--- /dev/null
+/*
+ * Copyright (c) 2003-2005 The BISON Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+package peersim.vector;
+
+import java.lang.reflect.*;
+import peersim.config.*;
+import peersim.core.*;
+
+/**
+ * Vectors can be written through this class. Typically {@link Control} classes
+ * use this to manipulate vectors.
+ * <p>
+ * The method to be used is specified at construction time.
+ * For backward compatibility, if no method is specified, the method
+ * <code>getValue</code> is used. In this way, protocols
+ * implementing the {@link SingleValue} interface can be manipulated using the
+ * old configuration syntax (i.e., without specifying the method).
+ * <p>
+ * Please refer to package {@link peersim.vector} for a detailed description of
+ * the concept of protocol vector and the role of getters and setters.
+ */
+public class Getter {
+
+// ============================ fields ===================================
+// =======================================================================
+
+private final String protocol;
+private final String methodn;
+private final String prefix;
+
+/** Identifier of the protocol that defines the vector */
+private int pid;
+
+/** Getter method name */
+private String methodName;
+
+/** Getter method */
+private Method method = null;
+
+/** Parameter type of getter method */
+private Class type;
+
+
+// ========================== initialization =============================
+// =======================================================================
+
+
+/**
+ * Constructs a Getter class based on the configuration. Note that the
+ * actual initialization is delayed until the first access to the class,
+ * so that if a class is not used, no unnecessary error messages and exceptions
+ * are generated.
+ * @param prefix the configuration prefix to use when reading the configuration
+ * @param protocol the configuration parameter name that contains
+ * the protocol we want to manipulate using a getter method.
+ * The parameter <code>prefix + "." + protocol</code> is read.
+ * @param methodn the configuration parameter name that contains the getter
+ * method name.
+ * The parameter <code>prefix + "." + methodn</code> is read, with the default
+ * value <code>getValue</code>.
+ */
+public Getter(String prefix, String protocol, String methodn) {
+
+ this.prefix=prefix;
+ this.protocol=protocol;
+ this.methodn=methodn;
+}
+
+// --------------------------------------------------------------------------
+
+/** Performs actual initialization */
+private void init() {
+
+ if( method!=null) return;
+
+ // Read configuration parameter
+ pid = Configuration.getPid(prefix + "." + protocol);
+ methodName = Configuration.getString(prefix+"."+methodn,"getValue");
+ // Search the method
+ Class clazz = Network.prototype.getProtocol(pid).getClass();
+ try {
+ method = GetterSetterFinder.getGetterMethod(clazz, methodName);
+ } catch (NoSuchMethodException e) {
+ throw new IllegalParameterException(prefix + "." +
+ methodn, e+"");
+ }
+ // Obtain the type of the field
+ type = GetterSetterFinder.getGetterType(method);
+}
+
+
+// =============================== methods =============================
+// =====================================================================
+
+/**
+* @return type of return value of getter method
+*/
+public Class getType() {
+
+ init();
+ return type;
+}
+
+// --------------------------------------------------------------------------
+
+/**
+* Gets the given value as a Number.
+* @param n The node to get the value on. The protocol is defined
+* by {@link #pid}.
+* @return the read value.
+*/
+public Number get(Node n) {
+
+ init();
+
+ try
+ {
+ Object ret =method.invoke(n.getProtocol(pid));
+ if (ret instanceof Boolean)
+ return ((Boolean) ret) ? 1 : 0;
+ else
+ return (Number) ret;
+ }
+ catch (Exception e)
+ {
+ throw new RuntimeException("While using getter "+methodName,e);
+ }
+}
+
+// --------------------------------------------------------------------------
+
+/**
+* Gets the given integer value.
+* @param n The node to get the value on. The protocol is defined
+* by {@link #pid}.
+* @return the read value.
+*/
+public long getLong(Node n) {
+
+ init();
+
+ if(type==long.class || type==int.class)
+ {
+ try
+ {
+ return ((Number)
+ method.invoke(n.getProtocol(pid))).longValue();
+ }
+ catch (Exception e)
+ {
+ throw new RuntimeException(
+ "While using getter "+methodName,e);
+ }
+ }
+ else throw new RuntimeException("type has to be int or long");
+}
+
+// --------------------------------------------------------------------------
+
+/**
+* Gets the given real value.
+* @param n The node to get the value on. The protocol is defined
+* by {@link #pid}.
+* @return the read value.
+*/
+public double getDouble(Node n) {
+
+ init();
+
+ if(type==double.class || type==float.class)
+ {
+ try
+ {
+ return ((Number)
+ method.invoke(n.getProtocol(pid))).doubleValue();
+ }
+ catch (Exception e)
+ {
+ throw new RuntimeException(
+ "While using getter "+methodName,e);
+ }
+ }
+ else throw new RuntimeException(
+ "type has to be double or float");
+}
+
+// --------------------------------------------------------------------------
+
+/**
+* Gets the given value as a Number.
+* @param i The index of the node to get the value on in the network.
+* The protocol is defined
+* by {@link #pid}.
+* @return the read value.
+*/
+public Number get(int i) { return get(Network.get(i)); }
+
+// --------------------------------------------------------------------------
+
+/**
+* Gets the given integer value.
+* @param i The index of the node to get the value on in the network.
+* The protocol is defined
+* by {@link #pid}.
+* @return the read value.
+*/
+public long getLong(int i) { return getLong(Network.get(i)); }
+
+// --------------------------------------------------------------------------
+
+/**
+* Gets the given real value.
+* @param i The index of the node to get the value on in the network.
+* The protocol is defined
+* by {@link #pid}.
+* @return the read value.
+*/
+public double getDouble(int i) { return getDouble(Network.get(i)); }
+
+}
+
