java语言利用MySQL数据库自带的DATE_SUB()函数查询一周、一个月、半年、一年之内的数据记录

在JSP页面中根据论坛帖子的发帖时间查询帖子记录，前台JSP页面代码如下：

<s:form id="postTime" action="findPostByTime" method="post" theme="simple" target="mFrame">
	<table class="tab_data" width="70%" >
		<tr>
			<td class="left" width="30%">
				请选择时间：
			</td>
			<td width="70">
			<s:select name="postTime" list="#{'最近一周':'最近一周','最近半个月':'最近半个月','最近一个月':'最近一个月','最近半年':'最近半年','最近一年':'最近一年'}" listKey="value"	listValue="key" theme="simple" headerKey="-1"	headerValue="—发帖时间—">
			</s:select>
			</td>
				
		</tr>
			
			
		<tr>
			<td	class="right" colspan="2" >
			<span style="white-space:pre">	</span><div align="center">
				    <s:submit  value="查询" theme="simple" cssClass="btn_normal" />
					 
				</div>
			</td>
			
		</tr>
	</table>
</s:form>

后台的java代码如下：

private List<McpForumPost> forumPostList;      
private String postTime;  		//类的私有成语变量及其get()和set()方法
public String getPostTime() {
	return postTime;
}


public void setPostTime(String postTime) {
	this.postTime = postTime;
}
public List<McpForumPost> getForumPostList() {
	return forumPostList;
}


public void setForumPostList(List<McpForumPost> forumPostList) {
	this.forumPostList = forumPostList;
}
            /**
		 * 
		 * 前台jsp页面传入一个String类型的postTime，根据发帖时间查询帖子
		 * **/

public String findPostByTime() {
System.out.println(postTime);		
private String columnSql = "select a.post_id,a.user_id,a.board_id,a.post_title,a.post_time,a.check_state,a.is_top,a.is_good,a.post_state,b.account from mcp_forum_post as a,scpn_user as b ";			
 String sql_fy;
try {		
//其中post_time在MySQL数据库中以datetime类型保存
if(postTime.equals("最近一周")){
sql_fy=columnSql+"where a.user_id=b.user_id and a.post_state=1 and a.post_time>DATE_SUB(CURDATE(), INTERVAL 7 DAY)" ;					
}else if(postTime.equals("最近半个月")){
sql_fy=columnSql+"where a.user_id=b.user_id and a.post_state=1 and a.post_time>DATE_SUB(CURDATE(), INTERVAL 15 DAY)";					
}else if(postTime.equals("最近一个月")){
sql_fy=columnSql+"where a.user_id=b.user_id and a.post_state=1 and a.post_time>DATE_SUB(CURDATE(), INTERVAL 1 MONTH)";
}else if(postTime.equals("最近半年")){
sql_fy=columnSql+"where a.user_id=b.user_id and a.post_state=1 and a.post_time>DATE_SUB(CURDATE(), INTERVAL 6 MONTH)";
}else if(postTime.equals("最近一年")){
sql_fy=columnSql+"where a.user_id=b.user_id and a.post_state=1 and a.post_time>DATE_SUB(CURDATE(), INTERVAL 1 YEAR)";
}else {
sql_fy=columnSql+"where a.user_id=b.user_id and a.post_state=1 ";					
}					
System.out.println(sql_fy);						
forumPostList = jdbcTemplate.queryForList(sql_fy); //将日志集合保存到List中
if(forumPostList.size()==0||flag==false) {
	return ERROR;
}	
					
return SUCCESS;	
				
				
} catch (Exception e) {				
	e.printStackTrace();
	return ERROR;
}
			
			
}