SpelMessage.java

/*
 * Copyright 2002-2009 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.expression.spel;

import java.text.MessageFormat;

/**
 * Contains all the messages that can be produced by the Spring Expression Language. Each message has a kind (info,
 * warn, error) and a code number. Tests can be written to expect particular code numbers rather than particular text,
 * enabling the message text to more easily be modified and the tests to run successfully in different locales.
 * <p>
 * When a message is formatted, it will have this kind of form
 * 
 * <pre>
 * &lt;code&gt;
 * EL1004E: (pos 34): Type cannot be found 'String'
 * </pre>
 * 
 * </code> The prefix captures the code and the error kind, whilst the position is included if it is known.
 * 
 * @author Andy Clement
 * @since 3.0
 */
public enum SpelMessage {

	TYPE_CONVERSION_ERROR(Kind.ERROR, 1001, "Type conversion problem, cannot convert from {0} to {1}"), //
	CONSTRUCTOR_NOT_FOUND(Kind.ERROR, 1002, "Constructor call: No suitable constructor found on type {0} for arguments {1}"), //
	CONSTRUCTOR_INVOCATION_PROBLEM(Kind.ERROR, 1003, "A problem occurred whilst attempting to construct an object of type ''{0}'' using arguments ''{1}''"), //
	METHOD_NOT_FOUND(Kind.ERROR, 1004, "Method call: Method {0} cannot be found on {1} type"), // 
	TYPE_NOT_FOUND(Kind.ERROR, 1005, "Type cannot be found ''{0}''"), //
	FUNCTION_NOT_DEFINED(Kind.ERROR, 1006, "The function ''{0}'' could not be found"), //
	PROPERTY_OR_FIELD_NOT_READABLE_ON_NULL(Kind.ERROR, 1007, "Field or property ''{0}'' cannot be found on null"), //
	PROPERTY_OR_FIELD_NOT_READABLE(Kind.ERROR, 1008, "Field or property ''{0}'' cannot be found on object of type ''{1}''"), //
	PROPERTY_OR_FIELD_NOT_WRITABLE_ON_NULL(Kind.ERROR, 1009, "Field or property ''{0}'' cannot be set on null"), //
	PROPERTY_OR_FIELD_NOT_WRITABLE(Kind.ERROR, 1010, "Field or property ''{0}'' cannot be set on object of type ''{1}''"), //
	METHOD_CALL_ON_NULL_OBJECT_NOT_ALLOWED(Kind.ERROR, 1011, "Method call: Attempted to call method {0} on null context object"), //
	CANNOT_INDEX_INTO_NULL_VALUE(Kind.ERROR, 1012, "Cannot index into a null value"),	
	NOT_COMPARABLE(Kind.ERROR, 1013, "Cannot compare instances of {0} and {1}"), //
	INCORRECT_NUMBER_OF_ARGUMENTS_TO_FUNCTION(Kind.ERROR, 1014, "Incorrect number of arguments for function, {0} supplied but function takes {1}"), //
	INVALID_TYPE_FOR_SELECTION(Kind.ERROR, 1015, "Cannot perform selection on input data of type ''{0}''"), //
	RESULT_OF_SELECTION_CRITERIA_IS_NOT_BOOLEAN(Kind.ERROR, 1016, "Result of selection criteria is not boolean"), //
	BETWEEN_RIGHT_OPERAND_MUST_BE_TWO_ELEMENT_LIST(Kind.ERROR, 1017, "Right operand for the 'between' operator has to be a two-element list"), //
	INVALID_PATTERN(Kind.ERROR, 1018, "Pattern is not valid ''{0}''"), //
	PROJECTION_NOT_SUPPORTED_ON_TYPE(Kind.ERROR, 1019, "Projection is not supported on the type ''{0}''"), //
	ARGLIST_SHOULD_NOT_BE_EVALUATED(Kind.ERROR, 1020, "The argument list of a lambda expression should never have getValue() called upon it"), //
	EXCEPTION_DURING_PROPERTY_READ(Kind.ERROR, 1021, "A problem occurred whilst attempting to access the property ''{0}'': ''{1}''"), //
	FUNCTION_REFERENCE_CANNOT_BE_INVOKED(Kind.ERROR, 1022, "The function ''{0}'' mapped to an object of type ''{1}'' which cannot be invoked"), //
	EXCEPTION_DURING_FUNCTION_CALL(Kind.ERROR, 1023, "A problem occurred whilst attempting to invoke the function ''{0}'': ''{1}''"), //
	ARRAY_INDEX_OUT_OF_BOUNDS(Kind.ERROR, 1024, "The array has ''{0}'' elements, index ''{1}'' is invalid"), //
	COLLECTION_INDEX_OUT_OF_BOUNDS(Kind.ERROR, 1025, "The collection has ''{0}'' elements, index ''{1}'' is invalid"), // 
	STRING_INDEX_OUT_OF_BOUNDS(Kind.ERROR, 1026, "The string has ''{0}'' characters, index ''{1}'' is invalid"), //
	INDEXING_NOT_SUPPORTED_FOR_TYPE(Kind.ERROR, 1027, "Indexing into type ''{0}'' is not supported"), //
	INSTANCEOF_OPERATOR_NEEDS_CLASS_OPERAND(Kind.ERROR, 1028, "The operator 'instanceof' needs the right operand to be a class, not a ''{0}''"), //
	EXCEPTION_DURING_METHOD_INVOCATION(Kind.ERROR, 1029, "A problem occurred when trying to execute method ''{0}'' on object of type ''{1}'': ''{2}''"), // 
	OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES(Kind.ERROR, 1030, "The operator ''{0}'' is not supported between objects of type ''{1}'' and ''{2}''"), //
	PROBLEM_LOCATING_METHOD(Kind.ERROR, 1031, "Problem locating method {0} cannot on type {1}"), 
	SETVALUE_NOT_SUPPORTED(	Kind.ERROR, 1032, "setValue(ExpressionState, Object) not supported for ''{0}''"), //
	MULTIPLE_POSSIBLE_METHODS(Kind.ERROR, 1033, "Method call of ''{0}'' is ambiguous, supported type conversions allow multiple variants to match"), //
	EXCEPTION_DURING_PROPERTY_WRITE(Kind.ERROR, 1034, "A problem occurred whilst attempting to set the property ''{0}'': {1}"), //
	NOT_AN_INTEGER(Kind.ERROR, 1035, "The value ''{0}'' cannot be parsed as an int"), //
	NOT_A_LONG(Kind.ERROR, 1036, "The value ''{0}'' cannot be parsed as a long"), // 
	INVALID_FIRST_OPERAND_FOR_MATCHES_OPERATOR(Kind.ERROR, 1037, "First operand to matches operator must be a string.  ''{0}'' is not"), //
	INVALID_SECOND_OPERAND_FOR_MATCHES_OPERATOR(Kind.ERROR, 1038, "Second operand to matches operator must be a string. ''{0}'' is not"), //
	FUNCTION_MUST_BE_STATIC(Kind.ERROR, 1039, "Only static methods can be called via function references. The method ''{0}'' referred to by name ''{1}'' is not static."),//
	NOT_A_REAL(Kind.ERROR, 1040, "The value ''{0}'' cannot be parsed as a double"), // 
	MORE_INPUT(Kind.ERROR,1041, "After parsing a valid expression, there is still more data in the expression: ''{0}''"),
	RIGHT_OPERAND_PROBLEM(Kind.ERROR,1042, "Problem parsing right operand"),
	NOT_EXPECTED_TOKEN(Kind.ERROR,1043,"Unexpected token.  Expected ''{0}'' but was ''{1}''"),
	OOD(Kind.ERROR,1044,"Unexpectedly ran out of input"), //
	NON_TERMINATING_DOUBLE_QUOTED_STRING(Kind.ERROR,1045,"Cannot find terminating \" for string"),//
	NON_TERMINATING_QUOTED_STRING(Kind.ERROR,1046,"Cannot find terminating ' for string"), //
	MISSING_LEADING_ZERO_FOR_NUMBER(Kind.ERROR,1047,"A real number must be prefixed by zero, it cannot start with just ''.''"), //
	REAL_CANNOT_BE_LONG(Kind.ERROR,1048,"Real number cannot be suffixed with a long (L or l) suffix"),//
	UNEXPECTED_DATA_AFTER_DOT(Kind.ERROR,1049,"Unexpected data after ''.'': ''{0}''"),//
	MISSING_CONSTRUCTOR_ARGS(Kind.ERROR,1050,"The arguments '(...)' for the constructor call are missing"),//
	RUN_OUT_OF_ARGUMENTS(Kind.ERROR,1051,"Unexpected ran out of arguments"),//
	UNABLE_TO_GROW_COLLECTION(Kind.ERROR,1052,"Unable to grow collection"),//
	UNABLE_TO_GROW_COLLECTION_UNKNOWN_ELEMENT_TYPE(Kind.ERROR,1053,"Unable to grow collection: unable to determine list element type"),//
	UNABLE_TO_CREATE_LIST_FOR_INDEXING(Kind.ERROR,1054,"Unable to create a List for the following indexer"),//
	;

	private Kind kind;
	private int code;
	private String message;


	private SpelMessage(Kind kind, int code, String message) {
		this.kind = kind;
		this.code = code;
		this.message = message;
	}


	/**
	 * Produce a complete message including the prefix, the position (if known) and with the inserts applied to the
	 * message.
	 * 
	 * @param pos the position, if less than zero it is ignored and not included in the message
	 * @param inserts the inserts to put into the formatted message
	 * @return a formatted message
	 */
	public String formatMessage(int pos, Object... inserts) {
		StringBuilder formattedMessage = new StringBuilder();
		formattedMessage.append("EL").append(code);
		switch (kind) {
//		case WARNING:
//			formattedMessage.append("W");
//			break;
//		case INFO:
//			formattedMessage.append("I");
//			break;
		case ERROR:
			formattedMessage.append("E");
			break;
		}
		formattedMessage.append(":");
		if (pos != -1) {
			formattedMessage.append("(pos ").append(pos).append("): ");
		}
		formattedMessage.append(MessageFormat.format(message, inserts));
		return formattedMessage.toString();
	}


	public static enum Kind {
		INFO, WARNING, ERROR
	}

}