java - servidor - http.server python 3 example

Cómo servir contenido estático usando soles simple httpserver

Question

Estoy usando HttpServerFactory de jersey para crear un Httpserver incrustado simple que aloja un par de servicios de descanso. Solo necesitábamos algo pequeño rápido y ligero. Necesito alojar una pequeña página html estática dentro de la misma instancia del servidor. ¿Hay una manera simple de agregar un controlador estático al servidor? ¿Hay un controlador predefinido que pueda usar? Parece una tarea bastante común, odiaría volver a escribir el código si ya existe.

        server = HttpServerFactory.create(url);
        server.setExecutor(Executors.newCachedThreadPool());
        server.createContext("/staticcontent", new HttpHandler() {

            @Override
            public void handle(HttpExchange arg0) throws IOException {
                //What goes here?

            }
        });
        server.start();

Answer 1

Aquí hay una versión segura. Es posible que desee agregar un par de tipos MIME, dependiendo de cuáles sean comunes (o use otro método si su plataforma lo tiene ).

package de.phihag.miniticker;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

public class StaticFileHandler implements HttpHandler {
    private static final Map<String,String> MIME_MAP = new HashMap<>();
    static {
        MIME_MAP.put("appcache", "text/cache-manifest");
        MIME_MAP.put("css", "text/css");
        MIME_MAP.put("gif", "image/gif");
        MIME_MAP.put("html", "text/html");
        MIME_MAP.put("js", "application/javascript");
        MIME_MAP.put("json", "application/json");
        MIME_MAP.put("jpg", "image/jpeg");
        MIME_MAP.put("jpeg", "image/jpeg");
        MIME_MAP.put("mp4", "video/mp4");
        MIME_MAP.put("pdf", "application/pdf");
        MIME_MAP.put("png", "image/png");
        MIME_MAP.put("svg", "image/svg+xml");
        MIME_MAP.put("xlsm", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        MIME_MAP.put("xml", "application/xml");
        MIME_MAP.put("zip", "application/zip");
        MIME_MAP.put("md", "text/plain");
        MIME_MAP.put("txt", "text/plain");
        MIME_MAP.put("php", "text/plain");
    };

    private String filesystemRoot;
    private String urlPrefix;
    private String directoryIndex;

    /**
     * @param urlPrefix The prefix of all URLs.
     *                   This is the first argument to createContext. Must start and end in a slash.
     * @param filesystemRoot The root directory in the filesystem.
     *                       Only files under this directory will be served to the client.
     *                       For instance "./staticfiles".
     * @param directoryIndex File to show when a directory is requested, e.g. "index.html".
     */
    public StaticFileHandler(String urlPrefix, String filesystemRoot, String directoryIndex) {
        if (!urlPrefix.startsWith("/")) {
            throw new RuntimeException("pathPrefix does not start with a slash");
        }
        if (!urlPrefix.endsWith("/")) {
            throw new RuntimeException("pathPrefix does not end with a slash");
        }
        this.urlPrefix = urlPrefix;

        assert filesystemRoot.endsWith("/");
        try {
            this.filesystemRoot = new File(filesystemRoot).getCanonicalPath();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

        this.directoryIndex = directoryIndex;
    }

    /**
     * Create and register a new static file handler.
     * @param hs The HTTP server where the file handler will be registered.
     * @param path The path in the URL prefixed to all requests, such as "/static/"
     * @param filesystemRoot The filesystem location.
     *                       For instance "/var/www/mystaticfiles/".
     *                       A request to "/static/x/y.html" will be served from the filesystem file "/var/www/mystaticfiles/x/y.html"
     * @param directoryIndex File to show when a directory is requested, e.g. "index.html".
     */
    public static void create(HttpServer hs, String path, String filesystemRoot, String directoryIndex) {
        StaticFileHandler sfh = new StaticFileHandler(path, filesystemRoot, directoryIndex);
        hs.createContext(path, sfh);
    }

    public void handle(HttpExchange he) throws IOException {
        String method = he.getRequestMethod(); 
        if (! ("HEAD".equals(method) || "GET".equals(method))) {
            sendError(he, 501, "Unsupported HTTP method");
            return;
        }

        String wholeUrlPath = he.getRequestURI().getPath();
        if (wholeUrlPath.endsWith("/")) {
            wholeUrlPath += directoryIndex;
        }
        if (! wholeUrlPath.startsWith(urlPrefix)) {
            throw new RuntimeException("Path is not in prefix - incorrect routing?");
        }
        String urlPath = wholeUrlPath.substring(urlPrefix.length());

        File f = new File(filesystemRoot, urlPath);
        File canonicalFile;
        try {
            canonicalFile = f.getCanonicalFile();
        } catch (IOException e) {
            // This may be more benign (i.e. not an attack, just a 403),
            // but we don''t want the attacker to be able to discern the difference.
            reportPathTraversal(he);
            return;
        }

        String canonicalPath = canonicalFile.getPath();
        if (! canonicalPath.startsWith(filesystemRoot)) {
            reportPathTraversal(he);
            return;
        }

        FileInputStream fis;
        try {
            fis = new FileInputStream(canonicalFile);
        } catch (FileNotFoundException e) {
            // The file may also be forbidden to us instead of missing, but we''re leaking less information this way 
            sendError(he, 404, "File not found"); 
            return;
        }

        String mimeType = lookupMime(urlPath);
        he.getResponseHeaders().set("Content-Type", mimeType);
        if ("GET".equals(method)) {
            he.sendResponseHeaders(200, canonicalFile.length());            
            OutputStream os = he.getResponseBody();
            copyStream(fis, os);
            os.close();
        } else {
            assert("HEAD".equals(method));
            he.sendResponseHeaders(200, -1);
        }
        fis.close();
    }

    private void copyStream(InputStream is, OutputStream os) throws IOException {
        byte[] buf = new byte[4096];
        int n;
        while ((n = is.read(buf)) >= 0) {
            os.write(buf, 0, n);
        }
    }

    private void sendError(HttpExchange he, int rCode, String description) throws IOException {
        String message = "HTTP error " + rCode + ": " + description;
        byte[] messageBytes = message.getBytes("UTF-8");

        he.getResponseHeaders().set("Content-Type", "text/plain; charset=utf-8");
        he.sendResponseHeaders(rCode, messageBytes.length);
        OutputStream os = he.getResponseBody();
        os.write(messageBytes);
        os.close();
    }

    // This is one function to avoid giving away where we failed 
    private void reportPathTraversal(HttpExchange he) throws IOException {
        sendError(he, 400, "Path traversal attempt detected");
    }

    private static String getExt(String path) {
        int slashIndex = path.lastIndexOf(''/'');
        String basename = (slashIndex < 0) ? path : path.substring(slashIndex + 1);

        int dotIndex = basename.lastIndexOf(''.'');
        if (dotIndex >= 0) {
            return basename.substring(dotIndex + 1);
        } else {
            return "";
        }
    }

    private static String lookupMime(String path) {
        String ext = getExt(path).toLowerCase();
        return MIME_MAP.getOrDefault(ext, "application/octet-stream");
    }
}

Answer 2

Esto hará el truco, aunque permite que cualquiera camine por el árbol solicitando ../../../ Puede cambiar ./wwwroot a cualquier ruta de archivo válida de Java.

static class MyHandler implements HttpHandler {
        public void handle(HttpExchange t) throws IOException {
            String root = "./wwwroot";
            URI uri = t.getRequestURI();
            System.out.println("looking for: "+ root + uri.getPath());
            String path = uri.getPath();
            File file = new File(root + path).getCanonicalFile();

            if (!file.isFile()) {
              // Object does not exist or is not a file: reject with 404 error.
              String response = "404 (Not Found)/n";
              t.sendResponseHeaders(404, response.length());
              OutputStream os = t.getResponseBody();
              os.write(response.getBytes());
              os.close();
            } else {
              // Object exists and is a file: accept with response code 200.
              String mime = "text/html";
              if(path.substring(path.length()-3).equals(".js")) mime = "application/javascript";
              if(path.substring(path.length()-3).equals("css")) mime = "text/css";            

              Headers h = t.getResponseHeaders();
              h.set("Content-Type", mime);
              t.sendResponseHeaders(200, 0);              

              OutputStream os = t.getResponseBody();
              FileInputStream fs = new FileInputStream(file);
              final byte[] buffer = new byte[0x10000];
              int count = 0;
              while ((count = fs.read(buffer)) >= 0) {
                os.write(buffer,0,count);
              }
              fs.close();
              os.close();
            }  
        }
    }