Issue #85: Marshal Duration config fields as milliseconds for easier …

…use in javascript.

src/main/java/com/github/mk23/jmxproxy/conf/AppConfig.java

@@ -1,6 +1,7 @@
 package com.github.mk23.jmxproxy.conf;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 
 import io.dropwizard.jackson.JsonSnakeCase;
 
@@ -49,6 +50,7 @@ public class AppConfig {
      */
     @Valid
     @JsonProperty
+    @JsonSerialize(using = DurationSerializer.class)
     private Duration cleanInterval = Duration.minutes(DEFAULT_CLEAN_INTERVAL);
 
     /**
@@ -57,6 +59,7 @@ public class AppConfig {
      */
     @Valid
     @JsonProperty
+    @JsonSerialize(using = DurationSerializer.class)
     private Duration cacheDuration = Duration.minutes(DEFAULT_CACHE_DURATION);
 
     /**
@@ -65,6 +68,7 @@ public class AppConfig {
      */
     @Valid
     @JsonProperty
+    @JsonSerialize(using = DurationSerializer.class)
     private Duration accessDuration = Duration.minutes(DEFAULT_ACCESS_DURATION);
 
     /**

src/main/java/com/github/mk23/jmxproxy/conf/DurationSerializer.java

@@ -0,0 +1,34 @@
+package com.github.mk23.jmxproxy.conf;
+
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+
+import io.dropwizard.util.Duration;
+
+import java.io.IOException;
+
+/**
+ * <p>Custom serializer for configuration Duration fields.</p>
+ *
+ * Converts <code>io.dropwizard.util.Duration</code> types to milliseconds
+ * for JSON requests.
+ *
+ * @see <a href="http://dropwizard.github.io/dropwizard/0.9.2/dropwizard-util/apidocs/io/dropwizard/util/Duration.html">io.dropwizard.util.Duration</a>
+ *
+ * @author  mk23
+ * @since   2016-01-29
+ * @version 3.2.1
+ */
+public class DurationSerializer extends JsonSerializer<Duration> {
+    /** {@inheritDoc} */
+    @Override
+    public final void serialize(
+        final Duration duration,
+        final JsonGenerator jgen,
+        final SerializerProvider provider
+    ) throws IOException, JsonProcessingException {
+        jgen.writeNumber(duration.toMilliseconds());
+    }
+}