REST API实战演练之JavaScript使用Rest API

咱们前面讲了一下如何创建REST API

假期别闲着：REST API实战演练之创建Rest API-CSDN博客

又讲了java客户端如何使用REST API

假期别闲着：REST API实战演练之客户端使用Rest API-CSDN博客

接下来咱们看看JavaScript怎么使用REST API。

一、新建一个HTML文件

二、添加几个控件元素

html 复制代码

<body>
	<h1>PIJON</h1>
		<p>(Person Info in JavaScript Object Notation)</p>
		<p><input type="text" value="Ada" id="name"><button type="button" onclick="getPersonInfo()">Get</button></p>
		<p>Birth year:</p>
		<input type="text" id="birthYear">
		<p>About:</p>
		<textarea id="about"></textarea>
		<p><button type="button" onclick="setPersonInfo()">Save</button></p>
</body>

三、添加一段JavaScript代码

html 复制代码

<head>
<meta charset="UTF-8">
<title>PIJON</title>
		<script>
			function getPersonInfo(){
				var name = document.getElementById('name').value;
				
				var ajaxRequest = new XMLHttpRequest();
				ajaxRequest.onreadystatechange = function(){
					if(ajaxRequest.readyState == 4){
						if(ajaxRequest.status == 200){
							var person = JSON.parse(ajaxRequest.responseText);
							document.getElementById('birthYear').value = person.birthYear;
							document.getElementById('about').value = person.about;
						}
					}			
				}
				ajaxRequest.open('GET', 'http://localhost:8080/HelloJSP/people/' + name);
				ajaxRequest.send();
			}
			
			function setPersonInfo(){
				var name = document.getElementById('name').value;
				var about = document.getElementById('about').value;
				var birthYear = document.getElementById('birthYear').value;
				
				var postData = 'name=' + name;
				postData += '&about=' + encodeURIComponent(about);
				postData += '&birthYear=' + birthYear;
				
				var ajaxRequest = new XMLHttpRequest();
				ajaxRequest.open('POST', 'http://localhost:8080/HelloJSP/people/' + name);
				ajaxRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
				ajaxRequest.send(postData);
			}
		</script>
</head>

修改后完整代码如下：

html 复制代码

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>PIJON</title>
		<script>
			function getPersonInfo(){
				var name = document.getElementById('name').value;
				
				var ajaxRequest = new XMLHttpRequest();
				ajaxRequest.onreadystatechange = function(){
					if(ajaxRequest.readyState == 4){
						if(ajaxRequest.status == 200){
							var person = JSON.parse(ajaxRequest.responseText);
							document.getElementById('birthYear').value = person.birthYear;
							document.getElementById('about').value = person.about;
						}
					}			
				}
				ajaxRequest.open('GET', 'http://localhost:8080/HelloJSP/people/' + name);
				ajaxRequest.send();
			}
			
			function setPersonInfo(){
				var name = document.getElementById('name').value;
				var about = document.getElementById('about').value;
				var birthYear = document.getElementById('birthYear').value;
				
				var postData = 'name=' + name;
				postData += '&about=' + encodeURIComponent(about);
				postData += '&birthYear=' + birthYear;
				
				var ajaxRequest = new XMLHttpRequest();
				ajaxRequest.open('POST', 'http://localhost:8080/HelloJSP/people/' + name);
				ajaxRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
				ajaxRequest.send(postData);
			}
		</script>
</head>
<body>
	<h1>PIJON</h1>
		<p>(Person Info in JavaScript Object Notation)</p>
		<p><input type="text" value="Ada" id="name"><button type="button" onclick="getPersonInfo()">Get</button></p>
		<p>Birth year:</p>
		<input type="text" id="birthYear">
		<p>About:</p>
		<textarea id="about"></textarea>
		<p><button type="button" onclick="setPersonInfo()">Save</button></p>
</body>
</html>