package org.jgroups.blocks;
import org.jgroups.logging.Log;
import org.jgroups.logging.LogFactory;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
* A method call is the JGroups representation of a remote method.
* It includes the name of the method (case sensitive) and a list of arguments.
* A method call is serializable and can be passed over the wire.
* @author Bela Ban
*/
public class MethodCall implements Externalizable {
private static final long serialVersionUID=7873471327078957662L;
/** The name of the method, case sensitive. */
protected String method_name;
/** The ID of a method, maps to a java.lang.reflect.Method */
protected short method_id;
/** The arguments of the method. */
protected Object[] args;
/** The class types, e.g., new Class[]{String.class, int.class}. */
protected Class[] types;
/** The Method of the call. */
protected Method method;
protected static final Log log=LogFactory.getLog(MethodCall.class);
/** Which mode to use. */
protected short mode;
/** Infer the method from the arguments. */
protected static final short OLD=1;
/** Explicitly ship the method, caller has to determine method himself. */
protected static final short METHOD=2;
/** Use class information. */
protected static final short TYPES=3;
/** Use an ID to map to a method */
protected static final short ID=5;
/**
* Creates an empty method call, this is always invalid, until
* <code>setName()</code> has been called.
*/
public MethodCall() {
}
public MethodCall(Method method) {
this(method, (Object[])null);
}
public MethodCall(Method method, Object... arguments) {
init(method);
if(arguments != null) args=arguments;
}
public MethodCall(short method_id, Object... args) {
this.method_id=method_id;
this.mode=ID;
this.args=args;
}
public MethodCall(String method_name, Object[] args, Class[] types) {
this.method_name=method_name;
this.args=args;
this.types=types;
this.mode=TYPES;
}
private void init(Method method) {
this.method=method;
this.mode=METHOD;
method_name=method.getName();
}
public int getMode() {
return mode;
}
/**
* returns the name of the method to be invoked using this method call object
* @return a case sensitive name, can be null for an invalid method call
*/
public String getName() {
return method_name;
}
/**
* sets the name for this MethodCall and allowing you to reuse the same object for
* a different method invokation of a different method
* @param n - a case sensitive method name
*/
public void setName(String n) {
method_name=n;
}
public short getId() {
return method_id;
}
public void setId(short method_id) {
this.method_id=method_id;
}
/**
* returns an ordered list of arguments used for the method invokation
* @return returns the list of ordered arguments
*/
public Object[] getArgs() {
return args;
}
public void setArgs(Object...args) {
this.args=args;
}
public Method getMethod() {
return method;
}
public void setMethod(Method m) {
init(m);
}
/**
*
* @param target_class
* @return
* @throws Exception
*/
Method findMethod(Class target_class) throws Exception {
int len=args != null? args.length : 0;
Method m;
Method[] methods=getAllMethods(target_class);
for(int i=0; i < methods.length; i++) {
m=methods[i];
if(m.getName().equals(method_name)) {
if(m.getParameterTypes().length == len)
return m;
}
}
return null;
}
public static Method findMethod(Class target_class, String method_name, Object[] args) throws Exception {
int len=args != null? args.length : 0;
Method[] methods=getAllMethods(target_class);
for(int i=0; i < methods.length; i++) {
Method m=methods[i];
if(m.getName().equals(method_name)) {
if(m.getParameterTypes().length == len)
return m;
}
}
return null;
}
/**
* The method walks up the class hierarchy and returns <i>all</i> methods of this class
* and those inherited from superclasses and superinterfaces.
*/
static Method[] getAllMethods(Class target) {
Class superclass = target;
List methods = new ArrayList();
int size = 0;
while(superclass != null) {
try {
Method[] m = superclass.getDeclaredMethods();
methods.add(m);
size += m.length;
superclass = superclass.getSuperclass();
}
catch(SecurityException e) {
// if it runs in an applet context, it won't be able to retrieve
// methods from superclasses that belong to the java VM and it will
// raise a security exception, so we catch it here.
if(log.isWarnEnabled())
log.warn("unable to enumerate methods of superclass "+superclass+" of class "+target);
superclass=null;
}
}
Method[] result = new Method[size];
int index = 0;
for(Iterator i = methods.iterator(); i.hasNext();) {
Method[] m = (Method[])i.next();
System.arraycopy(m, 0, result, index, m.length);
index += m.length;
}
return result;
}
/**
* Returns the first method that matches the specified name and parameter types. The overriding
* methods have priority. The method is chosen from all the methods of the current class and all
* its superclasses and superinterfaces.
*
* @return the matching method or null if no mathching method has been found.
*/
static Method getMethod(Class target, String methodName, Class[] types) {
if (types == null) {
types = new Class[0];
}
Method[] methods = getAllMethods(target);
methods: for(int i = 0; i < methods.length; i++) {
Method m = methods[i];
if (!methodName.equals(m.getName())) {
continue;
}
Class[] parameters = m.getParameterTypes();
if (types.length != parameters.length) {
continue;
}
for(int j = 0; j < types.length; j++) {
if(!parameters[j].isAssignableFrom(types[j])) {
// if (!types[j].equals(parameters[j])) {
continue methods;
}
}
return m;
}
return null;
}
/**
* Invokes the method with the supplied arguments against the target object.
* If a method lookup is provided, it will be used. Otherwise, the default
* method lookup will be used.
*
* @param target - the object that you want to invoke the method on
* @return an object
*/
public Object invoke(Object target) throws Exception {
Method meth=null;
if(method_name == null || target == null) {
if(log.isErrorEnabled()) log.error("method name or target is null");
return null;
}
Class cl=target.getClass();
switch(mode) {
case OLD:
meth=findMethod(cl);
break;
case METHOD:
if(this.method != null)
meth=this.method;
break;
case TYPES:
meth = getMethod(cl, method_name, types);
break;
case ID:
break;
default:
if(log.isErrorEnabled()) log.error("mode " + mode + " is invalid");
break;
}
if(meth != null) {
try {
return meth.invoke(target, args);
}
catch(InvocationTargetException target_ex) {
Throwable exception=target_ex.getTargetException();
if(exception instanceof Error) throw (Error)exception;
else if(exception instanceof RuntimeException) throw (RuntimeException)exception;
else if(exception instanceof Exception) throw (Exception)exception;
else throw new RuntimeException(exception);
}
}
else {
throw new NoSuchMethodException(method_name);
}
}
public Object invoke(Object target, Object[] args) throws Exception {
if(args != null)
this.args=args;
return invoke(target);
}
static Class[] getTypesFromString(Class cl, String[] signature) throws Exception {
String name;
Class parameter;
Class[] mytypes=new Class[signature.length];
for(int i=0; i < signature.length; i++) {
name=signature[i];
if("long".equals(name))
parameter=long.class;
else if("int".equals(name))
parameter=int.class;
else if("short".equals(name))
parameter=short.class;
else if("char".equals(name))
parameter=char.class;
else if("byte".equals(name))
parameter=byte.class;
else if("float".equals(name))
parameter=float.class;
else if("double".equals(name))
parameter=double.class;
else if("boolean".equals(name))
parameter=boolean.class;
else
parameter=Class.forName(name, false, cl.getClassLoader());
mytypes[i]=parameter;
}
return mytypes;
}
public String toString() {
StringBuilder ret=new StringBuilder();
boolean first=true;
if(method_name != null)
ret.append(method_name);
else
ret.append(method_id);
ret.append('(');
if(args != null) {
for(int i=0; i < args.length; i++) {
if(first)
first=false;
else
ret.append(", ");
ret.append(args[i]);
}
}
ret.append(')');
return ret.toString();
}
public String toStringDetails() {
StringBuilder ret=new StringBuilder();
ret.append("MethodCall ");
if(method_name != null)
ret.append("name=").append(method_name);
else
ret.append("id=").append(method_id);
ret.append(", number of args=").append((args != null? args.length : 0)).append(')');
if(args != null) {
ret.append("\nArgs:");
for(int i=0; i < args.length; i++) {
ret.append("\n[").append(args[i]).append(" (").
append((args[i] != null? args[i].getClass().getName() : "null")).append(")]");
}
}
return ret.toString();
}
public void writeExternal(ObjectOutput out) throws IOException {
if(method_name != null) {
out.writeBoolean(true);
out.writeUTF(method_name);
}
else {
out.writeBoolean(false);
out.writeShort(method_id);
}
out.writeObject(args);
out.writeShort(mode);
switch(mode) {
case OLD:
break;
case METHOD:
out.writeObject(method.getParameterTypes());
out.writeObject(method.getDeclaringClass());
break;
case TYPES:
out.writeObject(types);
break;
case ID:
break;
default:
if(log.isErrorEnabled()) log.error("mode " + mode + " is invalid");
break;
}
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
boolean name_available=in.readBoolean();
if(name_available)
method_name=in.readUTF();
else
method_id=in.readShort();
args=(Object[])in.readObject();
mode=in.readShort();
switch(mode) {
case OLD:
break;
case METHOD:
Class[] parametertypes=(Class[])in.readObject();
Class declaringclass=(Class)in.readObject();
try {
method=declaringclass.getDeclaredMethod(method_name, parametertypes);
}
catch(NoSuchMethodException e) {
throw new IOException(e.toString());
}
break;
case TYPES:
types=(Class[])in.readObject();
break;
case ID:
break;
default:
if(log.isErrorEnabled()) log.error("mode " + mode + " is invalid");
break;
}
}
public static Object convert(String arg, Class<?> type) {
if(type == String.class)
return arg;
if(type == boolean.class || type == Boolean.class)
return Boolean.valueOf(arg);
if(type == byte.class || type == Byte.class)
return Byte.valueOf(arg);
if(type == short.class || type == Short.class)
return Short.valueOf(arg);
if(type == int.class || type == Integer.class)
return Integer.valueOf(arg);
if(type == long.class || type == Long.class)
return Long.valueOf(arg);
if(type == float.class || type == Float.class)
return Float.valueOf(arg);
if(type == double.class || type == Double.class)
return Double.valueOf(arg);
return arg;
}
}