/**

* 模糊查询(分页)

*

* @project apqp

* @author liud JIRA:APQP-23

* @date 2013-04-16

* @param flow

* @param page

* 分页参数包装器

* @return pageData 分页结果集

* @history

*/

@Override

public PageData queryFlow(Attach attach, Pagination page) {

if (page.isReadTotal())

page.setTotal(this.selectOneByTotalCount("flow.queryList", attach));

RowBounds rowbounds = new RowBounds(page.getStart(), page.getLimit());

List result = this.sqlSession.selectList("flow.queryList",

attach, rowbounds);

PageData pageData = new PageData();

pageData.setResult(result);

pageData.setPagination(page);

return pageData;

}

/**

* 获得分页的总条数

*

* @author liud

* @date 2013-2-18

* @param s

* mybatis对应的命名空间

* @param obj

* 参数

* @return

*/

protected int selectOneByTotalCount(String s, Object obj) {

final BaseEntity baseEntity = new BaseEntity();

RowBounds rowbounds = new RowBounds(-1, -1);

this.sqlSession.select(s, obj, rowbounds, new ResultHandler() {

@Override

public void handleResult(ResultContext context) {

Object object = context.getResultObject();

if (object != null) {

BaseEntity base = (BaseEntity) object;

baseEntity.setTotal(base.getTotal());

}

}

});

return baseEntity.getTotal();

}

-- mybatis.xml flow.queryList

parameterType="com.eman.flow.entity.Attach">

SELECT f1.fileID

, f1.fileName

, f1.fileType

, f1.fileSize

, f1.uploadUser

, f1.uploadTime

, f2.userName uploadUserName

FROM

t_attachmentOfAPQPFlowPhase p INNER

JOIN t_attachment f1

ON p.fileID =

f1.fileID

INNER JOIN t_user f2 ON f1.uploadUser =

f2.userID

WHERE

p.phaseID = #{phaseID}

order by f1.uploadTime desc

-- mybatis.config.xml

/p>

"http://mybatis.org/dtd/mybatis-3-config.dtd">

package com.eman.core.interceptor;

import java.sql.Connection;

import java.util.Properties;

import org.apache.ibatis.executor.statement.StatementHandler;

import org.apache.ibatis.plugin.Interceptor;

import org.apache.ibatis.plugin.Intercepts;

import org.apache.ibatis.plugin.Invocation;

import org.apache.ibatis.plugin.Plugin;

import org.apache.ibatis.plugin.Signature;

import org.apache.ibatis.reflection.MetaObject;

import org.apache.ibatis.session.Configuration;

import org.apache.ibatis.session.RowBounds;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import com.eman.core.dialect.Dialect;

import com.eman.core.dialect.SQLServer2005Dialect;

import com.eman.core.dialect.SQLServer2008Dialect;

/**

* 拦截mybatis执行sql,以用于转换分页sql

*

* @author liud

*

*/

@Intercepts({ @Signature(type = StatementHandler.class, method = "prepare", args = { Connection.class }) })

public class PaginationInterceptor implements Interceptor {

private static final Logger log = LoggerFactory.getLogger("controller");

@Override

public Object intercept(Invocation invocation) throws Throwable {

StatementHandler sh = (StatementHandler) invocation.getTarget();

MetaObject mo = MetaObject.forObject(sh);

RowBounds rb = (RowBounds) mo.getValue("delegate.rowBounds");

if (rb == RowBounds.DEFAULT

|| (rb.getLimit() <= 0 && rb.getLimit() != -1)

|| rb.getLimit() > RowBounds.NO_ROW_LIMIT)

return invocation.proceed();

Configuration conf = (Configuration) mo

.getValue("delegate.configuration");

Dialect dialect = this.invokeDialect(conf.getVariables()

.getProperty("jdbc.db.type").toUpperCase());

if (dialect == null)

return invocation.proceed();

String bSql = (String) mo.getValue("delegate.boundSql.sql");

if (rb.getLimit() == -1 && rb.getOffset() == -1)

bSql = dialect.getTotalString(bSql);

else

bSql = dialect.getLimitString(bSql, rb.getOffset(), rb.getLimit());

mo.setValue("delegate.boundSql.sql", bSql);

mo.setValue("delegate.rowBounds.offset", RowBounds.NO_ROW_OFFSET);

mo.setValue("delegate.rowBounds.limit", RowBounds.NO_ROW_LIMIT);

return invocation.proceed();

}

@Override

public Object plugin(Object target) {

return Plugin.wrap(target, this);

}

@Override

public void setProperties(Properties properties) {

}

/**

* 通过配置获得sql数据库对象

*

* @author liud

* @date 2013-2-18

* @param param

* @return

*/

private Dialect invokeDialect(String param) {

Dialect.Type type = null;

try {

type = Dialect.Type.valueOf(param);

} catch (Exception e) {

log.debug(

"the value of the dialect property in mybatis-config.xml is not defined:{}",

param);

}

Dialect dialect = null;

switch (type) {

case SQLSERVER:

break;

case SQLSERVER2005:

dialect = new SQLServer2005Dialect();

break;

case SQLSERVER2008:

dialect = new SQLServer2008Dialect();

break;

case ORACLE9I:

break;

case ORACLE10G:

break;

case ORACLE11G:

break;

case MYSQL5:

break;

}

return dialect;

}

}

package com.eman.core.dialect;

/**

* sql2008数据库的实现

*

* @author liud

*

*/

public class SQLServer2008Dialect implements Dialect {

private static final String SELECT = "select";

private static final String FROM = "from";

private static final String DISTINCT = "distinct";

@Override

public String getTotalString(String sql) {

StringBuilder sb = new StringBuilder(sql.trim().toLowerCase());

int orderbyIndex = sb.indexOf("order by");

if (orderbyIndex != -1) {

sb.delete(orderbyIndex, sb.length());

}

sb.insert(0, "WITH query AS (").append(

") SELECT count(*) total FROM query ");

return sb.toString();

}

@Override

public String getLimitString(String sql, int offset, int limit) {

if (offset > 1 || limit > 1)

return getLimitString(sql, offset, limit, true);

return sql;

}

/**

* Add a LIMIT clause to the given SQL SELECT (HHH-2655: ROW_NUMBER for

* Paging)

*

* The LIMIT SQL will look like:

*

*

* WITH query AS (

* SELECT ROW_NUMBER() OVER (ORDER BY orderby) as __liud_row_nr__,

* original_query_without_orderby

* )

* SELECT * FROM query WHERE __liud_row_nr__ BEETWIN offset AND offset + last

*

*

*

* @param querySqlString

* The SQL statement to base the limit query off of.

* @param offset

* Offset of the first row to be returned by the query

* (zero-based)

* @param limit

* Maximum number of rows to be returned by the query

*

* @return A new SQL statement with the LIMIT clause applied.

*/

private String getLimitString(String querySqlString, int offset, int limit,

boolean hasOffset) {

StringBuilder sb = new StringBuilder(querySqlString.trim()

.toLowerCase());

int orderByIndex = sb.indexOf("order by");

CharSequence orderby = orderByIndex > 0 ? sb.subSequence(orderByIndex,

sb.length()) : "ORDER BY CURRENT_TIMESTAMP";

// Delete the order by clause at the end of the query

if (orderByIndex > 0) {

sb.delete(orderByIndex, orderByIndex + orderby.length());

}

// HHH-5715 bug fix

replaceDistinctWithGroupBy(sb);

insertRowNumberFunction(sb, orderby);

// Wrap the query within a with statement:

sb.insert(0, "WITH query AS (").append(") SELECT * FROM query ");

sb.append("WHERE __liud_row_nr__ BETWEEN ").append(offset + 1)

.append(" AND ").append(offset + limit);

return sb.toString();

}

/**

* Right after the select statement of a given query we must place the

* row_number function

*

* @param sql

* the initial sql query without the order by clause

* @param orderby

* the order by clause of the query

*/

protected static void insertRowNumberFunction(StringBuilder sql,

CharSequence orderby) {

// Find the end of the select statement

int selectEndIndex = sql.indexOf(SELECT) + SELECT.length();

// Insert after the select statement the row_number() function:

sql.insert(selectEndIndex, " ROW_NUMBER() OVER (" + orderby

+ ") as __liud_row_nr__,");

}

/**

* Utility method that checks if the given sql query is a select distinct

* one and if so replaces the distinct select with an equivalent simple

* select with a group by clause. See

* {@link SQLServer2005DialectTestCase#testReplaceDistinctWithGroupBy()}

*

* @param sql

* an sql query

*/

protected static void replaceDistinctWithGroupBy(StringBuilder sql) {

int distinctIndex = sql.indexOf(DISTINCT);

if (distinctIndex > 0) {

sql.delete(distinctIndex, distinctIndex + DISTINCT.length() + 1);

sql.append(" group by").append(getSelectFieldsWithoutAliases(sql));

}

}

/**

* This utility method searches the given sql query for the fields of the

* select statement and returns them without the aliases. See

* {@link SQLServer2005DialectTestCase#testGetSelectFieldsWithoutAliases()}

*

* @param an

* sql query

* @return the fields of the select statement without their alias

*/

protected static CharSequence getSelectFieldsWithoutAliases(

StringBuilder sql) {

String select = sql.substring(sql.indexOf(SELECT) + SELECT.length(),

sql.indexOf(FROM));

// Strip the as clauses

return stripAliases(select);

}

/**

* Utility method that strips the aliases. See

* {@link SQLServer2005DialectTestCase#testStripAliases()}

*

* @param a

* string to replace the as statements

* @return a string without the as statements

*/

protected static String stripAliases(String str) {

return str.replaceAll("\\sas[^,]+(,?)", "$1");

}

}

以上是集成了mybatis的分页功能，只需要调用第一方法即可以实现。实现方式采用了hibernate分页方式。

2013年6月09日 14:57