diff options
Diffstat (limited to 'src/main/TweetShell.java')
| -rw-r--r-- | src/main/TweetShell.java | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/src/main/TweetShell.java b/src/main/TweetShell.java new file mode 100644 index 0000000..533939b --- /dev/null +++ b/src/main/TweetShell.java @@ -0,0 +1,217 @@ +package main; + +import io.OAuthRequester; +import io.StreamImpl; +import java.io.IOException; +import java.util.Arrays; +import java.util.NoSuchElementException; +import java.util.Scanner; +import mining.Stream; +import mining.TwitterApi; +import org.json.JSONObject; +import provider.ExceptionListener; +import provider.ResultListener; + +/** + * Provides an interactive shell where requests can be made and displayed. + */ +public class TweetShell implements TwitterApi.PinSupplier { + + private final Scanner scanner = new Scanner(System.in); + + public TweetShell() { + + } + private TwitterApi api_cached; + private Stream stream_cached; + + private TwitterApi getApi() throws IOException { + if (api_cached == null) { + api_cached = TwitterApi.getOAuth(this); + } + return api_cached; + } + + private Stream getStream() throws IOException { + if (stream_cached == null) { + OAuthRequester requester = (OAuthRequester) getApi().getRequester(); + StreamHandler handler = new StreamHandler(); + stream_cached = new StreamImpl(handler, handler, requester); + } + return stream_cached; + } + + private class StreamHandler implements ResultListener, ExceptionListener { + + @Override + public void exceptionGenerated(Exception ex) { + System.err.println("Stream closed due to " + ex); + } + + @Override + public void tweetGenerated(JSONObject obj) { + throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. + } + + @Override + public void profileGenerated(JSONObject obj) { + throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. + } + } + + @Override + public String requestPin(String url) throws IOException { + System.err.println(url); + System.err.println("Please open the above URL and enter PIN:"); + return scanner.nextLine(); + } + + private void printPrompt() { + if (stream_cached == null) { + System.out.print("$ "); + } else { + System.out.print("€ "); + } + } + /** + * Processes commands from stdin until the exit command is received or EOF. + */ + public void process_forever() { + System.err.println("Entering interactive shell, type 'help' for help " + + "or 'exit' to leave."); + // print prompt for reading first command + printPrompt(); + while (scanner.hasNextLine()) { + String line = scanner.nextLine().trim(); + String[] args = line.split("\\s+", 2); + if (!args[0].isEmpty()) { + // non-empty command, let's see whether it makes sense? + if (!execute(args)) { + // requested to terminate + break; + } + } + // print prompt for reading next line + printPrompt(); + } + } + + /** + * Executes a command with optional parameters. + * + * @param args An array with the first argument containing the command with + * optional parameters in following arguments. + * @return true if more commands are allowed to be executed, false + * otherwise. + */ + public boolean execute(String[] args) { + try { + Command command = Command.fromString(args[0]); + String[] params = Arrays.copyOfRange(args, 1, args.length); + execute(command, params); + } catch (IllegalArgumentException ex) { + System.err.println(ex.getMessage()); + } catch (IOException ex) { + System.err.println("Command " + args[0] + " failed with " + ex); + ex.printStackTrace(); + } catch (NoSuchElementException ex) { + // thrown by the "exit" command to signal exit + return false; + } + // another satisfied customer, next! + return true; + } + + enum Command { + + add("Adds a keyword to search", 1), + del("Deletes a keyword from search", 1), + commit("Activate the stream or apply the stream keyword changes"), + close("Close the stream"), + test(""), + exit("Returns to shell"), + help("Get help"); + + private final String description; + private final int paramCount; + + Command(String description) { + this.description = description; + this.paramCount = 0; + } + + Command(String description, int paramCount) { + this.description = description; + this.paramCount = paramCount; + } + + public String getDescription() { + return description; + } + + public int getParamCount() { + return paramCount; + } + + public static Command fromString(String command) { + for (Command cmd : values()) { + if (cmd.name().equals(command)) { + return cmd; + } + } + throw new IllegalArgumentException("Unrecognized command. Hint: help"); + } + }; + + private final String[] HELP = new String[]{ + "Interactive TweetShell", + "", + "Available commands:" + }; + + private void execute(Command command, String[] params) throws IOException { + if (params.length < command.getParamCount()) { + throw new IllegalArgumentException("Expected " + + command.getParamCount() + " parameters, got only " + + params.length); + } + switch (command) { + case add: + getStream().watchKeyword(params[0]); + break; + case del: + getStream().unwatchKeyword(params[0]); + break; + case commit: + getStream().commit(); + break; + case close: + getStream().close(); + break; + case test: + getStream().poll(); + break; + case help: + for (String line : HELP) { + System.out.println(line); + } + for (Command cmd : Command.values()) { + System.out.printf(" %-10s", cmd.name()); + if (!cmd.getDescription().isEmpty()) { + System.out.print(" " + cmd.getDescription()); + } + if (cmd.getParamCount() == 1) { + System.out.print(" (1 arg)"); + } else if (cmd.getParamCount() > 1) { + System.out.printf(" (%d args)", cmd.getParamCount()); + } + System.out.println(); + } + break; + case exit: + throw new NoSuchElementException(); + default: + throw new AssertionError(command.name()); + } + } +} |