Java Code Examples for org.apache.commons.jexl3.introspection.JexlUberspect#getMethod()

/**
 * Prints to output.
 * <p>
 * This will dynamically try to find the best suitable method in the writer through uberspection.
 * Subclassing Writer by adding 'print' methods should be the preferred way to specialize output.
 * </p>
 * @param info the source info
 * @param arg  the argument to print out
 */
private void doPrint(JexlInfo info, Object arg) {
    try {
        if (writer != null) {
            if (arg instanceof CharSequence) {
                writer.write(arg.toString());
            } else if (arg != null) {
                Object[] value = {arg};
                JexlUberspect uber = jexl.getUberspect();
                JexlMethod method = uber.getMethod(writer, "print", value);
                if (method != null) {
                    method.invoke(writer, value);
                } else {
                    writer.write(arg.toString());
                }
            }
        }
    } catch (java.io.IOException xio) {
        throw TemplateEngine.createException(info, "call print", null, xio);
    } catch (java.lang.Exception xany) {
        throw TemplateEngine.createException(info, "invoke print", null, xany);
    }
}
 

/**
 * Calculate the <code>size</code> of various types:
 * Collection, Array, Map, String, and anything that has a int size() method.
 * <p>Note that the result may not be an integer.
 *
 * @param node   the node that gave the value to size
 * @param object the object to get the size of
 * @return the evaluation result
 */
protected Object size(JexlNode node, Object object) {
    if (object == null) {
        return 0;
    }
    Object result = tryOverload(node, JexlOperator.SIZE, object);
    if (result != JexlEngine.TRY_FAILED) {
        return result;
    }
    final JexlArithmetic arithmetic = interpreter.arithmetic;
    result = arithmetic.size(object, null);
    if (result == null) {
        final JexlUberspect uberspect = interpreter.uberspect;
        // check if there is a size method on the object that returns an
        // integer and if so, just use it
        JexlMethod vm = uberspect.getMethod(object, "size", Interpreter.EMPTY_PARAMS);
        if (returnsInteger(vm)) {
            try {
                result = vm.invoke(object, Interpreter.EMPTY_PARAMS);
            } catch (Exception xany) {
                interpreter.operatorError(node, JexlOperator.SIZE, xany);
            }
        }
    }
    return result instanceof Number ? ((Number) result).intValue() : 0;
}
 

/**
 * The 'startsWith' operator implementation.
 * @param node     the node
 * @param operator the calling operator, $= or $!
 * @param left     the left operand
 * @param right    the right operand
 * @return true if left starts with right, false otherwise
 */
protected boolean startsWith(JexlNode node, String operator, Object left, Object right) {
    final JexlArithmetic arithmetic = interpreter.arithmetic;
    final JexlUberspect uberspect = interpreter.uberspect;
    try {
        // try operator overload
        Object result = tryOverload(node, JexlOperator.STARTSWITH, left, right);
        if (result instanceof Boolean) {
            return (Boolean) result;
        }
        // use arithmetic / pattern matching ?
        Boolean matched = arithmetic.startsWith(left, right);
        if (matched != null) {
            return matched;
        }
        // try a startsWith method (duck type)
        try {
            Object[] argv = {right};
            JexlMethod vm = uberspect.getMethod(left, "startsWith", argv);
            if (returnsBoolean(vm)) {
                return (Boolean) vm.invoke(left, argv);
            } else if (arithmetic.narrowArguments(argv)) {
                vm = uberspect.getMethod(left, "startsWith", argv);
                if (returnsBoolean(vm)) {
                    return (Boolean) vm.invoke(left, argv);
                }
            }
        } catch (Exception e) {
            throw new JexlException(node, operator + " error", e);
        }
        // defaults to equal
        return arithmetic.equals(left, right) ? Boolean.TRUE : Boolean.FALSE;
    } catch (ArithmeticException xrt) {
        throw new JexlException(node, operator + " error", xrt);
    }
}
 

/**
 * The 'endsWith' operator implementation.
 * @param node     the node
 * @param operator the calling operator, ^= or ^!
 * @param left     the left operand
 * @param right    the right operand
 * @return true if left ends with right, false otherwise
 */
protected boolean endsWith(JexlNode node, String operator, Object left, Object right) {
    final JexlArithmetic arithmetic = interpreter.arithmetic;
    final JexlUberspect uberspect = interpreter.uberspect;
    try {
        // try operator overload
        Object result = tryOverload(node, JexlOperator.ENDSWITH, left, right);
        if (result instanceof Boolean) {
            return (Boolean) result;
        }
        // use arithmetic / pattern matching ?
        Boolean matched = arithmetic.endsWith(left, right);
        if (matched != null) {
            return matched;
        }
        // try a endsWith method (duck type)
        try {
            Object[] argv = {right};
            JexlMethod vm = uberspect.getMethod(left, "endsWith", argv);
            if (returnsBoolean(vm)) {
                return (Boolean) vm.invoke(left, argv);
            } else if (arithmetic.narrowArguments(argv)) {
                vm = uberspect.getMethod(left, "endsWith", argv);
                if (returnsBoolean(vm)) {
                    return (Boolean) vm.invoke(left, argv);
                }
            }
        } catch (Exception e) {
            throw new JexlException(node, operator + " error", e);
        }
        // defaults to equal
        return arithmetic.equals(left, right) ? Boolean.TRUE : Boolean.FALSE;
    } catch (ArithmeticException xrt) {
        throw new JexlException(node, operator + " error", xrt);
    }
}
 

/**
 * The 'match'/'in' operator implementation.
 * <p>
 * Note that 'x in y' or 'x matches y' means 'y contains x' ;
 * the JEXL operator arguments order syntax is the reverse of this method call.
 * </p>
 * @param node  the node
 * @param op    the calling operator, =~ or !~
 * @param right the left operand
 * @param left  the right operand
 * @return true if left matches right, false otherwise
 */
protected boolean contains(JexlNode node, String op, Object left, Object right) {
    final JexlArithmetic arithmetic = interpreter.arithmetic;
    final JexlUberspect uberspect = interpreter.uberspect;
    try {
        // try operator overload
        Object result = tryOverload(node, JexlOperator.CONTAINS, left, right);
        if (result instanceof Boolean) {
            return (Boolean) result;
        }
        // use arithmetic / pattern matching ?
        Boolean matched = arithmetic.contains(left, right);
        if (matched != null) {
            return matched;
        }
        // try a contains method (duck type set)
        try {
            Object[] argv = {right};
            JexlMethod vm = uberspect.getMethod(left, "contains", argv);
            if (returnsBoolean(vm)) {
                return (Boolean) vm.invoke(left, argv);
            } else if (arithmetic.narrowArguments(argv)) {
                vm = uberspect.getMethod(left, "contains", argv);
                if (returnsBoolean(vm)) {
                    return (Boolean) vm.invoke(left, argv);
                }
            }
        } catch (Exception e) {
            throw new JexlException(node, op + " error", e);
        }
        // defaults to equal
        return arithmetic.equals(left, right);
    } catch (ArithmeticException xrt) {
        throw new JexlException(node, op + " error", xrt);
    }
}
 

/**
 * Check for emptyness of various types: Collection, Array, Map, String, and anything that has a boolean isEmpty()
 * method.
 * <p>Note that the result may not be a boolean.
 *
 * @param node   the node holding the object
 * @param object the object to check the emptyness of
 * @return the evaluation result
 */
protected Object empty(JexlNode node, Object object) {
    if (object == null) {
        return true;
    }
    Object result = tryOverload(node, JexlOperator.EMPTY, object);
    if (result != JexlEngine.TRY_FAILED) {
        return result;
    }
    final JexlArithmetic arithmetic = interpreter.arithmetic;
    result = arithmetic.isEmpty(object, null);
    if (result == null) {
        final JexlUberspect uberspect = interpreter.uberspect;
        result = false;
        // check if there is an isEmpty method on the object that returns a
        // boolean and if so, just use it
        JexlMethod vm = uberspect.getMethod(object, "isEmpty", Interpreter.EMPTY_PARAMS);
        if (returnsBoolean(vm)) {
            try {
                result = vm.invoke(object, Interpreter.EMPTY_PARAMS);
            } catch (Exception xany) {
                interpreter.operatorError(node, JexlOperator.EMPTY, xany);
            }
        }
    }
    return result instanceof Boolean ? (Boolean) result : true;
}