Merge pull request #164 from hsrinara/bug/systemprop

[Java] Correctly load system properties in SystemUtil
aeron-io · Jan 30, 2019 · b4951af · b4951af
2 parents 7983876 + 832df4f
commit b4951af
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Showing 4 changed files with 36 additions and 5 deletions.
diff --git a/agrona/src/main/java/org/agrona/SystemUtil.java b/agrona/src/main/java/org/agrona/SystemUtil.java
@@ -151,7 +151,8 @@ public static String threadDump()
      */
     public static void loadPropertiesFile(final String filenameOrUrl)
     {
-        final Properties properties = new Properties(System.getProperties());
+        final Properties properties = new Properties();
+        System.getProperties().forEach(properties::put);
 
         final URL resource = ClassLoader.getSystemClassLoader().getResource(filenameOrUrl);
         if (null != resource)

diff --git a/agrona/src/test/java/org/agrona/SystemUtilTest.java b/agrona/src/test/java/org/agrona/SystemUtilTest.java
@@ -15,12 +15,12 @@
  */
 package org.agrona;
 
-import org.hamcrest.Matchers;
-import org.junit.Test;
-
 import static org.agrona.SystemUtil.parseDuration;
 import static org.agrona.SystemUtil.parseSize;
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertThat;
+
+import org.hamcrest.Matchers;
+import org.junit.Test;
 
 public class SystemUtilTest
 {
@@ -68,4 +68,32 @@ public void shouldThrowWhenParseSizeOverflows()
     {
         parseSize("", 8589934592L + "g");
     }
+
+    @Test
+    public void shouldDoNothingToSystemPropsWhenLoadingFileWhichDoesNotExist() {
+        final int originalSystemPropSize = System.getProperties().size();
+        SystemUtil.loadPropertiesFile("$unknown-file$");
+        assertThat(originalSystemPropSize, Matchers.equalTo(System.getProperties().size()));
+    }
+
+    @Test
+    public void shouldMergeMultiplePropFilesTogether() {
+        assertThat(System.getProperty("TestFileA.foo"), Matchers.isEmptyOrNullString());
+        assertThat(System.getProperty("TestFileB.foo"), Matchers.isEmptyOrNullString());
+
+        SystemUtil.loadPropertiesFiles(new String[]{"TestFileA.properties", "TestFileB.properties"});
+
+        assertThat(System.getProperty("TestFileA.foo"), Matchers.equalTo("AAA"));
+        assertThat(System.getProperty("TestFileB.foo"), Matchers.equalTo("BBB"));
+    }
+
+    @Test
+    public void shouldOverrideSystemPropertiesWithConfigFromPropFile() {
+        System.setProperty("TestFileA.foo", "ToBeOverridden");
+        assertThat(System.getProperty("TestFileA.foo"), Matchers.equalTo("ToBeOverridden"));
+
+        SystemUtil.loadPropertiesFile("TestFileA.properties");
+
+        assertThat(System.getProperty("TestFileA.foo"), Matchers.equalTo("AAA"));
+    }
 }
diff --git a/agrona/src/test/resources/TestFileA.properties b/agrona/src/test/resources/TestFileA.properties
@@ -0,0 +1 @@
+TestFileA.foo=AAA
diff --git a/agrona/src/test/resources/TestFileB.properties b/agrona/src/test/resources/TestFileB.properties
@@ -0,0 +1 @@
+TestFileB.foo=BBB