Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ?w#
>Cs(
*6*#"#D
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Wnl8XHPn
!gy'_Y
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 Hi|2z5=V
<Xy8}Z`s
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 +,>f-kaV
.Z&OKWL
。 5HG 7M&_
4PiN Q'*
分页支持类: D4'?
V
Iz
Bx&`$lW
java代码: sNvT0
$?Aez/
t@.gmUUA
package com.javaeye.common.util; mkBQX
j %TYyL-
import java.util.List; ^yK94U;<Gy
q22cp&gmX
publicclass PaginationSupport { kRiWNEw
}(E6:h;}~
publicfinalstaticint PAGESIZE = 30; T<54qe4`p
<zZAVGb4I
privateint pageSize = PAGESIZE; CX':nai
Tc:W=\ <
privateList items; -|[_j$g
(6+6]`c$
privateint totalCount; 8fM}UZI
zp4ru\
privateint[] indexes = newint[0]; U_}$QW0'
42p6l
privateint startIndex = 0; ?RpT_u
#C+Gk4"w
public PaginationSupport(List items, int a
#@Q.wL
--.j&w
totalCount){ T]^F%D%
setPageSize(PAGESIZE); V"$t>pAG
setTotalCount(totalCount); Sa,N1r
setItems(items); 'EZ[aY!);
setStartIndex(0); NYP3uGH]
} -&)^|Atm
sF+0v p
public PaginationSupport(List items, int Nr`nL_DQ
lR.a3.~
totalCount, int startIndex){ {+xUAmd
setPageSize(PAGESIZE); 1.,mNY^UN
setTotalCount(totalCount); d`~#uN {
setItems(items); 1xguG7
setStartIndex(startIndex); c+a f=ac
} f{AgKW9"
,dVCbAS@
public PaginationSupport(List items, int a|nlmH"l
_9z/>e
totalCount, int pageSize, int startIndex){ OM4s.BLY
setPageSize(pageSize);
=oQzL
setTotalCount(totalCount); 2jhVmK
setItems(items); CzvlZDo
setStartIndex(startIndex); m/eGnv;!
} On'3K+(_
6km
u'vw
publicList getItems(){ fykN\b
return items; {t=Nnc15K
} keJec`q=X
%+I(S`}
publicvoid setItems(List items){ Y~vTFOI
this.items = items; U~H'c
p
} Ep?a>\
JA(nDD/;
publicint getPageSize(){ MxdfuFss
return pageSize; v,D_^?] @
} y5Pw*?kn
gE
,j\M*
publicvoid setPageSize(int pageSize){ h5f>'lz
this.pageSize = pageSize; w4x 8
Sre
} mKsj7
Ki=7nKs
publicint getTotalCount(){ 4|2$b:t
return totalCount; VBH[aIW
} Nb];LCx
O"#`i{^?2
publicvoid setTotalCount(int totalCount){ %<M<'jxSca
if(totalCount > 0){ u^]yz&9V
this.totalCount = totalCount; E`?BaCrG~
int count = totalCount / cEqh|Q
P);Xke
pageSize; )K?GAj]Pq
if(totalCount % pageSize > 0) %'=oMbi>i4
count++; Qy70/on9
indexes = newint[count]; VuPET
for(int i = 0; i < count; i++){ dt \O7Rjw8
indexes = pageSize * <oXsn.'\
=d5!O~}r>
i; W^Rb~b^?
} J.nVEqLZ
}else{ xlwsZm{V
this.totalCount = 0; /7lkbL
} iit`'}+U
} N )!v-z,k
[e}]K:
publicint[] getIndexes(){ ky~ x4_y5
return indexes; mCE})S
} Dq?2mXOqD
SRD&Uf0M
publicvoid setIndexes(int[] indexes){ Z~c7r n
this.indexes = indexes; ^=W&p%Y(!
} TdE_\gEo/R
=#V11j
publicint getStartIndex(){ -$0S#/)Z
return startIndex; (mD]}{>
} SW; bE
xw-q)u
publicvoid setStartIndex(int startIndex){ &*yve}su
if(totalCount <= 0) }fCM_w
this.startIndex = 0; K%gFD?{^q
elseif(startIndex >= totalCount) )m'_>-`^:
this.startIndex = indexes P\AH9#XL
ZF
t^q/pw
[indexes.length - 1]; rx;U/)~#<
elseif(startIndex < 0) W" !amMQ
this.startIndex = 0; @s@
else{ 1(?J>{-lw
this.startIndex = indexes \1MDCP9:
+,-rb
[startIndex / pageSize]; {+[gf:Ev
} qN QsU
} [T%blaSX
\'EWur"
publicint getNextIndex(){ !K 9(OX2;
int nextIndex = getStartIndex() + EK#m?O:>
yJL"uleRT
pageSize; p)jxqg
if(nextIndex >= totalCount) g.]'0)DMW
return getStartIndex(); ]Bsq?e^
else .UYpPuAkn
return nextIndex; ye%F <:O7
} e)xWQ=,C
2)A
D'
publicint getPreviousIndex(){ UZ!hk*PF
int previousIndex = getStartIndex() - VM!x)i9z
mTPj@F>
pageSize; m#ie{u^
if(previousIndex < 0) :mrGB3x{
return0; 8`t%QhE2
else ks5'Z8X
return previousIndex; Vj]kJ,j\y
} X^W>
"q
5oKc=iX_3
} I I8nz[s
9y4rw]4zI
d!t@A
(FaT{W{
抽象业务类 nKO&ffb'<
java代码: } 8P}L@q
qck/b
+B m+Pj>
/** )
G{v>Z,
* Created on 2005-7-12 3XnXQ/({
*/ UIl_&|
package com.javaeye.common.business; TUaK:*x*
zEB1Br,
import java.io.Serializable; }j?S?= ;m=
import java.util.List; .+Ej%|l%
-^b^ 6=#
import org.hibernate.Criteria; r+\z0_'
w6
import org.hibernate.HibernateException; %p9bl ,x
import org.hibernate.Session; gJ&!w8v.
import org.hibernate.criterion.DetachedCriteria; , _$"6
import org.hibernate.criterion.Projections; tTt3D]h(
import 6.|~~/
LU{Z
org.springframework.orm.hibernate3.HibernateCallback; wB)+og-^1f
import is(!_Iv
95Qz1*TR
org.springframework.orm.hibernate3.support.HibernateDaoS p4'"Wk8
$<cZ<g5)
upport; %wf|nnieZ
pPZ/ O6
import com.javaeye.common.util.PaginationSupport; #CPP dU$
;}~=W!yz
public abstract class AbstractManager extends )sf~l6
'y?|shV{]
HibernateDaoSupport {
@__;RVQ
Nd_@J&
privateboolean cacheQueries = false; `I8^QcP
ymZ/(:3_
privateString queryCacheRegion; {+2cRr.
o"FiM5L^.
publicvoid setCacheQueries(boolean Xa@wN/"F
(UF!Zb]{
cacheQueries){ D-GU"^-9
this.cacheQueries = cacheQueries; Q:O>k CDV
} RfBb{?PP)
|y%].y)
publicvoid setQueryCacheRegion(String ~TH5>``;gF
LJwM M
queryCacheRegion){ M0SH-0T;Z
this.queryCacheRegion = t^,Qy.L0
358/t/4{p
queryCacheRegion; 9|?Lz
} ~(j'a!#Vvk
xLI{=sL
publicvoid save(finalObject entity){ N1~V +_mM
getHibernateTemplate().save(entity); |{)xC=
} 3\n{,Q
1fFb7n~3
publicvoid persist(finalObject entity){ 8 %j{4$
getHibernateTemplate().save(entity); ;q; C^l
} B)]{]z0+`
!><
%\K
publicvoid update(finalObject entity){ r`&|)Hx
getHibernateTemplate().update(entity); aT!9W'uY
} pPqN[OJ
0 l:pWc
publicvoid delete(finalObject entity){ 6b70w @P!
getHibernateTemplate().delete(entity); huJq#5?
} lK,=`xe
+.]}f}Y
publicObject load(finalClass entity, G}#/`]o!K
+MZO%4
finalSerializable id){ qW~R-g]
return getHibernateTemplate().load cIvYfgIo9
e=l5j"gq
(entity, id); Gd-.E7CH!
} RLz`aBT
ZQ9oZHU m
publicObject get(finalClass entity, 6b]d|
h
^h-pd
finalSerializable id){ "&#WMi
return getHibernateTemplate().get d^5SeCs6
Z'NbHwW}
(entity, id); D}/=\J/
} r!$NZ2I
mBZDl4 '
publicList findAll(finalClass entity){ cNo4UZvr
return getHibernateTemplate().find("from Ccr+SR2
oPu|Q^I=
" + entity.getName()); 5o| !f
} wUCDJY:,1
:"P hkR
publicList findByNamedQuery(finalString 7ml0
4A/,X>W61
namedQuery){ %HF$
return getHibernateTemplate !""!sFx)R
zt)PZff/YQ
().findByNamedQuery(namedQuery); As'M39*V
} ^T&u!{82j
Z!-<rajl
publicList findByNamedQuery(finalString query, =x0"6gTz>
!@Sf>DM"
finalObject parameter){ r\n
h.}s
return getHibernateTemplate r.wIk0
N9=r#![>,
().findByNamedQuery(query, parameter); mu6xL QdA
} PyT}}UKj:
"56?/ jF
publicList findByNamedQuery(finalString query, 2]NAs9aZ
gLaO#cQ%
finalObject[] parameters){ \8*,&ak%
return getHibernateTemplate ,AbKxT
f2
0"^oTmQN
().findByNamedQuery(query, parameters); 9U<)_E<y
} 7#9'2dI
380->
publicList find(finalString query){ '^ e/F)0
return getHibernateTemplate().find sL7`=a.&T
C*s0r;
(query); rF'^w56
} LbV]JP
%V %#y $l
publicList find(finalString query, finalObject c,+(FQ9
F%.9fUo
parameter){ *2Vp4
return getHibernateTemplate().find &Ev]x2YC
Kcw1uLb
(query, parameter); ;V"yMWjc
} T]nR=uK6LL
CS;W)F
public PaginationSupport findPageByCriteria K_&c5(-(_
]\a\6&R
(final DetachedCriteria detachedCriteria){ \buZ?
return findPageByCriteria <Sprp]n
7
zK>'tFU
(detachedCriteria, PaginationSupport.PAGESIZE, 0); :%uyy5AZ
} fa4951_
W\>^[c/
public PaginationSupport findPageByCriteria HhWwc#B
?|">),
(final DetachedCriteria detachedCriteria, finalint 4VmCW"b7h
)"_Ff,9Z!
startIndex){ 5S\][;u
return findPageByCriteria 6t_ 3%{
DYAwQ"i;6
(detachedCriteria, PaginationSupport.PAGESIZE, uq|vNLW26
Lov.E3S6;
startIndex); KO-Zz&2f
} z[5Y
Z~}*
[/AdeR
public PaginationSupport findPageByCriteria P^b:?%
yul<n>X|
(final DetachedCriteria detachedCriteria, finalint {(M&-~Yh
Lz9$,Y[
pageSize, ~Q_)>|R2
finalint startIndex){ *X=@yB*aK
return(PaginationSupport) L,L ~
.E
r;cI}'
getHibernateTemplate().execute(new HibernateCallback(){ m6_~`)R8
publicObject doInHibernate Ko$ $dkSE
4T==A#Z
(Session session)throws HibernateException { uG=t?C6
Criteria criteria = ^J#?hHz
;/?Z<[B
detachedCriteria.getExecutableCriteria(session); >}<29Ii
int totalCount = b:F Ep'ZS
ot@|blVC8
((Integer) criteria.setProjection(Projections.rowCount `'xQ6Sy
B?$ 01?9V
()).uniqueResult()).intValue(); 6z9R1&~%
criteria.setProjection ;}n9yci#
u#41osUVW>
(null); <}28=d
List items = K-2o9No?j`
vs\'1^*D
criteria.setFirstResult(startIndex).setMaxResults KFTf~!|
_[}G(<
(pageSize).list(); %w'/n>]j
PaginationSupport ps = aPD?Bh>JU
$f<eq7rRe
new PaginationSupport(items, totalCount, pageSize, a1
46kq
m4Phn~>Gg
startIndex); 3}>:
return ps; L _vblUDq
} 'DCKD4@C/
}, true); }b_R5U$@@
} lfxuc7Rdla
jw/'*e
public List findAllByCriteria(final <=;H[}
e
,]~u:Y}
DetachedCriteria detachedCriteria){ MB]#%g&
return(List) getHibernateTemplate ~/j$TT"
4ss&'h
().execute(new HibernateCallback(){ XGE
2J
publicObject doInHibernate xb4Pt`x)rS
]>
nPqL
(Session session)throws HibernateException { Ne &Xf
Criteria criteria = o,?!"*EP
]regi- LGU
detachedCriteria.getExecutableCriteria(session); DAjG*K{
return criteria.list(); +"k.E
x0:
} $R A4U<
}, true); tt+>8rxF:;
} .abyYVrN4?
/hm84La
public int getCountByCriteria(final dV5PhP>6
'ox0o:
DetachedCriteria detachedCriteria){ cJxW;WI!,
Integer count = (Integer) d{QMST2&
&_"ORqn&
getHibernateTemplate().execute(new HibernateCallback(){ ^y&q5p jj
publicObject doInHibernate ;\<""Yj@l
\p5|}<Sr)
(Session session)throws HibernateException { ^~ Ekg:`
Criteria criteria = gW%pM{PW
! 9d_Gf-
detachedCriteria.getExecutableCriteria(session); +<S9E'gT3V
return Wc~3^;U
&?SX4c~?u
criteria.setProjection(Projections.rowCount W3De|V^
C:]/8 l
()).uniqueResult(); M:R8<.{
} P7's8KOoS
}, true); _^_5K(Uq
return count.intValue(); <e;jWK
} dv"as4~%
} f'1(y\_fb
%9t{Z1$
{I4%
@)o0GHNP
rpUy$qrRc
nY OY"'z
用户在web层构造查询条件detachedCriteria,和可选的 +J"' 'cZ
By2s ']bw
startIndex,调用业务bean的相应findByCriteria方法,返回一个 7sXy`+TZ->
j'3j}G%\T
PaginationSupport的实例ps。 ec`bz "1
J4YT)-
ps.getItems()得到已分页好的结果集 *R5`.j =
ps.getIndexes()得到分页索引的数组 t(}/g
ps.getTotalCount()得到总结果数 A[RHw<
ps.getStartIndex()当前分页索引 J5O.*&
ps.getNextIndex()下一页索引 RG&I\DTyt
ps.getPreviousIndex()上一页索引 8jRs=I
#"::
'?,
-7k[Vg?
DeH0k[o
^uia`sOP4
},rav]
e,EK,,iY5
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 |)9thIQF
!6M Bxg >
,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 OFL|RLiD
-^yXLa;D
一下代码重构了。 kB8
M i
N*Yy&[
我把原本我的做法也提供出来供大家讨论吧: /dLA`=r Zx
$K})Q3FNi
首先,为了实现分页查询,我封装了一个Page类: d]8_l1O
java代码: Q8;#_HE
fO6[!M(
im8
-7Xt
/*Created on 2005-4-14*/ }7.#Dj/r6
package org.flyware.util.page; C)OG62
eI^gV'UK
/** 0mTEim
* @author Joa jO=*:{#x
* wtSvJI~o)
*/ Dv@PAnk3C
publicclass Page { {-HDkG' 8
s2^B(wP
/** imply if the page has previous page */ sm1;MF]/u
privateboolean hasPrePage; ^00{Hd6
'f*O#&?
/** imply if the page has next page */ mwIk^Sz]@
privateboolean hasNextPage; TtPr)F|
#:#Dz.$L
/** the number of every page */ 6a*83G,k
privateint everyPage; kae2 73"
?mMW*ico
/** the total page number */ :s"2Da3B
privateint totalPage; wZjlHe
fp{G|.SA
/** the number of current page */ 8.yCA
privateint currentPage; c_#*mA"+
1fY>>*oP
/** the begin index of the records by the current ^2EhlK^)
}z
wX
query */ ?W!ry7gXO
privateint beginIndex; _42Z={pZZq
F}D3,&9N
)7dEi+v52
/** The default constructor */ xdZ<|
vMR
public Page(){ 9*\g`fWc}{
0oSQY[ht/
} p>q&&;fe
n3$gx,KL
/** construct the page by everyPage lm$;:Roj*
* @param everyPage P`EgA
* */ #-{N
Ws\
public Page(int everyPage){ [(ygisqt
this.everyPage = everyPage; H-,TS^W
} M\9F:.t=
cvfUyp;P
/** The whole constructor */ IE;\7r+h
public Page(boolean hasPrePage, boolean hasNextPage, Qs l80~n_7
Q_]~0PoH
Ux}W&K/?'
int everyPage, int totalPage, |gv{z"
int currentPage, int beginIndex){ Efx=T$%^&
this.hasPrePage = hasPrePage; 90fs:.
this.hasNextPage = hasNextPage; >F[GVmC
this.everyPage = everyPage; KQ{Lt?S
this.totalPage = totalPage; <
bFy(+
this.currentPage = currentPage; 2n)gpLIJ
this.beginIndex = beginIndex; {q,?<zBzu
} Qdu$Os
ARF\fF|<2
/** T@P!L
* @return N*_"8LIfi_
* Returns the beginIndex. ;7Okyj6EP
*/ uw33:G
publicint getBeginIndex(){ t'g^W
return beginIndex; ;iU%Kt
} JoJukoy}F
g1{/ 5{XI
/** ?#BV+#(
* @param beginIndex \|%E%Yc
* The beginIndex to set. {<K=*rrZ
*/ 9x?'}
publicvoid setBeginIndex(int beginIndex){ aGK@)&h$
this.beginIndex = beginIndex; E^wyD-ii/
} 3v1 7"
AnMV <
/** dZ]Rqr
_!
* @return %dW%o{
* Returns the currentPage. |4mVT&63(
*/ ag8`O&+
publicint getCurrentPage(){ {eQWO.C{
return currentPage; GeV+/^u
} .z-UOyer
h5GU9M
/** zvO:"w}
* @param currentPage P:k+ y$
* The currentPage to set. <a|@t@R
*/ 8lP6-VA
publicvoid setCurrentPage(int currentPage){ L:@fP~Erh
this.currentPage = currentPage; ?djQZ*
} opp!0:jS*
pRi<cO
/** sgAzL
* @return XAuI7e
* Returns the everyPage. "=A>}q@;H
*/ kOjf #@c
publicint getEveryPage(){ Lm6**v
return everyPage; u =J&~
} ~L{l+jK$p
VkZ.6kV
/** =Op+v"
* @param everyPage "2{%JFE
* The everyPage to set. I ~$1Lu`~
*/ VhEka#
publicvoid setEveryPage(int everyPage){ lH2wG2
this.everyPage = everyPage; x({C(Q'O
} tR)H~l7q
)D/ 6%]O
/** +Xy*?5E;C
* @return 2SG$LIV 9Y
* Returns the hasNextPage. J7+w4q~cB`
*/ BKIjNV3
publicboolean getHasNextPage(){ lzhqcL"
return hasNextPage; vmX"+sHz$]
} Hd &{d+B
C6
"
/** ,6,]#R
:J
* @param hasNextPage m3.sVI0I
* The hasNextPage to set. (sTuG}
*/
t ls60h
publicvoid setHasNextPage(boolean hasNextPage){ 1m@^E:w
this.hasNextPage = hasNextPage; 9 OT,TpA
} N#ioJ^}n:
eQDX:b
/** 3EK9,:<Cf
* @return u2iXJmM*
* Returns the hasPrePage. s'\$t
*/ (gXN%rsY
publicboolean getHasPrePage(){ >:1P/U
return hasPrePage; RU#F8O
} Log|%P\
PXk?aJ
/** !L24+ $
* @param hasPrePage ,"2TArC'z
* The hasPrePage to set. <AoXEuD
*/ @n+=vC.xO
publicvoid setHasPrePage(boolean hasPrePage){ ?cy4&]s
this.hasPrePage = hasPrePage; @It>*B yB.
} #,NvO!j<4
L.'}e{ldW
/** Jkt4@h2Q}
* @return Returns the totalPage.
fV\]L4%
* DN] v_u+}
*/ )>a B
publicint getTotalPage(){ 5&!c7$K0
return totalPage; {XCf-{a]~
} 9KuD(EJS
g(E"4M@t!
/** t^tmz PWA
* @param totalPage gm"#:< )
* The totalPage to set. b #fTAC;<
*/ 8|^CK|m6*
publicvoid setTotalPage(int totalPage){ {*m ?Kc7k
this.totalPage = totalPage; SPkn3D6
} ipE]}0q
<wd]D@l7r
} K9Hqq7"%
/j2H A^GT
Cb;WZ3HR
h*i9m o
Kg\R+i@#<
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 {w6/[-^
3L5r*fa
个PageUtil,负责对Page对象进行构造: U9hS<}<Ki
java代码: OQ&'Dti
RP4Ku9hk
~ 5"JzT
/*Created on 2005-4-14*/ {FO$yw=>
package org.flyware.util.page; dt\jGD
G4 _,
import org.apache.commons.logging.Log; ?Bi*1V<R
import org.apache.commons.logging.LogFactory; KKe8
ly,
"tk-w{>
/** "Zv~QwC
* @author Joa $A_]:qI2
* <If35Z)~
*/ Q>< 0[EPj3
publicclass PageUtil { <.K4JlbT
9LJZ-/Wq
privatestaticfinal Log logger = LogFactory.getLog YX*x&5]lq
8+Llx
(PageUtil.class); !D^c3d
`{v?6:G:Q
/** BqK(DH^9N
* Use the origin page to create a new page l! bv^
* @param page i]{1^pKq
* @param totalRecords 3>M&D20Z
* @return !U%T&?E l
*/ cZ8.TsI~
publicstatic Page createPage(Page page, int ~Ou1WnmO
,MPB/j^o5!
totalRecords){ Gbpw5n;e
return createPage(page.getEveryPage(), rZXrT}Xh{W
2S[-$9
page.getCurrentPage(), totalRecords); 5Qwh(C^H
} AM"jX"F9/
ENVk{QE!
/** #18 FA|
* the basic page utils not including exception d~J-|yyT
Hy:V`>
handler YIhm$A"z0"
* @param everyPage +EXJ\wy
* @param currentPage Y*oDO$6
* @param totalRecords iSLGwTdLn
* @return page ,i9Byx#TN
*/ Ga>uFb}W~
publicstatic Page createPage(int everyPage, int CBYX]
PQmq5N6
currentPage, int totalRecords){ ?4H#G)F
everyPage = getEveryPage(everyPage); Z6C=T;w
currentPage = getCurrentPage(currentPage); @oP_;G
int beginIndex = getBeginIndex(everyPage, #65^w=Sp}
?
8aaD>OR$
currentPage); /wShUR{
int totalPage = getTotalPage(everyPage, eYUr-rN+)z
uE/T2BX*
totalRecords); .0 )Y
boolean hasNextPage = hasNextPage(currentPage, Yj|eji7y
Vgb *% I
totalPage); AI vXb\wL
boolean hasPrePage = hasPrePage(currentPage); 1+;C`bnA
Xl7aGlH
returnnew Page(hasPrePage, hasNextPage, M,5j5<7
everyPage, totalPage, d$ACDX2
currentPage, [&[^G25
hY5WJ;
beginIndex); $3T_.
} ^$>XW\yCs
~[o4a '
privatestaticint getEveryPage(int everyPage){ Qp,DL@mp>8
return everyPage == 0 ? 10 : everyPage; `N//A}9
} Gc]~wD$
wm{3&m
privatestaticint getCurrentPage(int currentPage){ -ezY= 0Q&
return currentPage == 0 ? 1 : currentPage; B5V_e!*5F*
} WF&[HKOy/
^efb
5
privatestaticint getBeginIndex(int everyPage, int O%~jop7#6
`vG,}Pt]
currentPage){ d,vNem-Z*L
return(currentPage - 1) * everyPage; h}_~y'^!
} ?<&O0'Q
kqYa*| l
privatestaticint getTotalPage(int everyPage, int fA%z*\
3ya1'qUC
totalRecords){ %=AxJp!a
int totalPage = 0; qW:)!z3\
GPhl4#'
if(totalRecords % everyPage == 0) {gA\ph%s
totalPage = totalRecords / everyPage; LTV{{Z+
else ZoB*0H-
totalPage = totalRecords / everyPage + 1 ; `(+o=HsD
iB0WEj[?
return totalPage; ,r^M?>
} r"2V
7'-Lp@an
privatestaticboolean hasPrePage(int currentPage){ 9j]sD/L5q
return currentPage == 1 ? false : true; w@-PqsF
} W6T|iZoV"r
"vYE+
privatestaticboolean hasNextPage(int currentPage, @ l1
+x?#DH-
int totalPage){ $8USyGi3J
return currentPage == totalPage || totalPage == m=AqV:%|
SVlua@]ChU
0 ? false : true; Ok7t@l$
} Z@8vL
f'I z
G.R
.x`M<L#M(
} \;-fi.Hrf$
|6UtW{2I/
\$aF&r<R
a07@C
{8,<ZZ_
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。 )#a[-.OI
<^b7cOFQ
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 G2LK]
<Llp\XcZ
做法如下: (Rk_-9_E.
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象
s cuHmY0
,P'P^0qJ
的信息,和一个结果集List: >&g}7d%
java代码: '}g*!jL
QIN."&qC^
ri`R<l8
/*Created on 2005-6-13*/ $@d9<83=
package com.adt.bo; wiaX&-c]8
;N B:e
import java.util.List; <2!v(EkI
>{eCh$L
import org.flyware.util.page.Page; nzjkX4KV
O%1v)AT&\
/** ]sz3]"2
* @author Joa Q%/<ZC.Mz6
*/ ,\ 2a=Fp
publicclass Result { ^l^fD t
Q6o(']0
private Page page; R1F5-#?'E
{7!UQrm<
private List content; )eUW5
tS
T5Q{{ @Q
/** 'Y$R~e^Y?
* The default constructor `c/*H29
*/ Y+4o B
public Result(){ O\K_q7iO6
super(); ;!o]wHmA
} *5zrZ]^
e*(b
/** Tu{h<Zy
* The constructor using fields )!g{Sbl
* EFpIp4_Y
* @param page #-3=o6DCK
* @param content K.G$]H
*/ =.y*_Ja
public Result(Page page, List content){ HL/bS/KX
this.page = page; uE[(cko
this.content = content; ^qCkt1C-M
} LG~S8u
JKer//ng4
/** 9Rm/V5
* @return Returns the content. f<+4rHT
*/ bX.ja;;
publicList getContent(){ @i^~0A#q*
return content; p^(&qk?ut
} ut>4U'.H
v7%X@j]ji
/** t9&cE:n
* @return Returns the page. `cx]e
*/ yNm:[bOER
public Page getPage(){ Z5c~^jL$-
return page; /h v4x9
} k3+e;[My+
Rwr 2gMt7
/** )s1Ib4C
* @param content K:'q>D@
* The content to set. k{gLMl
*/ _k^0m
public void setContent(List content){ >5R<;#8
this.content = content; |uW:r17
} L< zD<M
+A~\tK{
/** e4~>G?rM_
* @param page "Jjs"7
* The page to set. zEZLKWm9-
*/ LqdY Qd51
publicvoid setPage(Page page){ 0O k,oW{
this.page = page; & cNy
} Mv c`)_Md
} pfx3C*
;['[?wk
0&ByEN99
@!&}}"<
*9)SmSs
2. 编写业务逻辑接口,并实现它(UserManager, \rykBxs
mMMQ|ea
UserManagerImpl) o]IjK
java代码: IVr 2y8K
^m_yf|D$
nm7;ieMfr
/*Created on 2005-7-15*/ bCZ gcN
package com.adt.service; $A3<G-4O
i{D=l7j|w
import net.sf.hibernate.HibernateException; +GsWTEz
XC7%vDIt
import org.flyware.util.page.Page; B2Xn?i3 l
@"T"7c?Cv
import com.adt.bo.Result; i(?,6)9
FgL,k
/** +n}$pM|NKU
* @author Joa PSawMPw
*/ y*{Zbz#{
publicinterface UserManager { Rl|4S[
[i0Hm)Bd3
public Result listUser(Page page)throws k%y9aO
?PTk1sB
HibernateException; 3]-_q"Co4f
`nUO l
} rbT)=-(
p;?*}xa
S4witIK5
x.1-)\
!ZDzEP*
java代码: m\/ Tj0e
: S$l"wrh\
Ev!{n
/*Created on 2005-7-15*/ @|a>&~xX
package com.adt.service.impl; v#=`%]mL
~x{.jn
import java.util.List; K^r)CCO
E,n}HiAz7V
import net.sf.hibernate.HibernateException; ]d[ge6
$8l({:*q0
import org.flyware.util.page.Page; Wlh~)
import org.flyware.util.page.PageUtil; B*htN
`V[!@b:
import com.adt.bo.Result; iut`7
import com.adt.dao.UserDAO; ;Ut+yuy
import com.adt.exception.ObjectNotFoundException; $3D'4\X~?
import com.adt.service.UserManager; qH"Gm
]]}tdn _
/** Lp5U"6y
* @author Joa PX|=(:(k
*/ XWJwJ
publicclass UserManagerImpl implements UserManager { }FF W|f
H"2uxhdLK3
private UserDAO userDAO; F_xbwa*=
#S%Q*k<hw
/** y]%w )4PS
* @param userDAO The userDAO to set. S'dV>m`
*/ 6.t',LTB
publicvoid setUserDAO(UserDAO userDAO){ I2(zxq&2M\
this.userDAO = userDAO; :a:[.
} _WX#a|4h{
569}Xbc/
/* (non-Javadoc) $4jell
* @see com.adt.service.UserManager#listUser +7Kyyu)y@
Gamr6I"K
(org.flyware.util.page.Page) kF7(f|*
*/ I *c;H I
public Result listUser(Page page)throws 0'&X
T^"
n6F/Ac:
HibernateException, ObjectNotFoundException { PiFD^w
int totalRecords = userDAO.getUserCount(); b'zR 9V
if(totalRecords == 0) BF{w)=@/'
throw new ObjectNotFoundException ?}Z1(it0
FZB~|3eq{
("userNotExist"); 4Ij-Ilg)%
page = PageUtil.createPage(page, totalRecords); i?Ss: v^
List users = userDAO.getUserByPage(page); ,wwZI`>-
returnnew Result(page, users); > Oh?%%6
} P)dL?vkK
MJj4Hd
} {F&-7u0
>-E<