Make the configuration class work with streams instead of files.

workspace/ttnhabbridge/src/main/java/nl/sikken/bertrik/TtnHabBridge.java

@@ -1,6 +1,8 @@
 package nl.sikken.bertrik;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.BufferUnderflowException;
 import java.util.ArrayList;
@@ -138,11 +140,13 @@ public final class TtnHabBridge {
 
     private static ITtnHabBridgeConfig readConfig(File file) throws IOException {
         final TtnHabBridgeConfig config = new TtnHabBridgeConfig();
-        try {
-            config.load(file);
+        try (FileInputStream fis = new FileInputStream(file)) {
+            config.load(fis);
         } catch (IOException e) {
             LOG.info("Failed to load config {}, writing defaults", file.getAbsoluteFile());
-            config.save(file);
+            try (FileOutputStream fos = new FileOutputStream(file)) {
+                config.save(fos);
+            }
         }
         return config;
     }

workspace/ttnhabbridge/src/main/java/nl/sikken/bertrik/TtnHabBridgeConfig.java

@@ -1,9 +1,8 @@
 package nl.sikken.bertrik;
 
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.nio.charset.StandardCharsets;
@@ -54,16 +53,14 @@ public final class TtnHabBridgeConfig implements ITtnHabBridgeConfig {
     }
     
     /**
-     * Load settings from file.
+     * Load settings from stream.
      * 
-     * @param file the file
+     * @param is input stream containing the settings
      * @throws IOException in case of a problem reading the file
      */
-    public void load(File file) throws IOException {
+    public void load(InputStream is) throws IOException {
         final Properties properties = new Properties();
-        try (FileInputStream fis = new FileInputStream(file)) {
-            properties.load(fis);
-        }
+        properties.load(is);
         for (EConfigItem e : EConfigItem.values()) {
             String value = properties.getProperty(e.key);
             if (value != null) {
@@ -73,13 +70,13 @@ public final class TtnHabBridgeConfig implements ITtnHabBridgeConfig {
     }
     
     /**
-     * Save settings to file.
+     * Save settings to stream.
      * 
-     * @param file the file
+     * @param os the output stream
      * @throws IOException in case of a file problem
      */
-    public void save(File file) throws IOException {
-        try (Writer writer = new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.US_ASCII)) {
+    public void save(OutputStream os) throws IOException {
+        try (Writer writer = new OutputStreamWriter(os, StandardCharsets.US_ASCII)) {
             for (EConfigItem e : EConfigItem.values()) {
                 // comment line
                 writer.append("# " + e.comment + "\n");

workspace/ttnhabbridge/src/test/java/nl/sikken/bertrik/TtnHabBridgeConfigTest.java

@@ -1,21 +1,18 @@
 package nl.sikken.bertrik;
 
-import java.io.File;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 
 import org.junit.Assert;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
 
 /**
  * Unit tests for TtnHabBridgeConfig.
  */
 public final class TtnHabBridgeConfigTest {
     
-    @Rule
-    public TemporaryFolder tempFolder = new TemporaryFolder();    
-    
     /**
      * Verifies basic loading/saving of a configuration.
      * 
@@ -23,10 +20,17 @@ public final class TtnHabBridgeConfigTest {
      */
     @Test
     public void testLoadSave() throws IOException {
+        final byte[] data;
+        // save
         final TtnHabBridgeConfig config = new TtnHabBridgeConfig();
-        final File file = new File(tempFolder.getRoot(), "test.properties");
-        config.save(file);
-        config.load(file);
+        try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
+            config.save(os);
+            data = os.toByteArray();
+        }
+        // load
+        try (InputStream is = new ByteArrayInputStream(data)) {
+            config.load(is);
+        }
     }
     
     /**
@@ -40,6 +44,7 @@ public final class TtnHabBridgeConfigTest {
         Assert.assertNotNull(config.getTtnMqttUrl());
         Assert.assertNotNull(config.getTtnAppId());
         Assert.assertNotNull(config.getTtnAppKey());
+        Assert.assertNotNull(config.getTtnGwCacheExpiry());
     }
 
 }