Java 类javax.el.ExpressionFactory 实例源码

@Test
public void bug56185() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanC beanC = new TesterBeanC();
    ValueExpression var =
        factory.createValueExpression(beanC, TesterBeanC.class);
    context.getVariableMapper().setVariable("myBean", var);

    ValueExpression ve = factory.createValueExpression(context,
        "${(myBean.int1 > 1 and myBean.myBool) or "+
        "((myBean.myBool or myBean.myBool1) and myBean.int1 > 1)}",
        Boolean.class);
    assertEquals(Boolean.FALSE, ve.getValue(context));
    beanC.setInt1(2);
    beanC.setMyBool1(true);
    assertEquals(Boolean.TRUE, ve.getValue(context));
}

public Expression parseExpression(String expression,
                                  Class expectedType,
                                  FunctionMapper fMapper )
        throws ELException {

    ExpressionFactory fac = ExpressionFactory.newInstance();
    javax.el.ValueExpression expr;
    ELContextImpl elContext = new ELContextImpl(null);
    javax.el.FunctionMapper fm = new FunctionMapperWrapper(fMapper);
    elContext.setFunctionMapper(fm);
    try {
        expr = fac.createValueExpression(
                       elContext,
                       expression, expectedType);
    } catch (javax.el.ELException ex) {
        throw new ELException(ex);
    }
    return new ExpressionImpl(expr, pageContext);
}

@Test
public void testJavaKeyWordSuffix() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setInt("five");
    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("beanA", var);

    // Should fail
    Exception e = null;
    try {
        factory.createValueExpression(context, "${beanA.int}",
                String.class);
    } catch (ELException ele) {
        e = ele;
    }
    assertNotNull(e);
}

@Test
public void testJavaKeyWordIdentifier() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setInt("five");
    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("this", var);

    // Should fail
    Exception e = null;
    try {
        factory.createValueExpression(context, "${this}", String.class);
    } catch (ELException ele) {
        e = ele;
    }
    assertNotNull(e);
}

private void doTestBug56179(int parenthesesCount, String innerExpr) {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    ValueExpression var =
        factory.createValueExpression(Boolean.TRUE, Boolean.class);
    context.getVariableMapper().setVariable("test", var);

    StringBuilder expr = new StringBuilder();
    expr.append("${");
    for (int i = 0; i < parenthesesCount; i++) {
        expr.append("(");
    }
    expr.append(innerExpr);
    for (int i = 0; i < parenthesesCount; i++) {
        expr.append(")");
    }
    expr.append("}");
    ValueExpression ve = factory.createValueExpression(
            context, expr.toString(), String.class);

    String result = (String) ve.getValue(context);
    assertEquals("true", result);
}

private void testExpression(String expression, String expected) {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    ValueExpression ve = factory.createValueExpression(
            context, expression, String.class);

    String result = (String) ve.getValue(context);
    assertEquals(expected, result);
}

@Test
public void testGetValueReference() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanB beanB = new TesterBeanB();
    beanB.setName("Tomcat");
    ValueExpression var =
        factory.createValueExpression(beanB, TesterBeanB.class);
    context.getVariableMapper().setVariable("beanB", var);

    ValueExpression ve = factory.createValueExpression(
            context, "${beanB.name}", String.class);

    // First check the basics work
    String result = (String) ve.getValue(context);
    assertEquals("Tomcat", result);

    // Now check the value reference
    ValueReference vr = ve.getValueReference(context);
    assertNotNull(vr);

    assertEquals(beanB, vr.getBase());
    assertEquals("name", vr.getProperty());
}

@Test
public void testBug50105() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterEnum testEnum = TesterEnum.APPLE;

    ValueExpression var =
        factory.createValueExpression(testEnum, TesterEnum.class);
    context.getVariableMapper().setVariable("testEnum", var);

    // When coercing an Enum to a String, name() should always be used.
    ValueExpression ve1 = factory.createValueExpression(
            context, "${testEnum}", String.class);
    String result1 = (String) ve1.getValue(context);
    assertEquals("APPLE", result1);

    ValueExpression ve2 = factory.createValueExpression(
            context, "foo${testEnum}bar", String.class);
    String result2 = (String) ve2.getValue(context);
    assertEquals("fooAPPLEbar", result2);
}

@Test
public void testBug51177ObjectMap() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    Object o1 = "String value";
    Object o2 = Integer.valueOf(32);

    Map<Object,Object> map = new HashMap<Object,Object>();
    map.put("key1", o1);
    map.put("key2", o2);

    ValueExpression var =
        factory.createValueExpression(map, Map.class);
    context.getVariableMapper().setVariable("map", var);

    ValueExpression ve1 = factory.createValueExpression(
            context, "${map.key1}", Object.class);
    ve1.setValue(context, o2);
    assertEquals(o2, ve1.getValue(context));

    ValueExpression ve2 = factory.createValueExpression(
            context, "${map.key2}", Object.class);
    ve2.setValue(context, o1);
    assertEquals(o1, ve2.getValue(context));
}

@Test
public void testBug51177ObjectList() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    Object o1 = "String value";
    Object o2 = Integer.valueOf(32);

    List<Object> list = new ArrayList<Object>();
    list.add(0, o1);
    list.add(1, o2);

    ValueExpression var =
        factory.createValueExpression(list, List.class);
    context.getVariableMapper().setVariable("list", var);

    ValueExpression ve1 = factory.createValueExpression(
            context, "${list[0]}", Object.class);
    ve1.setValue(context, o2);
    assertEquals(o2, ve1.getValue(context));

    ValueExpression ve2 = factory.createValueExpression(
            context, "${list[1]}", Object.class);
    ve2.setValue(context, o1);
    assertEquals(o1, ve2.getValue(context));
}

/**
 * Test returning an empty list as a bean property.
 */
@Test
public void testBug51544Bean() throws Exception {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setValList(Collections.emptyList());

    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("beanA", var);

    ValueExpression ve = factory.createValueExpression(
            context, "${beanA.valList.size()}", Integer.class);

    Integer result = (Integer) ve.getValue(context);
    assertEquals(Integer.valueOf(0), result);
}

/**
 * Test using list directly as variable.
 */
@Test
public void testBug51544Direct() throws Exception {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    List<?> list = Collections.emptyList();

    ValueExpression var =
        factory.createValueExpression(list, List.class);
    context.getVariableMapper().setVariable("list", var);

    ValueExpression ve = factory.createValueExpression(
            context, "${list.size()}", Integer.class);

    Integer result = (Integer) ve.getValue(context);
    assertEquals(Integer.valueOf(0), result);
}

private static ValueExpression _createValueExpressionFromApplication(
  String expression,
  Class<?> expectedType)
{
  ApplicationFactory factory = (ApplicationFactory)
    FactoryFinder.getFactory(FactoryFinder.APPLICATION_FACTORY);
  if (factory != null)
  {
    Application application = factory.getApplication();
    if (application != null)
    {
      ELContext elContext = _getELContext(application);

      ExpressionFactory expressionFactory = application.getExpressionFactory();
      if (expressionFactory != null)
      {
        return expressionFactory.createValueExpression(elContext, expression, expectedType);
      }
    }
  }

  return null;
}

public static Object convertToType(Object value, Class desiredClass)
{
    if (value == null)
    {
        return null;
    }

    try
    {
        ExpressionFactory expFactory = FacesContext.getCurrentInstance().getApplication().getExpressionFactory();
        return expFactory.coerceToType(value, desiredClass);
    }
    catch (Exception e)
    {
        String message = "Cannot coerce " + value.getClass().getName()
                         + " to " + desiredClass.getName();
        log.log(Level.SEVERE, message, e);
        throw new FacesException(message, e);
    }
}

public void actionListener(ActionEvent event)
{
  String value = _actionListener;
  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();

    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value, Void.TYPE,
            new Class<?>[]
            { ActionEvent.class });
    methodExpression.invoke(context, new Object[]
    { event });
  }

}

public String doAction()
{
  String value = _action;

  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();
    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value,
            String.class, new Class<?>[]
            {});
    value = (String) methodExpression.invoke(context, null);
  }

  // Post me as the selected Node for the request
  postSelectedNode(this);

  return value;
}

/**
  * Gets the value of the node's action property.  The action attr value
  * could be one of 2 things:
  * 1) An EL expression
  * 2) An outcome referencing a navigation rule in the faces_config file.
  * 
  * Since this method is called only when an ItemNode is clicked, the model 
  * is notified that this node is the currently selected node.
  * 
  * @return String value of the ItemNode's "action" property.
  */
@Override
public String doAction()
{
  String value = _action;

  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();
    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value,
            String.class, new Class<?>[]
            {});
    value = (String) methodExpression.invoke(context, null);
  }

  // Post me as the selected Node for the request
  postSelectedNode(this);

  return value;
}

public void actionListener(ActionEvent event)
{
  String value = _actionListener;
  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();

    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value, Void.TYPE,
            new Class<?>[]
            { ActionEvent.class });
    methodExpression.invoke(context, new Object[]{ event });
  }

}

public void actionListener(ActionEvent event)
{
  String value = _actionListener;
  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();

    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value, Void.TYPE,
            new Class<?>[]
            { ActionEvent.class });
    methodExpression.invoke(context, new Object[]
    { event });
  }

}

public String doAction()
{
  String value = _action;

  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();
    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value,
            String.class, new Class<?>[]
            {});
    value = (String) methodExpression.invoke(context, null);
  }

  // Post me as the selected Node for the request
  postSelectedNode(this);

  return value;
}

/**
  * Gets the value of the node's action property.  The action attr value
  * could be one of 2 things:
  * 1) An EL expression
  * 2) An outcome referencing a navigation rule in the faces_config file.
  * 
  * Since this method is called only when an ItemNode is clicked, the model 
  * is notified that this node is the currently selected node.
  * 
  * @return String value of the ItemNode's "action" property.
  */
@Override
public String doAction()
{
  String value = _action;

  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();
    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value,
            String.class, new Class<?>[]
            {});
    value = (String) methodExpression.invoke(context, null);
  }

  // Post me as the selected Node for the request
  postSelectedNode(this);

  return value;
}

public void actionListener(ActionEvent event)
{
  String value = _actionListener;
  if (value != null)
  {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExpressionFactory expressionFactory =
        facesContext.getApplication().getExpressionFactory();
    ELContext context = facesContext.getELContext();

    MethodExpression methodExpression =
        expressionFactory.createMethodExpression(context, value, Void.TYPE,
            new Class<?>[]
            { ActionEvent.class });
    methodExpression.invoke(context, new Object[]{ event });
  }

}

/**
 * Allow node to validate itself
 * 
 * @param ef
 * @param ctx
 * @throws ELException
 */
public void validateEL(ExpressionFactory ef, ELContext ctx)
        throws ELException {
    if (this.el != null) {
        // determine exact type
        ValueExpression ve = ef.createValueExpression(ctx, this.value,
                String.class);
    }
}

@Test
public void testJavaKeyWordSuffix() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setInt("five");
    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("beanA", var);

    // Should fail
    Exception e = null;
    try {
        factory.createValueExpression(context, "${beanA.int}",
                String.class);
    } catch (ELException ele) {
        e = ele;
    }
    assertNotNull(e);
}

@Test
public void testJavaKeyWordIdentifier() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setInt("five");
    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("this", var);

    // Should fail
    Exception e = null;
    try {
        factory.createValueExpression(context, "${this}", String.class);
    } catch (ELException ele) {
        e = ele;
    }
    assertNotNull(e);
}

private void doTestBug56179(int parenthesesCount, String innerExpr) {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    ValueExpression var =
        factory.createValueExpression(Boolean.TRUE, Boolean.class);
    context.getVariableMapper().setVariable("test", var);

    StringBuilder expr = new StringBuilder();
    expr.append("${");
    for (int i = 0; i < parenthesesCount; i++) {
        expr.append("(");
    }
    expr.append(innerExpr);
    for (int i = 0; i < parenthesesCount; i++) {
        expr.append(")");
    }
    expr.append("}");
    ValueExpression ve = factory.createValueExpression(
            context, expr.toString(), String.class);

    String result = (String) ve.getValue(context);
    assertEquals("true", result);
}

@Test
public void bug56185() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanC beanC = new TesterBeanC();
    ValueExpression var =
        factory.createValueExpression(beanC, TesterBeanC.class);
    context.getVariableMapper().setVariable("myBean", var);

    ValueExpression ve = factory.createValueExpression(context,
        "${(myBean.int1 > 1 and myBean.myBool) or "+
        "((myBean.myBool or myBean.myBool1) and myBean.int1 > 1)}",
        Boolean.class);
    assertEquals(Boolean.FALSE, ve.getValue(context));
    beanC.setInt1(2);
    beanC.setMyBool1(true);
    assertEquals(Boolean.TRUE, ve.getValue(context));
}

@Test
public void testGetValueReference() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanB beanB = new TesterBeanB();
    beanB.setName("Tomcat");
    ValueExpression var =
        factory.createValueExpression(beanB, TesterBeanB.class);
    context.getVariableMapper().setVariable("beanB", var);

    ValueExpression ve = factory.createValueExpression(
            context, "${beanB.name}", String.class);

    // First check the basics work
    String result = (String) ve.getValue(context);
    assertEquals("Tomcat", result);

    // Now check the value reference
    ValueReference vr = ve.getValueReference(context);
    assertNotNull(vr);

    assertEquals(beanB, vr.getBase());
    assertEquals("name", vr.getProperty());
}

@Test
public void testBug50105() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterEnum testEnum = TesterEnum.APPLE;

    ValueExpression var =
        factory.createValueExpression(testEnum, TesterEnum.class);
    context.getVariableMapper().setVariable("testEnum", var);

    // When coercing an Enum to a String, name() should always be used.
    ValueExpression ve1 = factory.createValueExpression(
            context, "${testEnum}", String.class);
    String result1 = (String) ve1.getValue(context);
    assertEquals("APPLE", result1);

    ValueExpression ve2 = factory.createValueExpression(
            context, "foo${testEnum}bar", String.class);
    String result2 = (String) ve2.getValue(context);
    assertEquals("fooAPPLEbar", result2);
}

@Test
public void testBug51177ObjectMap() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    Object o1 = "String value";
    Object o2 = Integer.valueOf(32);

    Map<Object,Object> map = new HashMap<Object,Object>();
    map.put("key1", o1);
    map.put("key2", o2);

    ValueExpression var =
        factory.createValueExpression(map, Map.class);
    context.getVariableMapper().setVariable("map", var);

    ValueExpression ve1 = factory.createValueExpression(
            context, "${map.key1}", Object.class);
    ve1.setValue(context, o2);
    assertEquals(o2, ve1.getValue(context));

    ValueExpression ve2 = factory.createValueExpression(
            context, "${map.key2}", Object.class);
    ve2.setValue(context, o1);
    assertEquals(o1, ve2.getValue(context));
}

@Test
public void testBug51177ObjectList() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    Object o1 = "String value";
    Object o2 = Integer.valueOf(32);

    List<Object> list = new ArrayList<Object>();
    list.add(0, o1);
    list.add(1, o2);

    ValueExpression var =
        factory.createValueExpression(list, List.class);
    context.getVariableMapper().setVariable("list", var);

    ValueExpression ve1 = factory.createValueExpression(
            context, "${list[0]}", Object.class);
    ve1.setValue(context, o2);
    assertEquals(o2, ve1.getValue(context));

    ValueExpression ve2 = factory.createValueExpression(
            context, "${list[1]}", Object.class);
    ve2.setValue(context, o1);
    assertEquals(o1, ve2.getValue(context));
}

/**
 * Test returning an empty list as a bean property.
 */
@Test
public void testBug51544Bean() throws Exception {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setValList(Collections.emptyList());

    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("beanA", var);

    ValueExpression ve = factory.createValueExpression(
            context, "${beanA.valList.size()}", Integer.class);

    Integer result = (Integer) ve.getValue(context);
    assertEquals(Integer.valueOf(0), result);
}

/**
 * Test using list directly as variable.
 */
@Test
public void testBug51544Direct() throws Exception {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    List<?> list = Collections.emptyList();

    ValueExpression var =
        factory.createValueExpression(list, List.class);
    context.getVariableMapper().setVariable("list", var);

    ValueExpression ve = factory.createValueExpression(
            context, "${list.size()}", Integer.class);

    Integer result = (Integer) ve.getValue(context);
    assertEquals(Integer.valueOf(0), result);
}

public static MethodExpression getMethodExpression(
                                           String expression,
                                           PageContext pageContext,
                                           FunctionMapper functionMap,
                                           Class expectedType,
                                           Class[] paramTypes) {

    ELContextImpl elctxt = (ELContextImpl)pageContext.getELContext();
    elctxt.setFunctionMapper(functionMap);
    ExpressionFactory expFactory = getExpressionFactory(pageContext);
    return expFactory.createMethodExpression(
                                elctxt,
                                expression,
                                expectedType,
                                paramTypes);
}

protected Object evaluateSimpleExpression(String expression, RenderSession session) {
    if (!expression.startsWith("${"))
        throw new RuntimeException(expression + " is not a simple EL expression, expected to start with ${");
    if (!expression.endsWith("}"))
        throw new RuntimeException(expression + " is not a simple EL expression, expected to end with }");
    ExpressionFactory expressionFactory = elFactory.newExpressionFactory();
    ELContext context = new FauxELContext(elFactory.newElContext(), expressionFactory);
    populateVariables(context, expressionFactory, session);

    expression = Utils.unescapeHtml(expression);
    ValueExpression expr = expressionFactory.createValueExpression(context, expression, Object.class);
    try {
        Object result = expr.getValue(context);
        return result;
    } catch (Exception e) {
        throw new RuntimeException("Error when evaluating expression '" + expression + "'", e);
    }

}

/**
 * Get a config value by first looking at ViewRoot attributes, and then for init parameters.
 * <p>
 * If a value is found, it is resolved as an EL expression
 * *
 *
 * @param context The current FacesContext
 * @param key     The key to lookup
 * @return The resolved value or null if not found
 */
private String getConfigValue(FacesContext context, String key, String defaultValue) {
    UIViewRoot viewRoot = context.getViewRoot();
    Object value = viewRoot.getAttributes().get(key);

    if (value == null)
        value = context.getExternalContext().getInitParameter(key);

    if (value != null) {
        ELContext elContext = context.getELContext();
        ExpressionFactory expressionFactory = context.getApplication().getExpressionFactory();
        ValueExpression ve = expressionFactory.createValueExpression(elContext, value.toString(), String.class);

        return (String) ve.getValue(elContext);
    }

    return defaultValue;
}

public MethodExpression makeMethodExpression(final String expression,
        final Class<?> expectedReturnType,
        final Class<?> ... expectedParamTypes) {

    MethodExpression methodExpression = null;
    try {
        FacesContext fc = getContext();
        ExpressionFactory factory = getExpressionFactory();
        methodExpression = factory.createMethodExpression(
                fc.getELContext(), expression, expectedReturnType,
                expectedParamTypes);

        return methodExpression;
    } catch (Exception e) {
        throw new FacesException("Method expression '" + expression
                + "' no se puede crear.", e);
    }
}

/**
 * Retorna una EL expression correspondiente a un metodo.
 * 
 * @param valueExpression
 *            cadena que representa la expresion.
 * @param expectedReturnType
 *            clase del tipo que se espera que retorna la expresion
 * @param expectedParamTypes
 *            clase de los parametros esperados que reciba el metodo
 * 
 * @return {@link MethodExpression} correspondiente
 */
public MethodExpression createMethodExpression(
        final String valueExpression, final Class<?> expectedReturnType,
        final Class<?> ... expectedParamTypes) {

    MethodExpression methodExpression = null;
    try {
        FacesContext fc = getContext();
        ExpressionFactory factory = fc.getApplication()
                .getExpressionFactory();
        methodExpression = factory.createMethodExpression(
                fc.getELContext(), valueExpression, expectedReturnType,
                expectedParamTypes);
    } catch (Exception e) {
        throw new FacesException("Method expression '" + valueExpression
                + "' could not be created.", e);
    }

    return methodExpression;
}

@Test
public void testJavaKeyWordSuffix() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setInt("five");
    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("beanA", var);

    // Should fail
    Exception e = null;
    try {
        factory.createValueExpression(context, "${beanA.int}",
                String.class);
    } catch (ELException ele) {
        e = ele;
    }
    assertNotNull(e);
}

@Test
public void testJavaKeyWordIdentifier() {
    ExpressionFactory factory = ExpressionFactory.newInstance();
    ELContext context = new ELContextImpl();

    TesterBeanA beanA = new TesterBeanA();
    beanA.setInt("five");
    ValueExpression var =
        factory.createValueExpression(beanA, TesterBeanA.class);
    context.getVariableMapper().setVariable("this", var);

    // Should fail
    Exception e = null;
    try {
        factory.createValueExpression(context, "${this}", String.class);
    } catch (ELException ele) {
        e = ele;
    }
    assertNotNull(e);
}