Support multiple plugin root directories (#404)

9 files changed, 136 insertions, 71 deletions

diff --git a/pf4j/src/main/java/org/pf4j/AbstractPluginManager.java b/pf4j/src/main/java/org/pf4j/AbstractPluginManager.java
index 3d109e2..9562257 100644
--- a/pf4j/src/main/java/org/pf4j/AbstractPluginManager.java
+++ b/pf4j/src/main/java/org/pf4j/AbstractPluginManager.java
@@ -25,12 +25,14 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * This class implements the boilerplate plugin code that any {@link PluginManager}
@@ -51,7 +53,7 @@ public abstract class AbstractPluginManager implements PluginManager {
     public static final String DEFAULT_PLUGINS_DIR = "plugins";
     public static final String DEVELOPMENT_PLUGINS_DIR = "../plugins";
 
-    protected Path pluginsRoot;
+    protected final List<Path> pluginsRoots = new ArrayList<>();
 
     protected ExtensionFinder extensionFinder;
 
@@ -109,19 +111,28 @@ public abstract class AbstractPluginManager implements PluginManager {
     protected VersionManager versionManager;
 
     /**
-     * The plugins root is supplied by {@code System.getProperty("pf4j.pluginsDir", "plugins")}.
+     * The plugins roots are supplied as comma-separated list by {@code System.getProperty("pf4j.pluginsDir", "plugins")}.
      */
     public AbstractPluginManager() {
         initialize();
     }
 
     /**
-     * Constructs {@code AbstractPluginManager} with the given plugins root.
+     * Constructs {@code AbstractPluginManager} with the given plugins roots.
      *
-     * @param pluginsRoot the root to search for plugins
+     * @param pluginsRoots the roots to search for plugins
      */
-    public AbstractPluginManager(Path pluginsRoot) {
-        this.pluginsRoot = pluginsRoot;
+    public AbstractPluginManager(Path... pluginsRoots) {
+        this(Arrays.asList(pluginsRoots));
+    }
+
+    /**
+     * Constructs {@code AbstractPluginManager} with the given plugins roots.
+     *
+     * @param pluginsRoots the roots to search for plugins
+     */
+    public AbstractPluginManager(List<Path> pluginsRoots) {
+        this.pluginsRoots.addAll(pluginsRoots);
 
         initialize();
     }
@@ -200,12 +211,17 @@ public abstract class AbstractPluginManager implements PluginManager {
      */
     @Override
     public void loadPlugins() {
-        log.debug("Lookup plugins in '{}'", pluginsRoot);
-        // check for plugins root
-        if (Files.notExists(pluginsRoot) || !Files.isDirectory(pluginsRoot)) {
-            log.warn("No '{}' root", pluginsRoot);
+        log.debug("Lookup plugins in '{}'", pluginsRoots);
+        // check for plugins roots
+        if (pluginsRoots.isEmpty()) {
+            log.warn("No plugins roots configured");
             return;
         }
+        pluginsRoots.forEach(path -> {
+            if (Files.notExists(path) || !Files.isDirectory(path)) {
+                log.warn("No '{}' root", path);
+            }
+        });
 
         // get all plugin paths from repository
         List<Path> pluginPaths = pluginRepository.getPluginPaths();
@@ -599,8 +615,15 @@ public abstract class AbstractPluginManager implements PluginManager {
         return pluginLoader;
     }
 
+    @Override
     public Path getPluginsRoot() {
-        return pluginsRoot;
+        return pluginsRoots.stream()
+            .findFirst()
+            .orElseThrow(() -> new IllegalStateException("pluginsRoots have not been initialized, yet."));
+    }
+
+    public List<Path> getPluginsRoots() {
+        return Collections.unmodifiableList(pluginsRoots);
     }
 
     @Override
@@ -687,8 +710,8 @@ public abstract class AbstractPluginManager implements PluginManager {
 
         pluginStateListeners = new ArrayList<>();
 
-        if (pluginsRoot == null) {
-            pluginsRoot = createPluginsRoot();
+        if (pluginsRoots.isEmpty()) {
+            pluginsRoots.addAll(createPluginsRoot());
         }
 
         pluginRepository = createPluginRepository();
@@ -704,20 +727,24 @@ public abstract class AbstractPluginManager implements PluginManager {
     }
 
     /**
-     * Add the possibility to override the plugins root.
-     * If a {@link #PLUGINS_DIR_PROPERTY_NAME} system property is defined than this method returns that root.
+     * Add the possibility to override the plugins roots.
+     * If a {@link #PLUGINS_DIR_PROPERTY_NAME} system property is defined than this method returns that roots.
      * If {@link #getRuntimeMode()} returns {@link RuntimeMode#DEVELOPMENT} than {@link #DEVELOPMENT_PLUGINS_DIR}
      * is returned else this method returns {@link #DEFAULT_PLUGINS_DIR}.
      *
      * @return the plugins root
      */
-    protected Path createPluginsRoot() {
+    protected List<Path> createPluginsRoot() {
         String pluginsDir = System.getProperty(PLUGINS_DIR_PROPERTY_NAME);
-        if (pluginsDir == null) {
-            pluginsDir = isDevelopment() ? DEVELOPMENT_PLUGINS_DIR : DEFAULT_PLUGINS_DIR;
+        if (pluginsDir != null && !pluginsDir.isEmpty()) {
+            return Arrays.stream(pluginsDir.split(","))
+                .map(String::trim)
+                .map(Paths::get)
+                .collect(Collectors.toList());
         }
 
-        return Paths.get(pluginsDir);
+        pluginsDir = isDevelopment() ? DEVELOPMENT_PLUGINS_DIR : DEFAULT_PLUGINS_DIR;
+        return Collections.singletonList(Paths.get(pluginsDir));
     }
 
     /**
diff --git a/pf4j/src/main/java/org/pf4j/BasePluginRepository.java b/pf4j/src/main/java/org/pf4j/BasePluginRepository.java
index ea5ad3b..9ab8f96 100644
--- a/pf4j/src/main/java/org/pf4j/BasePluginRepository.java
+++ b/pf4j/src/main/java/org/pf4j/BasePluginRepository.java
@@ -22,11 +22,11 @@ import java.io.FileFilter;
 import java.io.IOException;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
-import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * @author Decebal Suiu
@@ -34,17 +34,21 @@ import java.util.List;
  */
 public class BasePluginRepository implements PluginRepository {
 
-    protected final Path pluginsRoot;
+    protected final List<Path> pluginsRoots;
 
     protected FileFilter filter;
     protected Comparator<File> comparator;
 
-    public BasePluginRepository(Path pluginsRoot) {
-        this(pluginsRoot, null);
+    public BasePluginRepository(Path... pluginsRoots) {
+        this(Arrays.asList(pluginsRoots));
     }
 
-    public BasePluginRepository(Path pluginsRoot, FileFilter filter) {
-        this.pluginsRoot = pluginsRoot;
+    public BasePluginRepository(List<Path> pluginsRoots) {
+        this(pluginsRoots, null);
+    }
+
+    public BasePluginRepository(List<Path> pluginsRoots, FileFilter filter) {
+        this.pluginsRoots = pluginsRoots;
         this.filter = filter;
 
         // last modified file is first
@@ -67,22 +71,11 @@ public class BasePluginRepository implements PluginRepository {
 
     @Override
     public List<Path> getPluginPaths() {
-        File[] files = pluginsRoot.toFile().listFiles(filter);
-
-        if ((files == null) || files.length == 0) {
-            return Collections.emptyList();
-        }
-
-        if (comparator != null) {
-            Arrays.sort(files, comparator);
-        }
-
-        List<Path> paths = new ArrayList<>(files.length);
-        for (File file : files) {
-            paths.add(file.toPath());
-        }
-
-        return paths;
+        return pluginsRoots.stream()
+            .flatMap(path -> streamFiles(path, filter))
+            .sorted(comparator)
+            .map(File::toPath)
+            .collect(Collectors.toList());
     }
 
     @Override
@@ -101,4 +94,11 @@ public class BasePluginRepository implements PluginRepository {
         }
     }
 
+    protected Stream<File> streamFiles(Path directory, FileFilter filter) {
+        File[] files = directory.toFile().listFiles(filter);
+        return files != null
+            ? Arrays.stream(files)
+            : Stream.empty();
+    }
+
 }
diff --git a/pf4j/src/main/java/org/pf4j/DefaultPluginManager.java b/pf4j/src/main/java/org/pf4j/DefaultPluginManager.java
index 9cad187..e2667d4 100644
--- a/pf4j/src/main/java/org/pf4j/DefaultPluginManager.java
+++ b/pf4j/src/main/java/org/pf4j/DefaultPluginManager.java
@@ -21,6 +21,7 @@ import org.slf4j.LoggerFactory;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.List;
 
 /**
  * Default implementation of the {@link PluginManager} interface.
@@ -41,8 +42,12 @@ public class DefaultPluginManager extends AbstractPluginManager {
         super();
     }
 
-    public DefaultPluginManager(Path pluginsRoot) {
-        super(pluginsRoot);
+    public DefaultPluginManager(Path... pluginsRoots) {
+        super(pluginsRoots);
+    }
+
+    public DefaultPluginManager(List<Path> pluginsRoots) {
+        super(pluginsRoots);
     }
 
     @Override
@@ -73,7 +78,11 @@ public class DefaultPluginManager extends AbstractPluginManager {
     @Override
     protected PluginStatusProvider createPluginStatusProvider() {
         String configDir = System.getProperty(PLUGINS_DIR_CONFIG_PROPERTY_NAME);
-        Path configPath = configDir != null ? Paths.get(configDir) : getPluginsRoot();
+        Path configPath = configDir != null
+            ? Paths.get(configDir)
+            : getPluginsRoots().stream()
+            .findFirst()
+            .orElseThrow(() -> new IllegalArgumentException("No pluginsRoot configured"));
 
         return new DefaultPluginStatusProvider(configPath);
     }
@@ -81,9 +90,9 @@ public class DefaultPluginManager extends AbstractPluginManager {
     @Override
     protected PluginRepository createPluginRepository() {
         return new CompoundPluginRepository()
-            .add(new DevelopmentPluginRepository(getPluginsRoot()), this::isDevelopment)
-            .add(new JarPluginRepository(getPluginsRoot()), this::isNotDevelopment)
-            .add(new DefaultPluginRepository(getPluginsRoot()), this::isNotDevelopment);
+            .add(new DevelopmentPluginRepository(getPluginsRoots()), this::isDevelopment)
+            .add(new JarPluginRepository(getPluginsRoots()), this::isNotDevelopment)
+            .add(new DefaultPluginRepository(getPluginsRoots()), this::isNotDevelopment);
     }
 
     @Override
diff --git a/pf4j/src/main/java/org/pf4j/DefaultPluginRepository.java b/pf4j/src/main/java/org/pf4j/DefaultPluginRepository.java
index 2fafbc7..82a447f 100644
--- a/pf4j/src/main/java/org/pf4j/DefaultPluginRepository.java
+++ b/pf4j/src/main/java/org/pf4j/DefaultPluginRepository.java
@@ -29,6 +29,7 @@ import java.io.File;
 import java.io.FileFilter;
 import java.io.IOException;
 import java.nio.file.Path;
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -38,8 +39,12 @@ public class DefaultPluginRepository extends BasePluginRepository {
 
     private static final Logger log = LoggerFactory.getLogger(DefaultPluginRepository.class);
 
-    public DefaultPluginRepository(Path pluginsRoot) {
-        super(pluginsRoot);
+    public DefaultPluginRepository(Path... pluginsRoots) {
+        this(Arrays.asList(pluginsRoots));
+    }
+
+    public DefaultPluginRepository(List<Path> pluginsRoots) {
+        super(pluginsRoots);
 
         AndFileFilter pluginsFilter = new AndFileFilter(new DirectoryFileFilter());
         pluginsFilter.addFileFilter(new NotFileFilter(createHiddenPluginFilter()));
@@ -64,16 +69,18 @@ public class DefaultPluginRepository extends BasePluginRepository {
 
     private void extractZipFiles() {
         // expand plugins zip files
-        File[] zipFiles = pluginsRoot.toFile().listFiles(new ZipFileFilter());
-        if ((zipFiles != null) && zipFiles.length > 0) {
-            for (File pluginZip : zipFiles) {
-                try {
-                    FileUtils.expandIfZip(pluginZip.toPath());
-                } catch (IOException e) {
-                    log.error("Cannot expand plugin zip '{}'", pluginZip);
-                    log.error(e.getMessage(), e);
-                }
-            }
+        pluginsRoots.stream()
+            .flatMap(path -> streamFiles(path, new ZipFileFilter()))
+            .map(File::toPath)
+            .forEach(this::expandIfZip);
+    }
+
+    private void expandIfZip(Path filePath) {
+        try {
+            FileUtils.expandIfZip(filePath);
+        } catch (IOException e) {
+            log.error("Cannot expand plugin zip '{}'", filePath);
+            log.error(e.getMessage(), e);
         }
     }
 
diff --git a/pf4j/src/main/java/org/pf4j/DevelopmentPluginRepository.java b/pf4j/src/main/java/org/pf4j/DevelopmentPluginRepository.java
index e8f2c69..fdc74c9 100644
--- a/pf4j/src/main/java/org/pf4j/DevelopmentPluginRepository.java
+++ b/pf4j/src/main/java/org/pf4j/DevelopmentPluginRepository.java
@@ -24,6 +24,8 @@ import org.pf4j.util.OrFileFilter;
 
 import java.io.FileFilter;
 import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
 
 /**
  * @author Decebal Suiu
@@ -33,8 +35,12 @@ public class DevelopmentPluginRepository extends BasePluginRepository {
     public static final String MAVEN_BUILD_DIR = "target";
     public static final String GRADLE_BUILD_DIR = "build";
 
-    public DevelopmentPluginRepository(Path pluginsRoot) {
-        super(pluginsRoot);
+    public DevelopmentPluginRepository(Path... pluginsRoots) {
+        this(Arrays.asList(pluginsRoots));
+    }
+
+    public DevelopmentPluginRepository(List<Path> pluginsRoots) {
+        super(pluginsRoots);
 
         AndFileFilter pluginsFilter = new AndFileFilter(new DirectoryFileFilter());
         pluginsFilter.addFileFilter(new NotFileFilter(createHiddenPluginFilter()));
diff --git a/pf4j/src/main/java/org/pf4j/JarPluginManager.java b/pf4j/src/main/java/org/pf4j/JarPluginManager.java
index f280466..ebbc63d 100644
--- a/pf4j/src/main/java/org/pf4j/JarPluginManager.java
+++ b/pf4j/src/main/java/org/pf4j/JarPluginManager.java
@@ -30,8 +30,8 @@ public class JarPluginManager extends DefaultPluginManager {
         super();
     }
 
-    public JarPluginManager(Path pluginsRoot) {
-        super(pluginsRoot);
+    public JarPluginManager(Path... pluginsRoots) {
+        super(pluginsRoots);
     }
 
     @Override
@@ -49,8 +49,8 @@ public class JarPluginManager extends DefaultPluginManager {
     @Override
     protected PluginRepository createPluginRepository() {
         return new CompoundPluginRepository()
-            .add(new DevelopmentPluginRepository(getPluginsRoot()), this::isDevelopment)
-            .add(new JarPluginRepository(getPluginsRoot()), this::isNotDevelopment);
+            .add(new DevelopmentPluginRepository(getPluginsRoots()), this::isDevelopment)
+            .add(new JarPluginRepository(getPluginsRoots()), this::isNotDevelopment);
     }
 
 }
diff --git a/pf4j/src/main/java/org/pf4j/JarPluginRepository.java b/pf4j/src/main/java/org/pf4j/JarPluginRepository.java
index a8be3ff..d629bbd 100644
--- a/pf4j/src/main/java/org/pf4j/JarPluginRepository.java
+++ b/pf4j/src/main/java/org/pf4j/JarPluginRepository.java
@@ -18,14 +18,20 @@ package org.pf4j;
 import org.pf4j.util.JarFileFilter;
 
 import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
 
 /**
  * @author Decebal Suiu
  */
 public class JarPluginRepository extends BasePluginRepository {
 
-    public JarPluginRepository(Path pluginsRoot) {
-        super(pluginsRoot, new JarFileFilter());
+    public JarPluginRepository(Path... pluginsRoots) {
+        this(Arrays.asList(pluginsRoots));
+    }
+
+    public JarPluginRepository(List<Path> pluginsRoots) {
+        super(pluginsRoots, new JarFileFilter());
     }
 
 }
diff --git a/pf4j/src/main/java/org/pf4j/PluginManager.java b/pf4j/src/main/java/org/pf4j/PluginManager.java
index 248b1ac..b717656 100644
--- a/pf4j/src/main/java/org/pf4j/PluginManager.java
+++ b/pf4j/src/main/java/org/pf4j/PluginManager.java
@@ -205,12 +205,22 @@ public interface PluginManager {
     String getSystemVersion();
 
     /**
-     * Gets the path of the folder where plugins are installed.
+     * Gets the first path of the folders where plugins are installed.
+     *
+     * @deprecated Use {@link #getPluginsRoots()} instead to get all paths where plugins are could be installed.
      *
      * @return Path of plugins root
      */
+    @Deprecated
     Path getPluginsRoot();
 
+    /**
+     * Gets the a read-only list of all paths of the folders where plugins are installed.
+     *
+     * @return Paths of plugins roots
+     */
+    List<Path> getPluginsRoots();
+
     VersionManager getVersionManager();
 
 }
diff --git a/pf4j/src/main/java/org/pf4j/ZipPluginManager.java b/pf4j/src/main/java/org/pf4j/ZipPluginManager.java
index a32d156..a22f3c6 100644
--- a/pf4j/src/main/java/org/pf4j/ZipPluginManager.java
+++ b/pf4j/src/main/java/org/pf4j/ZipPluginManager.java
@@ -42,8 +42,8 @@ public class ZipPluginManager extends DefaultPluginManager {
     @Override
     protected PluginRepository createPluginRepository() {
         return new CompoundPluginRepository()
-            .add(new DevelopmentPluginRepository(getPluginsRoot()), this::isDevelopment)
-            .add(new DefaultPluginRepository(getPluginsRoot()), this::isNotDevelopment);
+            .add(new DevelopmentPluginRepository(getPluginsRoots()), this::isDevelopment)
+            .add(new DefaultPluginRepository(getPluginsRoots()), this::isNotDevelopment);
     }
 
 }