From f554ef29b3a20ff058878a3940e97d1dc21f1df0 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Ritschard <pyr@spootnik.org>
Date: Tue, 29 Jul 2014 14:37:05 +0200
Subject: [PATCH] Bring in hostname as defined in the main configuration by
 default

supersedes collectd/collectd#530
---
 bindings/java/org/collectd/api/Collectd.java       |  7 +++++
 .../collectd/java/GenericJMXConfConnection.java    | 10 +------
 src/java.c                                         | 31 ++++++++++++++++++++--
 3 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/bindings/java/org/collectd/api/Collectd.java b/bindings/java/org/collectd/api/Collectd.java
index 84e65926..e962f6e0 100644
--- a/bindings/java/org/collectd/api/Collectd.java
+++ b/bindings/java/org/collectd/api/Collectd.java
@@ -252,6 +252,13 @@ public class Collectd
   native private static void log (int severity, String message);
 
   /**
+   * Yield contents of collectd/src/collectd.h:hostname_g
+   *
+   * @return The hostname as set in the collectd configuration.
+   */
+  native public static java.lang.String getHostname ();
+
+  /**
    * Prints an error message.
    */
   public static void logError (String message)
diff --git a/bindings/java/org/collectd/java/GenericJMXConfConnection.java b/bindings/java/org/collectd/java/GenericJMXConfConnection.java
index 99b140a2..186d1446 100644
--- a/bindings/java/org/collectd/java/GenericJMXConfConnection.java
+++ b/bindings/java/org/collectd/java/GenericJMXConfConnection.java
@@ -86,15 +86,7 @@ class GenericJMXConfConnection
       return (this._host);
     }
 
-    try
-    {
-      InetAddress localHost = InetAddress.getLocalHost();
-      return (localHost.getHostName ());
-    }
-    catch (UnknownHostException e)
-    {
-      return ("localhost");
-    }
+    return Collectd.getHostname();
   } /* }}} String getHost */
 
 private void connect () /* {{{ */
diff --git a/src/java.c b/src/java.c
index e4b10beb..2b6a5427 100644
--- a/src/java.c
+++ b/src/java.c
@@ -120,7 +120,7 @@ static int cjni_match_target_destroy (void **user_data);
 static int cjni_match_target_invoke (const data_set_t *ds, value_list_t *vl,
     notification_meta_t **meta, void **user_data);
 
-/* 
+/*
  * C to Java conversion functions
  */
 static int ctoj_string (JNIEnv *jvm_env, /* {{{ */
@@ -159,6 +159,23 @@ static int ctoj_string (JNIEnv *jvm_env, /* {{{ */
   return (0);
 } /* }}} int ctoj_string */
 
+static jstring ctoj_output_string (JNIEnv *jvm_env, /* {{{ */
+    const char *string)
+{
+  jstring o_string;
+
+  /* Create a java.lang.String */
+  o_string = (*jvm_env)->NewStringUTF (jvm_env,
+      (string != NULL) ? string : "");
+  if (o_string == NULL)
+  {
+    ERROR ("java plugin: ctoj_output_string: NewStringUTF failed.");
+    return NULL;
+  }
+
+  return (o_string);
+} /* }}} int ctoj_output_string */
+
 static int ctoj_int (JNIEnv *jvm_env, /* {{{ */
     jint value,
     jclass class_ptr, jobject object_ptr, const char *method_name)
@@ -1319,7 +1336,7 @@ static int jtoc_notification (JNIEnv *jvm_env, notification_t *n, /* {{{ */
 
   return (0);
 } /* }}} int jtoc_notification */
-/* 
+/*
  * Functions accessible from Java
  */
 static jint JNICALL cjni_api_dispatch_values (JNIEnv *jvm_env, /* {{{ */
@@ -1629,6 +1646,11 @@ static void JNICALL cjni_api_log (JNIEnv *jvm_env, /* {{{ */
   (*jvm_env)->ReleaseStringUTFChars (jvm_env, o_message, c_str);
 } /* }}} void cjni_api_log */
 
+static jstring JNICALL cjni_api_get_hostname (JNIEnv *jvm_env, jobject this)
+{
+    return ctoj_output_string(jvm_env, hostname_g);
+}
+
 /* List of ``native'' functions, i. e. C-functions that can be called from
  * Java. */
 static JNINativeMethod jni_api_functions[] = /* {{{ */
@@ -1688,6 +1710,11 @@ static JNINativeMethod jni_api_functions[] = /* {{{ */
   { "log",
     "(ILjava/lang/String;)V",
     cjni_api_log },
+
+  { "getHostname",
+    "()Ljava/lang/String;",
+    cjni_api_get_hostname },
+
 };
 static size_t jni_api_functions_num = sizeof (jni_api_functions)
   / sizeof (jni_api_functions[0]);
-- 
2.11.0