您的位置：首页 > 其它

关于Ajax中处理回传参数的几种实现

2008-05-23 10:19 399 查看

我的试验主要包括4种:
1.回传一个普通的String字符串.
2.回传一个组织好的Javascript字符串.
3.回传一个Json对象.(需要引入json.jar)
4.回传一个XML对象.
基本实现如下:
其中测试页面为:

<%...@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<%...request.setCharacterEncoding("UTF-8");%>

<html>

<head>

<title>测试Ajax页面</title>

</head>

<body>

<tr>

<td>

</td>

</tr>

<tr>

<td>

</td>

</tr>

<tr>

<td>

</td>

</tr>

<tr>

<td>

</td>

</tr>

</table>

</form>

</td>

</table>

</body>

</html>

var xmlHttp ;

function createXmlHttpRequest()...{

if(window.ActiveXObject)...{

xmlHttp = new ActiveXObject("Microsoft.XMLHTTP") ;

}else if(window.XMLHttpRequest)...{

xmlHttp = new XMLHttpRequest();

}

/**//*返回String*/

function testAjaxForString()...{

createXmlHttpRequest();

var url = "HelloWorld?";

var queryString = "name=songwei";

url += queryString ;

// xmlHttp.onreadystatechange = parseHello ;//如果是异步,既open中最后一个参数为true.则打开该选项.

xmlHttp.open("post",url,false);

xmlHttp.send(null);

alert(xmlHttp.responseText); //如果是字符串或者xml.

}

/**//*返回JsObject*/

function testAjaxForObject()...{

createXmlHttpRequest();

var url = "HelloWorldForObject?";

var queryString = "name=songwei";

url += queryString ;

// xmlHttp.onreadystatechange = parseHello ;

xmlHttp.open("post",url,false);

xmlHttp.send(null);

alert(xmlHttp.responseText);

var o = eval(xmlHttp.responseText);

alert("username="+o.username);

alert("password="+o.password);

var farray = o.friend ;

var fname ="";

for(var i=0;i<farray.length;i++)...{

fname += farray[i]+" ";

}

alert("friend list ="+fname);

}

//返回Json

function testAjaxForJson()...{

createXmlHttpRequest();

var url = "HelloWorldForJson?";

var queryString = "name=songwei";

url += queryString ;

xmlHttp.open("post",url,false);

xmlHttp.send(null);

alert(xmlHttp.responseText);

var o = eval("(" + xmlHttp.responseText + ")");

alert(o.userInfo.username);

alert(o.userInfo.password);

alert(o.userInfo.friends[0]);

alert(o.userInfo.friends[1]);

}

//返回XML

function testAjaxForXml()...{

createXmlHttpRequest();

var url = "HelloWorldForXML?";

var queryString = "name=songwei";

url += queryString ;

xmlHttp.open("post",url,false);

xmlHttp.send(null);

alert(xmlHttp.responseXML);

alert ("tagName: " + xmlHttp.responseXML.documentElement.tagName);

var xmlDoc = xmlHttp.responseXML ;

var xmlRoot=xmlDoc.documentElement;

var friendsItem=xmlRoot.getElementsByTagName("friends");

alert(friendsItem[0].firstChild.firstChild.data);

alert(friendsItem[0].firstChild.nextSibling.firstChild.data);

var usernameItem = xmlRoot.getElementsByTagName("username");

alert(usernameItem[0].firstChild.data);

}

</script>

对于各种回传方式的不同servlet实现:
1.普通字符串 ,HelloWorld.java(Servlet)

public class HelloWorld extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet ...{

public HelloWorld() ...{

super();

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

doPost(request,response);

}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

// TODO Auto-generated method stub

String name = request.getParameter("name");

String str = "Hello "+name ;

PrintWriter pw = response.getWriter();

pw.print(str);

pw.close();

}

}

2.Javascript字符串Servlet实现
HelloWorldForObject.java

public class HelloWorldForObject extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet ...{

public HelloWorldForObject() ...{

super();

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

doPost(request,response);

}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

String name = request.getParameter("name");

User user = new User();

user.setUsername(name);

user.setPassword("abc");

List<String> friend = new ArrayList<String>();

friend.add("wangdong");

friend.add("zhaoyong");

user.setFriend(friend);

StringBuffer sb = new StringBuffer();

sb.append("var o = new Object();");

sb.append("o.username ='"+user.getUsername()+"' ;");

sb.append("o.password ='"+user.getPassword()+"' ;");

sb.append("o.friend = new Array(");

String tmp = "" ;

for(String s : user.getFriend())...{

if(tmp.trim().length()<1)...{

tmp += "'"+s+"'" ;

}else...{

tmp +="," ;

tmp += "'"+s+"'" ;

}

sb.append(tmp+") ;");

sb.append("o;");

PrintWriter pw = response.getWriter();

pw.print(sb.toString());

pw.close();

}

}

3.JSon对象实现
HelloWorldForJson.java

public class HelloWorldForJson extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet ...{

public HelloWorldForJson() ...{

super();

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

doPost(request,response);

}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

response.setCharacterEncoding("UTF-8");

response.setHeader("Cache-Control","no-cache");

request.setCharacterEncoding("UTF-8");

String result = new String();

String name = request.getParameter("name");

try...{

JSONObject jsonResult = new JSONObject();

jsonResult.put("username",name);

jsonResult.put("password","password");

JSONArray jsonFriends = new JSONArray();

jsonFriends.put("张三");

jsonFriends.put("李四");

jsonResult.put("friends",jsonFriends);

result = new JSONObject().put("userInfo", jsonResult).toString();

}catch(JSONException jex)...{

jex.printStackTrace();

}

response.getWriter().print(result);

response.getWriter().close();

}

}

4.XML对象实现
HelloWorldForXML.java

public class HelloWorldForXML extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet ...{

public HelloWorldForXML() ...{

super();

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

doPost(request,response);

}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException ...{

String name = request.getParameter("name");

Document doc = null ;

String docStr ="" ;

try...{

DocumentBuilderFactory dbf =DocumentBuilderFactory.newInstance();

DocumentBuilder db = dbf.newDocumentBuilder();

doc = db.newDocument();

Element root = doc.createElement("userInfo");

doc.appendChild(root);

Element nameE = doc.createElement("username");

Text nameT = doc.createTextNode(name);

nameE.appendChild(nameT);

root.appendChild(nameE);

Element passE = doc.createElement("password");

Text passT = doc.createTextNode("password");

passE.appendChild(passT);

root.appendChild(passE);

Element friends = doc.createElement("friends");

Element friend1 = doc.createElement("friend");

Text f1T = doc.createTextNode("张三");

friend1.appendChild(f1T);

Element friend2 = doc.createElement("friend");

Text f2T = doc.createTextNode("李四");

friend2.appendChild(f2T);

friends.appendChild(friend1);

friends.appendChild(friend2);

root.appendChild(friends);

ByteArrayOutputStream bstream = null;

try ...{

bstream = new ByteArrayOutputStream();

Transformer xformer = TransformerFactory.newInstance()

.newTransformer();

Source source = new DOMSource(doc);

Result result = new StreamResult(bstream);

xformer.transform(source, result);

} catch (Exception e) ...{

e.printStackTrace();

}

try ...{

docStr = new String(bstream.toByteArray(), "UTF-8");

} catch (UnsupportedEncodingException e) ...{

e.printStackTrace();

docStr = new String(bstream.toByteArray());

}

System.out.println(docStr);

}catch(ParserConfigurationException ex)...{

ex.printStackTrace();

}

response.setContentType("text/xml;charset=UTF-8");

PrintWriter writer = response.getWriter();

writer.print(docStr);

writer.flush();

writer.close();

}

down!!

内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理

标签：

相关文章推荐

新的分享

章节导航