基于bbossgroups持久层框架实现数据库分页查询
bbossgroups中提供的分页查询方法，非常简单，也非常的高效。
java值对象：
在bbossgroups持久层框架中，主要是通过数据库适配器来实现不同数据库产品的分页查询算法，用户可以扩展这些适配器来实现自己的分页算法,以oracle为列：
写好后将com.frameworkset.orm.adaptors.MyOracle配置到poolman.xml文件中既可：
最新版本bbossgroups-2.0-RC1下载地址：
http://sourceforge.net/projects/bboss/files/
PreparedDBUtil dbUtil = new PreparedDBUtil();
try {
dbUtil.preparedSelect("select * from testnewface where object_id < ?",0,10);//分页查询方法
dbUtil.setInt(1, 100);
List list = dbUtil.executePreparedForList(TestNewface.class,new RowHandler<TestNewface>()
{
public void handleRow(TestNewface t, Record record) {
try {
t.setCREATED(record.getDate("created"));
t.setDATA_OBJECT_ID(record.getInt("DATA_OBJECT_ID"));
//........设置其他的属性
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("row handler:"+t);
}
});
int totalsize = dbUtil.getTotalSize();//获得总记录数
for(int i = 0; i < list.size()/*list.size()当页记录数*/; i ++)//遍历当页记录
{
TestNewface testNewface = (TestNewface)list.get(i);
... ...
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java值对象：
package com.frameworkset.common;
import java.util.Date;
/**
*
* <p>Title: TestNewface.java</p>
*
* <p>Description: </p>
*
* <p>Copyright: Copyright (c) 2007</p>
* @Date Nov 4, 2008 2:51:17 PM
* @author biaoping.yin
* @version 1.0
*/
public class TestNewface {
String OWNER ;
String OBJECT_NAME ;
String SUBOBJECT_NAME ;
int OBJECT_ID ;
int DATA_OBJECT_ID ;
String OBJECT_TYPE ;
Date CREATED ;
Date LAST_DDL_TIME ;
String TIMESTAMP ;
String STATUS ;
String TEMPORARY ;
String GENERATED ;
String SECONDARY ;
public String getOWNER() {
return OWNER;
}
public void setOWNER(String owner) {
OWNER = owner;
}
public String getOBJECT_NAME() {
return OBJECT_NAME;
}
public void setOBJECT_NAME(String object_name) {
OBJECT_NAME = object_name;
}
public String getSUBOBJECT_NAME() {
return SUBOBJECT_NAME;
}
public void setSUBOBJECT_NAME(String subobject_name) {
SUBOBJECT_NAME = subobject_name;
}
public int getOBJECT_ID() {
return OBJECT_ID;
}
public void setOBJECT_ID(int object_id) {
OBJECT_ID = object_id;
}
public int getDATA_OBJECT_ID() {
return DATA_OBJECT_ID;
}
public void setDATA_OBJECT_ID(int data_object_id) {
DATA_OBJECT_ID = data_object_id;
}
public String getOBJECT_TYPE() {
return OBJECT_TYPE;
}
public void setOBJECT_TYPE(String object_type) {
OBJECT_TYPE = object_type;
}
public Date getCREATED() {
return CREATED;
}
public void setCREATED(Date created) {
CREATED = created;
}
public Date getLAST_DDL_TIME() {
return LAST_DDL_TIME;
}
public void setLAST_DDL_TIME(Date last_ddl_time) {
LAST_DDL_TIME = last_ddl_time;
}
public String getTIMESTAMP() {
return TIMESTAMP;
}
public void setTIMESTAMP(String timestamp) {
TIMESTAMP = timestamp;
}
public String getSTATUS() {
return STATUS;
}
public void setSTATUS(String status) {
STATUS = status;
}
public String getTEMPORARY() {
return TEMPORARY;
}
public void setTEMPORARY(String temporary) {
TEMPORARY = temporary;
}
public String getGENERATED() {
return GENERATED;
}
public void setGENERATED(String generated) {
GENERATED = generated;
}
public String getSECONDARY() {
return SECONDARY;
}
public void setSECONDARY(String secondary) {
SECONDARY = secondary;
}
}
在bbossgroups持久层框架中，主要是通过数据库适配器来实现不同数据库产品的分页查询算法，用户可以扩展这些适配器来实现自己的分页算法,以oracle为列：
package com.frameworkset.orm.adaptors;
import com.frameworkset.orm.adapter.DBOracle;
public class MyOracle extends DBOracle {
public String getDBPagineSql(String sql, long offset, int maxsize) {
StringBuffer ret = new StringBuffer("select ss1.* from (select tt1.*,rownum rowno_ from (").append(sql).append(
") tt1 where rownum <= ").append((offset + maxsize)).append(") ss1 where ss1.rowno_ >= ").append(
(offset + 1));
return ret.toString();
}
}
写好后将com.frameworkset.orm.adaptors.MyOracle配置到poolman.xml文件中既可：
<?xml version="1.0" encoding="gb2312"?>
<poolman>
<adaptor dbtype="oracle">com.frameworkset.orm.adaptors.MyOracle</adaptor> <datasource>
<dbname>bspf</dbname>
<loadmetadata>false</loadmetadata>
<jndiName>bspf_datasource_jndiname</jndiName>
<autoprimarykey>false</autoprimarykey>
<cachequerymetadata>false</cachequerymetadata>
<driver>oracle.jdbc.driver.OracleDriver</driver>
<url>jdbc:oracle:thin:@//172.16.17.219:1521/orcl</url>
<username>baseline</username>
<password>baseline</password>
<txIsolationLevel>READ_COMMITTED</txIsolationLevel>
<nativeResults>true</nativeResults>
<poolPreparedStatements>false</poolPreparedStatements>
<initialConnections>2</initialConnections>
<minimumSize>0</minimumSize>
<maximumSize>10</maximumSize>
<!--
控制connection达到maximumSize是否允许再创建新的connection true：允许，缺省值 false：不允许
-->
<maximumSoft>false</maximumSoft>
<!--
是否检测超时链接（事务超时链接） true-检测，如果检测到有事务超时的链接，系统将强制回收（释放）该链接 false-不检测，默认值
-->
<removeAbandoned>true</removeAbandoned>
<!--
链接使用超时时间（事务超时时间）
单位：秒
-->
<userTimeout>50</userTimeout>
<!--
系统强制回收链接时，是否输出后台日志 true-输出，默认值 false-不输出
-->
<logAbandoned>true</logAbandoned>
<!--
数据库会话是否是readonly，缺省为false
-->
<readOnly>true</readOnly>
<!--
对应属性：timeBetweenEvictionRunsMillis the amount of time (in
milliseconds) to sleep between examining idle objects for eviction
-->
<skimmerFrequency>10</skimmerFrequency>
<!--
对应于minEvictableIdleTimeMillis 属性： minEvictableIdleTimeMillis the
minimum number of milliseconds an object can sit idle in the pool
before it is eligable for evcition 单位：秒 空闲链接回收时间，空闲时间超过指定的值时，将被回收
-->
<connectionTimeout>10</connectionTimeout>
<!--
numTestsPerEvictionRun the number of idle objects to examine per run
within the idle object eviction thread (if any) 每次回收的链接个数
-->
<shrinkBy>0</shrinkBy>
<!--
/** * 检测空闲链接处理时，是否对空闲链接进行有效性检查控制开关 * true-检查，都检查到有无效链接时，直接销毁无效链接 *
false-不检查，缺省值 */
-->
<testWhileidle>true</testWhileidle>
-->
<maxWait>60</maxWait>
<!--
链接有效性检查sql语句
-->
<validationQuery>select 1 from dual</validationQuery>
</datasource>
</poolman>
最新版本bbossgroups-2.0-RC1下载地址：
http://sourceforge.net/projects/bboss/files/