configuration may not have values for the given key

tomcz · Sep 3, 2012 · 47c705a · 47c705a
1 parent a8b2371
commit 47c705a
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Showing 4 changed files with 17 additions and 9 deletions.
diff --git a/src/main/java/example/framework/Configuration.java b/src/main/java/example/framework/Configuration.java
@@ -1,5 +1,7 @@
 package example.framework;
 
+import com.google.common.base.Optional;
+
 public interface Configuration {
-    String get(String key);
+    Optional<String> get(String key);
 }
diff --git a/src/main/java/example/framework/application/ConfigurationParameter.java b/src/main/java/example/framework/application/ConfigurationParameter.java
@@ -53,7 +53,7 @@ private String getConfiguredProperty(PicoContainer container) {
         if (configuration == null) {
             throw new IllegalStateException("Cannot find Configuration instance in container");
         }
-        String value = configuration.get(key);
+        String value = configuration.get(key).orNull();
         if (value == null) {
             value = defaultValue;
         }

diff --git a/src/main/java/example/framework/application/DefaultConfiguration.java b/src/main/java/example/framework/application/DefaultConfiguration.java
@@ -1,7 +1,8 @@
 package example.framework.application;
 
+import com.google.common.base.Function;
+import com.google.common.base.Optional;
 import example.framework.Configuration;
-import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.text.StrSubstitutor;
 
 import java.util.HashMap;
@@ -25,8 +26,12 @@ private static Map createTokensToSubstitute(Map<String, String> properties) {
         return tokens;
     }
 
-    public String get(String key) {
-        String value = properties.get(key);
-        return StringUtils.isNotBlank(value) ? substitutor.replace(value) : value;
+    public Optional<String> get(String key) {
+        Optional<String> optional = Optional.fromNullable(properties.get(key));
+        return optional.transform(new Function<String, String>() {
+            public String apply(String value) {
+                return substitutor.replace(value).trim();
+            }
+        });
     }
 }
diff --git a/src/test/java/example/framework/application/DefaultConfigurationTests.java b/src/test/java/example/framework/application/DefaultConfigurationTests.java
@@ -1,5 +1,6 @@
 package example.framework.application;
 
+import com.google.common.base.Optional;
 import org.apache.commons.lang3.SystemUtils;
 import org.junit.Test;
 
@@ -19,7 +20,7 @@ public void shouldSubstituteSystemPropertiesAndTokensFromConfiguration() {
         properties.put("foo", "bar");
 
         DefaultConfiguration configuration = new DefaultConfiguration(properties);
-        String value = configuration.get("foo.path");
+        String value = configuration.get("foo.path").get();
 
         assertThat(value, is(SystemUtils.USER_DIR + "/bar"));
     }
@@ -29,8 +30,8 @@ public void shouldReturnNullForUnknownKey() {
         Map<String, String> properties = newHashMap();
 
         DefaultConfiguration configuration = new DefaultConfiguration(properties);
-        String value = configuration.get("foo");
+        Optional<String> value = configuration.get("foo");
 
-        assertThat(value, nullValue());
+        assertThat(value.orNull(), nullValue());
     }
 }