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This commit is contained in:
Juergen Hoeller
2023-06-03 00:01:18 +02:00
parent 268b7a8931
commit 9decbf2158
6 changed files with 50 additions and 39 deletions
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55
spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJAdviceParameterNameDiscoverer.java
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@@ -1,5 +1,5 @@
/*
* Copyright 2002-2021 the original author or authors.
* Copyright 2002-2023 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.
@@ -38,6 +38,14 @@ import org.springframework.util.StringUtils;
* for an advice method from the pointcut expression, returning, and throwing clauses.
* If an unambiguous interpretation is not available, it returns {@code null}.
*
* <h3>Algorithm Summary</h3>
* <p>If an unambiguous binding can be deduced, then it is.
* If the advice requirements cannot possibly be satisfied, then {@code null}
* is returned. By setting the {@link #setRaiseExceptions(boolean) raiseExceptions}
* property to {@code true}, descriptive exceptions will be thrown instead of
* returning {@code null} in the case that the parameter names cannot be discovered.
*
* <h3>Algorithm Details</h3>
* <p>This class interprets arguments in the following way:
* <ol>
* <li>If the first parameter of the method is of type {@link JoinPoint}
@@ -65,15 +73,15 @@ import org.springframework.util.StringUtils;
* zero we proceed to the next stage. If {@code a} &gt; 1 then an
* {@code AmbiguousBindingException} is raised. If {@code a} == 1,
* and there are no unbound arguments of type {@code Annotation+},
* then an {@code IllegalArgumentException} is raised. if there is
* then an {@code IllegalArgumentException} is raised. If there is
* exactly one such argument, then the corresponding parameter name is
* assigned the value from the pointcut expression.</li>
* <li>If a returningName has been set, and there are no unbound arguments
* <li>If a {@code returningName} has been set, and there are no unbound arguments
* then an {@code IllegalArgumentException} is raised. If there is
* more than one unbound argument then an
* {@code AmbiguousBindingException} is raised. If there is exactly
* one unbound argument then the corresponding parameter name is assigned
* the value &lt;returningName&gt;.</li>
* the value of the {@code returningName}.</li>
* <li>If there remain unbound arguments, then the pointcut expression is
* examined once more for {@code this}, {@code target}, and
* {@code args} pointcut expressions used in the binding form (binding
@@ -99,20 +107,12 @@ import org.springframework.util.StringUtils;
* <p>The behavior on raising an {@code IllegalArgumentException} or
* {@code AmbiguousBindingException} is configurable to allow this discoverer
* to be used as part of a chain-of-responsibility. By default the condition will
* be logged and the {@code getParameterNames(..)} method will simply return
* be logged and the {@link #getParameterNames(Method)} method will simply return
* {@code null}. If the {@link #setRaiseExceptions(boolean) raiseExceptions}
* property is set to {@code true}, the conditions will be thrown as
* {@code IllegalArgumentException} and {@code AmbiguousBindingException},
* respectively.
*
* <p>Was that perfectly clear? ;)
*
* <p>Short version: If an unambiguous binding can be deduced, then it is.
* If the advice requirements cannot possibly be satisfied, then {@code null}
* is returned. By setting the {@link #setRaiseExceptions(boolean) raiseExceptions}
* property to {@code true}, descriptive exceptions will be thrown instead of
* returning {@code null} in the case that the parameter names cannot be discovered.
*
* @author Adrian Colyer
* @author Juergen Hoeller
* @since 2.0
@@ -158,7 +158,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
/** The pointcut expression associated with the advice, as a simple String. */
@Nullable
private String pointcutExpression;
private final String pointcutExpression;
private boolean raiseExceptions;
@@ -197,7 +197,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
/**
* If {@code afterReturning} advice binds the return value, the
* returning variable name must be specified.
* {@code returning} variable name must be specified.
* @param returningName the name of the returning variable
*/
public void setReturningName(@Nullable String returningName) {
@@ -206,18 +206,17 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
/**
* If {@code afterThrowing} advice binds the thrown value, the
* throwing variable name must be specified.
* {@code throwing} variable name must be specified.
* @param throwingName the name of the throwing variable
*/
public void setThrowingName(@Nullable String throwingName) {
this.throwingName = throwingName;
}
/**
* Deduce the parameter names for an advice method.
* <p>See the {@link AspectJAdviceParameterNameDiscoverer class level javadoc}
* for this class for details of the algorithm used.
* <p>See the {@link AspectJAdviceParameterNameDiscoverer class-level javadoc}
* for this class for details on the algorithm used.
* @param method the target {@link Method}
* @return the parameter names
*/
@@ -316,13 +315,13 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
private void bindParameterName(int index, String name) {
private void bindParameterName(int index, @Nullable String name) {
this.parameterNameBindings[index] = name;
this.numberOfRemainingUnboundArguments--;
}
/**
* If the first parameter is of type JoinPoint or ProceedingJoinPoint,bind "thisJoinPoint" as
* If the first parameter is of type JoinPoint or ProceedingJoinPoint, bind "thisJoinPoint" as
* parameter name and return true, else return false.
*/
private boolean maybeBindThisJoinPoint() {
@@ -367,8 +366,8 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
if (throwableIndex == -1) {
throw new IllegalStateException("Binding of throwing parameter '" + this.throwingName
+ "' could not be completed as no available arguments are a subtype of Throwable");
throw new IllegalStateException("Binding of throwing parameter '" + this.throwingName +
"' could not be completed as no available arguments are a subtype of Throwable");
}
else {
bindParameterName(throwableIndex, this.throwingName);
@@ -400,7 +399,6 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
}
/**
* Parse the string pointcut expression looking for:
* &#64;this, &#64;target, &#64;args, &#64;within, &#64;withincode, &#64;annotation.
@@ -465,7 +463,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
}
/*
/**
* If the token starts meets Java identifier conventions, it's in.
*/
@Nullable
@@ -533,7 +531,6 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
}
if (varNames.size() > 1) {
throw new AmbiguousBindingException("Found " + varNames.size() +
" candidate this(), target() or args() variables but only one unbound argument slot");
@@ -609,7 +606,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
// else varNames.size must be 0 and we have nothing to bind.
}
/*
/**
* We've found the start of a binding pointcut at the given index into the
* token array. Now we need to extract the pointcut body and return it.
*/
@@ -709,7 +706,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
return false;
}
/*
/**
* Return {@code true} if the given argument type is a subclass
* of the given supertype.
*/
@@ -737,7 +734,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
return count;
}
/*
/**
* Find the argument index with the given type, and bind the given
* {@code varName} in that position.
*/