Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ExpressionManager |
|
| 1.0;1 |
1 | /* | |
2 | * $Id: ExpressionManager.java 20424 2010-12-01 16:14:42Z dfeist $ | |
3 | * -------------------------------------------------------------------------------------- | |
4 | * Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com | |
5 | * | |
6 | * The software in this package is published under the terms of the CPAL v1.0 | |
7 | * license, a copy of which has been included with this distribution in the | |
8 | * LICENSE.txt file. | |
9 | */ | |
10 | package org.mule.api.expression; | |
11 | ||
12 | import org.mule.api.MuleMessage; | |
13 | ||
14 | /** | |
15 | * Provides universal access for evaluating expressions embedded in Mule configurations, such as Xml, Java, | |
16 | * scripting and annotations. | |
17 | * <p/> | |
18 | * Users can register or unregister {@link ExpressionEvaluator} through this interface. | |
19 | */ | |
20 | public interface ExpressionManager | |
21 | { | |
22 | String DEFAULT_EXPRESSION_PREFIX = "#["; | |
23 | String DEFAULT_EXPRESSION_POSTFIX = "]"; | |
24 | ||
25 | public void registerEvaluator(ExpressionEvaluator evaluator); | |
26 | ||
27 | /** | |
28 | * Checks whether an evaluator is registered with the manager | |
29 | * | |
30 | * @param name the name of the expression evaluator | |
31 | * @return true if the evaluator is registered with the manager, false otherwise | |
32 | */ | |
33 | public boolean isEvaluatorRegistered(String name); | |
34 | ||
35 | /** | |
36 | * Removes the evaluator with the given name | |
37 | * | |
38 | * @param name the name of the evaluator to remove | |
39 | * @return the evaluator that was removed. This will be null if the evaluator was not registered | |
40 | */ | |
41 | public ExpressionEvaluator unregisterEvaluator(String name); | |
42 | ||
43 | public void registerEnricher(ExpressionEnricher enricher); | |
44 | ||
45 | /** | |
46 | * Checks whether an enricher is registered with the manager | |
47 | * | |
48 | * @param name the name of the expression enricher | |
49 | * @return true if the enricher is registered with the manager, false otherwise | |
50 | */ | |
51 | public boolean isEnricherRegistered(String name); | |
52 | ||
53 | /** | |
54 | * Removes the enricher with the given name | |
55 | * | |
56 | * @param name the name of the enricher to remove | |
57 | * @return the enricher that was removed. This will be null if the enricher was not registered | |
58 | */ | |
59 | public ExpressionEnricher unregisterEnricher(String name); | |
60 | ||
61 | /** | |
62 | * Evaluates the given expression. The expression should be a single expression definition with or without | |
63 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. For situations where | |
64 | * one or more expressions need to be parsed within a single text, the {@link #parse(String,org.mule.api.MuleMessage,boolean)} | |
65 | * method should be used since it will iterate through all expressions in a string. | |
66 | * | |
67 | * @param expression a single expression i.e. xpath://foo | |
68 | * @param message The current message being processed | |
69 | * @return the result of the evaluation | |
70 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
71 | * 'failIfNull is set to true. | |
72 | */ | |
73 | public Object evaluate(String expression, MuleMessage message) throws ExpressionRuntimeException; | |
74 | ||
75 | /** | |
76 | * Evaluates the given expression. The expression should be a single expression definition with or without | |
77 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. For situations where | |
78 | * one or more expressions need to be parsed within a single text, the {@link #parse(String,org.mule.api.MuleMessage,boolean)} | |
79 | * method should be used since it will iterate through all expressions in a string. | |
80 | * | |
81 | * @param expression a single expression i.e. xpath://foo | |
82 | * @param message The current message being processed | |
83 | * @param failIfNull determines if an exception should be thrown if expression could not be evaluated or returns | |
84 | * null. @return the result of the evaluation | |
85 | * @return the parsered expression string | |
86 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
87 | * 'failIfNull is set to true. | |
88 | */ | |
89 | public Object evaluate(String expression, MuleMessage message, boolean failIfNull) throws ExpressionRuntimeException; | |
90 | ||
91 | /** | |
92 | * Evaluates the given expression. The expression should be a single expression definition with or without | |
93 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. For situations where | |
94 | * one or more expressions need to be parsed within a single text, the {@link #parse(String,org.mule.api.MuleMessage,boolean)} | |
95 | * method should be used since it will iterate through all expressions in a string. | |
96 | * | |
97 | * @param expression one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]." | |
98 | * @param evaluator the evaluator to use when executing the expression | |
99 | * @param message The current message being processed | |
100 | * @param failIfNull determines if an exception should be thrown if expression could not be evaluated or returns | |
101 | * null. @return the result of the evaluation | |
102 | * @return the parsered expression string | |
103 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
104 | * 'failIfNull is set to true. | |
105 | */ | |
106 | public Object evaluate(String expression, String evaluator, MuleMessage message, boolean failIfNull) throws ExpressionRuntimeException; | |
107 | ||
108 | /** | |
109 | * Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without | |
110 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. | |
111 | * | |
112 | * @param expression a single expression i.e. header:foo=bar | |
113 | * @param evaluator the evaluator to use when executing the expression | |
114 | * @param message The current message being processed | |
115 | * @return | |
116 | * @throws ExpressionRuntimeException | |
117 | */ | |
118 | public boolean evaluateBoolean(String expression, String evaluator, MuleMessage message) throws ExpressionRuntimeException; | |
119 | ||
120 | /** | |
121 | * Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without | |
122 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. | |
123 | * | |
124 | * @param expression a single expression i.e. header:foo=bar | |
125 | * @param message The current message being processed | |
126 | * @return | |
127 | * @throws ExpressionRuntimeException | |
128 | */ | |
129 | public boolean evaluateBoolean(String expression, MuleMessage message) throws ExpressionRuntimeException; | |
130 | ||
131 | /** | |
132 | * Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without | |
133 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. | |
134 | * | |
135 | * @param expression a single expression i.e. header:foo=bar | |
136 | * @param evaluator the evaluator to use when executing the expression | |
137 | * @param message The current message being processed | |
138 | * @param nullReturnsTrue determines if true should be returned if the result of the evaluation is null | |
139 | * @param nonBooleanReturnsTrue determines if true should returned if the result is not null but isn't recognised as a boolean | |
140 | * @return | |
141 | * @throws ExpressionRuntimeException | |
142 | */ | |
143 | public boolean evaluateBoolean(String expression, String evaluator, MuleMessage message, boolean nullReturnsTrue, boolean nonBooleanReturnsTrue) throws ExpressionRuntimeException; | |
144 | ||
145 | /** | |
146 | * Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without | |
147 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. | |
148 | * | |
149 | * @param expression a single expression i.e. header:foo=bar | |
150 | * @param message The current message being processed | |
151 | * @param nullReturnsTrue determines if true should be returned if the result of the evaluation is null | |
152 | * @param nonBooleanReturnsTrue determines if true should returned if the result is not null but isn't recognised as a boolean | |
153 | * @return | |
154 | * @throws ExpressionRuntimeException | |
155 | */ | |
156 | public boolean evaluateBoolean(String expression, MuleMessage message, boolean nullReturnsTrue, boolean nonBooleanReturnsTrue) throws ExpressionRuntimeException; | |
157 | ||
158 | /** | |
159 | * Enriches the current message using | |
160 | * @param expression a single expression i.e. header://foo that defines how the message shoud be enriched | |
161 | * @param message The current message being processed that will be enriched | |
162 | * @param object The object that will be used to enrich the message | |
163 | */ | |
164 | public void enrich(String expression, MuleMessage message, Object object); | |
165 | ||
166 | /** | |
167 | * Enriches the current message | |
168 | * @param expression a single expression i.e. header://foo that defines how the message shoud be enriched | |
169 | * @param enricher the enricher to use when executing the expression | |
170 | * @param message The current message being processed that will be enriched | |
171 | * @param object The object that will be used to enrich the message | |
172 | */ | |
173 | public void enrich(String expression, String enricher, MuleMessage message, Object object); | |
174 | ||
175 | /** | |
176 | * Evaluates expressions in a given string. This method will iterate through each expression and evaluate it. If | |
177 | * a user needs to evaluate a single expression they can use {@link #evaluate(String,org.mule.api.MuleMessage,boolean)}. | |
178 | * | |
179 | * @param expression one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]." | |
180 | * @param message The current message being processed | |
181 | * @return the result of the evaluation | |
182 | * @throws org.mule.api.expression.ExpressionRuntimeException | |
183 | * if the expression is invalid, or a null is found for the expression and | |
184 | * 'failIfNull is set to true. | |
185 | */ | |
186 | public String parse(String expression, MuleMessage message) throws ExpressionRuntimeException; | |
187 | ||
188 | /** | |
189 | * Evaluates expressions in a given string. This method will iterate through each expression and evaluate it. If | |
190 | * a user needs to evaluate a single expression they can use {@link #evaluate(String,org.mule.api.MuleMessage,boolean)}. | |
191 | * | |
192 | * @param expression one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]." | |
193 | * @param message The current message being processed | |
194 | * @param failIfNull determines if an exception should be thrown if expression could not be evaluated or returns | |
195 | * null. @return the result of the evaluation | |
196 | * @return the parsered expression string | |
197 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
198 | * 'failIfNull is set to true. | |
199 | */ | |
200 | public String parse(final String expression, final MuleMessage message, final boolean failIfNull) throws ExpressionRuntimeException; | |
201 | ||
202 | /** | |
203 | * Clears all registered evaluators from the manager. | |
204 | */ | |
205 | public void clearEvaluators(); | |
206 | ||
207 | /** | |
208 | * Clears all registered enrichers from the manager. | |
209 | */ | |
210 | public void clearEnrichers(); | |
211 | ||
212 | /** | |
213 | * Determines if the expression is valid or not. This method will validate a single expression or | |
214 | * expressions embedded in a string. the expression must be well formed i.e. #[bean:user] | |
215 | * | |
216 | * @param expression the expression to validate | |
217 | * @return true if the expression evaluator is recognised | |
218 | */ | |
219 | public boolean isValidExpression(String expression); | |
220 | ||
221 | /** | |
222 | * Determines if the expression is valid or not. This method will validate a single expression or | |
223 | * expressions embedded in a string. the expression must be well formed i.e. #[bean:user] | |
224 | * | |
225 | * @param expression the expression to validate | |
226 | * @throws InvalidExpressionException if the expression is invalid, including information about the position and fault | |
227 | * | |
228 | * @since 3.0 | |
229 | */ | |
230 | public void validateExpression(String expression) throws InvalidExpressionException; | |
231 | ||
232 | /** | |
233 | * Determines if the string is an expression. This method will validate that the string contains either the expression | |
234 | * prefix (malformed) or a full expression. This isn't full proof but catches most error cases | |
235 | * | |
236 | * @param string is this string an expression string | |
237 | * @return true if the string contains an expression | |
238 | * | |
239 | * @since 3.0 | |
240 | */ | |
241 | public boolean isExpression(String string); | |
242 | ||
243 | } |