AJAX基础应用一例

JS:

	<script>
		var xhr = AjaxXmlHttpRequest();
		 function getSups(){			
			if(xhr==null){
				alert('浏览器不支持Ajax');
				return;				
			}
			xhr.onreadystatechange=stateChanged;
			var url = "supliers.do?method=getAllSup";
			xhr.open("post",url,true);
			xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");		
		}
		
		function stateChanged(){
			//alert("测试");
			if(xhr.readyState==4){
				document.getElementById("sup").innerHTML=xhr.responseText;
				return;
			}
		}
		
		function AjaxXmlHttpRequest() { 
			var xmlHttp; 
			try { 
				// Firefox, Opera 8.0+, Safari 
				xmlHttp = new XMLHttpRequest(); 
			}catch (e) { 
				// Internet Explorer 
				try { 
					xmlHttp = new ActiveXObject("Msxml2.XMLHTTP"); } 
				catch (e) { 
					try { 
						xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 
					} catch (e) { 
							alert("您的浏览器不支持AJAX！"); 
							return false; 
					} 
				} 
			 } 
			 return xmlHttp; 
		}	
		
	</script>

JAVA代码

 

 public ActionForward getSups(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
  List<Supplier> rlist = this.supServices.getAllSupp();
  String beg1 = "<option value= ";
  String beg2=">";
  String end = "</option>";
  for(Supplier sup:rlist){
   beg1+=sup.getS_id();
   beg1+=beg2;
   beg1+=sup.getSupplier_name();
   beg1+=end;
  }
  PrintWriter pw = response.getWriter();
  pw.write(beg1);
  return null;
 }