src/jdk.jshell/share/classes/jdk/jshell/tool/JavaShellToolBuilder.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * accompanied this code).
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package jdk.jshell.tool;

import java.io.InputStream;
import java.io.PrintStream;
import java.util.Locale;
import java.util.Map;
import java.util.prefs.Preferences;
import jdk.internal.jshell.tool.JShellToolBuilder;

/**
 * Interface to configure and run a Java shell tool instance. An instance of the
 * builder is created with the static {@link #builder} method. This builder can,
 * optionally, be configured with the configuration methods. All configuration
 * methods return the builder instance for use in chained initialization. All
 * configuration methods have sensible defaults which will be used if they are
 * not called.. After zero or more calls to configuration methods, the tool is
 * launched with a call to {@link #run(java.lang.String...) }.
 *
 * @since 9
 */
public interface JavaShellToolBuilder {

    /**
     * Create a builder for launching the JDK jshell tool.
     *
     * @return a builder which can be used to configure and launch the jshell
     * tool
     */
    static JavaShellToolBuilder builder() {
        return new JShellToolBuilder();
    }

    /**
     * Set the input channels.
     *
     * @implSpec If this method is not called, the behavior should be
     * equivalent to calling {@code in(System.in, null)}.
     *
     * @param cmdIn source of command input
     * @param userIn source of input for running user code, or {@code null} to
     * extract user input from cmdIn
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder in(InputStream cmdIn, InputStream userIn);

    /**
     * Set the output channels. Same as {@code out(output, output, output)}.
     *
     * @implSpec If neither {@code out} method is called, the behavior should be
     * equivalent to calling {@code out(System.out)}.
     *
     * @param output destination of command feedback, console interaction, and
     * user code output
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder out(PrintStream output);

    /**
     * Set the output channels.
     *
     * @implSpec If neither {@code out} method is called, the behavior should be
     * equivalent to calling {@code out(System.out, System.out, System.out)}.
     *
     * @param cmdOut destination of command feedback including error messages
     * for users
     * @param console destination of console interaction
     * @param userOut destination of user code output.  For example, user snippet
     * {@code System.out.println("Hello")} when executed {@code Hello} goes to
     * userOut.
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder out(PrintStream cmdOut, PrintStream console, PrintStream userOut);

    /**
     * Set the error channels. Same as {@code err(error, error)}.
     *
     * @implSpec If neither {@code err} method is called, the behavior should be
     * equivalent to calling {@code err(System.err)}.
     *
     * @param error destination of tool errors, and
     * user code errors
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder err(PrintStream error);

    /**
     * Set the error channels.
     *
     * @implSpec If neither {@code err} method is called, the behavior should be
     * equivalent to calling {@code err(System.err, System.err, System.err)}.
     *
     * @param cmdErr destination of tool start-up and fatal errors
     * @param userErr destination of user code error output.
     * For example, user snippet  {@code System.err.println("Oops")}
     * when executed {@code Oops} goes to userErr.
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder err(PrintStream cmdErr, PrintStream userErr);

    /**
     * Set the storage mechanism for persistent information which includes
     * input history and retained settings.
     *
     * @implSpec If neither {@code persistence} method is called, the behavior
     * should be to use the tool's standard persistence mechanism.
     *
     * @param prefs an instance of {@link java.util.prefs.Preferences} that
     * is used to retrieve and store persistent information
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder persistence(Preferences prefs);

    /**
     * Set the storage mechanism for persistent information which includes
     * input history and retained settings.
     *
     * @implSpec If neither {@code persistence} method is called, the behavior
     * should be to use the tool's standard persistence mechanism.
     *
     * @param prefsMap  an instance of {@link java.util.Map} that
     * is used to retrieve and store persistent information
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder persistence(Map<String,String> prefsMap);

    /**
     * Set the source for environment variables.
     *
     * @implSpec If this method is not called, the behavior should be
     * equivalent to calling {@code env(System.getenv())}.
     *
     * @param vars the Map of environment variable names to values
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder env(Map<String,String> vars);

    /**
     * Set the locale.
     *
     * @implSpec If this method is not called, the behavior should be
     * equivalent to calling {@code locale(Locale.getDefault())}.
     *
     * @param locale the locale
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder locale(Locale locale);

    /**
     * Set to enable a command capturing prompt override.
     *
     * @implSpec If this method is not called, the behavior should be
     * equivalent to calling {@code promptCapture(false)}.
     *
     * @param capture if {@code true}, basic prompt is the {@code ENQ}
     * character and continuation prompt is the {@code ACK} character.
     * If false, prompts are as set with set-up or user {@code /set} commands.
     * @return the {@code JavaShellToolBuilder} instance
     */
    JavaShellToolBuilder promptCapture(boolean capture);

    /**
     * Set to true to specify the inputs and outputs are connected to an interactive terminal
     * that can interpret the ANSI escape codes. The characters sent to the output streams are
     * assumed to be interpreted by a terminal and shown to the user, and the exact order and nature
     * of characters sent to the outputs are unspecified.
     *
     * Set to false to specify a legacy simpler behavior whose output can be parsed by automatic
     * tools.
     *
     * When the input stream for this Java Shell is {@code System.in}, this value is ignored,
     * and the behavior is similar to specifying {@code true} in this method, but is more closely
     * following the specific terminal connected to {@code System.in}.
     *
     * @implSpec If this method is not called, the behavior should be
     * equivalent to calling {@code interactiveTerminal(false)}. The default implementation of
     * this method returns {@code this}.
     *
     * @param terminal if {@code true}, an terminal that can interpret the ANSI escape codes is
     *                 assumed to interpret the output. If {@code false}, a simpler output is selected.
     * @return the {@code JavaShellToolBuilder} instance
     * @since 17
     */
    default JavaShellToolBuilder interactiveTerminal(boolean terminal) {
        return this;
    }

    /**
     * Provide a hint of the display window's dimensions when using an interactive terminal.
     *
     * <p>
     * When the input stream for this Java Shell is {@code System.in}, this setting is ignored.
     *
     * @implSpec Implementations may choose to ignore this method. The default implementation
     * of this method returns {@code this}.
     *
     * @param columns number of displayed columns
     * @param rows number of displayed rows
     * @return the {@code JavaShellToolBuilder} instance
     * @since 24
     */
    default JavaShellToolBuilder windowSize(int columns, int rows) {
        return this;
    }

    /**
     * Run an instance of the Java shell tool as configured by the other methods
     * in this interface.  This call is not destructive, more than one call of
     * this method may be made from a configured builder. The  exit code from
     * the Java shell tool is ignored.
     *
     * @param arguments the command-line arguments (including options), if any
     * @throws Exception an unexpected fatal exception
     */
    void run(String... arguments) throws Exception;

    /**
     * Run an instance of the Java shell tool as configured by the other methods
     * in this interface.  This call is not destructive, more than one call of
     * this method may be made from a configured builder.
     *
     * @implSpec The default implementation always returns zero. Implementations
     * of this interface should override this method, returning the exit status.
     *
     * @param arguments the command-line arguments (including options), if any
     * @throws Exception an unexpected fatal exception
     * @return the exit status with which the tool explicitly exited (if any),
     * otherwise 0 for success or 1 for failure
     *
     * @since 10
     */
    default int start(String... arguments) throws Exception {
        run(arguments);
        return 0;
    }
}