^*99
/** YKj7~yK?
* @param currentPage 4,uH 4[7
* The currentPage to set. \+
K
^G
*/ g{dyDN$5|w
publicvoid setCurrentPage(int currentPage){ <~f/T]E,
this.currentPage = currentPage; %vMi
kibI
} YsLEbue
#K
]k
/** /EWF0XV!
* @return M)Y`u
* Returns the everyPage. 4,FuQ}
*/ V5M_N;h
publicint getEveryPage(){ ='YR;
return everyPage; fNQ.FAK":
} FJ~Dg3F1
VNaa(Q
/** e PlEd'Z
* @param everyPage )(y&U
* The everyPage to set. bp;)*
*/ N!$y`nwiw'
publicvoid setEveryPage(int everyPage){ IaN|S|n~
this.everyPage = everyPage; ,p0R4gi
} /G\-v2i D
% &{>oEQ
/** ]#_,?d
* @return O
/aC%%
* Returns the hasNextPage. spgY &OI;
*/ :MpIx&
publicboolean getHasNextPage(){ !*N#}6Jd
return hasNextPage; L;>tuJY1
} oE)tK1>;H
YI&7s_%
-
/** 389T6sP]
* @param hasNextPage &yWl8O
* The hasNextPage to set. X+Xjf(
*/ pX|\J>u)
publicvoid setHasNextPage(boolean hasNextPage){ 6i, d|
this.hasNextPage = hasNextPage; 0l{').!_
} 7w YSP&$
EcFYP"{U
/** J*qepq`_
* @return HIeWgw^"
* Returns the hasPrePage. +#n5w8T)M
*/ c.,eIiL
publicboolean getHasPrePage(){ sl>4O]N
return hasPrePage; ;?bRRW
} *p p1U>,
eQJLyeR+
/** R7( + ^%
* @param hasPrePage lB.P
* The hasPrePage to set. -7hU1j~I
*/ <HI5xB_
publicvoid setHasPrePage(boolean hasPrePage){ hP,SvN#!2
this.hasPrePage = hasPrePage; [Kx_ %Le
} 0}-&v+
zZGPA j
/** 74xI#`E
* @return Returns the totalPage. E.t9F3
* :>;-uve8'
*/ /w`{]Ntgu
publicint getTotalPage(){ C
KBLM2D
return totalPage; pu,/GBG_
} uXyNj2(d.
G{$9e}#
/** t&eY+3y,T
* @param totalPage 2-. g>'W
* The totalPage to set. }mk9-7
*/ fw'$HV76
publicvoid setTotalPage(int totalPage){ NhS0D=v6
this.totalPage = totalPage; ~`u?|+*BO
} c-n'F+fZ
^s_E |~U
} _|x%M}O},
]Y}faW(&Y
I?Hj,lN
(SU*fD!t
YNH>^cD1
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 3@\vU~=P:
[AfV+$
个PageUtil,负责对Page对象进行构造: GL9R
5
java代码: $BwWhR
lT DF5.aE
I^ppEgYSY
/*Created on 2005-4-14*/ 3JWHyo
package org.flyware.util.page; L5]*ZCDv
6P3ezl@#;
import org.apache.commons.logging.Log; rKP"|+^
import org.apache.commons.logging.LogFactory; 9v_gR52vh
{M$mrmG
/** LdDkd(k
* @author Joa DbH{;
Fb
* u3dh MnUn
*/ AW!|xA6'`:
publicclass PageUtil { :DR
G=-M
rX{QgyY&
privatestaticfinal Log logger = LogFactory.getLog WB"$NYB
tlA4oVII
(PageUtil.class); N"2P&Ho]
PQlG!
/** n)8bkcZCp+
* Use the origin page to create a new page -P!vCf^{
t
* @param page j}X4#{jgC
* @param totalRecords ^-f5;B`\i
* @return b=Zg1SqV
*/ 4qrPAt
publicstatic Page createPage(Page page, int 69`9!heu
H7H'0C
totalRecords){ Gg{@]9
return createPage(page.getEveryPage(), 4;7<)&#h
>8#(GXnSt
page.getCurrentPage(), totalRecords); 7=6p
} VQ$=F8ivG
mdoy1a
/** D-8%lGS
* the basic page utils not including exception ouPwhB,bg
~i=/@;wRp
handler 7Q/v#_e(
* @param everyPage LGgEq-
* @param currentPage |&o1i~Y
* @param totalRecords BB1'B-O
* @return page f>;5ZE4Zu
*/ tI{pu}/"#
publicstatic Page createPage(int everyPage, int #z6RzZu
nv2Y6e}dG
currentPage, int totalRecords){ mO?G[?*\
everyPage = getEveryPage(everyPage); wGBQ.Ve[
currentPage = getCurrentPage(currentPage); G$xuHHZ'
int beginIndex = getBeginIndex(everyPage, i('z~
a+{YTR>0m
currentPage); (|I0C 'Ki
int totalPage = getTotalPage(everyPage, mRW(]OFIai
GLv}|>W
totalRecords); tV[?WA[xt
boolean hasNextPage = hasNextPage(currentPage, tkR^dC
FJ!N)`[
totalPage); AA^3P?iD
boolean hasPrePage = hasPrePage(currentPage); QtW5;A-h
a`~$6
"v
returnnew Page(hasPrePage, hasNextPage, Iu[^"
everyPage, totalPage, 6aX m9J
currentPage, / d0LD
Vj:)w<],
beginIndex); 7Aq4YjbX
} ]zhFFq`
^pKC0E[%
privatestaticint getEveryPage(int everyPage){ RCND|X
return everyPage == 0 ? 10 : everyPage; Njc3X@4=
} YM1tP'4j@
aCM F[
3j
privatestaticint getCurrentPage(int currentPage){ 66[yL(*+
return currentPage == 0 ? 1 : currentPage; H
\.EKZ
} 0;!aO.l]K
MztT/31S
privatestaticint getBeginIndex(int everyPage, int sFx$
h%E25in
currentPage){ ' f}^/`J
return(currentPage - 1) * everyPage; yV$p(+KkS
} qusgX;)
BaR9X ?~O$
privatestaticint getTotalPage(int everyPage, int dGQy=T:
VrQw;-rQ
totalRecords){ Wa2V Z
int totalPage = 0; $kZ,uvKN
:c!7rh7O
if(totalRecords % everyPage == 0) kD >|e<}\
totalPage = totalRecords / everyPage; S;Lqx5Cd
else fdck/|`t
totalPage = totalRecords / everyPage + 1 ; $B2*
x$
qV/"30,K
return totalPage; *xkbKkm
} {S~2m2up0L
[77]0V7
privatestaticboolean hasPrePage(int currentPage){ mu=u!by.E
return currentPage == 1 ? false : true; o-("S|A-
} Lyt6DvAp"
XFG]%y=/6
privatestaticboolean hasNextPage(int currentPage, .: 87B=
K%2,z3ps
int totalPage){ FOquQr1cF
return currentPage == totalPage || totalPage == |b'tf:l
4w*F!E2H\}
0 ? false : true; !}l)okQH<#
} FK
}x*d
U%t:]6d&}
OAOG&6xu8
} f*NtnD=rJ
b?B"u^b!
8{4I6;e-
xZGR<+t
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。 6X7r=w
}{bO~L7
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 dK|MQ <
[0m'a\YE9
做法如下: o:f=dBmoX
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 7M3q|7?
^}U{O A
的信息,和一个结果集List: :*0k:h6g
java代码: &|n*&@fF
31w?bx !Pp
$ daI++v`
/*Created on 2005-6-13*/ KD-0NO=oL
package com.adt.bo; ^%IKlj-E
qf4|!UR{
import java.util.List; &7E 0H{
MCz+l0
import org.flyware.util.page.Page; 8%arA"#S
rya4sxCh
/** s^L\hr
* @author Joa Sn7.KYS
*/ Wj8\~B=('
publicclass Result { ]r'b(R; S
<2}"Y(zwKl
private Page page; &X}9D)\UJ
Wq&TbWR
private List content; 3j]La
I".d>]16|
/** 0t/ S_Q
* The default constructor T/-PSfbkj
*/ Fe"0Hp+
public Result(){ |+suGqo
super(); by>,h4
} G5TdAW
Nf<([8v;t
/** OWtN=Gk
* The constructor using fields XfViLBY(
>
* C
[=/40D
* @param page ZSKk*<=
* @param content &|/C*2A
*/ /3FC@?l
w4
public Result(Page page, List content){ 5IVASqYp
this.page = page; r[EN`AxDb
this.content = content; <0JW[m
} <9\_b6
_ F@>?\B
/** CDU^X$Q
* @return Returns the content. Gx'mVC"{
*/ 2=["jP!B
publicList getContent(){ KhXW5hS1
return content; X+P3a/T
} dRWp/3 }
$sGX%u
/** ?y]3kU
* @return Returns the page. ~Z.lvdA_5
*/ .6e5w1r63
public Page getPage(){ vlEd=H,LT
return page; 5OpK~f5
} k3S**&i!CR
\-V
/** QL_bg:hs
* @param content dXrv
* The content to set. jUW{Z@{U
*/ v,Ep2$
public void setContent(List content){ z Lf^O%zN
this.content = content; Ms{v;fT
} -_b}b)2iYN
42Kzdo|}
/** @105 @9F
* @param page CIO&VK
* The page to set. `lcpUWn
*/ ZuBVq
publicvoid setPage(Page page){ K'1rS[^>R
this.page = page; }KS[(Q
} 0DS<(
} D?X97jNm
-2% []
KZ/}Iy>As
|JuXOcr4
zzq/%jki
2. 编写业务逻辑接口,并实现它(UserManager, ?w3f;v
z'fGHiX7.0
UserManagerImpl) G78rpp
java代码: b4oZ@gVR;
F
=d L#@^
X1tAV>k5'L
/*Created on 2005-7-15*/ U{i9h6b"18
package com.adt.service; {U-VInu
WlWBYnphZs
import net.sf.hibernate.HibernateException;
<&$!;d8
^XZmtB
import org.flyware.util.page.Page; Q8z>0ci3o
If]g6
B.=
import com.adt.bo.Result; |}'}TYX0:
{,P&05iSi
/** i~ zL,/O8
* @author Joa QsI$4:yl
*/ +de.!oY
publicinterface UserManager { LLaoND6
VPtA
%1
public Result listUser(Page page)throws ;uR8pz e
-I\_v*nA
HibernateException; mP3:Fc_G
Q:=s99
} u )
fbR
BX+-KvT
i aP+Vab
%<I0-o
4y%N(^
java代码: d-xKm2sH
{9'"!fH
`|v0@-'$
/*Created on 2005-7-15*/ N \A)P
package com.adt.service.impl; 5vg@zH\z
]7'Q2OU7
import java.util.List; }ndH|,
3#0nus|=S
import net.sf.hibernate.HibernateException; PJh\U1Z
1c?,= ;>
import org.flyware.util.page.Page; :q^g+Bu=
import org.flyware.util.page.PageUtil; >{npg2
NTgk0cq
import com.adt.bo.Result; ]!h%Jlu
import com.adt.dao.UserDAO; 3lA<{m;V
import com.adt.exception.ObjectNotFoundException; k{"~G#GwP
import com.adt.service.UserManager; ZNG.W0{p
|Q.?<T:wt=
/** /$I&D}uR`
* @author Joa _%Mu{Ni&
*/ %)\Cwl
publicclass UserManagerImpl implements UserManager { DRf~l9f
q'q'v
S
private UserDAO userDAO; *A
c~
nSgg'I(
/** Y:*mAv;&
* @param userDAO The userDAO to set. 9OXrz}8C
*/ shnfH
publicvoid setUserDAO(UserDAO userDAO){ OuS{ve
this.userDAO = userDAO; IExQ}I
} l|j&w[c[Q0
P{rJG
'
/* (non-Javadoc) wF3mQ_hv:@
* @see com.adt.service.UserManager#listUser tlqDY1
od?Q&'A
(org.flyware.util.page.Page) AvP*p{we
*/ $T]1<3\G
public Result listUser(Page page)throws I2K52A+
"0zMx`Dh
HibernateException, ObjectNotFoundException { D.R5-
int totalRecords = userDAO.getUserCount(); [9aaHf@'
if(totalRecords == 0) l<z[)fE{uS
throw new ObjectNotFoundException Kq6m5A]z
~iF*+\
("userNotExist"); p~Dm3^Y
page = PageUtil.createPage(page, totalRecords); UxD1+\N6?
List users = userDAO.getUserByPage(page); sOU_j4M{
returnnew Result(page, users); >JCSOI
} OdwSNG
+<bq@.x
} McH*J j
D95$
.'D+De&y
POUB{ba
^D oJ='&
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 BFj@Z'7P
Yg2z=&p-{"
询,接下来编写UserDAO的代码: .B#Lt,m
3. UserDAO 和 UserDAOImpl: C'7W50b
java代码: :qgdn,Me
6TPcG d Z
,FS iE\
/*Created on 2005-7-15*/ SuGlNp>#qm
package com.adt.dao; A(;J
d'Gv \i&e
import java.util.List; z?1GJ8
|byB7f
import org.flyware.util.page.Page; f&^Ea-c
Y k~ i.p
import net.sf.hibernate.HibernateException; |[k6X=5
X] Tb4
/** _mXq]r0
* @author Joa =CRaMjN
*/ B;W=61d
publicinterface UserDAO extends BaseDAO { e/@udau
HzH_5kVW
publicList getUserByName(String name)throws fVR ~PG0
T']*h8
HibernateException; NF&\<2kX
2Ni{wg"
publicint getUserCount()throws HibernateException; VFA1p)n
0SvPyf%AC
publicList getUserByPage(Page page)throws )m5<gp `
y<3v/,Y
HibernateException; Ie4*#N_
uz'beE
} |W:kzTT-T
ua7I K~8l
b;!ilBc
S$muV9z2=
mpr["C"l
java代码: DgOoEHy[
9Cf^Q3)5o
RA.@(DN&
/*Created on 2005-7-15*/ ;F~GKn;}
package com.adt.dao.impl; qc*+;Wi+5
xW"J@OiKL
import java.util.List; Mh3zl
B(^fM!_%-6
import org.flyware.util.page.Page; (T'inNbJe
mjs*Z{_F^
import net.sf.hibernate.HibernateException; iCv &<C@
import net.sf.hibernate.Query; ^T^U:Zdq
%$sWNn
import com.adt.dao.UserDAO; TU[f"!z^
S@_@hFV jd
/** #+ n
&
* @author Joa }$AC0
*/ @ Cqg2
public class UserDAOImpl extends BaseDAOHibernateImpl ZTt%7K"L
$RA"NIZ:!
implements UserDAO { tQ2*kE
O5k's
/* (non-Javadoc)
-U*XA
* @see com.adt.dao.UserDAO#getUserByName xZ9y*Gv\=
xn}'!S2-b
(java.lang.String) bdcuO)3
*/ 4S"K%2'O
publicList getUserByName(String name)throws 2sittP
n]8_]0{qi
HibernateException { #NL1N_B
String querySentence = "FROM user in class zROyG
D-,sF8{ i
com.adt.po.User WHERE user.name=:name"; cteHuRd
Query query = getSession().createQuery |'KNR]:
N
h)A+5^:^
(querySentence); A]=?fyPh{'
query.setParameter("name", name); |ZRl.C/e
return query.list(); hj4A&`2
} 9lA YCsX
9=JU&/!
/* (non-Javadoc) \vm'D'9
* @see com.adt.dao.UserDAO#getUserCount() c#{<|
.
*/ F1%'
zsv
publicint getUserCount()throws HibernateException { 7g&_`(
int count = 0; OQ[>s(`*{
String querySentence = "SELECT count(*) FROM 7 ic]q,
@d4zSG/s5w
user in class com.adt.po.User"; a o7|8[
Query query = getSession().createQuery 162qx R[.
{nHy!{+qqG
(querySentence); );Gt!]p`;
count = ((Integer)query.iterate().next KJpM?:
wlKL|N
()).intValue(); .!9]I'9M
return count; 53(m9YLk
} w;#9 hW&
\LM'KD pP_
/* (non-Javadoc) 4>5%SzZT\3
* @see com.adt.dao.UserDAO#getUserByPage -,5g cD
K5w22L^=+
(org.flyware.util.page.Page) %LVk%kz
*/ v3]q2*`G#
publicList getUserByPage(Page page)throws E176O[(V=
'`3-X];p
HibernateException { possM'vC
String querySentence = "FROM user in class 5'z&kl0"S
N8nyTPw
com.adt.po.User"; spe9^.SI
Query query = getSession().createQuery {[Yv@CpN
yY&(?6\{<<
(querySentence); T>?sPq
query.setFirstResult(page.getBeginIndex()) 93'%aSDI%
.setMaxResults(page.getEveryPage()); h+*
return query.list(); Q&F@[k
} $6'xRUx X
W
tzV|e,
} b]Z@zS<8
uHf~KYL
aMz%H|/$
{s`1+6_&Vz
@cjhri|vH
至此,一个完整的分页程序完成。前台的只需要调用 *`l>1)B>
&Vonu*
userManager.listUser(page)即可得到一个Page对象和结果集对象 {b#c0>.8-
8^4X/n
的综合体,而传入的参数page对象则可以由前台传入,如果用 FG8bP
Bj]0Cz
webwork,甚至可以直接在配置文件中指定。 ~Q]B}qdm
M#|TQa N
下面给出一个webwork调用示例: p>!r[v'
java代码: a.]
!
Z;n}*^U
O-&n5
/*Created on 2005-6-17*/ 47icy-@kg
package com.adt.action.user; 0kiW629o
Rw.
Uz&
import java.util.List; ipbVQ7
[C d2L&9
import org.apache.commons.logging.Log; U9N}6a=
import org.apache.commons.logging.LogFactory; %NAz(B
import org.flyware.util.page.Page; @Sv
?Ar
:'rXu6c-
import com.adt.bo.Result; o oS4F1ta
import com.adt.service.UserService; ' !_44
import com.opensymphony.xwork.Action; WV&BZ:H
3cfkJ|fuwe
/** MA1,;pv6
* @author Joa %{Ls$Y)
*/ H$[--_dI{
publicclass ListUser implementsAction{ c}{e,t
5T;_k'qe
privatestaticfinal Log logger = LogFactory.getLog UW>~C
tSOF7N/<
(ListUser.class); uZQ)A,#n;
1-qQp.Wj
private UserService userService; mS);bs
}'Z(J)Bg
private Page page; UPgZj\t%{
G A7
privateList users; VvltVYOZA
r":<1+07
/* dj]sr!q+
* (non-Javadoc) Nf;vUYP
* TvQAy/Y0
* @see com.opensymphony.xwork.Action#execute() <"\K|2Sg
*/ APLu?wy7s5
publicString execute()throwsException{ +ATN2
o
Result result = userService.listUser(page); RCmPZ
page = result.getPage(); wZOO#&X#r
users = result.getContent(); 10 p+e_@
return SUCCESS; |]I?^:I
} Ik}*7D
!c*^:0
/** F\]rxl4(L
* @return Returns the page. ;nC+Kz:
*/ !
4s$93
public Page getPage(){ \XpPb{:>
return page; D&oC1
} @RnG K 5
3s|tS2^4
/** zY#U ]Is
* @return Returns the users. Np=*B_ @8
*/ %`}Qkb/Lyh
publicList getUsers(){ wIY#TBu
return users; !W3Le$aL
} oF*Y$OEu?c
fqr}tvMr=T
/** cw^FOV*
* @param page 0<s)xaN>Y
* The page to set. [t6)M~&e:_
*/ wo_FM
`@
publicvoid setPage(Page page){ n;q7?KW8
this.page = page; o%|1D'f^
} K]7@%cS
>Ek`PVPD
/** fx}R7GN2
* @param users t /47lYN)
* The users to set. [UI
bO@e
*/ A2vOI8
publicvoid setUsers(List users){ d>aZpJ[.
this.users = users; v\HGL56T
} a1}W2;W0]g
Z>D7C?v:(
/** bh_ALu^CSX
* @param userService PuOo^pFhH
* The userService to set. #h&?wE>
*/ S9L3/P]
publicvoid setUserService(UserService userService){ LEhi/>T
this.userService = userService; (Q'XjN\#
} .oe,#1Qh{
} +g.WO5A
c\x?k<=
2HTZ,W
I @z{Gr
-~aVt~{k/
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, gWlmQl
]c5Shj5|p
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 -\I0*L'$|\
+fwq9I>L
么只需要: C )PN
java代码: u_[Zu8
:J<S-d=
7v?Ygtv
<?xml version="1.0"?> 2GD%=rP2]
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork J[B8sa
3!}#@<j
1.0//EN" "http://www.opensymphony.com/xwork/xwork- $6J5yE
77
`/YE#M
1.0.dtd"> k\%{1oRA
>?DrC /
<xwork> NKMB,b
b"zq3$6*
<package name="user" extends="webwork- 9S<W~# zz
D!-zQ`^
interceptors"> %_z]iz4
fkI<RgM
<!-- The default interceptor stack name Zkz:h7GUG-
@&~BGh
--> mDq01fU4
<default-interceptor-ref tL3(( W"
U "}Kth
name="myDefaultWebStack"/> xL!05du
HN3
yA1<[V
<action name="listUser" JRNyvG>j
0\mM^+fO
class="com.adt.action.user.ListUser"> SZ0Zi\W
<param 5I<?HsK@
F>}).qx
name="page.everyPage">10</param> O+e8}Tmm
<result \
0CGS
`\qU.m0(j
name="success">/user/user_list.jsp</result> ypsCyDQK`
</action> MKH7d/x
' 1mygplW
</package> Bq _<v)M*
F{}z[0
</xwork> sn*s7v:
:l7\7IT
Fq{nc]L6
g\^(>Ouc
PEBQ|k8g&
w|M?t{
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=my;M-
a $KM
q>
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 0J_ x*k6
VVf~ULZ-
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 ngNg1zV/q
\/,SH?>4x
%%f=aPw
%bv<OMD
bEy%S"\<
我写的一个用于分页的类,用了泛型了,hoho <n#JOjHV
)wGC=,
java代码: SC!IQ80H#D
@!F9}n
AP
7N""w5
package com.intokr.util; NeWssSje
GRs ;-Jt
import java.util.List; l"vT@g|
foN;Q1?lS
/** 't>Qj7vh0
* 用于分页的类<br> iCc\p2p
* 可以用于传递查询的结果也可以用于传送查询的参数<br> Onk~1ks:
* H)4Rs~;{'g
* @version 0.01 L72GF5+!!
* @author cheng kQ:2 @SOm
*/ 5=
F-^
public class Paginator<E> { u}$U|Cw-;T
privateint count = 0; // 总记录数 p;B
+g X
privateint p = 1; // 页编号 jLEU V
privateint num = 20; // 每页的记录数 =N3~2=g~A
privateList<E> results = null; // 结果 G3e%~
^ZV xBQKg
/** ;Lu}>.t
* 结果总数 ,= PDL
*/ Mc\lzq8\ 1
publicint getCount(){
&hF>}O
return count; 6Qo6T][
} iffU}ce
E O}(MXS
publicvoid setCount(int count){ p3Gj=G
this.count = count; L,:U _\HQ
} *yJb4uALB
G{s ,Y^
/** $4?%Z>'
* 本结果所在的页码,从1开始 k20H|@g2
* 8G@FX $$Q
* @return Returns the pageNo. [6D>2b}:{[
*/ )XNcy"
publicint getP(){ qH(2 0Z!
return p; |l~ADEg
} !O.B,
Q/+a{m0f
/**
O35f5Kz
* if(p<=0) p=1 0(..]\p^d
* \mycn/e
* @param p ]-q:Z4rb
*/ [F>zM
publicvoid setP(int p){ n%O`K{86
if(p <= 0) ^X?[zc GE
p = 1; ;Joo!CXHO
this.p = p; .K0BK)axO
} ZuE0'9
2ru6bIb;
/** Ex Qld
* 每页记录数量 c.XLEjV|
*/ @e slF
publicint getNum(){ I4)vJ0
return num; Obd!
} `W/6xm(X5;
w gufk{:
/** y_nh~&
* if(num<1) num=1 7X.1QSuE
*/ B
O"+m
publicvoid setNum(int num){ {!="PnB
if(num < 1) %? g]{
num = 1; eFx*lYjA
this.num = num; k{;:KW|
} 44]ae~@a
^a]i&o[c
/** M\]E;C'"U
* 获得总页数 DnTM#i:
*/ 2<'gX>TW
publicint getPageNum(){ $X{& KLM[
return(count - 1) / num + 1; [R~HhM
} ZWFH5#=
h0gT/x
/** Z86[sQBg
* 获得本页的开始编号,为 (p-1)*num+1 n1LS*-@
*/ u|Ai<2b$
publicint getStart(){ }%}eyLm(
return(p - 1) * num + 1; MRa>@Jn??A
} x
1_(j
E^qKkl
/** z4<h)hh"k6
* @return Returns the results. A76=^iw
*/ R:fu n,
publicList<E> getResults(){ O=mJ8W@
return results; i44`$ps
} bv] ZUF0
c[YC}@l%a
public void setResults(List<E> results){ Xak~He
this.results = results; {Cd*y6lI
} LO2sP"9
</}[x2w?]
public String toString(){ .h6h&[TEU
StringBuilder buff = new StringBuilder %AJdtJ@0H
FkS{Z s
(); g_q{3PW.
buff.append("{"); HS2)vd@)
buff.append("count:").append(count); EEaFi8
buff.append(",p:").append(p); |GsLcUv6
buff.append(",nump:").append(num); Qejzp/2
buff.append(",results:").append yZ2,AR%
MdPwuXI
(results); 4f1*?HX&
buff.append("}"); !nd*U}q
return buff.toString(); RS93_F8
} "'8$hV65.p
vbWX`skU
} U@*z#T#"m
Ufk7%`
*s/F4?*