JdbcTemplate增加分页查询

package com.hundsun.fiam.service.generic;

import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang.ArrayUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Service;

/**
*
* JdbcTemplate增加分页查询
*
*
*/
@Service("jdbcTemplateWithPaging")
public class JdbcTemplateWithPaging {

private static final Logger logger = LoggerFactory.getLogger(JdbcTemplateWithPaging.class);

@Autowired
private JdbcTemplate jdbcTemplate;

public JdbcTemplateWithPaging() {
}

/**
* 分页查询
*
* @param sql
*            查询的sql语句
* @param args
*            参数
* @param start
*            起始行
* @param limit
*            获取的行数
* @return
* @throws DataAccessException
*/
public List<Map<String, Object>> queryPage(String sql, Object[] args,
int start, int limit) {
if (start <= 0 && limit <= 0) {
return (List<Map<String, Object>>) jdbcTemplate.queryForList(sql,
args);
}
if (start <= 1) {
sql = getLimitString(sql, false);
args = ArrayUtils.add(args, args.length, limit);
} else {
sql = getLimitString(sql, true);
args = ArrayUtils.add(args, args.length, start + limit);
args = ArrayUtils.add(args, args.length, start);
}

logger.info("paging sql : \n" + sql);
return (List<Map<String, Object>>) jdbcTemplate.queryForList(sql, args);
}

/**
* 分页查询
*
* @param sql
*            查询的sql语句
* @param start
*            起始行
* @param limit
*            获取的行数
* @return
*/
public List<Map<String, Object>> queryPage(String sql, int start, int limit) {
Object[] args = new Object[] {};
return this.queryPage(sql, args, start, limit);
}

/**
* 分页查询
*
* @param sql
*            查询的sql语句
* @param start
*            起始行
* @param limit
*            获取的行数
*           
* @param   RowMapper   
* @return
*/
public <T> List<T> queryPage(String sql,int start, int limit, RowMapper<T> rowMapper) throws DataAccessException {
if (start <= 0 && limit <= 0) {
return jdbcTemplate.query(sql, rowMapper);
}
Object[] args = new Object[] {};
if (start <= 1) {
sql = getLimitString(sql, false);
args = ArrayUtils.add(args, args.length, limit);
} else {
sql = getLimitString(sql, true);
args = ArrayUtils.add(args, args.length, start + limit);
args = ArrayUtils.add(args, args.length, start);
}

Pattern pattern = Pattern.compile("\\?");

Matcher matcher = pattern.matcher(sql);

for(int i  =  0 ; i<args.length ;  i++,matcher =  pattern.matcher(sql)){
sql  =  matcher.replaceFirst(args[i].toString()) ;
}

logger.info("paging sql : \n" + sql);
return  jdbcTemplate.query(sql, rowMapper);
}

private String getLimitString(String sql, boolean hasOffset) {
sql = sql.trim();
boolean isForUpdate = false;
if ( sql.toLowerCase().endsWith(" for update") ) {
sql = sql.substring( 0, sql.length()-11 );
isForUpdate = true;
}

StringBuffer pagingSelect = new StringBuffer( sql.length()+100 );
if (hasOffset) {
pagingSelect.append("select * from ( select row_.*, rownum rownum_ from ( ");
}
else {
pagingSelect.append("select * from ( ");
}
pagingSelect.append(sql);
if (hasOffset) {
pagingSelect.append(" ) row_ where rownum <= ?) where rownum_ > ?");
}
else {
pagingSelect.append(" ) where rownum <= ?");
}

if ( isForUpdate ) {
pagingSelect.append( " for update" );
}
return pagingSelect.toString();
}


}