dim.java

java中比较著名的js引擎当属mozilla开源的rhino

            Enumeration e = functionNames.keys();
            a = new String[functionNames.size()];
            int i = 0;
            while (e.hasMoreElements()) {
                a[i++] = (String)e.nextElement();
            }
        }
        return a;
    }

    /**
     * Returns the FunctionSource object for the function with the given name.
     */
    public FunctionSource functionSourceByName(String functionName) {
        return (FunctionSource)functionNames.get(functionName);
    }

    /**
     * Returns the SourceInfo object for the given URL.
     */
    public SourceInfo sourceInfo(String url) {
        return (SourceInfo)urlToSourceInfo.get(url);
    }

    /**
     * Returns the source URL for the given script or function.
     */
    private String getNormalizedUrl(DebuggableScript fnOrScript) {
        String url = fnOrScript.getSourceName();
        if (url == null) { url = "<stdin>"; }
        else {
            // Not to produce window for eval from different lines,
            // strip line numbers, i.e. replace all #[0-9]+\(eval\) by
            // (eval)
            // Option: similar teatment for Function?
            char evalSeparator = '#';
            StringBuffer sb = null;
            int urlLength = url.length();
            int cursor = 0;
            for (;;) {
                int searchStart = url.indexOf(evalSeparator, cursor);
                if (searchStart < 0) {
                    break;
                }
                String replace = null;
                int i = searchStart + 1;
                boolean hasDigits = false;
                while (i != urlLength) {
                    int c = url.charAt(i);
                    if (!('0' <= c && c <= '9')) {
                        break;
                    }
                    ++i;
                }
                if (i != searchStart + 1) {
                    // i points after #[0-9]+
                    if ("(eval)".regionMatches(0, url, i, 6)) {
                        cursor = i + 6;
                        replace = "(eval)";
                    }
                }
                if (replace == null) {
                    break;
                }
                if (sb == null) {
                    sb = new StringBuffer();
                    sb.append(url.substring(0, searchStart));
                }
                sb.append(replace);
            }
            if (sb != null) {
                if (cursor != urlLength) {
                    sb.append(url.substring(cursor));
                }
                url = sb.toString();
            }
        }
        return url;
    }

    /**
     * Returns an array of all functions in the given script.
     */
    private static DebuggableScript[] getAllFunctions
            (DebuggableScript function) {
        ObjArray functions = new ObjArray();
        collectFunctions_r(function, functions);
        DebuggableScript[] result = new DebuggableScript[functions.size()];
        functions.toArray(result);
        return result;
    }

    /**
     * Helper function for {@link #getAllFunctions(DebuggableScript)}.
     */
    private static void collectFunctions_r(DebuggableScript function,
                                             ObjArray array) {
        array.add(function);
        for (int i = 0; i != function.getFunctionCount(); ++i) {
            collectFunctions_r(function.getFunction(i), array);
        }
    }

    /**
     * Clears all breakpoints.
     */
    public void clearAllBreakpoints() {
        Enumeration e = urlToSourceInfo.elements();
        while (e.hasMoreElements()) {
            SourceInfo si = (SourceInfo)e.nextElement();
            si.removeAllBreakpoints();
        }
    }

    /**
     * Called when a breakpoint has been hit.
     */
    private void handleBreakpointHit(StackFrame frame, Context cx) {
        breakFlag = false;
        interrupted(cx, frame, null);
    }

    /**
     * Called when a script exception has been thrown.
     */
    private void handleExceptionThrown(Context cx, Throwable ex,
                                         StackFrame frame) {
        if (breakOnExceptions) {
            ContextData cd = frame.contextData();
            if (cd.lastProcessedException != ex) {
                interrupted(cx, frame, ex);
                cd.lastProcessedException = ex;
            }
        }
    }

    /**
     * Returns the current ContextData object.
     */
    public ContextData currentContextData() {
        return interruptedContextData;
    }

    /**
     * Sets the action to perform to end interruption.
     */
    public void setReturnValue(int returnValue) {
        synchronized (monitor) {
            this.returnValue = returnValue;
            monitor.notify();
        }
    }

    /**
     * Resumes execution of script.
     */
    public void go() {
        synchronized (monitor) {
            this.returnValue = GO;
            monitor.notifyAll();
        }
    }

    /**
     * Evaluates the given script.
     */
    public String eval(String expr) {
        String result = "undefined";
        if (expr == null) {
            return result;
        }
        ContextData contextData = currentContextData();
        if (contextData == null || frameIndex >= contextData.frameCount()) {
            return result;
        }
        StackFrame frame = contextData.getFrame(frameIndex);
        if (contextData.eventThreadFlag) {
            Context cx = Context.getCurrentContext();
            result = do_eval(cx, frame, expr);
        } else {
            synchronized (monitor) {
                if (insideInterruptLoop) {
                    evalRequest = expr;
                    evalFrame = frame;
                    monitor.notify();
                    do {
                        try {
                            monitor.wait();
                        } catch (InterruptedException exc) {
                            Thread.currentThread().interrupt();
                            break;
                        }
                    } while (evalRequest != null);
                    result = evalResult;
                }
            }
        }
        return result;
    }

    /**
     * Compiles the given script.
     */
    public void compileScript(String url, String text) {
        DimIProxy action = new DimIProxy(this, IPROXY_COMPILE_SCRIPT);
        action.url = url;
        action.text = text;
        action.withContext();
    }

    /**
     * Evaluates the given script.
     */
    public void evalScript(final String url, final String text) {
        DimIProxy action = new DimIProxy(this, IPROXY_EVAL_SCRIPT);
        action.url = url;
        action.text = text;
        action.withContext();
    }

    /**
     * Converts the given script object to a string.
     */
    public String objectToString(Object object) {
        DimIProxy action = new DimIProxy(this, IPROXY_OBJECT_TO_STRING);
        action.object = object;
        action.withContext();
        return action.stringResult;
    }

    /**
     * Returns whether the given string is syntactically valid script.
     */
    public boolean stringIsCompilableUnit(String str) {
        DimIProxy action = new DimIProxy(this, IPROXY_STRING_IS_COMPILABLE);
        action.text = str;
        action.withContext();
        return action.booleanResult;
    }

    /**
     * Returns the value of a property on the given script object.
     */
    public Object getObjectProperty(Object object, Object id) {
        DimIProxy action = new DimIProxy(this, IPROXY_OBJECT_PROPERTY);
        action.object = object;
        action.id = id;
        action.withContext();
        return action.objectResult;
    }

    /**
     * Returns an array of the property names on the given script object.
     */
    public Object[] getObjectIds(Object object) {
        DimIProxy action = new DimIProxy(this, IPROXY_OBJECT_IDS);
        action.object = object;
        action.withContext();
        return action.objectArrayResult;
    }

    /**
     * Returns the value of a property on the given script object.
     */
    private Object getObjectPropertyImpl(Context cx, Object object,
                                           Object id) {
        Scriptable scriptable = (Scriptable)object;
        Object result;
        if (id instanceof String) {
            String name = (String)id;
            if (name.equals("this")) {
                result = scriptable;
            } else if (name.equals("__proto__")) {
                result = scriptable.getPrototype();
            } else if (name.equals("__parent__")) {
                result = scriptable.getParentScope();
            } else {
                result = ScriptableObject.getProperty(scriptable, name);
                if (result == ScriptableObject.NOT_FOUND) {
                    result = Undefined.instance;
                }
            }
        } else {
            int index = ((Integer)id).intValue();
            result = ScriptableObject.getProperty(scriptable, index);
            if (result == ScriptableObject.NOT_FOUND) {
                result = Undefined.instance;
            }
        }
        return result;
    }

    /**
     * Returns an array of the property names on the given script object.
     */
    private Object[] getObjectIdsImpl(Context cx, Object object) {
        if (!(object instanceof Scriptable) || object == Undefined.instance) {
            return Context.emptyArgs;
        }

        Object[] ids;
        Scriptable scriptable = (Scriptable)object;
        if (scriptable instanceof DebuggableObject) {
            ids = ((DebuggableObject)scriptable).getAllIds();
        } else {
            ids = scriptable.getIds();
        }

        Scriptable proto = scriptable.getPrototype();
        Scriptable parent = scriptable.getParentScope();
        int extra = 0;
        if (proto != null) {
            ++extra;
        }
        if (parent != null) {
            ++extra;
        }
        if (extra != 0) {
            Object[] tmp = new Object[extra + ids.length];
            System.arraycopy(ids, 0, tmp, extra, ids.length);
            ids = tmp;
            extra = 0;
            if (proto != null) {
                ids[extra++] = "__proto__";
            }
            if (parent != null) {
                ids[extra++] = "__parent__";
            }
        }

        return ids;
    }

    /**
     * Interrupts script execution.
     */
    private void interrupted(Context cx, final StackFrame frame,
                               Throwable scriptException) {
        ContextData contextData = frame.contextData();
        int line = frame.getLineNumber();
        String url = frame.getUrl();
        boolean eventThreadFlag = callback.isGuiEventThread();
        contextData.eventThreadFlag = eventThreadFlag;

        boolean recursiveEventThreadCall = false;

interruptedCheck:
        synchronized (eventThreadMonitor) {
            if (eventThreadFlag) {
                if (interruptedContextData != null) {
                    recursiveEventThreadCall = true;
                    break interruptedCheck;
                }
            } else {
                while (interruptedContextData != null) {
                    try {
                        eventThreadMonitor.wait();
                    } catch (InterruptedException exc) {
                        return;
                    }
                }
            }
            interruptedContextData = contextData;
        }

        if (recursiveEventThreadCall) {
            // XXX: For now the following is commented out as on Linux
            // too deep recursion of dispatchNextGuiEvent causes GUI lockout.
            // Note: it can make GUI unresponsive if long-running script
            // will be called on GUI thread while processing another interrupt
            if (false) {
               // Run event dispatch until gui sets a flag to exit the initial
               // call to interrupted.
                while (this.returnValue == -1) {
                    try {
                        callback.dispatchNextGuiEvent();
                    } catch (InterruptedException exc) {
                    }
                }
            }
            return;
        }

        if (interruptedContextData == null) Kit.codeBug();

        try {
            do {
                int frameCount = contextData.frameCount();
                this.frameIndex = frameCount -1;

                final String threadTitle = Thread.currentThread().toString();