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Consolidated methods. 

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137178 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Robert Burrell Donkin 2002-12-10 19:06:49 +00:00
parent 5003e9c501
commit b91dfd1a2c
2 changed files with 117 additions and 158 deletions
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263
src/java/org/apache/commons/lang/reflect/MethodUtils.java
View File

@ -66,6 +66,7 @@
import org.apache.commons.lang.ArrayUtils;
import org.apache.commons.lang.StringUtils;
/**
* <code>MethodUtils</code> contains utility methods for working for
* methods by reflection.
@ -82,7 +83,7 @@
* @author Gregor Raýman
* @author Jan Sorensen
* @author Robert Burrell Donkin
* @version $Id: MethodUtils.java,v 1.8 2002/11/21 19:38:51 rdonkin Exp $
* @version $Id: MethodUtils.java,v 1.9 2002/12/10 19:06:49 rdonkin Exp $
*/
public class MethodUtils {
@ -116,6 +117,21 @@ public static Method getMethod(Class cls, String methodName) {
return getMethod(cls, methodName, ArrayUtils.EMPTY_CLASS_ARRAY, false);
}
/**
* Gets a Method by name. The method must be public.
* Superclasses will be considered.
*
* @param cls the class to reflect, must not be null
* @param methodName the field name to obtain
* @return the Method object
* @throws IllegalArgumentException if the class or method name is null
* @throws ReflectionException if an error occurs during reflection
*/
public static Method getMethod(Class cls, String methodName, Class paramType) {
Class[] paramTypes = {paramType};
return getMethod(cls, methodName, paramTypes);
}
/**
* Gets a Method by name. The method must be public.
* Superclasses will be considered.
@ -173,7 +189,24 @@ public static Method getMethod(Class cls, String methodName, Class[] paramTypes,
}
throw new NoSuchMethodException("The method '" + methodName + "' could not be found");
} else {
return cls.getMethod(methodName, paramTypes);
// apply workarounds
Method method = null;
try {
method = cls.getMethod(methodName, paramTypes);
} catch(NoSuchMethodException e) {
// swallow
}
if (method == null) {
// use the same as beanutils for the moment
Method[] compatibles = getCompatibleMethods(cls, methodName, paramTypes);
if (compatibles.length > 0) {
method = compatibles[0];
}
}
return getMethod(method);
}
} catch (ReflectionException ex) {
@ -186,6 +219,50 @@ public static Method getMethod(Class cls, String methodName, Class[] paramTypes,
ex, "getting method", cls.getName(), null, methodName), ex);
}
}
/**
* <p>Return an accessible method (that is, one that can be invoked via
* reflection) that implements the specified Method. If no such method
* can be found, return <code>null</code>.</p>
*
* @param method The method that we wish to call
*/
public static Method getMethod(Method method) {
Method accessibleMethod = getAccessibleMethod(method);
if (accessibleMethod == null) {
try {
//
// XXX Default access superclass workaround
//
// When a public class has a default access superclass
// with public methods, these methods are accessible.
// Calling them from compiled code works fine.
//
// Unfortunately, using reflection to invoke these methods
// seems to (wrongly) to prevent access even when the method
// modifer is public.
//
// The following workaround solves the problem but will only
// work from sufficiently privilages code.
//
// Better workarounds would be greatfully accepted.
//
if (ReflectionUtils.isPublicScope(method)) {
method.setAccessible(true);
accessibleMethod = method;
}
} catch (SecurityException se) {
// log but continue just in case the method.invoke works anyway
log(
"Cannot setAccessible on method. Therefore cannot use jvm access bug workaround.",
se);
}
}
return (accessibleMethod);
}
// -------------------------------------------------------------------------
@ -303,7 +380,7 @@ public static Object invokeMethod(
args = ArrayUtils.EMPTY_OBJECT_ARRAY;
}
Method method = getMatchingAccessibleMethod(
Method method = getMethod(
object.getClass(),
methodName,
parameterTypes);
@ -330,62 +407,11 @@ public static Object invokeMethod(
}
}
/**
* <p>Return an accessible method (that is, one that can be invoked via
* reflection) with given name and a single parameter. If no such method
* can be found, return <code>null</code>.
* Basically, a convenience wrapper that constructs a <code>Class</code>
* array for you.</p>
*
* @param clazz get method from this class
* @param methodName get method with this name
* @param parameterType taking this type of parameter
*/
public static Method getAccessibleMethod(
Class clazz,
String methodName,
Class parameterType) {
Class[] parameterTypes = {parameterType};
return getAccessibleMethod(clazz, methodName, parameterTypes);
}
/**
* <p>Return an accessible method (that is, one that can be invoked via
* reflection) with given name and parameters. If no such method
* can be found, return <code>null</code>.
* This is just a convenient wrapper for
* {@link #getAccessibleMethod(Method method)}.</p>
*
* @param clazz get method from this class
* @param methodName get method with this name
* @param parameterTypes with these parameters types
*/
public static Method getAccessibleMethod(
Class clazz,
String methodName,
Class[] parameterTypes) {
// -------------------------------------------------------- Private Methods
try {
return getAccessibleMethod
(clazz.getMethod(methodName, parameterTypes));
} catch (NoSuchMethodException e) {
return (null);
}
}
/**
* <p>Return an accessible method (that is, one that can be invoked via
* reflection) that implements the specified Method. If no such method
* can be found, return <code>null</code>.</p>
*
* @param method The method that we wish to call
*/
public static Method getAccessibleMethod(Method method) {
private static Method getAccessibleMethod(Method method) {
// Make sure we have a method to check
if (method == null) {
@ -394,14 +420,20 @@ public static Method getAccessibleMethod(Method method) {
// If the requested method is not public we cannot call it
if (!Modifier.isPublic(method.getModifiers())) {
log("Method is not public");
return (null);
}
// If the declaring class is public, we are done
Class clazz = method.getDeclaringClass();
if (Modifier.isPublic(clazz.getModifiers())) {
log("Class is public");
return (method);
}
if (debug) {
log("Method is in non-public class " + clazz);
}
// Check the implemented interfaces and subinterfaces
String methodName = method.getName();
@ -410,13 +442,12 @@ public static Method getAccessibleMethod(Method method) {
getAccessibleMethodFromInterfaceNest(clazz,
method.getName(),
method.getParameterTypes());
return (method);
}
// -------------------------------------------------------- Private Methods
/**
* <p>Return an accessible method (that is, one that can be invoked via
* reflection) that implements the specified method, by scanning through
@ -433,7 +464,9 @@ public static Method getAccessibleMethod(Method method) {
*/
private static Method getAccessibleMethodFromInterfaceNest
(Class clazz, String methodName, Class parameterTypes[]) {
if (debug) {
log("Finding accessible method " + methodName + " from interface nest");
}
Method method = null;
// Search up the superclass chain
@ -470,38 +503,18 @@ public static Method getAccessibleMethod(Method method) {
}
// If we found a method return it
if (method != null)
if (method != null) {
if (debug) {
log("Found method in class " + method.getDeclaringClass());
}
return (method);
}
// We did not find anything
return (null);
}
/**
* <p>Find an accessible method that matches the given name and has compatible parameters.
* Compatible parameters mean that every method parameter is assignable from
* the given parameters.
* In other words, it finds a method with the given name
* that will take the parameters given.<p>
*
* <p>This method is slightly undeterminstic since it loops
* through methods names and return the first matching method.</p>
*
* <p>This method is used by
* {@link
* #invokeMethod(Object object,String methodName,Object [] args,Class[] parameterTypes)}.
*
* <p>This method can match primitive parameter by passing in wrapper classes.
* For example, a <code>Boolean</code> will match a primitive <code>boolean</code>
* parameter.
*
* @param clazz find method in this class
* @param methodName find method with this name
* @param parameterTypes find method with compatible parameters
*/
private static Method getMatchingAccessibleMethod(
}
private static Method[] getCompatibleMethods(
Class clazz,
String methodName,
Class[] parameterTypes) {
@ -510,90 +523,36 @@ private static Method getMatchingAccessibleMethod(
log("Matching name=" + methodName + " on " + clazz);
}
// see if we can find the method directly
// most of the time this works and it's much faster
try {
Method method = clazz.getMethod(methodName, parameterTypes);
if (debug) {
log("Found straight match: " + method);
log("isPublic:" + Modifier.isPublic(method.getModifiers()));
}
try {
//
// XXX Default access superclass workaround
//
// When a public class has a default access superclass
// with public methods, these methods are accessible.
// Calling them from compiled code works fine.
//
// Unfortunately, using reflection to invoke these methods
// seems to (wrongly) to prevent access even when the method
// modifer is public.
//
// The following workaround solves the problem but will only
// work from sufficiently privilages code.
//
// Better workarounds would be greatfully accepted.
//
method.setAccessible(true);
} catch (SecurityException se) {
// log but continue just in case the method.invoke works anyway
log(
"Cannot setAccessible on method. Therefore cannot use jvm access bug workaround.",
se);
}
return method;
} catch (NoSuchMethodException e) { /* SWALLOW */ }
// search through all methods
int paramSize = parameterTypes.length;
Method[] methods = clazz.getMethods();
ArrayList compatibles = new ArrayList(methods.length);
for (int i = 0, size = methods.length; i < size ; i++) {
if (debug) {
log("Checking: " + methods[i]);
}
if (methods[i].getName().equals(methodName)) {
// log some trace information
if (debug) {
log("Found matching name:");
log(methods[i]);
log("Found matching name:" + methods[i]);
}
// compare parameters
Class[] methodsParams = methods[i].getParameterTypes();
if (ReflectionUtils.isCompatible(parameterTypes, methodsParams)) {
// get accessible version of method
Method method = getAccessibleMethod(methods[i]);
Method method = getMethod(methods[i]);
if (method != null) {
if (debug) {
log(method + " accessible version of "
+ methods[i]);
}
try {
//
// XXX Default access superclass workaround
// (See above for more details.)
//
method.setAccessible(true);
} catch (SecurityException se) {
// log but continue just in case the method.invoke works anyway
log(
"Cannot setAccessible on method. Therefore cannot use jvm access bug workaround.",
se);
}
return method;
compatibles.add(method);
} else {
log("Couldn't find accessible method for: " + methods[i]);
}
log("Couldn't find accessible method.");
}
}
}
// didn't find a match
log("No match found.");
return null;
}
return (Method[]) compatibles.toArray(new Method[compatibles.size()]);
}
private static void log(Object o) {
if (debug) {

12
src/test/org/apache/commons/lang/reflect/MethodUtilsTestCase.java
View File

@ -129,7 +129,7 @@ public void testGetAccessibleMethod() {
// easy bit first - find a public method
// METHOD ONE
Method method = MethodUtils.getAccessibleMethod
Method method = MethodUtils.getMethod
(TestBean.class, "setStringProperty", String.class);
// check that we've found one that matches
@ -141,7 +141,7 @@ public void testGetAccessibleMethod() {
// trickier this one - find a method in a direct interface
// METHOD TWO
method = MethodUtils.getAccessibleMethod
method = MethodUtils.getMethod
(privateBeanFactory.create().getClass(),
"methodBar",
String.class);
@ -155,7 +155,7 @@ public void testGetAccessibleMethod() {
// trickier this one - find a method in a indirect interface
// METHOD THREE
method = MethodUtils.getAccessibleMethod
method = MethodUtils.getMethod
(privateBeanFactory.createSubclass().getClass(),
"methodBaz",
String.class);
@ -478,7 +478,7 @@ public void testSimpleStatic3() {
try {
// Acquire the methods we need
Method currentCounterMethod = MethodUtils.getAccessibleMethod
Method currentCounterMethod = MethodUtils.getMethod
(TestBean.class, "currentCounter",
new Class[0]);
assertNotNull("currentCounterMethod exists",
@ -493,7 +493,7 @@ public void testSimpleStatic3() {
Modifier.isPublic(currentCounterMethod.getModifiers()));
assertTrue("currentCounterMethod static",
Modifier.isStatic(currentCounterMethod.getModifiers()));
Method incrementCounterMethod1 = MethodUtils.getAccessibleMethod
Method incrementCounterMethod1 = MethodUtils.getMethod
(TestBean.class, "incrementCounter",
new Class[0]);
assertNotNull("incrementCounterMethod1 exists",
@ -508,7 +508,7 @@ public void testSimpleStatic3() {
Modifier.isPublic(incrementCounterMethod1.getModifiers()));
assertTrue("incrementCounterMethod1 static",
Modifier.isStatic(incrementCounterMethod1.getModifiers()));
Method incrementCounterMethod2 = MethodUtils.getAccessibleMethod
Method incrementCounterMethod2 = MethodUtils.getMethod
(TestBean.class, "incrementCounter",
new Class[] { Integer.TYPE });
assertNotNull("incrementCounterMethod2 exists",