Adding config support.

5 files changed, 199 insertions, 4 deletions

diff --git a/build.xml b/build.xml
index 717de65..e409dc0 100644
--- a/build.xml
+++ b/build.xml
@@ -12,7 +12,10 @@
 
     <target name="frontend" depends="compile">
         <java classname="com.p4square.grow.frontend.GrowFrontend"
-            classpathref="classpath.run" fork="true" />
+            classpathref="classpath.run" fork="true">
+
+            <arg file="devfiles/dev-config-override.properties" />
+        </java>
     </target>
 
 </project>
diff --git a/devfiles/dev-config-override.properties b/devfiles/dev-config-override.properties
new file mode 100644
index 0000000..b1bd989
--- /dev/null
+++ b/devfiles/dev-config-override.properties
@@ -0,0 +1 @@
+dev.backendUri = http://localhost:9095
diff --git a/src/com/p4square/grow/config/Config.java b/src/com/p4square/grow/config/Config.java
new file mode 100644
index 0000000..f5ebe3c
--- /dev/null
+++ b/src/com/p4square/grow/config/Config.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.config;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.io.IOException;
+import java.util.Properties;
+
+import org.apache.log4j.Logger;
+
+/**
+ * Manage configuration for an application.
+ *
+ * Config reads one or more property files as the application config. Duplicate
+ * properties loaded later override properties loaded earlier. Config has the
+ * concept of a domain to distinguish settings for development and production.
+ * The default domain is prod for production. Domain can be any String such as
+ * dev for development or test for testing.
+ *
+ * The property files are processed like java.util.Properties except that the
+ * keys are specified as DOMAIN.KEY. An asterisk (*) can be used in place of a
+ * domain to indicate it should apply to all domains. If a domain specific entry
+ * exists for the current domain, it will override any global config.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class Config {
+    private static Logger cLog = Logger.getLogger(Config.class);
+
+    private String mDomain;
+    private Properties mProperties;
+
+    /**
+     * Construct a new Config object. Domain defaults to prod.
+     */
+    public Config() {
+        mDomain = "prod";
+        mProperties = new Properties();
+
+    }
+
+    /**
+     * Change the domain from the default string "prod".
+     *
+     * @param domain The new domain.
+     */
+    public void setDomain(String domain) {
+        mDomain = domain;
+    }
+
+    /**
+     * Load properties from a file.
+     * Any exceptions are logged and suppressed.
+     */
+    public void updateConfig(String propertyFilename) {
+        final File propFile = new File(propertyFilename);
+
+        cLog.info("Loading properties from " + propFile);
+
+        try {
+            InputStream in = new FileInputStream(propFile);
+            updateConfig(in);
+
+        } catch (IOException e) {
+            cLog.error("Could not load properties file: " + e.getMessage(), e);
+        }
+    }
+
+    /**
+     * Load properties from an InputStream.
+     * This method closes the InputStream when it completes.
+     *
+     * @param in The InputStream
+     */
+    public void updateConfig(InputStream in) throws IOException {
+        mProperties.load(in);
+        in.close();
+    }
+
+    /**
+     * Get a String from the config.
+     *
+     * @return The config value or null if it is not found.
+     */
+    public String getString(String key) {
+        return getString(key, null);
+    }
+
+    /**
+     * Get a String from the config.
+     *
+     * @return The config value or defaultValue if it can not be found.
+     */
+    public String getString(String key, String defaultValue) {
+        String result;
+
+        final String domainKey = mDomain + "." + key;
+        result = mProperties.getProperty(domainKey, defaultValue);
+        if (result != null) {
+            return result;
+        }
+
+        final String globalKey = "*." + key;
+        result = mProperties.getProperty(globalKey, defaultValue);
+        if (result != null) {
+            return result;
+        }
+
+        return defaultValue;
+    }
+
+    /**
+     * Get an integer from the config.
+     *
+     * @return The config value or Integer.MIN_VALUE if the key is not present or the
+     *         config can not be parsed.
+     */
+    public int getInt(String key) {
+        return getInt(key, Integer.MIN_VALUE);
+    }
+
+    /**
+     * Get an integer from the config.
+     *
+     * @return The config value or defaultValue if the key is not present or the
+     *         config can not be parsed.
+     */
+    public int getInt(String key, int defaultValue) {
+        final String propertyValue = getString(key);
+
+        if (propertyValue != null) {
+            try {
+                final int result = Integer.valueOf(propertyValue);
+                return result;
+
+            } catch (NumberFormatException e) {
+                cLog.warn("Expected property to be an integer: "
+                        + key + " = { " + propertyValue + " }");
+            }
+        }
+
+        return defaultValue;
+    }
+}
diff --git a/src/com/p4square/grow/frontend/GrowFrontend.java b/src/com/p4square/grow/frontend/GrowFrontend.java
index 72e2a8f..e3662d5 100644
--- a/src/com/p4square/grow/frontend/GrowFrontend.java
+++ b/src/com/p4square/grow/frontend/GrowFrontend.java
@@ -13,6 +13,8 @@ import org.apache.log4j.Logger;
 import net.jesterpm.fmfacade.FMFacade;
 import net.jesterpm.fmfacade.FreeMarkerPageResource;
 
+import com.p4square.grow.config.Config;
+
 /**
  * This is the Restlet Application implementing the Grow project front-end.
  * It's implemented as an extension of FMFacade that connects interactive pages
@@ -24,6 +26,34 @@ import net.jesterpm.fmfacade.FreeMarkerPageResource;
 public class GrowFrontend extends FMFacade {
     private static Logger cLog = Logger.getLogger(GrowFrontend.class);
 
+    private Config mConfig;
+
+    public GrowFrontend() {
+        mConfig = new Config();
+    }
+
+    public Config getConfig() {
+        return mConfig;
+    }
+
+    @Override
+    public void start() throws Exception {
+        super.start();
+
+        final String configDomain =
+            getContext().getParameters().getFirstValue("config-domain");
+        if (configDomain != null) {
+            mConfig.setDomain(configDomain);
+        }
+
+        final String configFilename =
+            getContext().getParameters().getFirstValue("config-file");
+
+        if (configFilename != null) {
+            mConfig.updateConfig(configFilename);
+        }
+    }
+
     @Override
     protected Router createRouter() {
         Router router = new Router(getContext());
@@ -54,7 +84,17 @@ public class GrowFrontend extends FMFacade {
         final Component component = new Component();
         component.getServers().add(Protocol.HTTP, 8085);
         component.getClients().add(Protocol.HTTP);
-        component.getDefaultHost().attach(new GrowFrontend());
+
+        // Setup App
+        GrowFrontend app = new GrowFrontend();
+
+        // Load an optional config file from the first argument.
+        app.getConfig().setDomain("dev");
+        if (args.length == 1) {
+            app.getConfig().updateConfig(args[0]);
+        }
+
+        component.getDefaultHost().attach(app);
 
         // Setup shutdown hook
         Runtime.getRuntime().addShutdownHook(new Thread() {
diff --git a/src/com/p4square/grow/frontend/SurveyPageResource.java b/src/com/p4square/grow/frontend/SurveyPageResource.java
index 72a2d34..e7fcd07 100644
--- a/src/com/p4square/grow/frontend/SurveyPageResource.java
+++ b/src/com/p4square/grow/frontend/SurveyPageResource.java
@@ -23,6 +23,8 @@ import net.jesterpm.fmfacade.json.JsonResponse;
 
 import net.jesterpm.fmfacade.FreeMarkerPageResource;
 
+import com.p4square.grow.config.Config;
+
 /**
  * SurveyPageResource handles rendering the survey and processing user's answers.
  *
@@ -36,6 +38,7 @@ import net.jesterpm.fmfacade.FreeMarkerPageResource;
 public class SurveyPageResource extends FreeMarkerPageResource {
     private static Logger cLog = Logger.getLogger(SurveyPageResource.class);
 
+    private Config mConfig;
     private Template mSurveyTemplate;
     private JsonRequestClient mJsonClient;
 
@@ -48,6 +51,7 @@ public class SurveyPageResource extends FreeMarkerPageResource {
         super.doInit();
 
         GrowFrontend growFrontend = (GrowFrontend) getApplication();
+        mConfig = growFrontend.getConfig();
         mSurveyTemplate = growFrontend.getTemplate("templates/survey.ftl");
         if (mSurveyTemplate == null) {
             cLog.fatal("Could not find survey template.");
@@ -172,8 +176,7 @@ public class SurveyPageResource extends FreeMarkerPageResource {
      * @return The backend endpoint URI
      */
     private String getBackendEndpoint() {
-        // TODO: Config
-        return "http://localhost:9095";
+        return mConfig.getString("backendUri", "http://localhost:9095");
     }
 
     /**