com.thoughtworks.paranamer.AnnotationParanamer Maven / Gradle / Ivy
/***
*
* Copyright (c) 2009 Paul Hammant
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.thoughtworks.paranamer;
import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import javax.inject.Named;
/**
* Implementation of Paranamer that uses @Named annotation of JSR 330.
* It is overridable to allow other annotations to be used (JBehave, Guice's original one)
*
* @author Paul Hammant
*/
public class AnnotationParanamer implements Paranamer {
public static final String __PARANAMER_DATA = "v1.0 \n"
+ "lookupParameterNames java.lang.AccessibleObject methodOrConstructor \n"
+ "lookupParameterNames java.lang.AccessibleObject,boolean methodOrCtor,throwExceptionIfMissing \n";
private final Paranamer fallback;
public AnnotationParanamer() {
this(new NullParanamer());
}
public AnnotationParanamer(Paranamer fallback) {
this.fallback = fallback;
}
public String[] lookupParameterNames(AccessibleObject methodOrConstructor) {
return lookupParameterNames(methodOrConstructor, true);
}
public String[] lookupParameterNames(AccessibleObject methodOrCtor, boolean throwExceptionIfMissing) {
// Oh for some commonality between Constructor and Method !!
Class[] types = null;
Class declaringClass = null;
String name = null;
Annotation[][] anns = null;
if (methodOrCtor instanceof Method) {
Method method = (Method) methodOrCtor;
types = method.getParameterTypes();
name = method.getName();
declaringClass = method.getDeclaringClass();
anns = method.getParameterAnnotations();
} else {
Constructor constructor = (Constructor) methodOrCtor;
types = constructor.getParameterTypes();
declaringClass = constructor.getDeclaringClass();
name = "";
anns = constructor.getParameterAnnotations();
}
if (types.length == 0) {
return EMPTY_NAMES;
}
final String[] names = new String[types.length];
boolean allDone = true;
for (int i = 0; i < names.length; i++) {
for (int j = 0; j < anns[i].length; j++) {
Annotation ann = anns[i][j];
if (isNamed(ann)) {
names[i] = getNamedValue(ann);
break;
}
}
if (names[i] == null) {
allDone = false;
}
}
// fill in blanks from fallback if possible.
if (!allDone) {
allDone = true;
String[] altNames = fallback.lookupParameterNames(methodOrCtor, false);
if (altNames.length > 0) {
for (int i = 0; i < names.length; i++) {
if (names[i] == null) {
if (altNames[i] != null) {
names[i] = altNames[i];
} else {
allDone = false;
}
}
}
} else {
allDone = false;
}
}
// error if applicable
if (!allDone) {
if (throwExceptionIfMissing) {
throw new ParameterNamesNotFoundException("One or more @Named annotations missing for class '" + declaringClass.getName() + "', methodOrCtor " + name
+" and parameter types "+ DefaultParanamer.getParameterTypeNamesCSV(types));
} else {
return Paranamer.EMPTY_NAMES;
}
}
return names;
}
/**
* Override this if you want something other than JSR 330's Named annotation.
*
* return ((Named) ann).value();
*
* @param ann the annotation in question
* @return a the name value.
*/
protected String getNamedValue(Annotation ann) {
if ("javax.inject.Named".equals(ann.annotationType().getName())) {
return Jsr330Helper.getNamedValue(ann);
} else {
return null;
}
}
/**
* Override this if you want something other than JSR 330's Named annotation.
*
* return ann instanceof Named;
*
* @param ann the annotation in question
* @return whether it is the annotation holding the parameter name
*/
protected boolean isNamed(Annotation ann) {
if ("javax.inject.Named".equals(ann.annotationType().getName())) {
return Jsr330Helper.isNamed(ann);
} else {
return false;
}
}
/**
* This is a different class, because the @Inject jar may not be in the classpath.
*/
public static class Jsr330Helper {
private static boolean isNamed(Annotation ann) {
return ann instanceof Named;
}
private static String getNamedValue(Annotation ann) {
return ((Named) ann).value();
}
}
}