Spring/spring-framework
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Modified public interface to expression parsing

Browse Source
This commit is contained in:
Andy Clement
2008-08-11 18:37:11 +00:00
parent ca010140fb
commit ca93824d2b
14 changed files with 92 additions and 310 deletions
Download Patch File Download Diff File Expand all files Collapse all files

66
org.springframework.expression/src/main/java/org/springframework/expression/EvaluationException.java
View File

@@ -1,66 +0,0 @@
/*
* Copyright 2004-2008 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.binding.expression;
/**
* Indicates an expression evaluation failed.
*
* @author Keith Donald
*/
public class EvaluationException extends RuntimeException {
private Class contextClass;
private String expressionString;
/**
* Creates a new evaluation exception.
* @param contextClass the class of object upon which evaluation was attempted
* @param expressionString the string form of the expression that failed to evaluate
* @param message the exception message
*/
public EvaluationException(Class contextClass, String expressionString, String message) {
this(contextClass, expressionString, message, null);
}
/**
* Creates a new evaluation exception.
* @param contextClass the class of object upon which evaluation was attempted
* @param expressionString the string form of the expression that failed to evaluate
* @param message the exception message
* @param cause the underlying cause of this evaluation exception
*/
public EvaluationException(Class contextClass, String expressionString, String message, Throwable cause) {
super(message, cause);
}
/**
* The class of object upon which evaluation was attempted and failed.
* @return the context class
*/
public Class getContextClass() {
return contextClass;
}
/**
* The string form of the expression that failed to evaluate against an instance of the the context class.
* @return the expression string
*/
public String getExpressionString() {
return expressionString;
}
}

45
org.springframework.expression/src/main/java/org/springframework/expression/Expression.java
View File

@@ -13,7 +13,10 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.binding.expression;
package org.springframework.expression;
import org.springframework.expression.spel.SpelException;
/**
* An expression capable of evaluating itself against context objects. Encapsulates the details of a previously parsed
@@ -21,16 +24,47 @@ package org.springframework.binding.expression;
* the Unified EL.
*
* @author Keith Donald
* @author Andy Clement
*/
public interface Expression {
/**
* Evaluate this expression in the default standard context.
* @return the evaluation result
* @throws EvaluationException an exception occurred during expression evaluation
*/
public Object getValue() throws EvaluationException;
/**
* Evaluate the expression in the default standard context. If the result of the evaluation
* does not match (and cannot be converted to) the expected result type then an
* exception will be returned.
*
* @param expectedResultType the class the caller would like the result to be
* @return the value of the expression
* @throws EvaluationException if there is a problem with evaluation of the expression.
*/
public Object getValue(Class<?> expectedResultType) throws EvaluationException;
/**
* Evaluate this expression in the provided context and return the result of evaluation.
* @param context the context to evaluate this expression in
* @return the evaluation result
* @throws EvaluationException an exception occurred during expression evaluation
*/
public Object getValue(Object context) throws EvaluationException;
public Object getValue(EvaluationContext context) throws EvaluationException;
/**
* Evaluate the expression in a specified context which can resolve references to properties, methods, types, etc -
* the type of the evaluation result is expected to be of a particular class and an exception will be thrown if it
* is not and cannot be converted to that type.
*
* @param context the context in which to evaluate the expression
* @param expectedResultType the class the caller would like the result to be
* @return the value of the expression
* @throws SpelException if there is a problem with evaluation of the expression.
*/
public Object getValue(EvaluationContext context, Class<?> expectedResultType) throws EvaluationException;
/**
* Set this expression in the provided context to the value provided.
@@ -38,16 +72,16 @@ public interface Expression {
* @param value the new value to set
* @throws EvaluationException an exception occurred during expression evaluation
*/
public void setValue(Object context, Object value) throws EvaluationException;
public void setValue(EvaluationContext context, Object value) throws EvaluationException;
/**
* Returns the most general type that can be passed to the {@link #setValue(Object, Object)} method for the given
* Returns the most general type that can be passed to the {@link #setValue(EvaluationContext, Object)} method for the given
* context.
* @param context the context to evaluate
* @return the most general type of value that can be set on this context
* @throws EvaluationException an exception occurred during expression evaluation
*/
public Class getValueType(Object context) throws EvaluationException;
public Class getValueType(EvaluationContext context) throws EvaluationException;
/**
* Returns the original string used to create this expression, unmodified.
@@ -55,4 +89,5 @@ public interface Expression {
*/
public String getExpressionString();
}

23
org.springframework.expression/src/main/java/org/springframework/expression/ExpressionParser.java
View File

@@ -13,18 +13,19 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.binding.expression;
package org.springframework.expression;
/**
* Parses expression strings into compiled expressions that can be evaluated. Supports parsing templates as well as
* standard expression strings.
*
* @author Keith Donald
* @author Andy Clement
*/
public interface ExpressionParser {
/**
* Parse the expression string and return a compiled Expression object you can use for evaluation. Some examples:
* Parse the expression string and return an Expression object you can use for repeated evaluation. Some examples:
*
* <pre>
* 3 + 4
@@ -34,8 +35,22 @@ public interface ExpressionParser {
* @param expressionString the raw expression string to parse
* @param context a context for influencing this expression parsing routine (optional)
* @return an evaluator for the parsed expression
* @throws ParserException an exception occurred during parsing
* @throws ParseException an exception occurred during parsing
*/
public Expression parseExpression(String expressionString, ParserContext context) throws ParserException;
public Expression parseExpression(String expressionString, ParserContext context) throws ParseException;
/**
* Parse the expression string and return an Expression object you can use for repeated evaluation. Some examples:
*
* <pre>
* 3 + 4
* name.firstName
* </pre>
*
* @param expressionString the raw expression string to parse
* @return an evaluator for the parsed expression
* @throws ParseException an exception occurred during parsing
*/
public Expression parseExpression(String expressionString) throws ParseException;
}

95
org.springframework.expression/src/main/java/org/springframework/expression/ExpressionVariable.java
View File

@@ -1,95 +0,0 @@
/*
* Copyright 2004-2008 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.binding.expression;
/**
* An expression variable.
* @author Keith Donald
*/
public class ExpressionVariable {
private String name;
private String valueExpression;
private ParserContext parserContext;
/**
* Creates a new expression variable.
* @param name the name of the variable, acting as an convenient alias (required)
* @param valueExpression the value expression (required)
*/
public ExpressionVariable(String name, String valueExpression) {
init(name, valueExpression, null);
}
/**
* Creates a new expression variable with a populated parser context.
* @param name the name of the variable, acting as an convenient alias (required)
* @param valueExpression the value expression (required)
* @param parserContext the parser context to use to parse the value expression (optional)
*/
public ExpressionVariable(String name, String valueExpression, ParserContext parserContext) {
init(name, valueExpression, parserContext);
}
/**
* Returns the variable name.
* @return the variable name
*/
public String getName() {
return name;
}
/**
* Returns the expression that will be evaluated when the variable is referenced by its name in another expression.
* @return the expression value.
*/
public String getValueExpression() {
return valueExpression;
}
/**
* Returns the parser context to use to parse the variable's value expression.
* @return the value expression parser context
*/
public ParserContext getParserContext() {
return parserContext;
}
public boolean equals(Object o) {
if (!(o instanceof ExpressionVariable)) {
return false;
}
ExpressionVariable var = (ExpressionVariable) o;
return name.equals(var.name);
}
public int hashCode() {
return name.hashCode();
}
public String toString() {
return "[Expression Variable '" + name + "']";
}
private void init(String name, String valueExpression, ParserContext parserContext) {
this.name = name;
this.valueExpression = valueExpression;
this.parserContext = parserContext;
}
}

43
org.springframework.expression/src/main/java/org/springframework/expression/ParserContext.java
View File

@@ -13,46 +13,43 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.binding.expression;
package org.springframework.expression;
/**
* Input provided to an expression parser that can influence an expression parsing/compilation routine.
*
* @author Keith Donald
* @author Andy Clement
*/
public interface ParserContext {
/**
* Returns the type of context object the parsed expression will evaluate in. An expression parser may use this
* value to install custom variable resolves for that particular type of context.
* @return the evaluation context type
*/
public Class getEvaluationContextType();
/**
* Returns the expected type of object returned from evaluating the parsed expression. An expression parser may use
* this value to coerce an raw evaluation result before it is returned.
* @return the expected evaluation result type
*/
public Class getExpectedEvaluationResultType();
/**
* Returns additional expression variables or aliases that can be referenced during expression evaluation. An
* expression parser will register these variables for reference during evaluation.
*/
public ExpressionVariable[] getExpressionVariables();
/**
* Whether or not the expression being parsed is a template. A template expression consists of literal text that can
* be mixed with evaluatable blocks. Some examples:
*
* <pre>
* Some literal text
* Hello #{name.firstName}!
* #{3 + 4}
* Hello ${name.firstName}!
* ${3 + 4}
* </pre>
*
* @return true if the expression is a template, false otherwise
*/
public boolean isTemplate();
/**
* For template expressions, returns the prefix that identifies the start of an expression block within a string.
* For example "${"
*
* @return the prefix that identifies the start of an expression
*/
public String getExpressionPrefix();
/**
* For template expressions, return the prefix that identifies the end of an expression block within a string. For
* example "}$"
*
* @return the suffix that identifies the end of an expression
*/
public String getExpressionSuffix();
}

56
org.springframework.expression/src/main/java/org/springframework/expression/ParserException.java
View File

@@ -1,56 +0,0 @@
/*
* Copyright 2004-2008 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.binding.expression;
/**
* Base class for exceptions thrown during expression parsing.
*
* @author Keith Donald
*/
public class ParserException extends RuntimeException {
/**
* The expression string that could not be parsed.
*/
private String expressionString;
/**
* Creates a new expression parsing exception.
* @param expressionString the expression string that could not be parsed
* @param cause the underlying cause of this exception
*/
public ParserException(String expressionString, Throwable cause) {
this(expressionString, "Unable to parse expression string '" + expressionString + "'", cause);
}
/**
* Creates a new expression parsing exception.
* @param expressionString the expression string that could not be parsed
* @param message a descriptive message
* @param cause the underlying cause of this exception
*/
public ParserException(String expressionString, String message, Throwable cause) {
super(message, cause);
this.expressionString = expressionString;
}
/**
* Returns the expression string that could not be parsed.
*/
public Object getExpressionString() {
return expressionString;
}
}

36
org.springframework.expression/src/main/java/org/springframework/expression/PropertyNotFoundException.java
View File

@@ -1,36 +0,0 @@
/*
* Copyright 2004-2008 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.binding.expression;
/**
* An evaluation exception indicating a expression that references a property failed to evaluate because the property
* could not be found.
* @author Keith Donald
*/
public class PropertyNotFoundException extends EvaluationException {
/**
* Creates a new property not found exception
* @param contextClass the class of object upon which property evaluation was attempted
* @param property the property that could not be found
* @param cause root cause of the failure
*/
public PropertyNotFoundException(Class contextClass, String property, Throwable cause) {
super(contextClass, property, "Property '" + property + "' not found on context of class ["
+ contextClass.getName() + "]", cause);
}
}

7
org.springframework.expression/src/main/java/org/springframework/expression/package.html
View File

@@ -1,7 +0,0 @@
<html>
<body>
<p>
Core expression language abstraction for parsing and evaluating expressions.
</p>
</body>
</html>

7
org.springframework.expression/src/main/java/overview.html
View File

@@ -1,7 +0,0 @@
<html>
<body>
<p>
The Spring Data Binding framework, an internal library used by Spring Web Flow.
</p>
</body>
</html>