XMLHttpRequest

  1 /*
  2 
  3 Cross-Browser XMLHttpRequest v1.2
  4 =================================
  5 
  6 Emulate Gecko 'XMLHttpRequest()' functionality in IE and Opera. Opera requires
  7 the Sun Java Runtime Environment <http://www.java.com/>.
  8 
  9 by Andrew Gregory
 10 http://www.scss.com.au/family/andrew/webdesign/xmlhttprequest/
 11 
 12 This work is licensed under the Creative Commons Attribution License. To view a
 13 copy of this license, visit http://creativecommons.org/licenses/by-sa/2.5/ or
 14 send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California
 15 94305, USA.
 16 
 17 Attribution: Leave my name and web address in this script intact.
 18 
 19 Not Supported in Opera
 20 ----------------------
 21 * user/password authentication
 22 * responseXML data member
 23 
 24 Not Fully Supported in Opera
 25 ----------------------------
 26 * async requests
 27 * abort()
 28 * getAllResponseHeaders(), getAllResponseHeader(header)
 29 
 30 */
 31 // IE support
 32 if (window.ActiveXObject && !window.XMLHttpRequest) {
 33   window.XMLHttpRequest = function() {
 34     var msxmls = new Array(
 35       'Msxml2.XMLHTTP.5.0',
 36       'Msxml2.XMLHTTP.4.0',
 37       'Msxml2.XMLHTTP.3.0',
 38       'Msxml2.XMLHTTP',
 39       'Microsoft.XMLHTTP');
 40     for (var i = 0; i < msxmls.length; i++) {
 41       try {
 42         return new ActiveXObject(msxmls[i]);
 43       } catch (e) {
 44       }
 45     }
 46     return null;
 47   };
 48 }
 49 // Gecko support
 50 /* ;-) */
 51 // Opera support
 52 if (window.opera && !window.XMLHttpRequest) {
 53   window.XMLHttpRequest = function() {
 54     this.readyState = 0; // 0=uninitialized,1=loading,2=loaded,3=interactive,4=complete
 55     this.status = 0; // HTTP status codes
 56     this.statusText = '';
 57     this._headers = [];
 58     this._aborted = false;
 59     this._async = true;
 60     this._defaultCharset = 'ISO-8859-1';
 61     this._getCharset = function() {
 62       var charset = _defaultCharset;
 63       var contentType = this.getResponseHeader('Content-type').toUpperCase();
 64       val = contentType.indexOf('CHARSET=');
 65       if (val != -1) {
 66         charset = contentType.substring(val);
 67       }
 68       val = charset.indexOf(';');
 69       if (val != -1) {
 70         charset = charset.substring(0, val);
 71       }
 72       val = charset.indexOf(',');
 73       if (val != -1) {
 74         charset = charset.substring(0, val);
 75       }
 76       return charset;
 77     };
 78     this.abort = function() {
 79       this._aborted = true;
 80     };
 81     this.getAllResponseHeaders = function() {
 82       return this.getAllResponseHeader('*');
 83     };
 84     this.getAllResponseHeader = function(header) {
 85       var ret = '';
 86       for (var i = 0; i < this._headers.length; i++) {
 87         if (header == '*' || this._headers[i].h == header) {
 88           ret += this._headers[i].h + ': ' + this._headers[i].v + '\n';
 89         }
 90       }
 91       return ret;
 92     };
 93     this.getResponseHeader = function(header) {
 94       var ret = getAllResponseHeader(header);
 95       var i = ret.indexOf('\n');
 96       if (i != -1) {
 97         ret = ret.substring(0, i);
 98       }
 99       return ret;
100     };
101     this.setRequestHeader = function(header, value) {
102       this._headers[this._headers.length] = {h:header, v:value};
103     };
104     this.open = function(method, url, async, user, password) {
105       this.method = method;
106       this.url = url;
107       this._async = true;
108       this._aborted = false;
109       this._headers = [];
110       if (arguments.length >= 3) {
111         this._async = async;
112       }
113       if (arguments.length > 3) {
114         opera.postError('XMLHttpRequest.open() - user/password not supported');
115       }
116       this.readyState = 1;
117       if (this.onreadystatechange) {
118         this.onreadystatechange();
119       }
120     };
121     this.send = function(data) {
122       if (!navigator.javaEnabled()) {
123         alert("XMLHttpRequest.send() - Java must be installed and enabled.");
124         return;
125       }
126       if (this._async) {
127         setTimeout(this._sendasync, 0, this, data);
128         // this is not really asynchronous and won't execute until the current
129         // execution context ends
130       } else {
131         this._sendsync(data);
132       }
133     }
134     this._sendasync = function(req, data) {
135       if (!req._aborted) {
136         req._sendsync(data);
137       }
138     };
139     this._sendsync = function(data) {
140       this.readyState = 2;
141       if (this.onreadystatechange) {
142         this.onreadystatechange();
143       }
144       // open connection
145       var url = new java.net.URL(new java.net.URL(window.location.href), this.url);
146       var conn = url.openConnection();
147       for (var i = 0; i < this._headers.length; i++) {
148         conn.setRequestProperty(this._headers[i].h, this._headers[i].v);
149       }
150       this._headers = [];
151       if (this.method == 'POST') {
152         // POST data
153         conn.setDoOutput(true);
154         var wr = new java.io.OutputStreamWriter(conn.getOutputStream(), this._getCharset());
155         wr.write(data);
156         wr.flush();
157         wr.close();
158       }
159       // read response headers
160       // NOTE: the getHeaderField() methods always return nulls for me :(
161       var gotContentEncoding = false;
162       var gotContentLength = false;
163       var gotContentType = false;
164       var gotDate = false;
165       var gotExpiration = false;
166       var gotLastModified = false;
167       for (var i = 0; ; i++) {
168         var hdrName = conn.getHeaderFieldKey(i);
169         var hdrValue = conn.getHeaderField(i);
170         if (hdrName == null && hdrValue == null) {
171           break;
172         }
173         if (hdrName != null) {
174           this._headers[this._headers.length] = {h:hdrName, v:hdrValue};
175           switch (hdrName.toLowerCase()) {
176             case 'content-encoding': gotContentEncoding = true; break;
177             case 'content-length'  : gotContentLength   = true; break;
178             case 'content-type'    : gotContentType     = true; break;
179             case 'date'            : gotDate            = true; break;
180             case 'expires'         : gotExpiration      = true; break;
181             case 'last-modified'   : gotLastModified    = true; break;
182           }
183         }
184       }
185       // try to fill in any missing header information
186       var val;
187       val = conn.getContentEncoding();
188       if (val != null && !gotContentEncoding) this._headers[this._headers.length] = {h:'Content-encoding', v:val};
189       val = conn.getContentLength();
190       if (val != -1 && !gotContentLength) this._headers[this._headers.length] = {h:'Content-length', v:val};
191       val = conn.getContentType();
192       if (val != null && !gotContentType) this._headers[this._headers.length] = {h:'Content-type', v:val};
193       val = conn.getDate();
194       if (val != 0 && !gotDate) this._headers[this._headers.length] = {h:'Date', v:(new Date(val)).toUTCString()};
195       val = conn.getExpiration();
196       if (val != 0 && !gotExpiration) this._headers[this._headers.length] = {h:'Expires', v:(new Date(val)).toUTCString()};
197       val = conn.getLastModified();
198       if (val != 0 && !gotLastModified) this._headers[this._headers.length] = {h:'Last-modified', v:(new Date(val)).toUTCString()};
199       // read response data
200       var reqdata = '';
201       var stream = conn.getInputStream();
202       if (stream) {
203         var reader = new java.io.BufferedReader(new java.io.InputStreamReader(stream, this._getCharset()));
204         var line;
205         while ((line = reader.readLine()) != null) {
206           if (this.readyState == 2) {
207             this.readyState = 3;
208             if (this.onreadystatechange) {
209               this.onreadystatechange();
210             }
211           }
212           reqdata += line + '\n';
213         }
214         reader.close();
215         this.status = 200;
216         this.statusText = 'OK';
217         this.responseText = reqdata;
218         this.readyState = 4;
219         if (this.onreadystatechange) {
220           this.onreadystatechange();
221         }
222         if (this.onload) {
223           this.onload();
224         }
225       } else {
226         // error
227         this.status = 404;
228         this.statusText = 'Not Found';
229         this.responseText = '';
230         this.readyState = 4;
231         if (this.onreadystatechange) {
232           this.onreadystatechange();
233         }
234         if (this.onerror) {
235           this.onerror();
236         }
237       }
238     };
239   };
240 }
241 // ActiveXObject emulation
242 if (!window.ActiveXObject && window.XMLHttpRequest) {
243   window.ActiveXObject = function(type) {
244     switch (type.toLowerCase()) {
245       case 'microsoft.xmlhttp':
246       case 'msxml2.xmlhttp':
247       case 'msxml2.xmlhttp.3.0':
248       case 'msxml2.xmlhttp.4.0':
249       case 'msxml2.xmlhttp.5.0':
250         return new XMLHttpRequest();
251     }
252     return null;
253   };
254 }

 

posted @ 2020-06-11 11:53  xlsdg  阅读(68)  评论(0)    收藏  举报