关于Ajax中处理回传参数的几种实现

发布时间：2020-12-16 00:47:53 所属栏目：百科来源：网络整理

导读：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: 001 %@page language = " java " contentType = "text/html; charset=

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:

 
 
  
   
    
     
     
     
     
     
    
  
 
 
 
 
  
   
    
     
     001 
     <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> 
     
     
     002 
     <%request.setCharacterEncoding("UTF-8");%> 
     
     
     003 
     <html> 
     
     
     004 
     <head> 
     
     
     005 
     <title>测试Ajax页面</title> 
     
     
     006 
     </head> 
     
     
     007 
     <body> 
     
     
     008 
     <table width="100%" height="100%" > 
     
     
     009 
         <td align="center" valign="center" > 
     
     
     010 
             <form action="" method="post" onsubmit=""> 
     
     
     011 
                 <table border="3" > 
     
     
     012 
                     <tr> 
     
     
     013 
                         <td> 
     
     
     014 
                             <input name="试验返回String" type="button" value="试验返回String" onclick="testAjaxForString();" style="width:140px;"> 
     
     
     015 
                         </td> 
     
     
     016 
                     </tr> 
     
     
     017 
                     <tr> 
     
     
     018 
                         <td> 
     
     
     019 
                             <input name="试验返回javascriptString" type="button" value="试验返回javascriptString" onclick="testAjaxForObject();" style="width:140px;"> 
     
     
     020 
                         </td> 
     
     
     021 
                     </tr> 
     
     
     022 
                     <tr> 
     
     
     023 
                         <td> 
     
     
     024 
                             <input name="试验返回json" type="button" value="试验返回json" onclick="testAjaxForJson();" style="width:140px;"> 
     
     
     025 
                         </td> 
     
     
     026 
                     </tr> 
     
     
     027 
                     <tr> 
     
     
     028 
                         <td> 
     
     
     029 
                             <input name="试验返回xml" type="button" value="试验返回xml" onclick="testAjaxForXml();" style="width:140px;"> 
     
     
     030 
                         </td> 
     
     
     031 
                     </tr> 
     
     
     032 
                 </table> 
     
     
     033 
             </form> 
     
     
     034 
         </td> 
     
     
     035 
     </table> 
     
     
     036 
     </body> 
     
     
     037 
     </html> 
     
     
     038 
      
     
     
     039 
     <script type="text/javascript"> 
     
     
     040 
     var xmlHttp ; 
     
     
     041 
     function createXmlHttpRequest(){ 
     
     
     042 
         if(window.ActiveXObject){ 
     
     
     043 
             xmlHttp = new ActiveXObject("Microsoft.XMLHTTP") ; 
     
     
     044 
         }else if(window.XMLHttpRequest){ 
     
     
     045 
             xmlHttp = new XMLHttpRequest(); 
     
     
     046 
         } 
     
     
     047 
     } 
     
     
     048 
     /*返回String*/ 
     
     
     049 
     function testAjaxForString(){ 
     
     
     050 
         createXmlHttpRequest(); 
     
     
     051 
         var url = "HelloWorld?"; 
     
     
     052 
         var queryString = "name=songwei"; 
     
     
     053 
         url += queryString ; 
     
     
     054 
     //    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. 
     
     
     055 
         xmlHttp.open("post",url,false); 
     
     
     056 
         xmlHttp.send(null); 
     
     
     057 
         alert(xmlHttp.responseText); //如果是字符串或者xml. 
     
     
     058 
     } 
     
     
     059 
      
     
     
     060 
     /*返回JsObject*/ 
     
     
     061 
     function testAjaxForObject(){ 
     
     
     062 
         createXmlHttpRequest(); 
     
     
     063 
         var url = "HelloWorldForObject?"; 
     
     
     064 
         var queryString = "name=songwei"; 
     
     
     065 
         url += queryString ; 
     
     
     066 
     //    xmlHttp.onreadystatechange = parseHello ; 
     
     
     067 
         xmlHttp.open("post",false); 
     
     
     068 
         xmlHttp.send(null); 
     
     
     069 
         alert(xmlHttp.responseText); 
     
     
     070 
         var o = eval(xmlHttp.responseText); 
     
     
     071 
         alert("username="+o.username); 
     
     
     072 
         alert("password="+o.password); 
     
     
     073 
         var farray = o.friend ; 
     
     
     074 
         var fname =""; 
     
     
     075 
         for(var i=0;i<farray.length;i++){ 
     
     
     076 
             fname += farray[i]+"    "; 
     
     
     077 
         } 
     
     
     078 
         alert("friend list ="+fname);     
     
     
     079 
     } 
     
     
     080 
     //返回Json 
     
     
     081 
     function testAjaxForJson(){ 
     
     
     082 
         createXmlHttpRequest(); 
     
     
     083 
         var url = "HelloWorldForJson?"; 
     
     
     084 
         var queryString = "name=songwei"; 
     
     
     085 
         url += queryString ; 
     
     
     086 
         xmlHttp.open("post",false); 
     
     
     087 
         xmlHttp.send(null); 
     
     
     088 
         alert(xmlHttp.responseText); 
     
     
     089 
         var o = eval("(" + xmlHttp.responseText + ")"); 
     
     
     090 
         alert(o.userInfo.username); 
     
     
     091 
         alert(o.userInfo.password); 
     
     
     092 
         alert(o.userInfo.friends[0]); 
     
     
     093 
         alert(o.userInfo.friends[1]); 
     
     
     094 
     } 
     
     
     095 
      
     
     
     096 
     //返回XML 
     
     
     097 
     function testAjaxForXml(){ 
     
     
     098 
         createXmlHttpRequest(); 
     
     
     099 
         var url = "HelloWorldForXML?"; 
     
     
     100 
         var queryString = "name=songwei"; 
     
     
     101 
         url += queryString ; 
     
     
     102 
         xmlHttp.open("post",false); 
     
     
     103 
         xmlHttp.send(null); 
     
     
     104 
         alert(xmlHttp.responseXML); 
     
     
     105 
         alert ("tagName: " + xmlHttp.responseXML.documentElement.tagName); 
     
     
     106 
         var xmlDoc = xmlHttp.responseXML ; 
     
     
     107 
         var xmlRoot=xmlDoc.documentElement; 
     
     
     108 
      
     
     
     109 
         var friendsItem=xmlRoot.getElementsByTagName("friends"); 
     
     
     110 
         alert(friendsItem[0].firstChild.firstChild.data); 
     
     
     111 
         alert(friendsItem[0].firstChild.nextSibling.firstChild.data); 
     
     
     112 
         var usernameItem = xmlRoot.getElementsByTagName("username"); 
     
     
     113 
         alert(usernameItem[0].firstChild.data); 
     
     
     114 
      
     
     
     115 
     } 
     
     
     116 
     </script>

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

 
 
  
   
    
     
     
     
     
     
    
  
 
 
 
 
  
   
    
     
     01 
      public class HelloWorld extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { 
     
     
     02 
         public HelloWorld() { 
     
     
     03 
             super(); 
     
     
     04 
         }        
     
     
     05 
         protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { 
     
     
     06 
             doPost(request,response); 
     
     
     07 
         }       
     
     
     08 
         protected void doPost(HttpServletRequest request,IOException { 
     
     
     09 
             // TODO Auto-generated method stub 
     
     
     10 
             String name = request.getParameter("name"); 
     
     
     11 
             String str = "Hello "+name ; 
     
     
     12 
             PrintWriter pw = response.getWriter(); 
     
     
     13 
             pw.print(str); 
     
     
     14 
             pw.close(); 
     
     
     15 
         }                  
     
     
     16 
     }

2.Javascript字符串Servlet实现
HelloWorldForObject.java

 
 
  
   
    
     
     
     
     
     
    
  
 
 
 
 
  
   
    
     
     01 
      public class HelloWorldForObject extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { 
     
     
     02 
         public HelloWorldForObject() { 
     
     
     03 
             super(); 
     
     
     04 
         }        
     
     
     05 
         protected void doGet(HttpServletRequest request,response); 
     
     
     07 
         }       
     
     
     08 
      
     
     
     09 
         protected void doPost(HttpServletRequest request,IOException { 
     
     
     10 
             String name = request.getParameter("name"); 
     
     
     11 
             User user = new User(); 
     
     
     12 
             user.setUsername(name); 
     
     
     13 
             user.setPassword("abc"); 
     
     
     14 
             List<String> friend = new ArrayList<String>(); 
     
     
     15 
             friend.add("wangdong"); 
     
     
     16 
             friend.add("zhaoyong"); 
     
     
     17 
             user.setFriend(friend); 
     
     
     18 
             StringBuffer sb = new StringBuffer(); 
     
     
     19 
             sb.append("var o = new Object();"); 
     
     
     20 
             sb.append("o.username ='"+user.getUsername()+"' ;"); 
     
     
     21 
             sb.append("o.password ='"+user.getPassword()+"' ;"); 
     
     
     22 
             sb.append("o.friend = new Array("); 
     
     
     23 
             String tmp = "" ; 
     
     
     24 
             for(String s : user.getFriend()){ 
     
     
     25 
                 if(tmp.trim().length()<1){ 
     
     
     26 
                     tmp += "'"+s+"'" ; 
     
     
     27 
                 }else{ 
     
     
     28 
                     tmp +="," ; 
     
     
     29 
                     tmp += "'"+s+"'" ; 
     
     
     30 
                 } 
     
     
     31 
             } 
     
     
     32 
             sb.append(tmp+") ;"); 
     
     
     33 
             sb.append("o;"); 
     
     
     34 
             PrintWriter pw = response.getWriter(); 
     
     
     35 
             pw.print(sb.toString()); 
     
     
     36 
             pw.close(); 
     
     
     37 
         }                  
     
     
     38 
     }

3.JSon对象实现
HelloWorldForJson.java

 
 
  
   
    
     
     
     
     
     
    
  
 
 
 
 
  
   
    
     
     01 
     public class HelloWorldForJson extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { 
     
     
     02 
         public HelloWorldForJson() { 
     
     
     03 
             super(); 
     
     
     04 
         }        
     
     
     05 
         protected void doGet(HttpServletRequest request,IOException { 
     
     
     09 
              response.setCharacterEncoding("UTF-8");   
     
     
     10 
              response.setHeader("Cache-Control","no-cache");   
     
     
     11 
              request.setCharacterEncoding("UTF-8");           
     
     
     12 
             String result = new String(); 
     
     
     13 
             String name = request.getParameter("name"); 
     
     
     14 
             try{ 
     
     
     15 
                 JSONObject jsonResult = new JSONObject(); 
     
     
     16 
                 jsonResult.put("username",name); 
     
     
     17 
                 jsonResult.put("password","password"); 
     
     
     18 
                 JSONArray jsonFriends = new JSONArray(); 
     
     
     19 
                 jsonFriends.put("张三"); 
     
     
     20 
                 jsonFriends.put("李四"); 
     
     
     21 
                 jsonResult.put("friends",jsonFriends); 
     
     
     22 
                 result = new JSONObject().put("userInfo",jsonResult).toString(); 
     
     
     23 
             }catch(JSONException jex){ 
     
     
     24 
                 jex.printStackTrace(); 
     
     
     25 
             } 
     
     
     26 
             response.getWriter().print(result); 
     
     
     27 
             response.getWriter().close(); 
     
     
     28 
         }                  
     
     
     29 
     }

4.XML对象实现
HelloWorldForXML.java

 
 
  
   
    
     
     
     
     
     
    
  
 
 
 
 
  
   
    
     
     01 
      public class HelloWorldForXML extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { 
     
     
     02 
         public HelloWorldForXML() { 
     
     
     03 
             super(); 
     
     
     04 
         }        
     
     
     05 
         protected void doGet(HttpServletRequest request,IOException { 
     
     
     09 
             String name = request.getParameter("name"); 
     
     
     10 
             Document doc = null ; 
     
     
     11 
             String docStr ="" ; 
     
     
     12 
             try{ 
     
     
     13 
                 DocumentBuilderFactory dbf =DocumentBuilderFactory.newInstance(); 
     
     
     14 
                 DocumentBuilder db = dbf.newDocumentBuilder(); 
     
     
     15 
                 doc = db.newDocument(); 
     
     
     16 
                 Element root = doc.createElement("userInfo"); 
     
     
     17 
                 doc.appendChild(root); 
     
     
     18 
                 Element nameE = doc.createElement("username"); 
     
     
     19 
                 Text nameT = doc.createTextNode(name); 
     
     
     20 
                 nameE.appendChild(nameT); 
     
     
     21 
                 root.appendChild(nameE);     
     
     
     22 
      
     
     
     23 
                 Element passE = doc.createElement("password"); 
     
     
     24 
                 Text passT = doc.createTextNode("password"); 
     
     
     25 
                 passE.appendChild(passT); 
     
     
     26 
                 root.appendChild(passE);     
     
     
     27 
      
     
     
     28 
                 Element friends = doc.createElement("friends"); 
     
     
     29 
      
     
     
     30 
                 Element friend1 = doc.createElement("friend"); 
     
     
     31 
                 Text f1T = doc.createTextNode("张三"); 
     
     
     32 
                 friend1.appendChild(f1T); 
     
     
     33 
                 Element friend2 = doc.createElement("friend"); 
     
     
     34 
                 Text f2T = doc.createTextNode("李四"); 
     
     
     35 
                 friend2.appendChild(f2T); 
     
     
     36 
      
     
     
     37 
                 friends.appendChild(friend1); 
     
     
     38 
                 friends.appendChild(friend2); 
     
     
     39 
                 root.appendChild(friends); 
     
     
     40 
      
     
     
     41 
                 ByteArrayOutputStream bstream = null; 
     
     
     42 
                 try { 
     
     
     43 
                     bstream = new ByteArrayOutputStream(); 
     
     
     44 
                     Transformer xformer = TransformerFactory.newInstance() 
     
     
     45 
                             .newTransformer(); 
     
     
     46 
                     Source source = new DOMSource(doc); 
     
     
     47 
                     Result result = new StreamResult(bstream); 
     
     
     48 
                     xformer.transform(source,result); 
     
     
     49 
                 } catch (Exception e) { 
     
     
     50 
                     e.printStackTrace(); 
     
     
     51 
                 }         
     
     
     52 
                 try { 
     
     
     53 
                     docStr =  new String(bstream.toByteArray(),"UTF-8"); 
     
     
     54 
                 } catch (UnsupportedEncodingException e) { 
     
     
     55 
                     e.printStackTrace(); 
     
     
     56 
                     docStr = new String(bstream.toByteArray()); 
     
     
     57 
                 } 
     
     
     58 
                 System.out.println(docStr); 
     
     
     59 
      
     
     
     60 
             }catch(ParserConfigurationException ex){ 
     
     
     61 
                 ex.printStackTrace(); 
     
     
     62 
             } 
     
     
     63 
             response.setContentType("text/xml;charset=UTF-8");  
     
     
     64 
             PrintWriter writer = response.getWriter(); 
     
     
     65 
             writer.print(docStr);  
     
     
     66 
             writer.flush();  
     
     
     67 
             writer.close();         
     
     
     68 
         }

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