Ajax表单验证

 一、导包

json-lib-2.3-jdk15.jar
mysql-connector-java-5.1.0-bin.jar

二、编写js

<script type="text/javascript">
      function test(){
		var stdNum=document.getElementById("stdNum").value;
		if(stdNum ==""){
			alert("不能为空");
		}else{
		$.ajax({
			url:"check.action",
			type:"post",
			data:"standard.std_num="+stdNum,
			async:true,
			success:function(data){
				alert(data.message);
			}
		})
		}
	}

</script>

//jsp
标准号:<input id="stdNum" name="standard.std_num" value="<s:property value='standard.std_num'/>" onblur="test()"/><br/>

验证是否与数据库里的数据相同

Dao层写入方法：

public long sFindHQL(String stdNum){
		String hql="select count(*) from Standard s where s.std_num = ?";
		return findHQL(hql,stdNum);
	}

Action 中：

    private String message;
	
	public String getMessage() {
		return message;
	}
	public void setMessage(String message) {
		this.message = message;
	}
	public String check(){
		long count =dbz.bfindHQL(standard.getStd_num());
		if(count ==1){
			message="已存在";
		}else{
			message="可用";
		}
		return "success";
	}

Struts配置

        <action name="check" class="standardAction" method="check">
			<result type="json">
				<param name="includeProperties">
					message
				</param>
			</result>
		</action>