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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package com.sun.tools.script.shell;

import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;
import javax.script.*;

This is the main class for Java script shell.
/** * This is the main class for Java script shell. */
public class Main {
main entry point to the command line tool
Params:
  • args – command line argument array
/** * main entry point to the command line tool * @param args command line argument array */
public static void main(String[] args) { // parse command line options String[] scriptArgs = processOptions(args); // process each script command for (Command cmd : scripts) { cmd.run(scriptArgs); } System.exit(EXIT_SUCCESS); } // Each -e or -f or interactive mode is represented // by an instance of Command. private static interface Command { public void run(String[] arguments); }
Parses and processes command line options.
Params:
  • args – command line argument array
/** * Parses and processes command line options. * @param args command line argument array */
private static String[] processOptions(String[] args) { // current scripting language selected String currentLanguage = DEFAULT_LANGUAGE; // current script file encoding selected String currentEncoding = null; // check for -classpath or -cp first checkClassPath(args); // have we seen -e or -f ? boolean seenScript = false; // have we seen -f - already? boolean seenStdin = false; for (int i=0; i < args.length; i++) { String arg = args[i]; if (arg.equals("-classpath") || arg.equals("-cp")) { // handled already, just continue i++; continue; } // collect non-option arguments and pass these as script arguments if (!arg.startsWith("-")) { int numScriptArgs; int startScriptArg; if (seenScript) { // if we have seen -e or -f already all non-option arguments // are passed as script arguments numScriptArgs = args.length - i; startScriptArg = i; } else { // if we have not seen -e or -f, first non-option argument // is treated as script file name and rest of the non-option // arguments are passed to script as script arguments numScriptArgs = args.length - i - 1; startScriptArg = i + 1; ScriptEngine se = getScriptEngine(currentLanguage); addFileSource(se, args[i], currentEncoding); } // collect script arguments and return to main String[] result = new String[numScriptArgs]; System.arraycopy(args, startScriptArg, result, 0, numScriptArgs); return result; } if (arg.startsWith("-D")) { String value = arg.substring(2); int eq = value.indexOf('='); if (eq != -1) { System.setProperty(value.substring(0, eq), value.substring(eq + 1)); } else { if (!value.equals("")) { System.setProperty(value, ""); } else { // do not allow empty property name usage(EXIT_CMD_NO_PROPNAME); } } continue; } else if (arg.equals("-?") || arg.equals("-help")) { usage(EXIT_SUCCESS); } else if (arg.equals("-e")) { seenScript = true; if (++i == args.length) usage(EXIT_CMD_NO_SCRIPT); ScriptEngine se = getScriptEngine(currentLanguage); addStringSource(se, args[i]); continue; } else if (arg.equals("-encoding")) { if (++i == args.length) usage(EXIT_CMD_NO_ENCODING); currentEncoding = args[i]; continue; } else if (arg.equals("-f")) { seenScript = true; if (++i == args.length) usage(EXIT_CMD_NO_FILE); ScriptEngine se = getScriptEngine(currentLanguage); if (args[i].equals("-")) { if (seenStdin) { usage(EXIT_MULTIPLE_STDIN); } else { seenStdin = true; } addInteractiveMode(se); } else { addFileSource(se, args[i], currentEncoding); } continue; } else if (arg.equals("-l")) { if (++i == args.length) usage(EXIT_CMD_NO_LANG); currentLanguage = args[i]; continue; } else if (arg.equals("-q")) { listScriptEngines(); } // some unknown option... usage(EXIT_UNKNOWN_OPTION); } if (! seenScript) { ScriptEngine se = getScriptEngine(currentLanguage); addInteractiveMode(se); } return new String[0]; }
Adds interactive mode Command
Params:
  • se – ScriptEngine to use in interactive mode.
/** * Adds interactive mode Command * @param se ScriptEngine to use in interactive mode. */
private static void addInteractiveMode(final ScriptEngine se) { scripts.add(new Command() { public void run(String[] args) { setScriptArguments(se, args); processSource(se, "-", null); } }); }
Adds script source file Command
Params:
  • se – ScriptEngine used to evaluate the script file
  • fileName – script file name
  • encoding – script file encoding
/** * Adds script source file Command * @param se ScriptEngine used to evaluate the script file * @param fileName script file name * @param encoding script file encoding */
private static void addFileSource(final ScriptEngine se, final String fileName, final String encoding) { scripts.add(new Command() { public void run(String[] args) { setScriptArguments(se, args); processSource(se, fileName, encoding); } }); }
Adds script string source Command
Params:
  • se – ScriptEngine to be used to evaluate the script string
  • source – Script source string
/** * Adds script string source Command * @param se ScriptEngine to be used to evaluate the script string * @param source Script source string */
private static void addStringSource(final ScriptEngine se, final String source) { scripts.add(new Command() { public void run(String[] args) { setScriptArguments(se, args); String oldFile = setScriptFilename(se, "<string>"); try { evaluateString(se, source); } finally { setScriptFilename(se, oldFile); } } }); }
Prints list of script engines available and exits.
/** * Prints list of script engines available and exits. */
private static void listScriptEngines() { List<ScriptEngineFactory> factories = engineManager.getEngineFactories(); for (ScriptEngineFactory factory: factories) { getError().println(getMessage("engine.info", new Object[] { factory.getLanguageName(), factory.getLanguageVersion(), factory.getEngineName(), factory.getEngineVersion() })); } System.exit(EXIT_SUCCESS); }
Processes a given source file or standard input.
Params:
  • se – ScriptEngine to be used to evaluate
  • filename – file name, can be null
  • encoding – script file encoding, can be null
/** * Processes a given source file or standard input. * @param se ScriptEngine to be used to evaluate * @param filename file name, can be null * @param encoding script file encoding, can be null */
private static void processSource(ScriptEngine se, String filename, String encoding) { if (filename.equals("-")) { BufferedReader in = new BufferedReader (new InputStreamReader(getIn())); boolean hitEOF = false; String prompt = getPrompt(se); se.put(ScriptEngine.FILENAME, "<STDIN>"); while (!hitEOF) { getError().print(prompt); String source = ""; try { source = in.readLine(); } catch (IOException ioe) { getError().println(ioe.toString()); } if (source == null) { hitEOF = true; break; } Object res = evaluateString(se, source, false); if (res != null) { res = res.toString(); if (res == null) { res = "null"; } getError().println(res); } } } else { FileInputStream fis = null; try { fis = new FileInputStream(filename); } catch (FileNotFoundException fnfe) { getError().println(getMessage("file.not.found", new Object[] { filename })); System.exit(EXIT_FILE_NOT_FOUND); } evaluateStream(se, fis, filename, encoding); } }
Evaluates given script source
Params:
  • se – ScriptEngine to evaluate the string
  • script – Script source string
  • exitOnError – whether to exit the process on script error
/** * Evaluates given script source * @param se ScriptEngine to evaluate the string * @param script Script source string * @param exitOnError whether to exit the process on script error */
private static Object evaluateString(ScriptEngine se, String script, boolean exitOnError) { try { return se.eval(script); } catch (ScriptException sexp) { getError().println(getMessage("string.script.error", new Object[] { sexp.getMessage() })); if (exitOnError) System.exit(EXIT_SCRIPT_ERROR); } catch (Exception exp) { exp.printStackTrace(getError()); if (exitOnError) System.exit(EXIT_SCRIPT_ERROR); } return null; }
Evaluate script string source and exit on script error
Params:
  • se – ScriptEngine to evaluate the string
  • script – Script source string
/** * Evaluate script string source and exit on script error * @param se ScriptEngine to evaluate the string * @param script Script source string */
private static void evaluateString(ScriptEngine se, String script) { evaluateString(se, script, true); }
Evaluates script from given reader
Params:
  • se – ScriptEngine to evaluate the string
  • reader – Reader from which is script is read
  • name – file name to report in error.
/** * Evaluates script from given reader * @param se ScriptEngine to evaluate the string * @param reader Reader from which is script is read * @param name file name to report in error. */
private static Object evaluateReader(ScriptEngine se, Reader reader, String name) { String oldFilename = setScriptFilename(se, name); try { return se.eval(reader); } catch (ScriptException sexp) { getError().println(getMessage("file.script.error", new Object[] { name, sexp.getMessage() })); System.exit(EXIT_SCRIPT_ERROR); } catch (Exception exp) { exp.printStackTrace(getError()); System.exit(EXIT_SCRIPT_ERROR); } finally { setScriptFilename(se, oldFilename); } return null; }
Evaluates given input stream
Params:
  • se – ScriptEngine to evaluate the string
  • is – InputStream from which script is read
  • name – file name to report in error
/** * Evaluates given input stream * @param se ScriptEngine to evaluate the string * @param is InputStream from which script is read * @param name file name to report in error */
private static Object evaluateStream(ScriptEngine se, InputStream is, String name, String encoding) { BufferedReader reader = null; if (encoding != null) { try { reader = new BufferedReader(new InputStreamReader(is, encoding)); } catch (UnsupportedEncodingException uee) { getError().println(getMessage("encoding.unsupported", new Object[] { encoding })); System.exit(EXIT_NO_ENCODING_FOUND); } } else { reader = new BufferedReader(new InputStreamReader(is)); } return evaluateReader(se, reader, name); }
Prints usage message and exits
Params:
  • exitCode – process exit code
/** * Prints usage message and exits * @param exitCode process exit code */
private static void usage(int exitCode) { getError().println(getMessage("main.usage", new Object[] { PROGRAM_NAME })); System.exit(exitCode); }
Gets prompt for interactive mode
Returns:prompt string to use
/** * Gets prompt for interactive mode * @return prompt string to use */
private static String getPrompt(ScriptEngine se) { List<String> names = se.getFactory().getNames(); return names.get(0) + "> "; }
Get formatted, localized error message
/** * Get formatted, localized error message */
private static String getMessage(String key, Object[] params) { return MessageFormat.format(msgRes.getString(key), params); } // input stream from where we will read private static InputStream getIn() { return System.in; } // stream to print error messages private static PrintStream getError() { return System.err; } // get current script engine private static ScriptEngine getScriptEngine(String lang) { ScriptEngine se = engines.get(lang); if (se == null) { se = engineManager.getEngineByName(lang); if (se == null) { getError().println(getMessage("engine.not.found", new Object[] { lang })); System.exit(EXIT_ENGINE_NOT_FOUND); } // initialize the engine initScriptEngine(se); // to avoid re-initialization of engine, store it in a map engines.put(lang, se); } return se; } // initialize a given script engine private static void initScriptEngine(ScriptEngine se) { // put engine global variable se.put("engine", se); // load init.<ext> file from resource List<String> exts = se.getFactory().getExtensions(); InputStream sysIn = null; ClassLoader cl = Thread.currentThread().getContextClassLoader(); for (String ext : exts) { sysIn = cl.getResourceAsStream("com/sun/tools/script/shell/init." + ext); if (sysIn != null) break; } if (sysIn != null) { evaluateStream(se, sysIn, "<system-init>", null); } }
Checks for -classpath, -cp in command line args. Creates a ClassLoader and sets it as Thread context loader for current thread.
Params:
  • args – command line argument array
/** * Checks for -classpath, -cp in command line args. Creates a ClassLoader * and sets it as Thread context loader for current thread. * * @param args command line argument array */
private static void checkClassPath(String[] args) { String classPath = null; for (int i = 0; i < args.length; i++) { if (args[i].equals("-classpath") || args[i].equals("-cp")) { if (++i == args.length) { // just -classpath or -cp with no value usage(EXIT_CMD_NO_CLASSPATH); } else { classPath = args[i]; } } } if (classPath != null) { /* We create a class loader, configure it with specified * classpath values and set the same as context loader. * Note that ScriptEngineManager uses context loader to * load script engines. So, this ensures that user defined * script engines will be loaded. For classes referred * from scripts, Rhino engine uses thread context loader * but this is script engine dependent. We don't have * script engine independent solution anyway. Unless we * know the class loader used by a specific engine, we * can't configure correct loader. */ ClassLoader parent = Main.class.getClassLoader(); URL[] urls = pathToURLs(classPath); URLClassLoader loader = new URLClassLoader(urls, parent); Thread.currentThread().setContextClassLoader(loader); } // now initialize script engine manager. Note that this has to // be done after setting the context loader so that manager // will see script engines from user specified classpath engineManager = new ScriptEngineManager(); }
Utility method for converting a search path string to an array of directory and JAR file URLs.
Params:
  • path – the search path string
Returns:the resulting array of directory and JAR file URLs
/** * Utility method for converting a search path string to an array * of directory and JAR file URLs. * * @param path the search path string * @return the resulting array of directory and JAR file URLs */
private static URL[] pathToURLs(String path) { String[] components = path.split(File.pathSeparator); URL[] urls = new URL[components.length]; int count = 0; while(count < components.length) { URL url = fileToURL(new File(components[count])); if (url != null) { urls[count++] = url; } } if (urls.length != count) { URL[] tmp = new URL[count]; System.arraycopy(urls, 0, tmp, 0, count); urls = tmp; } return urls; }
Returns the directory or JAR file URL corresponding to the specified local file name.
Params:
  • file – the File object
Returns:the resulting directory or JAR file URL, or null if unknown
/** * Returns the directory or JAR file URL corresponding to the specified * local file name. * * @param file the File object * @return the resulting directory or JAR file URL, or null if unknown */
private static URL fileToURL(File file) { String name; try { name = file.getCanonicalPath(); } catch (IOException e) { name = file.getAbsolutePath(); } name = name.replace(File.separatorChar, '/'); if (!name.startsWith("/")) { name = "/" + name; } // If the file does not exist, then assume that it's a directory if (!file.isFile()) { name = name + "/"; } try { return new URL("file", "", name); } catch (MalformedURLException e) { throw new IllegalArgumentException("file"); } } private static void setScriptArguments(ScriptEngine se, String[] args) { se.put("arguments", args); se.put(ScriptEngine.ARGV, args); } private static String setScriptFilename(ScriptEngine se, String name) { String oldName = (String) se.get(ScriptEngine.FILENAME); se.put(ScriptEngine.FILENAME, name); return oldName; } // exit codes private static final int EXIT_SUCCESS = 0; private static final int EXIT_CMD_NO_CLASSPATH = 1; private static final int EXIT_CMD_NO_FILE = 2; private static final int EXIT_CMD_NO_SCRIPT = 3; private static final int EXIT_CMD_NO_LANG = 4; private static final int EXIT_CMD_NO_ENCODING = 5; private static final int EXIT_CMD_NO_PROPNAME = 6; private static final int EXIT_UNKNOWN_OPTION = 7; private static final int EXIT_ENGINE_NOT_FOUND = 8; private static final int EXIT_NO_ENCODING_FOUND = 9; private static final int EXIT_SCRIPT_ERROR = 10; private static final int EXIT_FILE_NOT_FOUND = 11; private static final int EXIT_MULTIPLE_STDIN = 12; // default scripting language private static final String DEFAULT_LANGUAGE = "js"; // list of scripts to process private static List<Command> scripts; // the script engine manager private static ScriptEngineManager engineManager; // map of engines we loaded private static Map<String, ScriptEngine> engines; // error messages resource private static ResourceBundle msgRes; private static String BUNDLE_NAME = "com.sun.tools.script.shell.messages"; private static String PROGRAM_NAME = "jrunscript"; static { scripts = new ArrayList<Command>(); engines = new HashMap<String, ScriptEngine>(); msgRes = ResourceBundle.getBundle(BUNDLE_NAME, Locale.getDefault()); } }