nodejs取参四种方法req.body,req.params,req.param,req.body
摘要: nodejs取参四种方法req.body,req.params,req.param,req.body 获取请求很中的参数是每个web后台处理的必经之路,nodejs提供了四种方法来实现。
获取请求很中的参数是每个web后台处理的必经之路,nodejs的 express框架 提供了四种方法来实现。
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req.body
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req.query
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req.params
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req.param()
首先介绍第一个req.body
- <code class="hljs sql" style="">官方文档解释:
- Contains key-value pairs of data submitted in the request body. By default, it is undefined,
- and is populated when you <span class="hljs-keyword" style="">use</span> <span class="hljs-keyword" style="">body</span>-parsing middleware such <span class="hljs-keyword" style="">as</span> <span class="hljs-keyword" style="">body</span>-parser <span class="hljs-keyword" style="">and</span> multer.
- 稍微翻译一下:包含了提交数据的键值对在请求的<span class="hljs-keyword" style="">body</span>中,默认是underfined,
- 你可以用<span class="hljs-keyword" style="">body</span>-parser或者multer来解析<span class="hljs-keyword" style="">body</span></code>
解析body不是nodejs默认提供的,你需要载入body-parser中间件才可以使用req.body
此方法通常用来解析POST请求中的数据
第二种是req.query
- <code class="hljs cs" style="">官方文档解释:
- An <span class="hljs-keyword" style="">object</span> containing a property <span class="hljs-keyword" style="">for</span> each query <span class="hljs-keyword" style="">string</span> parameter <span class="hljs-keyword" style="">in</span> the route.
- If there <span class="hljs-keyword" style="">is</span> no query <span class="hljs-keyword" style="">string</span>, it <span class="hljs-keyword" style="">is</span> the empty <span class="hljs-keyword" style="">object</span>, {}.
- 翻译一下:包含在路由中每个查询字符串参数属性的对象。如果没有,默认为{}</code>
有nodejs默认提供,无需载入中间件
举例说明(官方摘抄):
- <code class="hljs haskell" style="">// <span class="hljs-type" style="">GET</span> /search?q=tobi+ferret
- <span class="hljs-title" style="">req</span>.query.q
- // => <span class="hljs-string" style="">"tobi ferret"</span>
- // <span class="hljs-type" style="">GET</span> /shoes?order=desc&shoe[color]=blue&shoe[<span class="hljs-class" style=""><span class="hljs-keyword" style=""><span class="hljs-class" style=""><span class="hljs-keyword" style="">type</span></span></span><span class="hljs-class" style="">]=converse</span></span>
- <span class="hljs-title" style="">req</span>.query.order
- // => <span class="hljs-string" style="">"desc"</span>
- <span class="hljs-title" style="">req</span>.query.shoe.color
- // => <span class="hljs-string" style="">"blue"</span>
- <span class="hljs-title" style="">req</span>.query.shoe.<span class="hljs-class" style=""><span class="hljs-keyword" style="">type</span></span>
- // => <span class="hljs-string" style="">"converse"</span></code>
此方法多适用于GET请求,解析GET里的参数
第三种是 req.params
- <code class="hljs cs" style="">官方文档:
- An <span class="hljs-keyword" style="">object</span> containing properties mapped to the named route “parameters”.
- For example, <span class="hljs-keyword" style="">if</span> you have the route /user/:name,
- then the “name” property <span class="hljs-keyword" style="">is</span> available <span class="hljs-keyword" style="">as</span> req.<span class="hljs-keyword" style="">params</span>.name. This <span class="hljs-keyword" style="">object</span> defaults to {}.
- 翻译:包含映射到指定的路线“参数”属性的对象。
- 例如,如果你有route/user/:name,那么“name”属性可作为req.<span class="hljs-keyword" style="">params</span>.name。
- 该对象默认为{}。</code>
nodejs默认提供,无需载入其他中间件
举例说明
- <code class="hljs cs" style=""><span class="hljs-comment" style="">// GET /user/tj</span>
- req.<span class="hljs-keyword" style="">params</span>.name
- <span class="hljs-comment" style="">// => "tj"</span></code>
多适用于restful风格url中的参数的解析
req.query与req.params的区别
req.params包含路由参数(在URL的路径部分),而req.query包含URL的查询参数(在URL的?后的参数)。
最后一种req.param()
此方法被弃用,请看官方解释
- <code class="hljs css" style=""><span class="hljs-selector-tag" style="">Deprecated</span>. <span class="hljs-selector-tag" style="">Use</span> <span class="hljs-selector-tag" style="">either</span> <span class="hljs-selector-tag" style="">req</span><span class="hljs-selector-class" style="">.params</span>, <span class="hljs-selector-tag" style="">req</span><span class="hljs-selector-class" style="">.body</span> <span class="hljs-selector-tag" style="">or</span> <span class="hljs-selector-tag" style="">req</span><span class="hljs-selector-class" style="">.query</span>, <span class="hljs-selector-tag" style="">as</span> <span class="hljs-selector-tag" style="">applicable</span>.
- 翻译:被弃用,用其他三种方式替换</code>
取得 GET Request 的 Query Strings:
GET /test?name=fred&tel=0926xxx572
app.get('/test', function(req, res) {
console.log(req.query.name);
console.log(req.query.tel);
});
如果是表单且是用 POST method:
<form action='/test' method='post'>
<input type='text' name='name' value='fred'>
<input type='text' name='tel' value='0926xxx572'>
<input type='submit' value='Submit'>
</form>
app.post('/test', function(req, res) {
console.log(req.query.id);
console.log(req.body.name);
console.log(req.body.tel);
});
当然也可以 Query Strings 和 POST method 的表单同时使用:
<form action='/test?id=3' method='post'>
<input type='text' name='name' value='fred'>
<input type='text' name='tel' value='0926xxx572'>
<input type='submit' value='Submit'>
</form>
app.post('/test', function(req, res) {
console.log(req.query.id);
console.log(req.body.name);
console.log(req.body.tel);
});
顺带补充,还有另一种方法传递参数给 Server,就是使用路径的方式,可以利用 Web Server 的 HTTP Routing 來解析,常见于各种 Web Framework。這不算是传统标准规范的做法,是属于 HTTP Routing 的延伸应用。
GET /hello/fred/0926xxx572
app.get('/hello/:name/:tel', function(req, res) {
console.log(req.params.name);
console.log(req.params.tel);
});
来源:http://liuxufei.com/blog/jishu/798.html