WELDX-181 enforce JavaBean conventions

- enforce the JavaBean conventions when creating a property from a method
- write tests to validate that method is handled propertly
- include reference to JavaBean spec document

impl/src/main/java/org/jboss/weld/extensions/properties/MethodPropertyImpl.java

@@ -15,31 +15,71 @@
  * 
  * @author Pete Muir
  * @author Shane Bryzak
+ * @author Dan Allen
  */
 class MethodPropertyImpl<V> implements MethodProperty<V>
 {
+   private static final String GETTER_METHOD_PREFIX = "get";
+   private static final String SETTER_METHOD_PREFIX = "set";
+   private static final String BOOLEAN_GETTER_METHOD_PREFIX = "is";
+
+   private static final int GETTER_METHOD_PREFIX_LENGTH = GETTER_METHOD_PREFIX.length();
+   private static final int SETTER_METHOD_PREFIX_LENGTH = SETTER_METHOD_PREFIX.length();
+   private static final int BOOLEAN_GETTER_METHOD_PREFIX_LENGTH = BOOLEAN_GETTER_METHOD_PREFIX.length();
+
    private final Method getterMethod;
    private final String propertyName;
    private final Method setterMethod;
 
    public MethodPropertyImpl(Method method)
    {
-      if (method.getName().startsWith("get"))
+      final String accessorMethodPrefix;
+      final String propertyNameInAccessorMethod;
+      if (method.getName().startsWith(GETTER_METHOD_PREFIX))
       {
-         this.propertyName = Introspector.decapitalize(method.getName().substring(3));
+         if (method.getReturnType() == Void.TYPE)
+         {
+            throw new IllegalArgumentException("Invalid accessor method, must have return value if starts with 'get'. Method: " + method);
+         }
+         else if (method.getParameterTypes().length > 0)
+         {
+            throw new IllegalArgumentException("Invalid accessor method, must have zero arguments if starts with 'get'. Method: " + method);
+         }
+         propertyNameInAccessorMethod = method.getName().substring(GETTER_METHOD_PREFIX_LENGTH);
+         accessorMethodPrefix = GETTER_METHOD_PREFIX;
       }
-      else if (method.getName().startsWith("set"))
+      else if (method.getName().startsWith(SETTER_METHOD_PREFIX))
       {
-         this.propertyName = Introspector.decapitalize(method.getName().substring(3));
+         if (method.getReturnType() != Void.TYPE)
+         {
+            throw new IllegalArgumentException("Invalid accessor method, must not have return value if starts with 'set'. Method: " + method);
+         }
+         else if (method.getParameterTypes().length != 1)
+         {
+            throw new IllegalArgumentException("Invalid accessor method, must have one argument if starts with 'set'. Method: " + method);
+         }
+         propertyNameInAccessorMethod = method.getName().substring(SETTER_METHOD_PREFIX_LENGTH);
+         accessorMethodPrefix = SETTER_METHOD_PREFIX;
       }
-      else if (method.getName().startsWith("is"))
+      else if (method.getName().startsWith(BOOLEAN_GETTER_METHOD_PREFIX))
       {
-         this.propertyName = Introspector.decapitalize(method.getName().substring(2));
+         if (method.getReturnType() != Boolean.class || !method.getReturnType().isPrimitive())
+         {
+            throw new IllegalArgumentException("Invalid accessor method, must return boolean primitive if starts with 'is'. Method: " + method);
+         }
+         propertyNameInAccessorMethod = method.getName().substring(BOOLEAN_GETTER_METHOD_PREFIX_LENGTH);
+         accessorMethodPrefix = BOOLEAN_GETTER_METHOD_PREFIX;
       }
       else
       {
          throw new IllegalArgumentException("Invalid accessor method, must start with 'get', 'set' or 'is'.  " + "Method: " + method);
       }
+      if (propertyNameInAccessorMethod.length() == 0 || !Character.isUpperCase(propertyNameInAccessorMethod.charAt(0)))
+      {
+         throw new IllegalArgumentException("Invalid accessor method, prefix '" + accessorMethodPrefix +
+               "' must be followed a non-empty property name, capitalized. Method: " + method);
+      }
+      this.propertyName = Introspector.decapitalize(propertyNameInAccessorMethod);
       this.getterMethod = getGetterMethod(method.getDeclaringClass(), propertyName);
       this.setterMethod = getSetterMethod(method.getDeclaringClass(), propertyName);
    }
@@ -86,9 +126,9 @@ private static Method getSetterMethod(Class<?> clazz, String name)
       for (Method method : methods)
       {
          String methodName = method.getName();
-         if (methodName.startsWith("set") && method.getParameterTypes().length == 1)
+         if (methodName.startsWith(SETTER_METHOD_PREFIX) && method.getParameterTypes().length == 1)
          {
-            if (Introspector.decapitalize(methodName.substring(3)).equals(name))
+            if (Introspector.decapitalize(methodName.substring(SETTER_METHOD_PREFIX_LENGTH)).equals(name))
             {
                return method;
             }
@@ -104,16 +144,16 @@ private static Method getGetterMethod(Class<?> clazz, String name)
          String methodName = method.getName();
          if (method.getParameterTypes().length == 0)
          {
-            if (methodName.startsWith("get"))
+            if (methodName.startsWith(GETTER_METHOD_PREFIX))
             {
-               if (Introspector.decapitalize(methodName.substring(3)).equals(name))
+               if (Introspector.decapitalize(methodName.substring(GETTER_METHOD_PREFIX_LENGTH)).equals(name))
                {
                   return method;
                }
             }
-            else if (methodName.startsWith("is"))
+            else if (methodName.startsWith(BOOLEAN_GETTER_METHOD_PREFIX))
             {
-               if (Introspector.decapitalize(methodName.substring(2)).equals(name))
+               if (Introspector.decapitalize(methodName.substring(BOOLEAN_GETTER_METHOD_PREFIX_LENGTH)).equals(name))
                {
                   return method;
                }

impl/src/main/java/org/jboss/weld/extensions/properties/Properties.java

@@ -36,6 +36,8 @@ public static <V> FieldProperty<V> createProperty(Field field)
     * @param method
     * @return
     * @throws IllegalArgumentException if the method does not match JavaBean conventions
+    * 
+    * @see http://www.oracle.com/technetwork/java/javase/documentation/spec-136004.html
     */
    public static <V> MethodProperty<V> createProperty(Method method)
    {
@@ -49,6 +51,8 @@ public static <V> MethodProperty<V> createProperty(Method method)
     * @param member
     * @return
     * @throws IllegalArgumentException if the method does not match JavaBean conventions
+    * 
+    * @see http://www.oracle.com/technetwork/java/javase/documentation/spec-136004.html
     */
    public static <V> Property<V> createProperty(Member member)
    {

impl/src/test/java/org/jboss/weld/extensions/test/properties/ClassToIntrospect.java

@@ -0,0 +1,70 @@
+package org.jboss.weld.extensions.test.properties;
+
+import java.net.URL;
+
+public class ClassToIntrospect
+{
+   private String name;
+
+   private String p;
+
+   private URL URL;
+
+   public String getName()
+   {
+      return name;
+   }
+
+   public void setName(String name)
+   {
+      this.name = name;
+   }
+
+   public String getP()
+   {
+      return p;
+   }
+
+   public void setP(String p)
+   {
+      this.p = p;
+   }
+
+   public String getTitle()
+   {
+      return "Hero";
+   }
+
+   public String get()
+   {
+      return null;
+   }
+
+   public boolean is()
+   {
+      return false;
+   }
+
+   public void getFooBar()
+   {
+   }
+
+   public void setSalary(Double base, Double bonus)
+   {
+   }
+
+   public URL getURL()
+   {
+      return URL;
+   }
+
+   public void setURL(URL URL)
+   {
+      this.URL = URL;
+   }
+
+   public Boolean isValid()
+   {
+      return false;
+   }
+}

impl/src/test/java/org/jboss/weld/extensions/test/properties/PropertyFromMethodTest.java

@@ -0,0 +1,106 @@
+package org.jboss.weld.extensions.test.properties;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.lang.reflect.Method;
+import java.net.URL;
+
+import org.jboss.weld.extensions.properties.Properties;
+import org.jboss.weld.extensions.properties.Property;
+import org.junit.Test;
+
+/**
+ * Verify that only valid properties are permitted, as per the JavaBean specification.
+ * 
+ * @author Dan Allen
+ * @see http://www.oracle.com/technetwork/java/javase/documentation/spec-136004.html
+ */
+public class PropertyFromMethodTest
+{
+   @Test
+   public void testValidPropertyGetterMethod() throws Exception
+   {
+      Method getter = ClassToIntrospect.class.getMethod("getName");
+      Property<String> p = Properties.createProperty(getter);
+      assertNotNull(p);
+      assertEquals("name", p.getName());
+      assertEquals(getter, p.getMember());
+   }
+
+   @Test
+   public void testValidPropertySetterMethod() throws Exception
+   {
+      Property<String> p = Properties.createProperty(ClassToIntrospect.class.getMethod("setName", String.class));
+      assertNotNull(p);
+      assertEquals("name", p.getName());
+   }
+
+   @Test
+   public void testReadOnlyProperty() throws Exception
+   {
+      Property<String> p = Properties.createProperty(ClassToIntrospect.class.getMethod("getTitle"));
+      assertNotNull(p);
+      assertEquals("title", p.getName());
+      assertTrue(p.isReadOnly());
+   }
+
+   @Test(expected = IllegalArgumentException.class)
+   public void testEmptyPropertyGetterMethod() throws Exception
+   {
+      Properties.createProperty(ClassToIntrospect.class.getMethod("get"));
+   }
+
+   @Test(expected = IllegalArgumentException.class)
+   public void testEmptyBooleanPropertyGetterMethod() throws Exception
+   {
+      Properties.createProperty(ClassToIntrospect.class.getMethod("is"));
+   }
+
+   @Test(expected = IllegalArgumentException.class)
+   public void testNonPrimitiveBooleanPropertyIsMethod() throws Exception
+   {
+      Properties.createProperty(ClassToIntrospect.class.getMethod("isValid"));
+   }
+
+   @Test
+   public void testSingleCharPropertyGetterMethod() throws Exception
+   {
+      Method getter = ClassToIntrospect.class.getMethod("getP");
+      Property<String> p = Properties.createProperty(getter);
+      assertNotNull(p);
+      assertEquals("p", p.getName());
+      assertEquals(getter, p.getMember());
+   }
+
+   @Test
+   public void testSingleCharPropertySetterMethod() throws Exception
+   {
+      Property<String> p = Properties.createProperty(ClassToIntrospect.class.getMethod("setP", String.class));
+      assertNotNull(p);
+      assertEquals("p", p.getName());
+   }
+
+   @Test(expected = IllegalArgumentException.class)
+   public void testGetterMethodWithVoidReturnType() throws Exception
+   {
+      Properties.createProperty(ClassToIntrospect.class.getMethod("getFooBar"));
+   }
+
+   @Test(expected = IllegalArgumentException.class)
+   public void testSetterMethodWithMultipleParameters() throws Exception
+   {
+      Properties.createProperty(ClassToIntrospect.class.getMethod("setSalary", Double.class, Double.class));
+   }
+
+   @Test
+   public void testAcronymProperty() throws Exception
+   {
+      Method getter = ClassToIntrospect.class.getMethod("getURL");
+      Property<URL> p = Properties.createProperty(getter);
+      assertNotNull(p);
+      assertEquals("URL", p.getName());
+      assertEquals(getter, p.getMember());
+   }
+}