iBatis分页（基于Struts2和Freemarke） -

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iBatis分页（基于Struts2和Freemarke）

之前介绍过基于Hibernate分页的原理和设计，这里我们所用的分页都是物理分页技术，不是JS实现的页面分页技术，是在SQL语句上执行的分页，可以获取结果集数量固定的列表，执行效率很高。下面来看看iBatis中如何设计分页，本文基于Struts2，Spring3来整合，因为暂时 Spring不支持MyBatis3（可以选用MyBatis官方的MyBatis-Spring插件来实现，配有中文文档，很好理解），我们这里仍然以 iBatis2作为载体来介绍。
    首先就是搭建开发环境，这里可以说也是对Struts2，Spring3和iBatis2进行了简单的整合，大家也可以来参考。项目的结构如下，使用Maven创建的web项目：

    添加必要的依赖，因为整合了Struts2和Spring，依赖就比较多了，如下：

    首先来配置一下Struts2，这个就比较简单了，相信大家都不陌生。在web.xml中：

Xml代码

< filter >
< filter-name > struts2 </ filter-name >
< filter-class > org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter </ filter-class >
</ filter >
< filter-mapping >
< filter-name > struts2 </ filter-name >
< url-pattern > *.action </ url-pattern >
</ filter-mapping >

然后是struts.xml，配置Struts相关的内容，这里我们配置freemarker为默认的结果类型，然后配置一个测试的Action，因为和Spring进行了集成，所以Action具体的配置放到Spring中来进行，如下即可：

Xml代码

<? xml version = "1.0" encoding = "UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
< struts >
< package name = "ibatis-paging" extends = "struts-default"
namespace = "/" >
< result-types >
< result-type name = "freemarker"
class = "org.apache.struts2.views.freemarker.FreemarkerResult"
default = "true" />
</ result-types >
< action name = "user_*" class = "userAction" method = "{1}" >
< result name = "list" > user_list.ftl </ result >
</ action >
</ package >
</ struts >

对Freemarker做一个简单的设置，卸载freeemarer.properties文件中即可，这里我们主要是引用了一个宏文件，就是分页宏的配置，如下：

Properties代码

template_update_delay= 5
default_encoding=UTF-8
url_escaping_charset=UTF-8
number_format=0 .#
date_format=yyyy-MM-dd
time_format=HH:mm:ss
datetime_format=yyyy-MM-dd HH:mm:ss
boolean_format=true,false
whitespace_stripping=true
tag_syntax=auto_detect
auto_import=/Freemarker/page_macro.ftl as p

Log4J的配置这里不再贴出代码，大家可以去下载源码，一看就明白了，之后我们配置Spring，在resources文件夹下创建spring子目录，里面放置Spring的配置文件，在web.xml中如下设置即可加载Spring的配置文件：

Xml代码

< context-param >
< param-name > contextConfigLocation </ param-name >
< param-value > classpath:spring/*.xml </ param-value >
</ context-param >
< listener > < listener-class > org.springframework.web.context.ContextLoaderListener </ listener-class >
</ listener >

Spring中主要配置数据源，iBatis的SqlMapClient和SqlMapClientTemplate，事务处理还有Action和Service的管理，其实内容大家也都很熟悉了，比较简单：

Xml代码

< bean id = "dataSource" class = "org.apache.commons.dbcp.BasicDataSource"
destroy-method = "close" >
< property name = "driverClassName" value = "com.mysql.jdbc.Driver" />
< property name = "url" value = "jdbc:mysql://localhost:3306/test" />
< property name = "username" value = "root" />
< property name = "password" value = "123" />
< property name = "maxActive" value = "100" />
< property name = "maxIdle" value = "50" />
< property name = "maxWait" value = "100" />
< property name = "defaultAutoCommit" value = "true" />
</ bean >
< bean id = "jdbcTemplate" class = "org.springframework.jdbc.core.JdbcTemplate" >
< property name = "dataSource" ref = "dataSource" />
</ bean >
< bean id = "sqlMapClient" class = "org.springframework.orm.ibatis.SqlMapClientFactoryBean" >
< property name = "configLocation" value = "classpath:sqlMapConfig.xml" />
< property name = "dataSource" ref = "dataSource" />
</ bean >
< bean id = "sqlMapClientTemplate" class = "org.springframework.orm.ibatis.SqlMapClientTemplate" >
< constructor-arg >
< ref bean = "sqlMapClient" />
</ constructor-arg >
</ bean >
< bean id = "transactionManager"
class = "org.springframework.jdbc.datasource.DataSourceTransactionManager" >
< property name = "dataSource" ref = "dataSource" />
</ bean >
< tx:advice id = "txAdvice" transaction-manager = "transactionManager" >
< tx:attributes >
< tx:method name = "get*" read-only = "true" />
< tx:method name = "add*" rollback-for = "Exception" />
< tx:method name = "addOrUpdate*" rollback-for = "Exception" />
< tx:method name = "del*" rollback-for = "Exception" />
< tx:method name = "update*" rollback-for = "Exception" />
</ tx:attributes >
</ tx:advice >
< aop:config proxy-target-class = "true" >
< aop:pointcut id = "serviceMethod"
expression = "execution(* org.ourpioneer.service.*Service.*(..))" />
< aop:advisor advice-ref = "txAdvice" pointcut-ref = "serviceMethod" />
</ aop:config >

之后对Service和Action进行配置：

Xml代码

< bean id = "baseService" class = "org.ourpioneer.service.BaseService" >
< property name = "jdbcTemplate" ref = "jdbcTemplate" > </ property >
</ bean >
< bean id = "userService" class = "org.ourpioneer.service.UserService"
parent = "baseService" >
< property name = "sqlMapClientTemplate" ref = "sqlMapClientTemplate" />
</ bean >
< bean id = "userAction" class = "org.ourpioneer.action.UserAction" >
< property name = "userService" ref = "userService" />
</ bean >

下面来看一下iBatis的配置，在配置SqlMapClient的时候，加入了iBatis的配置文件，我们来看看sqlMapConfig.xml如何来设置：

Xml代码

<? xml version = "1.0" encoding = "UTF-8" ?>
<!DOCTYPE sqlMapConfig
PUBLIC "-//iBATIS.com//DTD SQL Map Config 2.0//EN"
"http://www.ibatis.com/dtd/sql-map-config-2.dtd">
< sqlMapConfig >
< settings cacheModelsEnabled = "true" enhancementEnabled = "true"
lazyLoadingEnabled = "true" errorTracingEnabled = "true" maxRequests = "32"
maxSessions = "10" maxTransactions = "5" />
< sqlMap resource = "sqlMaps/user.xml" />
</ sqlMapConfig >

其实内容也很简单，就是设置一下必要的信息，其中的含义可以参考之前写过的对iBatis的介绍的相关文章，最后不要忘了加入sqlMaps配置文件即可，这里我们就一个user.xml文件，为了测试，也就是一条查询，针对这个查询进行分页操作：

Xml代码

<? xml version = "1.0" encoding = "UTF-8" ?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd">
< sqlMap >
< typeAlias alias = "parameterMap" type = "org.pioneer.bean.ParameterMap" />
< select id = "selectAllUsers" resultClass = "java.util.HashMap" >
select * from user
</ select >
</ sqlMap >

ParameterMap在之前的介绍中也多次出现，这里我们也再来看下：

Java代码

package org.ourpioneer.bean;
import java.util.HashMap;
public class ParameterMap extends HashMap {
public ParameterMap(Object... parameters) {
for ( int i = 0 ; i < parameters.length - 1 ; i += 2 ) {
super .put(parameters[i], parameters[i + 1 ]);
}
}
}

其实就是扩展了一下HashMap类，来进行参数的放置，注意参数类型是可变参数的形式，也就是名-值对的形式出现的，不过本例中没有使用它。下面就是分页类的设计了：

Java代码

package org.ourpioneer.bean;
import java.util.HashMap;
import java.util.List;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.orm.ibatis.SqlMapClientTemplate;
import com.ibatis.sqlmap.engine.impl.SqlMapClientImpl;
import com.ibatis.sqlmap.engine.mapping.sql.Sql;
import com.ibatis.sqlmap.engine.mapping.statement.MappedStatement;
import com.ibatis.sqlmap.engine.scope.SessionScope;
import com.ibatis.sqlmap.engine.scope.StatementScope;
/**
* iBatis分页类
*
* @author Nanlei
*
*/
public class PagingList {
private int rowCount = 0 ; // 记录总数
private int pageCount = 1 ; // 分页总数
private int pageSize = 10 ; // 每页记录数
private int pageNum = 1 ; // 当前页数
private int startIndex = 1 ; // 起始记录数
private int endIndex = 1 ; // 结束记录数
private List list; // 记录列表
/**
* 构造方法，进行分页
*
* @param statementName
* iBatis中语句的ID
* @param parameterObject
* SQL语句参数
* @param pageNum
* 起始页数
* @param pageSize
* 每页大小
* @param sqlMapClientTemplate
* iBatis的sqlMapClientTemplate对象
*/
public PagingList(String statementName, Object parameterObject,
int pageNum, int pageSize,
SqlMapClientTemplate sqlMapClientTemplate, JdbcTemplate jdbcTemplate) {
preProcessParams(pageNum, pageSize);
execute(statementName, parameterObject, pageNum, pageSize,
sqlMapClientTemplate, jdbcTemplate);
}
/**
* 构造方法，进行分页
*
* @param statementName
* iBatis中语句的ID
* @param pageNum
* 起始页数
* @param pageSize
* 每页大小
* @param sqlMapClientTemplate
* iBatis的sqlMapClientTemplate对象
*/
public PagingList(String statementName, int pageNum, int pageSize,
SqlMapClientTemplate sqlMapClientTemplate, JdbcTemplate jdbcTemplate) {
preProcessParams(pageNum, pageSize);
execute(statementName, pageNum, pageSize, sqlMapClientTemplate,
jdbcTemplate);
}
/**
* 执行方法
*
* @param statementName
* @param parameterObject
* @param pageNum
* @param pageSize
* @param sqlMapClientTemplate
*/
public void execute(String statementName, Object parameterObject,
int pageNum, int pageSize,
SqlMapClientTemplate sqlMapClientTemplate, JdbcTemplate jdbcTemplate) {
// 计算记录总数
this .rowCount = jdbcTemplate.queryForInt(
getCountSql(getSrcSql(statementName, parameterObject,
sqlMapClientTemplate)), ((HashMap) parameterObject)
.values().toArray());
System.out.println(rowCount);
// 计算分页数及起止记录
countPage();
// 获取分页列表
this .list = sqlMapClientTemplate.queryForList(statementName,
parameterObject, (pageNum - 1 ) * pageSize, pageSize);
}
/**
* 执行方法
*
* @param statementName
* @param pageNum
* @param pageSize
* @param sqlMapClientTemplate
*/
public void execute(String statementName, int pageNum, int pageSize,
SqlMapClientTemplate sqlMapClientTemplate, JdbcTemplate jdbcTemplate) {
// 计算记录总数
this .rowCount = jdbcTemplate.queryForInt(getCountSql(getSrcSql(
statementName, null , sqlMapClientTemplate)));
System.out.println(rowCount);
// 计算分页数及起止记录
countPage();
// 获取分页列表
this .list = sqlMapClientTemplate.queryForList(statementName,
(pageNum - 1 ) * pageSize, pageSize);
}
/**
* 预处理SQL语句和页面参数
*/
private void preProcessParams( int pageNum, int pageSize) {
if (pageNum > 0 ) {
this .pageNum = pageNum;
}
if (pageSize > 0 ) {
this .pageSize = pageSize;
}
if (pageSize > 1000 ) {
this .pageSize = 1000 ;
}
}
/**
* 计算分页数及起止记录
*/
private void countPage() {
// 计算分页总数
if ((rowCount % pageSize) == 0 ) {
pageCount = rowCount / pageSize;
} else {
pageCount = rowCount / pageSize + 1 ;
}
if (pageCount == 0 ) {
pageCount = 1 ;
}
// 判断pageNum是否过界
if (pageNum > pageCount && rowCount != 0 ) {
pageNum = pageCount;
}
// 计算起止记录
startIndex = (pageNum - 1 ) * pageSize + 1 ;
endIndex = (pageNum) * pageSize;
}
/**
* 获得对象列表
*/
public List getList() {
return list;
}
/* 获得起始记录数 */
public int getStartIndex() {
return startIndex;
}
public Integer getStartIndexInteger() {
return new Integer(startIndex);
}
/* 获得结束记录数 */
public int getEndIndex() {
return endIndex;
}
public Integer getEndIndexInteger() {
return new Integer(endIndex);
}
/* 获得分页其它信息 */
public int getPageCount() {
return pageCount;
}
public int getPageNum() {
return pageNum;
}
public int getPageSize() {
return pageSize;
}
public int getRowCount() {
return rowCount;
}
private String getSrcSql(String statementName, Object parameterObject,
SqlMapClientTemplate sqlMapClientTemplate) {
SqlMapClientImpl sqlMapClientImpl = (SqlMapClientImpl) sqlMapClientTemplate
.getSqlMapClient();
MappedStatement mappedStatement = sqlMapClientImpl
.getMappedStatement(statementName);
Sql sql = mappedStatement.getSql();
StatementScope statementScope = new StatementScope( new SessionScope());
String srcSql = sql.getSql(statementScope, parameterObject);
return srcSql;
}
private String getCountSql(String srcSql) {
return "SELECT COUNT(*) FROM ( " + srcSql + " ) CTBL_" ;
}
}

写好分页类，还要和框架进行集成，那么我们可以抽象出Service的基类，在业务逻辑层中调用它来获取分页信息：

Java代码

package org.ourpioneer.service;
import org.ourpioneer.bean.PagingList;
import org.springframework.orm.ibatis.SqlMapClientTemplate;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.util.ValueStack;
public class BaseService {
private JdbcTemplate jdbcTemplate;
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this .jdbcTemplate = jdbcTemplate;
}
/**
* 获取ValueStack
*
* @return ValueStack对象
*/
public ValueStack getValueStack() {
return ActionContext.getContext().getValueStack();
}
/**
* 获取分页的List
*
* @param statementName
* @param sqlMapClientTemplate
* @return
*/
public PagingList getPagingList(String statementName,
SqlMapClientTemplate sqlMapClientTemplate) {
int pageNum = ((Integer) getValueStack().findValue( "pageNum" ))
.intValue();
int pageSize = ((Integer) getValueStack().findValue( "pageSize" ))
.intValue();
return new PagingList(statementName, pageNum, pageSize,
sqlMapClientTemplate, jdbcTemplate);
}
/**
* 获取分页的List
*
* @param statementName
* @param parameterObject
* @param sqlMapClientTemplate
* @return
*/
public PagingList getPagingList(String statementName,
Object parameterObject, SqlMapClientTemplate sqlMapClientTemplate) {
int pageNum = ((Integer) getValueStack().findValue( "pageNum" ))
.intValue();
int pageSize = ((Integer) getValueStack().findValue( "pageSize" ))
.intValue();
return new PagingList(statementName, parameterObject, pageNum,
pageSize, sqlMapClientTemplate, jdbcTemplate);
}
}

两个构造方法我们都使用了，也就是一个带参数，一个不带参数。下面来看抽象出的Action基类，主要是处理页面传入的分页参数的处理：

Java代码

package org.ourpioneer.action;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts2.ServletActionContext;
import org.ourpioneer.util.QueryUtil;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class BaseAction extends ActionSupport {
@Override
public String execute() throws Exception {
return SUCCESS;
}
public Map<String, Object> getParameters() {
return ActionContext.getContext().getParameters();
}
public HttpServletRequest getRequest() {
return ServletActionContext.getRequest();
}
/* 分页信息 */
protected int pageNum = 1 ;
protected int pageSize = 10 ;
public int getPageNum() {
return pageNum;
}
public void setPageNum( int pageNum) {
this .pageNum = pageNum;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize( int pageSize) {
this .pageSize = pageSize;
}
public int getMaxPageSize() {
return 1000 ;
}
public int getDefaultPageSize() {
return 10 ;
}
// 页面解析分页信息使用的方法
public String getQueryStringWithoutPageNum() {
Map<String, Object> m = getParameters();
m.remove("pageNum" );
return QueryUtil.getQueryString(m);
}
public String getFullUrlWithoutPageNum() {
return getRequest().getServletPath() + "?"
+ getQueryStringWithoutPageNum();
}
public String getQueryStringWithoutPageInfo() {
Map<String, Object> m = getParameters();
m.remove("pageNum" );
m.remove("pageSize" );
return QueryUtil.getQueryString(m);
}
public String getFullUrlWithoutPageInfo() {
return getRequest().getServletPath() + "?"
+ getQueryStringWithoutPageInfo();
}
}

这里为了演示，我们将分页的信息都直接定义死了，大家可以根据需要来修改，其中处理信息的QueryUtil大家可以直接参考源代码，这里不做说明了，下面是UserAction处理代码的编写：

Java代码

package org.ourpioneer.action;
import org.ourpioneer.bean.PagingList;
import org.ourpioneer.service.UserService;
public class UserAction extends BaseAction {
private UserService userService;
public PagingList userList;
public void setUserService(UserService userService) {
this .userService = userService;
}
public PagingList getUserList() {
return userList;
}
public String list() {
userList = userService.getAllUsers();
return "list" ;
}
}

根据前面的配置，我们也不难写出代码，下面就是视图处理了，我们使用了Freemarker进行解析，也编写了FreeMarker的分页宏：

Html代码

< #-- 处理分页参数 -- >
< #function getPageUrl pageNum >
< #local pageUrl = base +fullUrlWithoutPageInfo >
< #if pageUrl?ends_with("?") >
< #return pageUrl + " pageSize = " + pageSize + " & pageNum =" + pageNum >
< #else >
< #return pageUrl + "& pageSize = " + pageSize + " & pageNum =" + pageNum >
</ #if >
</ #function >
< #-- 全部或分页显示 -- >
< #function getPageUrlResize size >
< #local pageUrl = base +fullUrlWithoutPageInfo >
< #if pageUrl?ends_with("?") >
< #return pageUrl + " pageNum = 1 & pageSize =" + size >
< #else >
< #return pageUrl + "& pageNum = 1 & pageSize =" + size >
</ #if >
</ #function >
< #-- 分页信息 -- >
< #macro paging pagingList >
< #local pageCount = pagingList .pageCount >
< #local rowCount = pagingList .rowCount >
< #local pageNum = pagingList .pageNum >
< #local pageSize = pagingList .pageSize >
< #if rowCount == 0 >
< #if useFlag?exists >
< div style = "border:1px solid #666;padding:2 5 2 5;background:#efefef;color:#333" > 没有相关记录 </ div >
< #else >
< #assign useFlag = 1 >
</ #if >
< #else >
< table >
< tr >
< td style = "line-height:150%" > 共 ${rowCount} 条记录 ${pageCount} 页
< #if pageCount gt 1 && pageSize!=maxPageSize >
< span class = "selectedPage" style = "padding:2px 3px 0 3px" > < a class = "page" href = "${getPageUrlResize(maxPageSize)}" > 全部显示 </ a > </ span >
< #elseif pageSize ==maxPageSize >
< span class = "selectedPage" style = "padding:2px 3px 0 3px" > < a class = "page" href = "${getPageUrlResize(defaultPageSize)}" > 分页显示 </ a > </ span >
</ #if >
< #if (pageCount < = 11) >
< #local startPage = 1 >
< #local endPage = pageCount >
< #elseif (pageNum + 5 > pageCount) >
< #local startPage = pageCount - 10 >
< #local endPage = pageCount >
< #elseif (pageNum - 5 < 1 ) >
< #local startPage = 1 >
< #local endPage = 11 >
< #else >
< #local startPage = pageNum - 5 >
< #local endPage = pageNum + 5 >
</ #if >
< #if (pageCount > 1) >
< #if (pageNum != 1) >
< #if (pageCount > 11) >
< a class = "page" href = "${getPageUrl(1)}" style = "font-family:Webdings" title = "首页" > 9 </ a >
</ #if >
< a class = "page" href = "${getPageUrl(pageNum-1)}" style = "font-family:Webdings" title = "上页" > 3 </ a >
< #else >
< #if (pageCount > 11) >
< span style = "font-family:Webdings;color:#999" > 9 </ span >
</ #if >
< span style = "font-family:Webdings;color:#999" > 3 </ span >
</ #if >
< #list startPage..endPage as x >
< #if x = pageNum >
< span class = "selectedPage" > ${x} </ span >
< #else >
< span class = "noSelectedPage" > < a class = "page" href = "${getPageUrl(x)}" > ${x} </ a > </ span >
</ #if >
</ #list >
< #if (pageCount != pageNum) >
< a class = "page" href = "${getPageUrl(pageNum+1)}" style = "font-family:Webdings" title = "下页" > 4 </ a >
< #if (pageCount > 11) >
< a class = "page" href = "${getPageUrl(pageCount)}" style = "font-family:Webdings" title = "尾页" > : </ a >
</ #if >
< #else >
< span style = "font-family:Webdings;color:#999" > 4 </ span >
< #if (pageCount > 11) >
< span style = "font-family:Webdings;color:#999" > : </ span >
</ #if >
</ #if >
</ #if >
</ td >
</ tr >
</ table >
</ #if >
</ #macro >

    之后，我们来运行项目：

    可以通过点击全部显示和页面来查看分页效果。
     本文系作者本人的实践探索，方案可能不是最佳实践，希望和大家交流沟通，源码随附件可以下载。另外关于本文涉及到的技术可以参看本博客中以往对iBatis的介绍：
框架系列：框架技术，
    最后，希望它对使用者和学习有用。根据大家的反馈意见全新修改。