1 /*
2 * Copyright 2002-2011 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.springframework.security.oauth2.provider.expression;
17
18 import org.springframework.expression.Expression;
19 import org.springframework.expression.ExpressionParser;
20 import org.springframework.expression.ParseException;
21 import org.springframework.expression.ParserContext;
22 import org.springframework.util.Assert;
23
24 /**
25 * <p>
26 * A custom {@link ExpressionParser} that automatically wraps SpEL expression with
27 * {@link OAuth2SecurityExpressionMethods#throwOnError(boolean)}. This makes it simple for users to specify an
28 * expression and then have it verified (providing errors) after the result of the expression is known.
29 * </p>
30 * <p>
31 * Note: The implication is that all expressions that are parsed must return a boolean result. This expectation is
32 * already true since Spring Security expects the result to be a boolean.
33 * </p>
34 *
35 * @author Rob Winch
36 *
37 */
38 public class OAuth2ExpressionParser implements ExpressionParser {
39
40 private final ExpressionParser delegate;
41
42 public OAuth2ExpressionParser(ExpressionParser delegate) {
43 Assert.notNull(delegate, "delegate cannot be null");
44 this.delegate = delegate;
45 }
46
47 public Expression parseExpression(String expressionString) throws ParseException {
48 return delegate.parseExpression(wrapExpression(expressionString));
49 }
50
51 public Expression parseExpression(String expressionString, ParserContext context) throws ParseException {
52 return delegate.parseExpression(wrapExpression(expressionString), context);
53 }
54
55 private String wrapExpression(String expressionString) {
56 return "#oauth2.throwOnError(" + expressionString + ")";
57 }
58 }