plugin descriptor from a properties file

pf4j/src/main/java/ro/fortsoft/pf4j/DefaultPluginDescriptorFinder.java

@@ -19,6 +19,8 @@ import java.io.IOException;
 import java.util.jar.Attributes;
 import java.util.jar.Manifest;
 
+import ro.fortsoft.pf4j.util.StringUtils;
+
 /**
  * Read the plugin descriptor from the manifest file.
  *
@@ -31,7 +33,6 @@ public class DefaultPluginDescriptorFinder implements PluginDescriptorFinder {
     	// TODO it's ok with classes/ ?
         File manifestFile = new File(pluginRepository, "classes/META-INF/MANIFEST.MF");
         if (!manifestFile.exists()) {
-            // not found a 'plugin.xml' file for this plugin
             throw new PluginException("Cannot find '" + manifestFile + "' file");
         }
 
@@ -60,19 +61,19 @@ public class DefaultPluginDescriptorFinder implements PluginDescriptorFinder {
         // TODO validate !!!
         Attributes attrs = manifest.getMainAttributes();
         String id = attrs.getValue("Plugin-Id");
-        if (isEmpty(id)) {
+        if (StringUtils.isEmpty(id)) {
         	throw new PluginException("Plugin-Id cannot be empty");
         }
         pluginDescriptor.setPluginId(id);
         
         String clazz = attrs.getValue("Plugin-Class");
-        if (isEmpty(clazz)) {
+        if (StringUtils.isEmpty(clazz)) {
         	throw new PluginException("Plugin-Class cannot be empty");
         }
         pluginDescriptor.setPluginClass(clazz);
         
         String version = attrs.getValue("Plugin-Version");
-        if (isEmpty(version)) {
+        if (StringUtils.isEmpty(version)) {
         	throw new PluginException("Plugin-Version cannot be empty");
         }
         pluginDescriptor.setPluginVersion(PluginVersion.createVersion(version));
@@ -85,7 +86,4 @@ public class DefaultPluginDescriptorFinder implements PluginDescriptorFinder {
 		return pluginDescriptor;
 	}
     	
-	private boolean isEmpty(String value) {
-		return (value == null) || value.isEmpty();
-	}
 }

pf4j/src/main/java/ro/fortsoft/pf4j/DefaultPluginManager.java

@@ -117,7 +117,15 @@ public class DefaultPluginManager implements PluginManager {
         System.setProperty("pf4j.pluginsDir", pluginsDirectory.getAbsolutePath());
     }
 
-    @Override
+    public PluginDescriptorFinder getPluginDescriptorFinder() {
+		return pluginDescriptorFinder;
+	}
+
+	public void setPluginDescriptorFinder(PluginDescriptorFinder pluginDescriptorFinder) {
+		this.pluginDescriptorFinder = pluginDescriptorFinder;
+	}
+
+	@Override
     public List<PluginWrapper> getPlugins() {
         return new ArrayList<PluginWrapper>(plugins.values());
     }

pf4j/src/main/java/ro/fortsoft/pf4j/PropertiesPluginDescriptorFinder.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright 2012 Decebal Suiu
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with
+ * the License. You may obtain a copy of the License in the LICENSE file, or at:
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package ro.fortsoft.pf4j;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+import ro.fortsoft.pf4j.util.StringUtils;
+
+/**
+ * Find a plugin descriptor in a properties file (in plugin repository).
+ * 
+ * @author Decebal Suiu
+ */
+public class PropertiesPluginDescriptorFinder implements PluginDescriptorFinder {
+
+	private String propertiesFileName;
+
+	public PropertiesPluginDescriptorFinder() {
+		this("plugin.properties");
+	}
+
+	public PropertiesPluginDescriptorFinder(String propertiesFileName) {
+		this.propertiesFileName = propertiesFileName;
+	}
+	
+	@Override
+	public PluginDescriptor find(File pluginRepository) throws PluginException {
+        File propertiesFile = new File(pluginRepository, propertiesFileName);
+        if (!propertiesFile.exists()) {
+            throw new PluginException("Cannot find '" + propertiesFile + "' file");
+        }
+
+    	InputStream input = null;
+		try {
+			input = new FileInputStream(propertiesFile);
+		} catch (FileNotFoundException e) {
+			// not happening 
+		}
+		
+    	Properties properties = new Properties();
+        try {
+        	properties.load(input);
+        } catch (IOException e) {
+            throw new PluginException(e.getMessage(), e);
+        } finally {
+            try {
+				input.close();
+			} catch (IOException e) {
+				throw new PluginException(e.getMessage(), e);
+			}
+        } 
+        
+        PluginDescriptor pluginDescriptor = new PluginDescriptor();
+        
+        // TODO validate !!!
+        String id = properties.getProperty("plugin.id");
+        if (StringUtils.isEmpty(id)) {
+        	throw new PluginException("plugin.id cannot be empty");
+        }
+        pluginDescriptor.setPluginId(id);
+        
+        String clazz = properties.getProperty("plugin.class");
+        if (StringUtils.isEmpty(clazz)) {
+        	throw new PluginException("plugin.class cannot be empty");
+        }
+        pluginDescriptor.setPluginClass(clazz);
+        
+        String version = properties.getProperty("plugin.version");
+        if (StringUtils.isEmpty(version)) {
+        	throw new PluginException("plugin.version cannot be empty");
+        }
+        pluginDescriptor.setPluginVersion(PluginVersion.createVersion(version));
+        
+        String provider = properties.getProperty("plugin.provider");
+        pluginDescriptor.setProvider(provider);        
+        String dependencies = properties.getProperty("plugin.dependencies");
+        pluginDescriptor.setDependencies(dependencies);
+
+		return pluginDescriptor;
+	}
+
+}

pf4j/src/main/java/ro/fortsoft/pf4j/util/StringUtils.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2012 Decebal Suiu
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with
+ * the License. You may obtain a copy of the License in the LICENSE file, or at:
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package ro.fortsoft.pf4j.util;
+
+/**
+ * @author Decebal Suiu
+ */
+public class StringUtils {
+
+	public static boolean isEmpty(String str) {
+		return (str == null) || str.isEmpty();
+	}
+
+}