X-Git-Url: http://wamblee.org/gitweb/?a=blobdiff_plain;f=system%2Fgeneral%2Fsrc%2Fmain%2Fjava%2Forg%2Fwamblee%2Fsystem%2Fadapters%2FConstructorConfiguration.java;fp=system%2Fgeneral%2Fsrc%2Fmain%2Fjava%2Forg%2Fwamblee%2Fsystem%2Fadapters%2FConstructorConfiguration.java;h=2725d0338fcae9026cf8f02754da8c2e5453f6f8;hb=7273d083a2f03cd3d2061d3c6628a46b679e718b;hp=0000000000000000000000000000000000000000;hpb=54b3f906ff4cb24e0deb3714a1c31a832abe1b5d;p=utils

diff --git a/system/general/src/main/java/org/wamblee/system/adapters/ConstructorConfiguration.java b/system/general/src/main/java/org/wamblee/system/adapters/ConstructorConfiguration.java
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+/*
+ * Copyright 2008 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */ 
+package org.wamblee.system.adapters;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Member;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.wamblee.collections.CollectionFilter;
+import org.wamblee.conditions.Condition;
+import org.wamblee.system.core.RequiredInterface;
+import org.wamblee.system.core.Scope;
+import org.wamblee.system.core.SystemAssemblyException;
+
+public class ConstructorConfiguration {
+	private Class _class; 
+	private Constructor<?> _constructor;
+	private ParameterValues _values;
+	private boolean _publicOnly; 
+
+	/**
+	 * Constructs the configuration. By default no constructor is selected and 
+	 * one of {@link #select(Class...)} or 
+	 * {@link #greedy()} must be called.  
+	 * @param aClass Class to construct. 
+	 */
+	public ConstructorConfiguration(Class aClass) {
+		_class = aClass; 
+		_constructor = null;  
+		_publicOnly = true; 
+	}
+	
+	/**
+	 * Sets whether or no non public constructors are also considered.
+	 * Reset the choice of a constructor. 
+	 * @param aNonPublic
+	 * @return
+	 */
+	public ConstructorConfiguration setNonPublic(boolean aNonPublic) { 
+		_publicOnly = !aNonPublic;
+		_constructor = null;
+		_values = null;
+		return this; 
+	}
+	
+	/**
+	 * Selects an explicit constructor.
+	 * @param aTypes Arguments of the constructor.
+	 * @return Return the injector to allow call chaining. 
+	 */
+	public ConstructorConfiguration select(Class... aTypes) {
+		try {
+			_constructor = _class.getDeclaredConstructor(aTypes); 
+		} catch (Exception e) {
+			throw new SystemAssemblyException(e.getMessage(), e);
+		}
+		resetValues(); 
+		return this; 
+	}
+	
+	/**
+	 * Selects the greediest constructor. 
+	 * @return The injector to allow call chaining.
+	 * @throws SystemAssemblyException if the greediest constructor cannot be uniquely 
+	 *    identified.  
+	 */
+	public ConstructorConfiguration greedy() { 
+		Constructor<?>[] declared = _class.getDeclaredConstructors();
+		if (declared.length == 0) {
+			throw new SystemAssemblyException("Class '" + _class
+					+ " is an interface, primitive type, or array");
+		}
+		int max = -1;
+		List<Constructor<?>> checked = new ArrayList<Constructor<?>>();
+		CollectionFilter.filter(Arrays.asList(declared), checked, 
+			new Condition<Constructor<?>>() { 
+			@Override
+			public boolean matches(Constructor<?> aObject) {
+				if ( !_publicOnly ) { 
+					return true; 
+				} else { 
+					return Modifier.isPublic(aObject.getModifiers());
+				}
+			}
+		});
+		for (Constructor ctor : checked) {
+			if (ctor.getParameterTypes().length > max) {
+				max = ctor.getParameterTypes().length;
+			}
+		}
+		final int max2 = max;
+		List<Constructor<?>> ctors = checked;
+		List<Constructor<?>> longest = new ArrayList<Constructor<?>>();
+		CollectionFilter.filter(ctors, longest,
+				new Condition<Constructor<?>>() {
+					@Override
+					public boolean matches(Constructor<?> aObject) {
+						return aObject.getParameterTypes().length == max2;
+					}
+				});
+		if (longest.size() > 1) {
+			throw new SystemAssemblyException(
+					"Greediest constructor cannot be uniquely determined");
+		}
+	    _constructor = longest.get(0);
+	    resetValues();
+	    return this; 
+	}
+	
+	public ParameterValues getParameters() {
+		getConstructor(); // initialize constructor if needed.
+		return _values; 
+	}
+
+	/**
+	 * Resets the values. 
+	 */
+	private void resetValues() {
+		_constructor.setAccessible(true);
+		_values = new ParameterValues(_constructor.getParameterTypes()); 	
+	}
+
+	/**
+	 * Creates the object in the given scope. 
+	 * @param aScope Scope containing required interfaces for this object. 
+	 * @return object. 
+	 */
+	public Object create(Scope aScope) {
+		Object[] values = _values.values(aScope);
+		try {
+			return getConstructor().newInstance(values);
+		} catch (Exception e) {
+			throw new SystemAssemblyException("Could not construct object "
+					+ getConstructor() + " " + Arrays.asList(values), e);
+		}
+	}
+	
+	public List<RequiredInterface> getRequiredInterfaces() {
+		getConstructor(); // initialize constructor if needed.
+		return _values.getRequiredInterfaces(); 
+	}
+	
+	private Constructor getConstructor() { 
+		if (_constructor == null ) { 
+			greedy(); 
+		}
+		return _constructor; 
+	}
+}