org.weakref.jmx.internal.paranamer.DefaultParanamer Maven / Gradle / Ivy
/***
*
* Copyright (c) 2007 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 org.weakref.jmx.internal.paranamer;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.lang.reflect.AccessibleObject;
/**
* Default implementation of Paranamer
*
* @author Paul Hammant
* @author Mauro Talevi
* @author Guilherme Silveira
*/
public class DefaultParanamer implements Paranamer {
private static final String COMMA = ",";
private static final String SPACE = " ";
public static final String __PARANAMER_DATA = "v1.0 \n"
+ " \n"
+ "toString \n"
+ "lookupParameterNames java.lang.AccessibleObject methodOrCtor \n"
+ "getParameterTypeName java.lang.Class cls\n";
public DefaultParanamer() {
}
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;
if (methodOrCtor instanceof Method) {
Method method = (Method) methodOrCtor;
types = method.getParameterTypes();
name = method.getName();
declaringClass = method.getDeclaringClass();
} else {
Constructor constructor = (Constructor) methodOrCtor;
types = constructor.getParameterTypes();
declaringClass = constructor.getDeclaringClass();
name = "";
}
if (types.length == 0) {
return EMPTY_NAMES;
}
final String parameterTypeNames = getParameterTypeNamesCSV(types);
final String[] names = getParameterNames(declaringClass, parameterTypeNames, name + SPACE);
if ( names == null ){
if (throwExceptionIfMissing) {
throw new ParameterNamesNotFoundException("No parameter names found for class '"+declaringClass+"', methodOrCtor " + name
+" and parameter types "+parameterTypeNames);
} else {
return Paranamer.EMPTY_NAMES;
}
}
return names;
}
private static String[] getParameterNames(Class declaringClass, String parameterTypes, String prefix) {
String data = getParameterListResource(declaringClass);
String line = findFirstMatchingLine(data, prefix + parameterTypes + SPACE);
String[] parts = line.split(SPACE);
// assumes line structure: constructorName parameterTypes parameterNames
if (parts.length == 3 && parts[1].equals(parameterTypes)) {
String parameterNames = parts[2];
return parameterNames.split(COMMA);
}
return Paranamer.EMPTY_NAMES;
}
private static String getParameterTypeNamesCSV(Class[] parameterTypes) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < parameterTypes.length; i++) {
sb.append(getParameterTypeName(parameterTypes[i]));
if (i < parameterTypes.length - 1) {
sb.append(COMMA);
}
}
return sb.toString();
}
private static String getParameterListResource(Class declaringClass) {
try {
Field field = declaringClass.getDeclaredField("__PARANAMER_DATA");
// TODO create acc test which finds field?
// TODO create acc test which does not find field?
// TODO create acc test what to do with private? access anyway?
// TODO create acc test with non static field?
// TODO create acc test with another type of field?
if(!Modifier.isStatic(field.getModifiers()) || !field.getType().equals(String.class)) {
return null;
}
return (String) field.get(null);
} catch (NoSuchFieldException e) {
return null;
} catch (IllegalAccessException e) {
return null;
}
}
/**
* Filter the mappings and only return lines matching the prefix passed in.
* @param data the data encoding the mappings
* @param prefix the String prefix
* @return A list of lines that match the prefix
*/
private static String findFirstMatchingLine(String data, String prefix) {
if (data == null) {
return "";
}
int ix = data.indexOf(prefix);
if (ix >= 0) {
int iy = data.indexOf("\n", ix);
if(iy >0) {
return data.substring(ix,iy);
}
}
return "";
}
private static String getParameterTypeName(Class cls){
String parameterTypeNameName = cls.getName();
int arrayNestingDepth = 0;
int ix = parameterTypeNameName.indexOf("[");
while (ix>-1){
arrayNestingDepth++;
parameterTypeNameName=parameterTypeNameName.replaceFirst("(\\[\\w)|(\\[)","");
ix = parameterTypeNameName.indexOf("[");
}
parameterTypeNameName =parameterTypeNameName.replaceFirst(";","");
for (int k=0;k © 2015 - 2025 Weber Informatics LLC | Privacy Policy