Add converters module and protobuf converter.

pom.xml

@@ -34,6 +34,7 @@
 
   <modules>
     <module>retrofit</module>
+    <module>retrofit-converters</module>
     <module>retrofit-samples</module>
   </modules>
 
@@ -48,8 +49,10 @@
     <android.version>4.1.1.4</android.version>
     <android.platform>16</android.platform>
     <gson.version>2.2.4</gson.version>
-    <javax.inject.version>1</javax.inject.version>
-    <okhttp.version>1.0.2</okhttp.version>
+    <okhttp.version>1.1.1</okhttp.version>
+
+    <!-- Converter Dependencies -->
+    <protobuf.version>2.5.0</protobuf.version>
 
     <!-- Test Dependencies -->
     <junit.version>4.10</junit.version>
@@ -99,6 +102,12 @@
         <version>${gson.version}</version>
       </dependency>
 
+      <dependency>
+        <groupId>com.google.protobuf</groupId>
+        <artifactId>protobuf-java</artifactId>
+        <version>${protobuf.version}</version>
+      </dependency>
+
       <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>

retrofit-converters/README.md

@@ -0,0 +1,14 @@
+Retrofit Converters
+===================
+
+Retrofit ships with a default converter for JSON that uses Gson but the library is content-format
+agnostic. The child modules contained herein are additional converters for other popular formats.
+
+To use, supply an instance of your desired converter when building your `RestAdapter` instance.
+
+```java
+RestAdapter restAdapter = new RestAdapter.Builder()
+    .setServer("https://api.fake.google.com")
+    .setConverter(new ProtoConverter())
+    .build();
+```

retrofit-converters/pom.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>com.squareup.retrofit</groupId>
+    <artifactId>parent</artifactId>
+    <version>1.1.2-SNAPSHOT</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+
+  <artifactId>retrofit-converters</artifactId>
+  <name>Converters</name>
+  <packaging>pom</packaging>
+
+  <modules>
+    <module>protobuf</module>
+  </modules>
+</project>

retrofit-converters/protobuf/pom.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>com.squareup.retrofit</groupId>
+    <artifactId>retrofit-converters</artifactId>
+    <version>1.1.2-SNAPSHOT</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+
+  <artifactId>converter-protobuf</artifactId>
+  <name>Converter: Protocol Buffers</name>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.squareup.retrofit</groupId>
+      <artifactId>retrofit</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.google.protobuf</groupId>
+      <artifactId>protobuf-java</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.easytesting</groupId>
+      <artifactId>fest-assert-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+</project>

retrofit-converters/protobuf/src/main/java/retrofit/converter/ProtoConverter.java

@@ -0,0 +1,55 @@
+// Copyright 2013 Square, Inc.
+package retrofit.converter;
+
+import com.google.protobuf.AbstractMessageLite;
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+import retrofit.mime.TypedByteArray;
+import retrofit.mime.TypedInput;
+import retrofit.mime.TypedOutput;
+
+/** A {@link Converter} that reads and writes protocol buffers. */
+public class ProtoConverter implements Converter {
+  private static final String MIME_TYPE = "application/x-protobuf";
+
+  @Override public Object fromBody(TypedInput body, Type type) throws ConversionException {
+    if (!(type instanceof Class<?>)) {
+      throw new IllegalArgumentException("Expected a raw Class<?> but was " + type);
+    }
+    Class<?> c = (Class<?>) type;
+    if (!AbstractMessageLite.class.isAssignableFrom(c)) {
+      throw new IllegalArgumentException("Expected a protobuf message but was " + c.getName());
+    }
+
+    String mimeType = body.mimeType();
+    if (!MIME_TYPE.equals(mimeType)) {
+      throw new ConversionException("Response content type was not a proto: " + mimeType);
+    }
+
+    try {
+      Method parseFrom = c.getMethod("parseFrom", InputStream.class);
+      return parseFrom.invoke(null, body.in());
+    } catch (InvocationTargetException e) {
+      throw new ConversionException(c.getName() + ".parseFrom() failed", e.getCause());
+    } catch (NoSuchMethodException e) {
+      throw new IllegalArgumentException("Expected a protobuf message but was " + c.getName());
+    } catch (IllegalAccessException e) {
+      throw new AssertionError();
+    } catch (IOException e) {
+      throw new ConversionException(e);
+    }
+  }
+
+  @Override public TypedOutput toBody(Object object) {
+    if (!(object instanceof AbstractMessageLite)) {
+      throw new IllegalArgumentException(
+          "Expected a protobuf message but was " + (object != null ? object.getClass().getName()
+              : "null"));
+    }
+    byte[] bytes = ((AbstractMessageLite) object).toByteArray();
+    return new TypedByteArray(MIME_TYPE, bytes);
+  }
+}

retrofit-converters/protobuf/src/test/gen-protos.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+set -ex
+protoc --java_out=java/ protos/phone.proto