Polish AspectJAdviceParameterNameDiscoverer

This commit also converts PointcutBody to a record.
This commit is contained in:
Sam Brannen 2023-02-24 11:19:03 +01:00
parent 8979ac789f
commit 7ace9aa429
1 changed files with 23 additions and 38 deletions

View File

@ -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
@ -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
*/
@ -309,7 +308,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
/**
* 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() {
@ -387,7 +386,6 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
}
/**
* Parse the string pointcut expression looking for:
* &#64;this, &#64;target, &#64;args, &#64;within, &#64;withincode, &#64;annotation.
@ -452,7 +450,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
}
}
/*
/**
* If the token starts meets Java identifier conventions, it's in.
*/
@Nullable
@ -520,7 +518,6 @@ 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");
@ -596,7 +593,7 @@ 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.
*/
@ -696,7 +693,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
return false;
}
/*
/**
* Return {@code true} if the given argument type is a subclass
* of the given supertype.
*/
@ -724,7 +721,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
return count;
}
/*
/**
* Find the argument index with the given type, and bind the given
* {@code varName} in that position.
*/
@ -741,22 +738,10 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
/**
* Simple struct to hold the extracted text from a pointcut body, together
* Simple record to hold the extracted text from a pointcut body, together
* with the number of tokens consumed in extracting it.
*/
private static class PointcutBody {
private final int numTokensConsumed;
@Nullable
private final String text;
public PointcutBody(int tokens, @Nullable String text) {
this.numTokensConsumed = tokens;
this.text = text;
}
}
private record PointcutBody(int numTokensConsumed, @Nullable String text) {}
/**
* Thrown in response to an ambiguous binding being detected when