HttpContext: Lightweight HTTP protocol support.

src/main/com/jdbernard/net/HttpContext.groovy

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+/** @author Jonathan Bernard (jdbernard@gmail.com)
+  * @copyright 2013 Jonathan Bernard. */
+package com.jdbernard.net
+
+import java.net.Socket
+import groovy.json.JsonBuilder
+import groovy.json.JsonSlurper
+
+/** Helper class to perform basic HTTP communication. */
+public class HttpContext {
+
+    /** The host to which this object will connect. This also affects the
+      * `Host` header in requests. */
+    public String host = 'vbs-test'
+
+    /** The port number.*/
+    public int port = 8000
+
+    /** A cookie value to send in the request. This value will be automatically
+      * set from any `Set-Cookie` header in the request response. */
+    public String cookie
+
+    /** #### makeMessage
+      * Make and return an HTTP request for the given HTTP method and URL. If
+      * `request` is not null, it is expected to be an object which will be
+      * converted to JSON and included as the request body. The `Host`,
+      * `Cookie`, and `Content-Length` headers will be added based on the
+      * `host` and `cookie` fields and the `request` object. */
+    public String makeMessage(String method, String url, def request) {
+        StringBuilder message = new StringBuilder()
+        message.append(method)
+        message.append(" ")
+        message.append(url)
+        message.append(" HTTP/1.1\r\n")
+
+        if (host && port) {
+            message.append("Host: ")
+            message.append(host)
+            message.append(":")
+            message.append(port)
+            message.append("\r\n") }
+
+        if (cookie) {
+            message.append("Cookie: ")
+            message.append(cookie)
+            message.append("\r\n") }
+
+        if (request) {
+            def jsonRequestBuilder = new JsonBuilder(request)
+            String requestBody = jsonRequestBuilder.toString()
+
+            message.append("Content-Length: ")
+            message.append(requestBody.length())
+            message.append("\r\n\r\n")
+            message.append(requestBody) }
+
+        message.append("\r\n")
+        return message.toString()
+    }
+
+   /** #### send
+      * A wrapper around `makeMessage` and `send(String message)` to create a
+      * request, send it, and return the response. */
+    public def send(String method, String url, def request) {
+        return send(makeMessage(method, url, request)) }
+
+    /** #### send
+      * Send a message to the host specified by the object's `host` and `port`
+      * fields and parses the response. Returns an object with the following
+      * properties:
+      *
+      * - `status`: the HTTP response status (200, 404, etc.).
+      * - `headers`: A list of header lines (one line per list entry).
+      * - `content`: the response body (expected as JSON from the server) parsed
+      *   into a Groovy object.
+      * - `responseTime`: the time measured immediately after the client flushes
+      *   its output buffer to the time it completely reads the server response.
+      */
+    public def send(String message) {
+        Map result = [headers:[], content: null]
+        Socket sock = new Socket(host, port)
+        def startTime
+
+        sock.withStreams { strin, out ->
+            def writer = new BufferedWriter(new OutputStreamWriter(out))
+            def reader = new BufferedReader(new InputStreamReader(strin))
+            int bytesExpected
+            writer.write(message)
+            startTime = System.currentTimeMillis()
+            writer.flush()
+
+            def line = reader.readLine().trim()
+            result.status = line.split(/\s/)[1]
+            line = reader.readLine().trim()
+
+            while(line) {
+                def m = (line =~ /Content-Length: (\d+)/)
+                if (m) bytesExpected = m[0][1] as int
+
+                m = (line =~ /Set-Cookie: ([^=]+=[^;]+);.+/)
+                if (m) this.cookie = m[0][1]
+
+                result.headers << line
+                line = reader.readLine() }
+
+            if (bytesExpected) {
+                StringBuilder sb = new StringBuilder()
+                for (int i = 0; i < bytesExpected; i++) {
+                    sb.append(reader.read() as char) }
+
+                result.responseTime = System.currentTimeMillis() - startTime
+                
+                try { result.content = new JsonSlurper().parseText(sb.toString()) }
+                catch (Exception e) { result.content = sb.toString() } }
+            else 
+                result.responseTime = System.currentTimeMillis() - startTime
+        }
+
+        sock.close()
+        return result
+    }
+
+    /** #### get
+      * A wrapper to perform a simple `GET` request. This calls
+      * `send(String method, String url, def request)` with `method = "GET"`,
+      * and `request = null`. */
+    public def get(String url) { return send('GET', url, null) }
+
+    /** #### post
+      * A wrapper to perform a `POST` request. This calls
+      * `send(String method, String url, def request)` with `method =
+      * "POST"`. */
+    public def post(String url, def body) { return send('POST', url, body) }
+}