Add support for serving static files (#42)

* Add support for serving static files

- Introduced `StaticFileHandler` to serve static files from the `www` directory.
- Enhanced `HttpResponseBuilder` to support byte array bodies.
- Made `setReader` method public in `HttpParser` to improve flexibility.
- Code tested via Insomnia by coding a temporary method for multithreads in TcpServer.java, this is now removed before future implementations of ConnectionHandler

Co-authored-by: Daniel Fahlén xsz300@gmail.com

* Fix typo in `HttpResponseBuilder` (contentLength) and refine body handling logic
Co-authored-by: Daniel Fahlén xsz300@gmail.com

* Add basic HTML structure to `index.html` in `www` directory

* Make `handleGetRequest` method private in `StaticFileHandler` to encapsulate functionality

Author: codebyNorthsteep

src/main/java/org/example/StaticFileHandler.java

@@ -0,0 +1,34 @@
+package org.example;
+
+import org.example.http.HttpResponseBuilder;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.nio.file.Files;
+import java.util.Map;
+
+public class StaticFileHandler {
+    private static final String WEB_ROOT = "www";
+    private byte[] fileBytes;
+
+    public StaticFileHandler(){}
+
+    private void handleGetRequest(String uri) throws IOException {
+
+        File file = new File(WEB_ROOT, uri);
+        fileBytes = Files.readAllBytes(file.toPath());
+    }
+
+    public void sendGetRequest(OutputStream outputStream, String uri) throws IOException{
+        handleGetRequest(uri);
+        HttpResponseBuilder response = new HttpResponseBuilder();
+        response.setHeaders(Map.of("Content-Type", "text/html; charset=utf-8"));
+        response.setBody(fileBytes);
+        PrintWriter writer = new PrintWriter(outputStream, true);
+        writer.println(response.build());
+
+    }
+
+}

src/main/java/org/example/http/HttpResponseBuilder.java

@@ -9,6 +9,7 @@ public class HttpResponseBuilder {
     private static final String PROTOCOL = "HTTP/1.1";
     private int statusCode = 200;
     private String body = "";
+    private byte[] bytebody;
     private Map<String, String> headers = new LinkedHashMap<>();
 
     private static final String CRLF = "\r\n";
@@ -17,10 +18,13 @@ public class HttpResponseBuilder {
     public void setStatusCode(int statusCode) {
         this.statusCode = statusCode;
     }
-
     public void setBody(String body) {
         this.body = body != null ? body : "";
     }
+
+    public void setBody(byte[] body) {
+        this.bytebody = body;
+    }
     public void setHeaders(Map<String, String> headers) {
         this.headers = new LinkedHashMap<>(headers);
     }
@@ -31,14 +35,22 @@ public void setHeaders(Map<String, String> headers) {
             400, "Bad Request",
             404, "Not Found",
             500, "Internal Server Error");
-
     public String build(){
         StringBuilder sb = new StringBuilder();
+        int contentLength;
+        if(body.isEmpty() && bytebody != null){
+            contentLength = bytebody.length;
+            setBody(new String(bytebody, StandardCharsets.UTF_8));
+        }else{
+            contentLength = body.getBytes(StandardCharsets.UTF_8).length;
+        }
+
+
         String reason = REASON_PHRASES.getOrDefault(statusCode, "OK");
         sb.append(PROTOCOL).append(" ").append(statusCode).append(" ").append(reason).append(CRLF);
         headers.forEach((k,v) -> sb.append(k).append(": ").append(v).append(CRLF));
         sb.append("Content-Length: ")
-                .append(body.getBytes(StandardCharsets.UTF_8).length);
+                .append(contentLength);
         sb.append(CRLF);
         sb.append("Connection: close").append(CRLF);
         sb.append(CRLF);

src/main/java/org/example/httpparser/HttpParser.java

@@ -13,7 +13,7 @@ public class HttpParser extends HttpParseRequestLine {
     private Map<String, String> headersMap = new HashMap<>();
     private BufferedReader reader;
 
-    protected void setReader(InputStream in) {
+    public void setReader(InputStream in) {
         if (this.reader == null) {
             this.reader = new BufferedReader(new InputStreamReader(in, StandardCharsets.UTF_8));
         }

www/index.html

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Welcome</title>
+    </head>
+<body>
+<h1>Website works!</h1>
+<p>Greetings from StaticFileHandler.</p>
+</body>
+</html>
+