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_flash_core-concepts_request-response" data-v-e6f2a212><div><h1 id="📥-request-and-response" tabindex="-1">📥 Request and Response <a class="header-anchor" href="#📥-request-and-response" aria-label="Permalink to "📥 Request and Response""></a></h1><p>Generally speaking, in an HTTP request-response cycle, the client sends a request to the server, and the server generates a response based on the request. In this section, we illustrate the <code>Request</code> and <code>Response</code> objects in Flash, which are used to interact with the request data and generate responses. We will learn to read and interpret the request data, and model the correct response to send back to the client. <img src="https://miro.medium.com/v2/resize:fit:696/1*wzzLb_xz5Mlykcd1bBqDig.png" alt=""></p><h2 id="request-and-response-objects" tabindex="-1">Request and Response Objects <a class="header-anchor" href="#request-and-response-objects" aria-label="Permalink to "Request and Response Objects""></a></h2><p>The <code>Request</code> and <code>Response</code> objects are passed to the handler constructor and provide access to the request data and response methods. Under the hood, these objects are provided by the <code>RouteController</code> during the registration stage of the handler, and they are continously updated for each request on that specific handler's instance, but for now, you can consider them as magic.</p><p>These objects are a very powerful tool to interact with the lifecycle of the server's response, and they provide a wide range of methods that makes our lives as developers easier.</p><h2 id="requesthandler-context" tabindex="-1">RequestHandler context <a class="header-anchor" href="#requesthandler-context" aria-label="Permalink to "RequestHandler context""></a></h2><p>Inside a <code>RequestHandler</code> class, you can access the <code>Request</code> and <code>Response</code> objects inside the <code>handle</code> method by simply typing <code>req</code> and <code>res</code>, respectively. You can use the methods provided by these objects both outside of a handler, and inside of it, to interact with the request and response objects. Although, the advantages of being inside a handler are that Flash supports out-of-the-box methods that can significantly clean up your code and improve the overall readability of your handlers.</p><p>Specifically, the <code>ExpectedRequestParameter</code>, <code>ExpectedBodyField</code>, and <code>ExpectedBodyFile</code> objects are used to get the expected properties of the request, and they are used by <code>Flash</code> to validate the request data before the <code>handle</code> method is even executed.</p><p><em><strong>The developer can then simply assume that all the expected parameters are present and valid, without having to write a single line of validation code: Flash will do it for you.</strong></em></p><p>The three objects mentioned above are fairly similar in their usage, providing getter methods which safely return the data in the expected format and type, thanks to Flash's built-in validation and casting system.</p><div class="warning custom-block"><p class="custom-block-title">NOTE</p><p><code>Flash</code> will take care of informing the client of any missing or invalid parameters, parameters that are not in the expected format, or any other kind of error that might occur during the validation process.</p></div><div class="danger custom-block"><p class="custom-block-title">REMEMBER</p><p>The <code>ExpectedRequestParameter</code>, <code>ExpectedBodyField</code>, and <code>ExpectedBodyFile</code> instances are <strong><em>ONLY</em></strong> supposed to be retrieved by calling the respective <code>expectedRequestParameter()</code>, <code>expectedBodyField()</code>, and <code>expectedBodyFile()</code> methods <strong><em>INSIDE</em></strong> of the super constructor of your handler class.</p></div><h2 id="example-usage" tabindex="-1">Example Usage <a class="header-anchor" href="#example-usage" aria-label="Permalink to "Example Usage""></a></h2><ul><li><code>ExpectedRequestParameter</code></li></ul><details class="details custom-block"><summary>Click to expand</summary><p>The <code>ExpectedRequestParameter</code> object is used to get the expected parameters of the request. You can use the getter methods to safely get the parameter value, such as <code>getString</code>, <code>getInt</code>, <code>getDouble</code>, and <code>getBoolean</code> methods to safely cast the parameter to the expected type.</p><div class="language-java vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">java</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">@</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">RouteInfo</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">method</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> HttpMethod.GET, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">path</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "/hello"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">)</span></span>
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<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">public</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> class</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> MyHandler</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> extends</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> RequestHandler</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
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<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Store the expected parameter in a private field</span></span>
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<span class="line highlighted"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> private</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> final</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> ExpectedRequestParameter myExpectedReqParam;</span></span>
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<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> public</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> MyHandler</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(Request </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">req</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, Response </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">res</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
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<span class="line"><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> super</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(req, res);</span></span>
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<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Get the expected parameter "myParam", and optionally provide a description</span></span>
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<span class="line highlighted"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myExpectedReqParam </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> expectedRequestParameter</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"myParam"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"A description of the parameter"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
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<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
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<span class="line"></span>
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<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> @</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">Override</span></span>
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<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> public</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> Object </span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">handle</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
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<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // OPTIONAL: specify the response status code and type</span></span>
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<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> res.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">status</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">200</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> res.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">type</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"text/plain"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> </span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Safely get the parameter value as a String</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> String myParamValue </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myExpectedReqParam.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">getString</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">();</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> </span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Return the response to the client</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "Hello, "</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> +</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myParamValue </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">+</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "!"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre></div><p>Visiting <code>/hello?myParam=John</code> from your browser, will return <code>Hello, John!</code>.</p></details><ul><li><code>ExpectedBodyField</code></li></ul><details class="details custom-block"><summary>Click to expand</summary><p>The <code>ExpectedBodyField</code> object is used to get the expected fields of the request body. You can use the getter methods to safely get the field value, such as <code>getString</code>, <code>getInt</code>, <code>getDouble</code>, and <code>getBoolean</code> methods to safely cast the field to the expected type.</p><div class="language-java vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">java</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">@</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">RouteInfo</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">method</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> HttpMethod.GET, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">path</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "/helloBody"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">)</span></span>
|
||
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">public</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> class</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> MyHandler</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> extends</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> RequestHandler</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Store the expected field in a private field</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> private</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> final</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> ExpectedBodyField myExpectedBodyField;</span></span>
|
||
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> public</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> MyHandler</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(Request </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">req</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, Response </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">res</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
|
||
<span class="line"><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> super</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(req, res);</span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Get the expected field "myField", and optionally provide a description</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myExpectedBodyField </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> expectedBodyField</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"myField"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"A description of the field"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> @</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">Override</span></span>
|
||
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> public</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> Object </span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">handle</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // OPTIONAL: specify the response status code and type</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> res.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">status</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">200</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> res.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">type</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"text/plain"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> </span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Safely get the field value as a String</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> String myFieldValue </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myExpectedBodyField.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">getString</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">();</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> </span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Return the response to the client</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "Field value: "</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> +</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myFieldValue;</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre></div><p>This time, since we are expecting a field in the request body, using our browser would not be enough to test the handler. Instead, you can use a tool like <code>Postman</code> to send a GET request to <code>/helloBody</code> with a multipart form data body containing a field named <code>myField</code>. You should receive a response like <code>Field value: <value></code>.</p></details><ul><li><code>ExpectedBodyFile</code></li></ul><details class="details custom-block"><summary>Click to expand</summary><p>The <code>ExpectedBodyFile</code> object is used to get the expected files of the request body. The methods provided by this object are slightly different from the other two, but still extremely powerful and simple to use.</p><ul><li><code>createFile(Path/String)</code> accepts either a Path or a String as input. It writes the file's contents to the specified location on the filesystem and returns a <code>File</code> object for further interaction.</li><li><code>getFileName()</code> simply returns the name of the file specified by the client.</li><li><code>getInputStream()</code> returns an <code>InputStream</code> object containing the file's contents.</li></ul><div class="language-java vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">java</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">@</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">RouteInfo</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">method</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> HttpMethod.POST, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">path</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "/helloFile"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">)</span></span>
|
||
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">public</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> class</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> MyHandler</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> extends</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> RequestHandler</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Store the expected file in a private field</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> private</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> final</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> ExpectedBodyFile myExpectedBodyFile;</span></span>
|
||
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> public</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> MyHandler</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(Request </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">req</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, Response </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">res</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
|
||
<span class="line"><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> super</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(req, res);</span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Get the expected file "myFile", and optionally provide a description</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myExpectedBodyFile </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> expectedBodyFile</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"myFile"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"A description of the file"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> @</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">Override</span></span>
|
||
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> public</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> Object </span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">handle</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // OPTIONAL: specify the response status code and type</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> res.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">status</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">200</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> res.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">type</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"text/plain"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> </span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Write the file to filesystem and get the File object</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> File myFile </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myExpectedBodyFile.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">createFile</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(Paths.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">get</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"path/to/save"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">));</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> </span></span>
|
||
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // Return the response to the client</span></span>
|
||
<span class="line highlighted"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "File saved at: "</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> +</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> myFile.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">getAbsolutePath</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">();</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
|
||
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre></div><p>This time, you will need to use a tool like <code>Postman</code> to send a POST request to <code>/helloFile</code> with a multipart form data body containing a file named <code>myFile</code>. You should receive a response like <code>File saved at: <path></code> where <code><path></code> is the location where the server saved the file.</p></details></div></div></main><footer class="VPDocFooter" data-v-e6f2a212 data-v-1bcd8184><!--[--><!--]--><!----><nav class="prev-next" aria-labelledby="doc-footer-aria-label" data-v-1bcd8184><span class="visually-hidden" id="doc-footer-aria-label" data-v-1bcd8184>Pager</span><div class="pager" data-v-1bcd8184><a class="VPLink link pager-link prev" href="/flash/core-concepts/request-handler.html" data-v-1bcd8184><!--[--><span class="desc" data-v-1bcd8184>Previous page</span><span class="title" data-v-1bcd8184>RequestHandler</span><!--]--></a></div><div class="pager" data-v-1bcd8184><a class="VPLink link pager-link next" href="/flash/core-concepts/server-router.html" data-v-1bcd8184><!--[--><span class="desc" data-v-1bcd8184>Next page</span><span class="title" data-v-1bcd8184>Server Router</span><!--]--></a></div></nav></footer><!--[--><!--]--></div></div></div><!--[--><!--]--></div></div><!----><!--[--><!--]--></div></div>
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