Migrated attachment for Guice issue 22, comment 1

guice-converter.patch

Index: C:/Documents and Settings/Michael.Barker/src/guice/test/com/google/inject/CustomConverterTest.java
===================================================================
--- C:/Documents and Settings/Michael.Barker/src/guice/test/com/google/inject/CustomConverterTest.java	(revision 0)
+++ C:/Documents and Settings/Michael.Barker/src/guice/test/com/google/inject/CustomConverterTest.java	(revision 0)
@@ -0,0 +1,111 @@
+package com.google.inject;
+
+import java.lang.reflect.Member;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import junit.framework.TestCase;
+
+import com.google.inject.name.Named;
+import com.google.inject.name.Names;
+
+public class CustomConverterTest extends TestCase {
+
+  public void testURLConversion() {
+    Injector inj = Guice.createInjector(new AbstractModule() {
+      protected void configure() {
+        bind(Foo.class).to(FooImpl.class);
+        binder().bindConverter(URL.class, new URLConverter());
+        Map<String,String> config = new HashMap<String,String>();
+        config.put("bar", "http://www.google.com");
+        Names.bindProperties(binder(), config);
+      }
+    });
+    Foo f = inj.getInstance(Foo.class);
+    URL url = f.getBar();
+    assertEquals("www.google.com", url.getHost());
+  }
+  
+  public void testArrayConversion() {
+    Injector inj = Guice.createInjector(new AbstractModule() {
+      protected void configure() {
+        bind(Tee.class).to(TeeImpl.class);
+        binder().bindConverter(String[].class, new ArrayConverter());
+        Map<String,String> config = new HashMap<String,String>();
+        config.put("bar", "this,is,a,test,string");
+        Names.bindProperties(binder(), config);
+      }
+    });
+    Tee tee = inj.getInstance(Tee.class);
+    String[] bar = tee.getBar();
+    assertTrue(Arrays.equals(bar, 
+        new String[] { "this","is","a","test","string" }));
+  }
+  
+  public void testURLConversionError() {
+    try {
+      Injector inj = Guice.createInjector(new AbstractModule() {
+        protected void configure() {
+          bind(Foo.class).to(FooImpl.class);
+          binder().bindConverter(URL.class, new URLConverter());
+          Map<String,String> config = new HashMap<String,String>();
+          config.put("bar", "www.google.com");
+          Names.bindProperties(binder(), config);
+        }
+      });
+      inj.getInstance(Foo.class);
+      assertFalse("CreationException should be thrown", true);
+    } catch (CreationException e) {
+    }
+  }
+  
+  static class URLConverter implements Converter<URL> {
+
+    public URL convert(Member member, Key<URL> key, String value) 
+        throws ConstantConversionException {
+      try {
+        return new URL(value);
+      } catch (MalformedURLException e) {
+        throw new ConstantConversionException(member, key, value, e);
+      }
+    }
+    
+  }
+  
+  static class ArrayConverter implements Converter<String[]> {
+
+    public String[] convert(Member member, Key<String[]> key, String value) 
+        throws ConstantConversionException {
+      return value.split(",");
+    }
+    
+  }
+  
+  static interface Foo {
+    URL getBar();
+  }
+  
+  static class FooImpl implements Foo {
+    @Inject @Named("bar") URL bar;
+
+    public URL getBar() {
+      return bar;
+    }
+  }
+  
+  static interface Tee {
+    String[] getBar();
+  }
+  
+  static class TeeImpl implements Tee {
+    @Inject @Named("bar") String[] bar;
+
+    public String[] getBar() {
+      return bar;
+    }
+  }
+  
+}
Index: C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/Binder.java
===================================================================
--- C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/Binder.java	(revision 326)
+++ C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/Binder.java	(working copy)
@@ -16,13 +16,15 @@
 
 package com.google.inject;
 
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
+
+import org.aopalliance.intercept.MethodInterceptor;
+
 import com.google.inject.binder.AnnotatedBindingBuilder;
 import com.google.inject.binder.AnnotatedConstantBindingBuilder;
 import com.google.inject.binder.LinkedBindingBuilder;
 import com.google.inject.matcher.Matcher;
-import java.lang.annotation.Annotation;
-import java.lang.reflect.Method;
-import org.aopalliance.intercept.MethodInterceptor;
 
 /**
  * Collects configuration information (primarily <i>bindings</i>) which will be
@@ -201,6 +203,11 @@
    * Binds a scope to an annotation.
    */
   void bindScope(Class<? extends Annotation> annotationType, Scope scope);
+  
+  /**
+   * Binds a convertor to a class.
+   */
+  <T> void bindConverter(Class<T> type, Converter<? extends T> customConverter);
 
   /**
    * See the EDSL examples at {@link Binder}.
Index: C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/Converter.java
===================================================================
--- C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/Converter.java	(revision 0)
+++ C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/Converter.java	(revision 0)
@@ -0,0 +1,15 @@
+package com.google.inject;
+
+import java.lang.reflect.Member;
+
+/**
+ * Converts a {@code String} to another type.
+ */
+public interface Converter<T> {
+
+  /**
+   * Converts {@code String} value.
+   */
+  T convert(Member member, Key<T> key, String value)
+      throws ConstantConversionException;
+}
\ No newline at end of file
Index: C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/InjectorImpl.java
===================================================================
--- C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/InjectorImpl.java	(revision 326)
+++ C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/InjectorImpl.java	(working copy)
@@ -86,16 +86,20 @@
   final Map<Key<?>, BindingImpl<?>> bindings;
   final BindingsMultimap bindingsMultimap = new BindingsMultimap();
   final Map<Class<? extends Annotation>, Scope> scopes;
+  final Map<Class<?>, Converter<?>> customConverters;
 
   ErrorHandler errorHandler = new InvalidErrorHandler();
   Object defaultSource = SourceProviders.UNKNOWN_SOURCE;
 
+
   InjectorImpl(ConstructionProxyFactory constructionProxyFactory,
       Map<Key<?>, BindingImpl<?>> bindings,
-      Map<Class<? extends Annotation>, Scope> scopes) {
+      Map<Class<? extends Annotation>, Scope> scopes,
+      Map<Class<?>, Converter<?>> customConverters) {
     this.constructionProxyFactory = constructionProxyFactory;
     this.bindings = bindings;
     this.scopes = scopes;
+    this.customConverters = customConverters;
   }
 
   /**
@@ -220,6 +224,18 @@
 
       // TODO: Generalize everything below here and enable users to plug in
       // their own converters.
+      // Do we need a custom conversion?
+      Converter<T> custom = (Converter<T>) customConverters.get(rawType);
+      if (custom != null) {
+        try {
+          T t = custom.convert(member, key, value);
+          return new ConstantFactory<T>(t);
+        }
+        catch (ConstantConversionException e) {
+          return handleConstantConversionError(
+              member, stringBinding, rawType, e);
+        }
+      }
 
       // Do we need a primitive?
       Converter<T> converter = (Converter<T>) PRIMITIVE_CONVERTERS.get(rawType);
@@ -861,18 +877,6 @@
     }
   }
 
-  /**
-   * Converts a {@code String} to another type.
-   */
-  interface Converter<T> {
-
-    /**
-     * Converts {@code String} value.
-     */
-    T convert(Member member, Key<T> key, String value)
-        throws ConstantConversionException;
-  }
-
   Map<Class<?>, InternalFactory<?>> implicitBindings =
       new HashMap<Class<?>, InternalFactory<?>>();
 
Index: C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/BinderImpl.java
===================================================================
--- C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/BinderImpl.java	(revision 326)
+++ C:/Documents and Settings/Michael.Barker/src/guice/src/com/google/inject/BinderImpl.java	(working copy)
@@ -61,6 +61,8 @@
       = new ArrayList<ConstantBindingBuilderImpl>();
   final Map<Class<? extends Annotation>, Scope> scopes =
       new HashMap<Class<? extends Annotation>, Scope>();
+  final Map<Class<?>, Converter<?>> customConverters =
+      new HashMap<Class<?>, Converter<?>>();
 
   final List<StaticInjection> staticInjections
       = new ArrayList<StaticInjection>();
@@ -168,6 +170,13 @@
       scopes.put(annotationType, nonNull(scope, "scope"));
     }
   }
+  
+  /* (non-Javadoc)
+   * @see com.google.inject.Binder#bindConverter(java.lang.Class, com.google.inject.Converter)
+   */
+  public <T> void bindConverter(Class<T> type, Converter<? extends T> customConverter) {
+    customConverters.put(type, customConverter);
+  }
 
   public <T> BindingBuilderImpl<T> bind(Key<T> key) {
     BindingBuilderImpl<T> builder =
@@ -245,7 +254,7 @@
 
     Map<Key<?>, BindingImpl<?>> bindings = new HashMap<Key<?>, BindingImpl<?>>();
     injector = new InjectorImpl(
-        proxyFactoryBuilder.create(), bindings, scopes);
+        proxyFactoryBuilder.create(), bindings, scopes, customConverters);
     injector.setErrorHandler(configurationErrorHandler);
 
     createConstantBindings();