Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 uX`Jc:1q3
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ,:;nq> ;
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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 _!w# {5~
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 Rn-L:o@?
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分页支持类: mL3'/3-7:V
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java代码: jd(=? !_
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package com.javaeye.common.util; p3sz32RX
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import java.util.List; h2uO+qEsu
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publicclass PaginationSupport { Wq"pKI#x
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publicfinalstaticint PAGESIZE = 30; q(a6@6f"kD
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privateint pageSize = PAGESIZE; y"2#bq
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privateList items; 7xWX:2l*?
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privateint totalCount; =B;rj
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privateint[] indexes = newint[0]; -,zNFC:6g
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privateint startIndex = 0; :Wb+&|dU
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public PaginationSupport(List items, int 6=|Q>[K
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totalCount){ Z>Sv[Ec
setPageSize(PAGESIZE);
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setTotalCount(totalCount); !X
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setItems(items); %T1(3T{Li
setStartIndex(0); > `z^AB
} ){8^l0b
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public PaginationSupport(List items, int ^H&6'A`
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totalCount, int startIndex){ H(
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setPageSize(PAGESIZE); 5UjXpS
setTotalCount(totalCount); p?6w/ n
setItems(items); OP``g/x)
setStartIndex(startIndex); `q4\w[0+p
} Lo9+#ITyx
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public PaginationSupport(List items, int kdgQ -UN$
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totalCount, int pageSize, int startIndex){ =Z%&jul
setPageSize(pageSize); K<\TF+
setTotalCount(totalCount); >f}rM20Vm
setItems(items); b"{7f
setStartIndex(startIndex); Uv5E$Y"e10
} LTFA2X&E=
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publicList getItems(){ L88oh&M
return items; 8G(wYlxi
} ;~xkT'
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publicvoid setItems(List items){ o2F6K*u}
this.items = items; ~TurYvf
} &hqGGfVsd
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publicint getPageSize(){ U
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return pageSize; 5RZAs63t
} qmJFXnf
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publicvoid setPageSize(int pageSize){ X8?|5$Ey
this.pageSize = pageSize; 4sROMk=l
} ioh_5
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publicint getTotalCount(){ *i)GoQoB
return totalCount; &bA;>Lu#|o
} [(UQQa=+
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publicvoid setTotalCount(int totalCount){ 8 rnr>Ee@
if(totalCount > 0){ &ec_jxF
this.totalCount = totalCount; zBqr15
int count = totalCount / 3$WK%"%T
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pageSize; ,!u^E|24
if(totalCount % pageSize > 0) #YhKAG@|
count++; .KK"KO5k
indexes = newint[count]; :t9(T?2
for(int i = 0; i < count; i++){ H6e^"E
indexes = pageSize * <>2QDI6_
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} Fda<cS]
}else{ )lH?XpfTjm
this.totalCount = 0; 1!BV]&,[
} w;{k\=W3Ff
} scN}eg:5
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publicint[] getIndexes(){ AF **@iG
return indexes; ];j8vts&
} U3A>#EV
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publicvoid setIndexes(int[] indexes){ :n>:*e@w%
this.indexes = indexes; ZhM-F0;`
} o<T>G{XYB
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publicint getStartIndex(){ 'Y>!xm
return startIndex; u4fTC})4{C
} j+Wgjf
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publicvoid setStartIndex(int startIndex){ .{)b^gE
if(totalCount <= 0) Z&J417buk
this.startIndex = 0; ~5]AXi'e~
elseif(startIndex >= totalCount) ZL~}B.nqS
this.startIndex = indexes bNIT 1'v
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[indexes.length - 1]; p72+:I
elseif(startIndex < 0) WV?iYX!
this.startIndex = 0; c( gUH
else{ ;41s&~eR
this.startIndex = indexes mQ' ]0D S
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[startIndex / pageSize]; t_P1a0Zu
} 28Q`O$=v
} !A!zG)Ue<
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publicint getNextIndex(){ O(WFjmHx
int nextIndex = getStartIndex() + Re,0RM\
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pageSize; $W`
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if(nextIndex >= totalCount) :GGsQ
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return getStartIndex(); K\n %&w
else 0Wv9K~F
return nextIndex; Tz%l9aC
} ,3N8
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publicint getPreviousIndex(){ /A##Yv!biR
int previousIndex = getStartIndex() - F-_RL-hbN%
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pageSize; -c|O!Lc-
if(previousIndex < 0) @{t^8I#]
return0; 7+=j]+O
else MS,H12h
return previousIndex; C8NbxP
} yHT}rRS8
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} \U~ggg0h
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抽象业务类 s?OGB}
java代码: zA( 2+e 7
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/** SHz& o[u
* Created on 2005-7-12 eb.`Q+Gb
*/ :gQc@)jZ(*
package com.javaeye.common.business; kl2]#G(
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import java.io.Serializable; ?e&CbVc4
import java.util.List; P\SD_8
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import org.hibernate.Criteria; oHeo]<Fbv
import org.hibernate.HibernateException; 'fK_J}+P
import org.hibernate.Session; MQ,$'Y5~H
import org.hibernate.criterion.DetachedCriteria; | b@?]M
import org.hibernate.criterion.Projections; |Zkcs]8M!
import S7N54X2JwL
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org.springframework.orm.hibernate3.HibernateCallback; $o]suF;3
import dqd Qt_
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org.springframework.orm.hibernate3.support.HibernateDaoS ,9W 0fm\t
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upport; 3PBg3Y$
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import com.javaeye.common.util.PaginationSupport; ~49+$.2
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public abstract class AbstractManager extends Rs<,kMRGVL
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HibernateDaoSupport { e(!a~{(kq%
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privateboolean cacheQueries = false; ;Oe6SNquT
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privateString queryCacheRegion; %}$6#5"';
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publicvoid setCacheQueries(boolean TzX>d<x
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cacheQueries){ }8x[
this.cacheQueries = cacheQueries; Ep0Aogp29
} N} Q,
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publicvoid setQueryCacheRegion(String : PQA9U|
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queryCacheRegion){ q{KRM\ooYs
this.queryCacheRegion = ~ RTjcE
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queryCacheRegion; gdkO|x
} p4aM`PW8>=
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publicvoid save(finalObject entity){ fI}-?@
getHibernateTemplate().save(entity); LJI&j \
} I-;JDC?
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publicvoid persist(finalObject entity){ Snh\Fgdz
getHibernateTemplate().save(entity); dcXtT3,kpX
} i37W^9 R
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publicvoid update(finalObject entity){ +cjNA2@
getHibernateTemplate().update(entity); u&pLF%'EQ
} EH4WR/x
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publicvoid delete(finalObject entity){ %J+$p\c
getHibernateTemplate().delete(entity); '| Ag,x[
} sy>P n
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publicObject load(finalClass entity, %\5y6
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finalSerializable id){ b[BSUdCB
return getHibernateTemplate().load G%'h'AV"
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(entity, id); $dwv1@M2
} %iJ6;V4
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publicObject get(finalClass entity, pCpj#+|_)
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finalSerializable id){ Ww8C![ ,
return getHibernateTemplate().get u#
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(entity, id); egP3q5~
} QjZ}*p
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publicList findAll(finalClass entity){ +S3'ms
return getHibernateTemplate().find("from %81tVhg
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" + entity.getName()); CQv
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} "rAm6b-`
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publicList findByNamedQuery(finalString J'B;
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namedQuery){ J^t=.-a|
return getHibernateTemplate U*6-Y%7
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().findByNamedQuery(namedQuery); L^ +0K}eD
} 75^-93
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publicList findByNamedQuery(finalString query, mZq*o<kTA
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finalObject parameter){ !gT6So
return getHibernateTemplate -u8@ .
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().findByNamedQuery(query, parameter);
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} w#JF7;
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publicList findByNamedQuery(finalString query, Oe;9[=L[
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finalObject[] parameters){ 7:1Hgj(
return getHibernateTemplate ?m~x%[Vn
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().findByNamedQuery(query, parameters); +<3tv&"
} c4;
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publicList find(finalString query){ |
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return getHibernateTemplate().find px-*uh<
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(query); +;*])N%q
} 8PQ$X2)
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publicList find(finalString query, finalObject M5%xp.B
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parameter){ IE,g
return getHibernateTemplate().find Qh{=Z^r
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(query, parameter); 'fg`td
} aC%0jJ<eo
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public PaginationSupport findPageByCriteria 69IBG,N'
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(final DetachedCriteria detachedCriteria){ y:W$~<E`p
return findPageByCriteria g`1*p|
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); }. ,xhF[
} 3w^q 0/GD
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public PaginationSupport findPageByCriteria '!y ^
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(final DetachedCriteria detachedCriteria, finalint B!8]\D
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startIndex){ *Qyw
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return findPageByCriteria h,\_F#hi
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(detachedCriteria, PaginationSupport.PAGESIZE, 9OTw6
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startIndex); #}B~V3UD
} MKQa&Dvw
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public PaginationSupport findPageByCriteria 35c9c(A
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(final DetachedCriteria detachedCriteria, finalint [F6=JZ
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pageSize, /,B"H@J
finalint startIndex){ X@\! \
return(PaginationSupport) np)-Yzr
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getHibernateTemplate().execute(new HibernateCallback(){ !E$S&zVMQ
publicObject doInHibernate 55yP.@i9J
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(Session session)throws HibernateException { 5g/WQo\
Criteria criteria = D6v0n6w
);$~/H4
detachedCriteria.getExecutableCriteria(session); *emUQ/uvf
int totalCount = vK$T$SL
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((Integer) criteria.setProjection(Projections.rowCount 38 B\ \
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()).uniqueResult()).intValue(); Oz n7C?\*
criteria.setProjection :v&GAs6H
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(null); ZPMX19
List items = (zTr/
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criteria.setFirstResult(startIndex).setMaxResults u2!8'-Ai
qOk4qbl[
(pageSize).list();
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PaginationSupport ps = N5~g:([k
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new PaginationSupport(items, totalCount, pageSize, x.45!8Zb
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startIndex); O>'o; 0
return ps; /n:s9eq
} > m5j.GP;
}, true); /#Ew{RvW'
} qAG0t{K
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public List findAllByCriteria(final ty7a&>G
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DetachedCriteria detachedCriteria){ yqB{QFXO
return(List) getHibernateTemplate op}x}Ioz
}F@`A?k
().execute(new HibernateCallback(){ YDDwvk
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publicObject doInHibernate ;rk}\M$+
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(Session session)throws HibernateException { ;9;.!4g/T
Criteria criteria = tuUk48!2I
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detachedCriteria.getExecutableCriteria(session); %P yU3
return criteria.list(); 3 :f5xF
} @++
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}, true); ( XE`,#
} ~A"ODLgU9
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public int getCountByCriteria(final OlV>zam
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DetachedCriteria detachedCriteria){ =Ybbh`$<
Integer count = (Integer) |w\D6d]o
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getHibernateTemplate().execute(new HibernateCallback(){ qQVqS7 t
publicObject doInHibernate CZ1tqAk-
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(Session session)throws HibernateException { }3N8EmS
Criteria criteria = lOZ.{0{f,
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detachedCriteria.getExecutableCriteria(session); ~;U!?
return EB>laZy>
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criteria.setProjection(Projections.rowCount aeP4%h
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()).uniqueResult(); />+JK5
} ^DIN(0u)
}, true); e6{/e+/R
return count.intValue(); "I_3!Yu
} '!En,*'IS
} DY,Sfh;tp
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用户在web层构造查询条件detachedCriteria,和可选的 'v\!}6
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 UVU}
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PaginationSupport的实例ps。
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ps.getItems()得到已分页好的结果集 v*#Z{)r
ps.getIndexes()得到分页索引的数组 {J|P2a[
ps.getTotalCount()得到总结果数 ~\XB'
ps.getStartIndex()当前分页索引 x6F\|nb
ps.getNextIndex()下一页索引 !.p!
ps.getPreviousIndex()上一页索引 @Z.Ne:*J
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 4(Y5n? /
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,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 }H^# }
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一下代码重构了。 n>iPAD
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我把原本我的做法也提供出来供大家讨论吧: #=$4U!yL
A7:
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首先,为了实现分页查询,我封装了一个Page类: *~fN^{B'!
java代码: 4e*0kItC
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/*Created on 2005-4-14*/ 6bqJM#y@
package org.flyware.util.page; 21cIWvy
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/** R[#5E|` `9
* @author Joa \ iP[iE=
* zBc7bbK
*/ hvpn=0@M
publicclass Page { %/'[GC'y!
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/** imply if the page has previous page */ 85s{;3
privateboolean hasPrePage; 0A}'.LI
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/** imply if the page has next page */ crvWAsm
privateboolean hasNextPage; 6aK%s{%3s
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/** the number of every page */ _X@:-_
privateint everyPage; MjG.Ili$m
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/** the total page number */ 9|#h )*
privateint totalPage; _&B