global.java

java中比较著名的js引擎当属mozilla开源的rhino

                               Function funObj)
    {
        Scriptable scope = funObj.getParentScope();
        Runner runner;
        if (args.length != 0 && args[0] instanceof Function) {
            Object[] newArgs = null;
            if (args.length > 1 && args[1] instanceof Scriptable) {
                newArgs = cx.getElements((Scriptable) args[1]);
            }
            if (newArgs == null) { newArgs = ScriptRuntime.emptyArgs; }
            runner = new Runner(scope, (Function) args[0], newArgs);
        } else if (args.length != 0 && args[0] instanceof Script) {
            runner = new Runner(scope, (Script) args[0]);
        } else {
            throw reportRuntimeError("msg.spawn.args");
        }
        runner.factory = cx.getFactory();
        Thread thread = new Thread(runner);
        thread.start();
        return thread;
    }

    /**
     * The sync function creates a synchronized function (in the sense
     * of a Java synchronized method) from an existing function. The
     * new function synchronizes on the <code>this</code> object of
     * its invocation.
     * js> var o = { f : sync(function(x) {
     *       print("entry");
     *       Packages.java.lang.Thread.sleep(x*1000);
     *       print("exit");
     *     })};
     * js> spawn(function() {o.f(5);});
     * Thread[Thread-0,5,main]
     * entry
     * js> spawn(function() {o.f(5);});
     * Thread[Thread-1,5,main]
     * js>
     * exit
     * entry
     * exit
     */
    public static Object sync(Context cx, Scriptable thisObj, Object[] args,
                              Function funObj)
    {
        if (args.length == 1 && args[0] instanceof Function) {
            return new Synchronizer((Function)args[0]);
        }
        else {
            throw reportRuntimeError("msg.sync.args");
        }
    }

    /**
     * Execute the specified command with the given argument and options
     * as a separate process and return the exit status of the process.
     * <p>
     * Usage:
     * <pre>
     * runCommand(command)
     * runCommand(command, arg1, ..., argN)
     * runCommand(command, arg1, ..., argN, options)
     * </pre>
     * All except the last arguments to runCommand are converted to strings
     * and denote command name and its arguments. If the last argument is a
     * JavaScript object, it is an option object. Otherwise it is converted to
     * string denoting the last argument and options objects assumed to be
     * empty.
     * Te following properties of the option object are processed:
     * <ul>
     * <li><tt>args</tt> - provides an array of additional command arguments
     * <li><tt>env</tt> - explicit environment object. All its enumeratable
     *   properties define the corresponding environment variable names.
     * <li><tt>input</tt> - the process input. If it is not
     *   java.io.InputStream, it is converted to string and sent to the process
     *   as its input. If not specified, no input is provided to the process.
     * <li><tt>output</tt> - the process output instead of
     *   java.lang.System.out. If it is not instance of java.io.OutputStream,
     *   the process output is read, converted to a string, appended to the
     *   output property value converted to string and put as the new value of
     *   the output property.
     * <li><tt>err</tt> - the process error output instead of
     *   java.lang.System.err. If it is not instance of java.io.OutputStream,
     *   the process error output is read, converted to a string, appended to
     *   the err property value converted to string and put as the new
     *   value of the err property.
     * </ul>
     */
    public static Object runCommand(Context cx, Scriptable thisObj,
                                    Object[] args, Function funObj)
        throws IOException
    {
        int L = args.length;
        if (L == 0 || (L == 1 && args[0] instanceof Scriptable)) {
            throw reportRuntimeError("msg.runCommand.bad.args");
        }

        InputStream in = null;
        OutputStream out = null, err = null;
        ByteArrayOutputStream outBytes = null, errBytes = null;
        Object outObj = null, errObj = null;
        String[] environment = null;
        Scriptable params = null;
        Object[] addArgs = null;
        if (args[L - 1] instanceof Scriptable) {
            params = (Scriptable)args[L - 1];
            --L;
            Object envObj = ScriptableObject.getProperty(params, "env");
            if (envObj != Scriptable.NOT_FOUND) {
                if (envObj == null) {
                    environment = new String[0];
                } else {
                    if (!(envObj instanceof Scriptable)) {
                        throw reportRuntimeError("msg.runCommand.bad.env");
                    }
                    Scriptable envHash = (Scriptable)envObj;
                    Object[] ids = ScriptableObject.getPropertyIds(envHash);
                    environment = new String[ids.length];
                    for (int i = 0; i != ids.length; ++i) {
                        Object keyObj = ids[i], val;
                        String key;
                        if (keyObj instanceof String) {
                            key = (String)keyObj;
                            val = ScriptableObject.getProperty(envHash, key);
                        } else {
                            int ikey = ((Number)keyObj).intValue();
                            key = Integer.toString(ikey);
                            val = ScriptableObject.getProperty(envHash, ikey);
                        }
                        if (val == ScriptableObject.NOT_FOUND) {
                            val = Undefined.instance;
                        }
                        environment[i] = key+'='+ScriptRuntime.toString(val);
                    }
                }
            }
            Object inObj = ScriptableObject.getProperty(params, "input");
            if (inObj != Scriptable.NOT_FOUND) {
                in = toInputStream(inObj);
            }
            outObj = ScriptableObject.getProperty(params, "output");
            if (outObj != Scriptable.NOT_FOUND) {
                out = toOutputStream(outObj);
                if (out == null) {
                    outBytes = new ByteArrayOutputStream();
                    out = outBytes;
                }
            }
            errObj = ScriptableObject.getProperty(params, "err");
            if (errObj != Scriptable.NOT_FOUND) {
                err = toOutputStream(errObj);
                if (err == null) {
                    errBytes = new ByteArrayOutputStream();
                    err = errBytes;
                }
            }
            Object addArgsObj = ScriptableObject.getProperty(params, "args");
            if (addArgsObj != Scriptable.NOT_FOUND) {
                Scriptable s = Context.toObject(addArgsObj,
                                                getTopLevelScope(thisObj));
                addArgs = cx.getElements(s);
            }
        }
        Global global = getInstance(funObj);
        if (out == null) {
            out = (global != null) ? global.getOut() : System.out;
        }
        if (err == null) {
            err = (global != null) ? global.getErr() : System.err;
        }
        // If no explicit input stream, do not send any input to process,
        // in particular, do not use System.in to avoid deadlocks
        // when waiting for user input to send to process which is already
        // terminated as it is not always possible to interrupt read method.

        String[] cmd = new String[(addArgs == null) ? L : L + addArgs.length];
        for (int i = 0; i != L; ++i) {
            cmd[i] = ScriptRuntime.toString(args[i]);
        }
        if (addArgs != null) {
            for (int i = 0; i != addArgs.length; ++i) {
                cmd[L + i] = ScriptRuntime.toString(addArgs[i]);
            }
        }

        int exitCode = runProcess(cmd, environment, in, out, err);
        if (outBytes != null) {
            String s = ScriptRuntime.toString(outObj) + outBytes.toString();
            ScriptableObject.putProperty(params, "output", s);
        }
        if (errBytes != null) {
            String s = ScriptRuntime.toString(errObj) + errBytes.toString();
            ScriptableObject.putProperty(params, "err", s);
        }

        return new Integer(exitCode);
    }

    /**
     * The seal function seals all supplied arguments.
     */
    public static void seal(Context cx, Scriptable thisObj, Object[] args,
                            Function funObj)
    {
        for (int i = 0; i != args.length; ++i) {
            Object arg = args[i];
            if (!(arg instanceof ScriptableObject) || arg == Undefined.instance)
            {
                if (!(arg instanceof Scriptable) || arg == Undefined.instance)
                {
                    throw reportRuntimeError("msg.shell.seal.not.object");
                } else {
                    throw reportRuntimeError("msg.shell.seal.not.scriptable");
                }
            }
        }

        for (int i = 0; i != args.length; ++i) {
            Object arg = args[i];
            ((ScriptableObject)arg).sealObject();
        }
    }

    /**
     * The readFile reads the given file context and convert it to a string
     * using the specified character coding or default character coding if
     * explicit coding argument is not given.
     * <p>
     * Usage:
     * <pre>
     * readFile(filePath)
     * readFile(filePath, charCoding)
     * </pre>
     * The first form converts file's context to string using the default
     * character coding.
     */
    public static Object readFile(Context cx, Scriptable thisObj, Object[] args,
                                  Function funObj)
        throws IOException
    {
        if (args.length == 0) {
            throw reportRuntimeError("msg.shell.readFile.bad.args");
        }
        String path = ScriptRuntime.toString(args[0]);
        String charCoding = null;
        if (args.length >= 2) {
            charCoding = ScriptRuntime.toString(args[1]);
        }

        return readUrl(path, charCoding, true);
    }

    /**
     * The readUrl opens connection to the given URL, read all its data
     * and converts them to a string
     * using the specified character coding or default character coding if
     * explicit coding argument is not given.
     * <p>
     * Usage:
     * <pre>
     * readUrl(url)
     * readUrl(url, charCoding)
     * </pre>
     * The first form converts file's context to string using the default
     * charCoding.
     */
    public static Object readUrl(Context cx, Scriptable thisObj, Object[] args,
                                 Function funObj)
        throws IOException
    {
        if (args.length == 0) {
            throw reportRuntimeError("msg.shell.readUrl.bad.args");
        }
        String url = ScriptRuntime.toString(args[0]);
        String charCoding = null;
        if (args.length >= 2) {
            charCoding = ScriptRuntime.toString(args[1]);
        }

        return readUrl(url, charCoding, false);
    }

    /**
     * Convert the argumnet to int32 number.
     */
    public static Object toint32(Context cx, Scriptable thisObj, Object[] args,
                                 Function funObj)
    {
        Object arg = (args.length != 0 ? args[0] : Undefined.instance);
        if (arg instanceof Integer)
            return arg;
        return ScriptRuntime.wrapInt(ScriptRuntime.toInt32(arg));
    }

    public InputStream getIn() {
        return inStream == null ? System.in : inStream;
    }

    public void setIn(InputStream in) {
        inStream = in;
    }

    public PrintStream getOut() {
        return outStream == null ? System.out : outStream;
    }

    public void setOut(PrintStream out) {
        outStream = out;
    }

    public PrintStream getErr() {
        return errStream == null ? System.err : errStream;
    }

    public void setErr(PrintStream err) {
        errStream = err;
    }

    public void setSealedStdLib(boolean value)
    {
        sealedStdLib = value;
    }

    private static Global getInstance(Function function)
    {
        Scriptable scope = function.getParentScope();
        if (!(scope instanceof Global))
            throw reportRuntimeError("msg.bad.shell.function.scope",
                                     String.valueOf(scope));
        return (Global)scope;
    }

    /**
     * If any of in, out, err is null, the corresponding process stream will
     * be closed immediately, otherwise it will be closed as soon as
     * all data will be read from/written to process
     */
    private static int runProcess(String[] cmd, String[] environment,
                                  InputStream in, OutputStream out,
                                  OutputStream err)
        throws IOException
    {
        Process p;
        if (environment == null) {
            p = Runtime.getRuntime().exec(cmd);
        } else {
            p = Runtime.getRuntime().exec(cmd, environment);
        }
        PipeThread inThread = null, errThread = null;
        try {