The jwebserver Command

Name

jwebserver - launch the Java Simple Web Server

Synopsis

jwebserver [options]

options: Command-line options. For a detailed description of the options, see Options.

Description

The jwebserver tool provides a minimal HTTP server, designed to be used for prototyping, testing, and debugging. It serves a single directory hierarchy, and only serves static files. Only HTTP/1.1 is supported; HTTP/2 and HTTPS are not supported.

Only idempotent HEAD and GET requests are served. Any other requests receive a 501 - Not Implemented or a 405 - Not Allowed response. GET requests are mapped to the directory being served, as follows:

If the requested resource is a file, its content is served.
If the requested resource is a directory that contains an index file, the content of the index file is served.
Otherwise, the names of all files and subdirectories of the directory are listed. Symbolic links and hidden files are not listed or served.

MIME types are configured automatically, using the built-in table. For example, .html files are served as text/html and .java files are served as text/plain.

jwebserver is located in the jdk.httpserver module, and can alternatively be started with java -m jdk.httpserver. It is based on the web server implementation in the com.sun.net.httpserver package. The com.sun.net.httpserver.SimpleFileServer class provides a programmatic way to retrieve the server and its components for reuse and extension.

Usage

jwebserver [-b bind address] [-p port] [-d directory]
           [-o none|info|verbose] [-h to show options]
           [-version to show version information]

Options

-h or -? or --help: Prints the help message and exits.
-b addr or --bind-address addr: Specifies the address to bind to. Default: 127.0.0.1 or ::1 (loopback). For all interfaces use -b 0.0.0.0 or -b ::.
-d dir or --directory dir: Specifies the directory to serve. Default: current directory.
-o level or --output level: Specifies the output format. none | info | verbose. Default: info.
-p port or --port port: Specifies the port to listen on. Default: 8000.
-version or --version: Prints the version information and exits.

To stop the server, press Ctrl + C.

Starting the Server

The following command starts the Simple Web Server:

$ jwebserver

If startup is successful, the server prints a message to System.out listing the local address and the absolute path of the directory being served. For example:

$ jwebserver
Binding to loopback by default. For all interfaces use "-b 0.0.0.0" or "-b ::".
Serving /cwd and subdirectories on 127.0.0.1 port 8000
URL http://127.0.0.1:8000/

Configuration

By default, the server runs in the foreground and binds to the loopback address and port 8000. This can be changed with the -b and -p options. For example, to bind the Simple Web Server to all interfaces, use:

$ jwebserver -b 0.0.0.0
Serving /cwd and subdirectories on 0.0.0.0 (all interfaces) port 8000
URL http://123.456.7.891:8000/

Note that this makes the web server accessible to all hosts on the network. Do not do this unless you are sure the server cannot leak any sensitive information.

As another example, use the following command to run on port 9000:

$ jwebserver -p 9000

By default, the files of the current directory are served. A different directory can be specified with the -d option.

By default, every request is logged on the console. The output looks like this:

127.0.0.1 - - [10/Feb/2021:14:34:11 +0000] "GET /some/subdirectory/ HTTP/1.1" 200 -

Logging output can be changed with the -o option. The default setting is info. The verbose setting additionally includes the request and response headers as well as the absolute path of the requested resource.

Stopping the Server

Once started successfully, the server runs until it is stopped. On Unix platforms, the server can be stopped by sending it a SIGINT signal (Ctrl+C in a terminal window).

Help Option

The -h option displays a help message describing the usage and the options of the jwebserver.