Application: gvSIG desktop

    private boolean enableExceptions;

        this.enableExceptions = false;

    public boolean isEnableExceptions() {

        return enableExceptions;

    }

    public void setEnableExceptions(boolean enableExceptions) {

        this.enableExceptions = enableExceptions;

    }

            if( this.enableExceptions ) {

                throw ex;

            }

import org.apache.commons.lang3.ArrayUtils;

            descriptor.setDataProfileName(

                StringUtils.defaultIfBlank((String) this.cboDataProfile.getSelectedItem(),null)

            );

                    if( !emulator.isValid() ) {

                        ThreadSafeDialogsManager dialogs = ToolsSwingLocator.getThreadSafeDialogsManager();

                        dialogs.messageDialog(

                                i18n.getTranslation("_The_expression_of_virtual_field_is_not_valid")+

                                    "\n"+

                                    emulator.getErrorMessage(), 

                                i18n.getTranslation("_Warning"), 

                                JOptionPane.WARNING_MESSAGE

                        );

                        return null;

                    }

                    for (String requiredFieldName : emulator.getRequiredFieldNames()) {

                        if( StringUtils.equalsIgnoreCase(requiredFieldName, descriptor.getName()) ) {

                            ThreadSafeDialogsManager dialogs = ToolsSwingLocator.getThreadSafeDialogsManager();

                            dialogs.messageDialog(

                                    i18n.getTranslation("_The_expression_of_virtual_field_is_not_valid")+

                                        "\n\n"+

                                        i18n.getTranslation("_The_expression_contains_a_reference_to_itself"), 

                                    i18n.getTranslation("_Warning"), 

                                    JOptionPane.WARNING_MESSAGE

                            );

                            return null;

                        }

                    }

                    //

                    // No se porque esto de abajo no funciona.

                    // Nunca se lanza la excepcion en el get(Feature) de

                    // DefaultFeatureAttributeEmulatorExpression.

                    //

//                    try {

//                        emulator.setEnableExceptions(true);

//                        descriptor.setFeatureAttributeEmulator(emulator);

//                        this.pickerVirtualField.getPreviewSymbolTable().value(descriptor.getName());

//                    } catch(Throwable ex) {

//                        emulator.setEnableExceptions(false);

//                        descriptor.setFeatureAttributeEmulator(null);

//                        ThreadSafeDialogsManager dialogs = ToolsSwingLocator.getThreadSafeDialogsManager();

//                        dialogs.messageDialog(

//                                i18n.getTranslation("_The_expression_of_virtual_field_is_not_valid")+

//                                    "\n"+

//                                    ex.getMessage(), 

//                                i18n.getTranslation("_Warning"), 

//                                JOptionPane.WARNING_MESSAGE

//                        );

//                        return null;

//                    } finally {

//                        emulator.setEnableExceptions(false);

//                    }

    public void setEnableExceptions(boolean enableException);

    public boolean isEnableExceptions();

_The_expression_of_virtual_field_is_not_valid=La expresi\u00f3n del campo virtual no es valida.

_The_expression_contains_a_reference_to_itself=La expresi\u00f3n tiene una referencia a ella misma.

_See_log_for_details=See log for details.

_The_expression_of_virtual_field_is_not_valid=The expression of virtual field es not valid.

_The_expression_contains_a_reference_to_itself=The expression contains a reference to itself.

    public interface RecursionControlSupport {

        public boolean enterCode(int max);

        public void exitCode();

        public void resetRecursionState();

    }

    private class RecursionSupport implements RecursionControlSupport {

        private int counter;

        public RecursionSupport() {

            this.counter = 0;

        }

        @Override

        public boolean enterCode(int max) {

            this.counter += 1;

            return this.counter < max;

        }

        @Override

        public void exitCode() {

            this.counter -= 1;

        }

        @Override

        public void resetRecursionState() {

            this.counter = 0;

        }

    }

    public class BaseIdentifier extends BaseCode implements Identifier, RecursionControlSupport {

        private String name;

        private RecursionSupport recursionSupport;

            this.recursionSupport = new RecursionSupport();

        @Override

        public boolean enterCode(int max) {

            return this.recursionSupport.enterCode(max);

        }

        @Override

        public void exitCode() {

            this.recursionSupport.exitCode();

        }

        @Override

        public void resetRecursionState() {

            this.recursionSupport.resetRecursionState();

        }

    public class BaseCaller extends BaseCode implements Caller, RecursionControlSupport {

        private RecursionSupport recursionSupport;

            this.recursionSupport = new RecursionSupport();

        @Override

        public boolean enterCode(int max) {

            return this.recursionSupport.enterCode(max);

        }

        @Override

        public void exitCode() {

            this.recursionSupport.exitCode();

        }

        @Override

        public void resetRecursionState() {

            this.recursionSupport.resetRecursionState();

        }

import org.gvsig.expressionevaluator.impl.DefaultCodeBuilder.RecursionControlSupport;

    public static int DEFAULT_MAX_RECURSION_LIMIT = 20;

    private int maxRecursionLimit;

        this.maxRecursionLimit = DEFAULT_MAX_RECURSION_LIMIT;

    public int getMaxRecursionLimit() {

        return this.maxRecursionLimit;

    }

    public void setMaxRecursionLimit(int limit) {

        this.maxRecursionLimit = limit;

    }

        RecursionControlSupport recursionControl = null;

        if( code instanceof RecursionControlSupport ) {

            recursionControl = (RecursionControlSupport) code;

            if( !recursionControl.enterCode(this.maxRecursionLimit) ) {

                recursionControl.resetRecursionState();

                throw new ExpressionRuntimeException(code, I18N.Maximum_recursion_limit_exceeded());

            }

        }

        Object value = null;

        try {

            switch( code.code() ) {

            case Code.CONSTANT:

                value = ((Constant) code).value();

                break;

            case Code.IDENTIFIER:

                String name = ((Identifier) code).name();

                if( !this.getSymbolTable().exists(name) ) {

                    throw new ExpressionRuntimeException(

                            code, 

                            I18N.Undefined_variable_XIdentifierX(name),

                            I18N.Use_single_quotes_to_enter_literal_strings()

                    );

                }

                value = this.getSymbolTable().value(name);

                break;

            case Code.METHOD: {

                    Method method = (Method) code;

                    Function function = method.function();

                    if( function == null ) {

                        Object obj = this.runCode(method.obj());

                        if( obj == null ) {

                            throw new NullPointerException("An object pointer was expected to invoke method "+method.methodname()+" and a null was received");

                        }

                        method.function(new CallMethodFunction(obj, method.methodname()));

            case Code.CALLER:

                Caller caller = (Caller) code;

                Function function = caller.function();

                    function = this.getSymbolTable().function(caller.name());

                    if( function == null ) {

                        throw new ExpressionRuntimeException(code, I18N.Undefined_function_XIdentifierX(caller.name()));

                    }

                    caller.function(function);

                Codes args = caller.args();

                try {

                    switch( caller.type() ) {

                    case Caller.UNARY_OPERATOR:

                        if( args == null || args.size() != 1 ) {

                            throw new ExpressionRuntimeException(code, I18N.Number_of_argument_mistmatch_in_operator_XIdentifierX_expected_1_got_XargcX(function.name(),args==null?0:args.size()));

                        }

                        value = ((UnaryOperator) function).call(this, runCode(args.get(0)));

                        break;

                    case Caller.BINARY_OPERATOR:

                        if( args == null || args.size() != 2 ) {

                            throw new ExpressionRuntimeException(code, I18N.Number_of_argument_mistmatch_in_operator_XIdentifierX_expected_2_got_XargcX(function.name(),args==null?0:args.size()));

                        }

                        value = ((BinaryOperator) function).call(this, runCode(args.get(0)), runCode(args.get(1)));

                        break;

                    case Caller.FUNCTION:

                        int argc = (args == null) ? 0 : args.size();

                        if( !function.argc().contains(argc) ) {

                            throw new ExpressionRuntimeException(code, I18N.Number_of_argument_mistmatch_in_function_XIdentifierX_expected_XexpectedX_got_XfoundX(function.name(),function.argc(),argc));

                        }

                        if( function.useArgumentsInsteadObjects() ) {

                            value = function.call(this, args);

                        } else {

                            Object[] argvalues = new Object[argc];

                            if( args != null ) {

                                int i = 0;

                                for( Code arg : args ) {

                                    argvalues[i++] = runCode(arg);

                                }

                            value = function.call(this, argvalues);

                } catch (RuntimeException ex) {

                    throw ex;

                } catch (Exception ex) {

                    String argsstr = "???";

                    try {

                        argsstr = args.toString();

                    } catch(Exception ex2) {

                        // Ignore.

                    }

                    throw new ExpressionRuntimeException(code, I18N.Problems_calling_function_XIdentifierX_with_args_XargsX(function.name(),argsstr));

                break;

        } finally {

            this.currentCode = null;

            if( recursionControl!=null ) {

                recursionControl.exitCode();

            }

    static String Maximum_recursion_limit_exceeded() {

        return "Maximum recursion limit exceeded.";

    }