{"id":2486,"date":"2020-11-19T10:18:47","date_gmt":"2020-11-19T02:18:47","guid":{"rendered":"http:\/\/admin.evshou.com\/?p=2486"},"modified":"2020-11-23T11:26:17","modified_gmt":"2020-11-23T03:26:17","slug":"2020javaweb%e6%95%99%e7%a8%8b%e4%b9%8bajax","status":"publish","type":"post","link":"https:\/\/www.9713job.com\/?p=2486","title":{"rendered":"2020javaweb\u6559\u7a0b\u4e4bAjax"},"content":{"rendered":"

2020javaweb\u6559\u7a0b\u4e4bAjax<\/h3>\n

\u6982\u8ff0<\/strong><\/span><\/p>\n

AJAX \u662f\u4e00\u79cd\u5728\u65e0\u9700\u91cd\u65b0\u52a0\u8f7d\u6574\u4e2a\u7f51\u9875\u7684\u60c5\u51b5\u4e0b\uff0c\u80fd\u591f\u5b9e\u73b0\u5c40\u90e8\u66f4\u65b0\u7684\u6280\u672f\u3002<\/p>\n

\u4ec0\u4e48\u662fajax\uff1f<\/strong><\/span><\/p>\n

AJAX = \u5f02\u6b65 JavaScript \u548c XML\u3002 (Asynchronized JavaScript And XML)<\/p>\n

AJAX \u662f\u4e00\u79cd\u7528\u4e8e\u5feb\u901f\u521b\u5efa\u52a8\u6001\u7f51\u9875\u7684\u6280\u672f\u3002<\/p>\n

AJAX\u5de5\u4f5c\u539f\u7406<\/strong><\/span><\/p>\n

\"\"
\n<\/p>\n

ajax\u662f\u57fa\u4e8e\u73b0\u6709\u7684Internet\u6807\u51c6\uff0c\u5e76\u4e14\u8054\u5408\u4f7f\u7528\u5b83\u4eec\uff1a<\/p>\n

1.XMLHttpRequest\u5bf9\u8c61(\u5f02\u6b65\u7684\u670d\u52a1\u5668\u4ea4\u6362\u6570\u636e)
\n2.JavaScript\/DOM(\u4fe1\u606f\u663e\u793a\/\u4ea4\u4e92)
\n3.CSS(\u7ed9\u6570\u636e\u5b9a\u4e49\u6837\u5f0f)
\n4.XML (\u4f5c\u4e3a\u8f6c\u6362\u6570\u636e\u7684\u683c\u5f0f)\u3001JSON<\/p>\n

ajax\u5b9e\u4f8b<\/strong><\/span><\/p>\n

1.\u521b\u5efaXMLHttpRequest\u5bf9\u8c61<\/span>
\n2.\u8bbe\u7f6eonreadystatechange\u56de\u8c03\u51fd\u6570<\/span>
\n3.open()\u6253\u5f00\u94fe\u63a5<\/span>
\n4.send()\u53d1\u9001\u8bf7\u6c42<\/span><\/p>\n

function changes(){\r\n    \/\/1.\u521b\u5efa XMLHttpRequest \u5bf9\u8c61\r\n    var xhr=new XMLHttpRequest();\r\n    \/\/2.\u8bbe\u7f6eonreadystatechange\u56de\u8c03\u51fd\u6570\r\n    xhr.onreadystatechange=function () {\r\n        \/\/\u670d\u52a1\u5668\u72b6\u6001             \u54cd\u5e94\u7ed3\u679c\r\n        if(xhr.readyState==4&&xhr.status==200){\r\n            \/\/\u52a8\u6001\u4fee\u6539\u9875\u9762\u7684\u5c40\u90e8\u5185\u5bb9\r\n            document.getElementById(\"div1\").innerHTML=xhr.responseText;\r\n        }\r\n    }\r\n    \/\/3.\u6253\u5f00\u8fde\u63a5  \u8bf7\u6c42\u65b9\u5f0f  \u8bf7\u6c42\u5730\u5740    \u5f02\u6b65\/\u540c\u6b65\r\n    xhr.open(\"GET\",\"test.html\",true);\r\n    \/\/4.\u53d1\u9001\u8bf7\u6c42\r\n    xhr.send();\r\n}<\/pre>\n
\u521b\u5efaXMLHttpRequest\u5bf9\u8c61<\/strong><\/span><\/p>\n
IE7+\u4ee5\u53ca\u5176\u4ed6\u4e3b\u6d41\u6d4f\u89c8\u5668\u521b\u5efa\u8bed\u6cd5\uff1a
\nvar xhr=new XMLHttpRequest();<\/p>\n
\u8001\u7248\u672cIE5\uff0cIE6\u521b\u5efa\u8bed\u6cd5
\nvar xmlhttp=new ActiveXObject(“Microsoft.XMLHTTP<\/span>“);<\/p>\n
\u5224\u65ad\u6d4f\u89c8\u5668\u662f\u5426\u652f\u6301\uff1a
\nvar xmlhttp;
\nif (window.XMLHttpRequest)
\n{
\n\/\/ IE7+, Firefox, Chrome, Opera, Safari \u6d4f\u89c8\u5668\u6267\u884c\u4ee3\u7801
\nxmlhttp=new XMLHttpRequest();
\n}
\nelse
\n{
\n\/\/ IE6, IE5 \u6d4f\u89c8\u5668\u6267\u884c\u4ee3\u7801
\nxmlhttp=new ActiveXObject(“Microsoft.XMLHTTP”);
\n}<\/p>\n
onreadystatechange\u56de\u8c03\u51fd\u6570<\/strong><\/span><\/p>\n
\u5c5e\u6027\uff1aonreadystatechange
\n\u63cf\u8ff0\uff1a\u5b58\u50a8\u51fd\u6570\uff08\u6216\u51fd\u6570\u540d\uff09\uff0c\u6bcf\u5f53 readyState \u5c5e\u6027\u6539\u53d8\u65f6\uff0c\u5c31\u4f1a\u8c03\u7528\u8be5\u51fd\u6570\u3002<\/p>\n
\u5c5e\u6027\uff1areadyState
\n\u63cf\u8ff0\uff1a\u5b58\u6709 XMLHttpRequest \u7684\u72b6\u6001\u3002
\n\u4ece 0 \u5230 4 \u53d1\u751f\u53d8\u5316\u3002
\n0: \u8bf7\u6c42\u672a\u521d\u59cb\u5316
\n1: \u670d\u52a1\u5668\u8fde\u63a5\u5df2\u5efa\u7acb
\n2: \u8bf7\u6c42\u5df2\u63a5\u6536
\n3: \u8bf7\u6c42\u5904\u7406\u4e2d
\n4: \u8bf7\u6c42\u5df2\u5b8c\u6210\uff0c\u4e14\u54cd\u5e94\u5df2\u5c31\u7eea<\/p>\n
\u5c5e\u6027\uff1astatus
\n\u63cf\u8ff0\uff1a200: “OK”404: \u672a\u627e\u5230\u9875\u9762<\/p>\n
xhr.onreadystatechange=function () {\r\n    \/\/\u670d\u52a1\u5668\u72b6\u6001             \u54cd\u5e94\u7ed3\u679c\r\n    if(xhr.readyState==4&&xhr.status==200){\r\n        \/\/\u52a8\u6001\u4fee\u6539\u9875\u9762\u7684\u5c40\u90e8\u5185\u5bb9\r\n        document.getElementById(\"div1\").innerHTML=xhr.responseText;\r\n    }\r\n}<\/pre>\n
XMLHttpRequest\u8bf7\u6c42<\/strong><\/span><\/p>\n
\u5982\u9700\u5c06\u8bf7\u6c42\u53d1\u9001\u5230\u670d\u52a1\u5668\uff0c\u6211\u4eec\u4f7f\u7528 XMLHttpRequest \u5bf9\u8c61\u7684 open() \u548c send() \u65b9\u6cd5<\/p>\n
xhr.open(\"GET\",\"test.html\");\r\nxhr.send();<\/pre>\n
\u65b9\u6cd5\uff1aopen(method,url,async)
\n\u63cf\u8ff0\uff1a\u89c4\u5b9a\u8bf7\u6c42\u7684\u7c7b\u578b\u3001URL \u4ee5\u53ca\u662f\u5426\u5f02\u6b65\u5904\u7406\u8bf7\u6c42\u3002
\nmethod\uff1a\u8bf7\u6c42\u7684\u7c7b\u578b\uff1bGET \u6216 POST
\nurl\uff1a\u6587\u4ef6\u5728\u670d\u52a1\u5668\u4e0a\u7684\u4f4d\u7f6e
\nasync\uff1atrue\uff08\u5f02\u6b65\uff09\u6216 false\uff08\u540c\u6b65\uff09<\/p>\n
\u65b9\u6cd5\uff1asend(String)
\n\u63cf\u8ff0\uff1a\u5c06\u8bf7\u6c42\u53d1\u9001\u5230\u670d\u52a1\u5668\u3002string\uff1a\u4ec5\u7528\u4e8e POST \u8bf7\u6c42<\/p>\n
\u8bf7\u6c42\u65b9\u5f0f<\/strong><\/span><\/p>\n
GET\u8bf7\u6c42\uff1a
\nxhr.open(“GET”,”test.html”,true);
\nxhr.send();<\/p>\n
POST\u8bf7\u6c42\uff1a
\nxmlhttp.open(“POST”,”\/try\/ajax\/servlet4″,true);
\nxmlhttp.setRequestHeader(“Content-type”,”application\/x-www-form-urlencoded”);
\nxmlhttp.send(“username=leilei&password=123”);<\/p>\n
\u65b9\u6cd5\uff1asetRequestHeader(header,value)
\n\u63cf\u8ff0\uff1a\u5411\u8bf7\u6c42\u6dfb\u52a0 HTTP \u5934\u3002
\nheader: \u89c4\u5b9a\u5934\u7684\u540d\u79f0
\nvalue: \u89c4\u5b9a\u5934\u7684\u503c<\/p>\n
ajax\u4e0ejson<\/strong><\/span><\/p>\n
\u670d\u52a1\u5668\u4f20\u7ed9\u6d4f\u89c8\u5668<\/p>\n
\"\"<\/p>\n
\"\"<\/p>\n
 <\/p>\n
\u6d4f\u89c8\u5668\u4f20\u7ed9\u670d\u52a1\u5668<\/p>\n
\"\"\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"
2020javaweb\u6559\u7a0b\u4e4bAjax \u6982\u8ff0 AJAX \u662f\u4e00\u79cd\u5728\u65e0\u9700\u91cd\u65b0\u52a0\u8f7d\u6574\u4e2a\u7f51\u9875\u7684\u60c5\u51b5\u4e0b\uff0c\u80fd\u591f\u5b9e\u73b0\u5c40\u90e8\u66f4\u65b0\u7684 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-2486","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2486","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2486"}],"version-history":[{"count":1,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2486\/revisions"}],"predecessor-version":[{"id":2487,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2486\/revisions\/2487"}],"wp:attachment":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2486"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2486"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2486"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}