AMP dependency checking on the tool side.

This is work in progress and the repo is not currently double checking the runtime dependencies.

To declare a dependency, add the following to your module.properties:
   module.depends.ABC=ABCfromVersion - ABCtoVersion
Wildcard * can be used in place of fromVersion or toVersion, as well as just a single version.
The most common usage will be:
   module.depends.ABC=1.0-*
i.e. this module depends on ABC version 1.0 or later being present.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@5601 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/module/ModuleDetailsImpl.java

@@ -32,9 +32,11 @@ import java.util.Properties;
 import java.util.StringTokenizer;
 
 import org.alfresco.error.AlfrescoRuntimeException;
+import org.alfresco.service.cmr.module.ModuleDependency;
 import org.alfresco.service.cmr.module.ModuleDetails;
 import org.alfresco.service.cmr.module.ModuleInstallState;
 import org.alfresco.util.ISO8601DateFormat;
+import org.alfresco.util.Pair;
 import org.alfresco.util.VersionNumber;
 
 /**
@@ -49,6 +51,8 @@ import org.alfresco.util.VersionNumber;
  */
 public class ModuleDetailsImpl implements ModuleDetails
 {
+    private static final long serialVersionUID = 5782747774317351424L;
+
     private String id;
     private List<String> aliases;
     private VersionNumber version;
@@ -56,6 +60,7 @@ public class ModuleDetailsImpl implements ModuleDetails
     private String description;
     private VersionNumber repoVersionMin;
     private VersionNumber repoVersionMax;
+    private List<ModuleDependency> dependencies;
     private Date installDate;
     private ModuleInstallState installState;
     
@@ -67,6 +72,7 @@ public class ModuleDetailsImpl implements ModuleDetails
         aliases = new ArrayList<String>(0);
         repoVersionMin = VersionNumber.VERSION_ZERO;
         repoVersionMax = VersionNumber.VERSION_BIG;
+        dependencies = new ArrayList<ModuleDependency>(0);
         this.installState = ModuleInstallState.UNKNOWN;
     }
     
@@ -151,6 +157,8 @@ public class ModuleDetailsImpl implements ModuleDetails
         {
             repoVersionMax = new VersionNumber(trimmedProperties.getProperty(PROP_REPO_VERSION_MAX));
         }
+        // DEPENDENCIES
+        this.dependencies = extractDependencies(trimmedProperties);
         // INSTALL DATE
         if (trimmedProperties.getProperty(PROP_INSTALL_DATE) != null)
         {
@@ -212,6 +220,34 @@ public class ModuleDetailsImpl implements ModuleDetails
         this.title = title;
         this.description = description;
     }
+    
+    private static List<ModuleDependency> extractDependencies(Properties properties)
+    {
+        int prefixLength = PROP_DEPENDS_PREFIX.length();
+        
+        List<ModuleDependency> dependencies = new ArrayList<ModuleDependency>(2);
+        for (Map.Entry entry : properties.entrySet())
+        {
+            String key = (String) entry.getKey();
+            String value = (String) entry.getValue();
+            if (!key.startsWith(PROP_DEPENDS_PREFIX))
+            {
+                continue;
+            }
+            if (key.length() == prefixLength)
+            {
+                // Just ignore it
+                continue;
+            }
+            String dependencyId = key.substring(prefixLength);
+            // Build the dependency
+            ModuleDependency dependency = new ModuleDependencyImpl(dependencyId, value);
+            // Add it
+            dependencies.add(dependency);
+        }
+        // Done
+        return dependencies;
+    }
 
     public Properties getProperties()
     {
@@ -230,6 +266,15 @@ public class ModuleDetailsImpl implements ModuleDetails
         {
             properties.setProperty(PROP_REPO_VERSION_MAX, repoVersionMax.toString());
         }
+        if (dependencies.size() > 0)
+        {
+            for (ModuleDependency dependency : dependencies)
+            {
+                String key = PROP_DEPENDS_PREFIX + dependency.getDependencyId();
+                String value = dependency.getVersionString();
+                properties.setProperty(key, value);
+            }
+        }
         if (installDate != null)
         {
             String installDateStr = ISO8601DateFormat.format(installDate);
@@ -310,6 +355,11 @@ public class ModuleDetailsImpl implements ModuleDetails
         this.repoVersionMax = repoVersionMax;
     }
 
+    public List<ModuleDependency> getDependencies()
+    {
+        return dependencies;
+    }
+
     public Date getInstallDate()
     {
         return installDate;
@@ -329,4 +379,164 @@ public class ModuleDetailsImpl implements ModuleDetails
     {
         this.installState = installState;
     }
+    
+    /**
+     * @author Derek Hulley
+     */
+    public static final class ModuleDependencyImpl implements ModuleDependency
+    {
+        private static final long serialVersionUID = -6850832632316987487L;
+
+        private String dependencyId;
+        private String versionStr;
+        private List<Pair<VersionNumber, VersionNumber>> versionRanges;
+        
+        private ModuleDependencyImpl(String dependencyId, String versionStr)
+        {
+            this.dependencyId = dependencyId;
+            this.versionStr = versionStr;
+            try
+            {
+                versionRanges = buildVersionRanges(versionStr);
+            }
+            catch (Throwable e)
+            {
+                throw new AlfrescoRuntimeException("Unable to interpret the module version ranges: " + versionStr, e);
+            }
+        }
+        
+        @Override
+        public String toString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.append(dependencyId).append(":").append(versionStr);
+            return sb.toString();
+        }
+
+        private static List<Pair<VersionNumber, VersionNumber>> buildVersionRanges(String versionStr)
+        {
+            List<Pair<VersionNumber, VersionNumber>> versionRanges = new ArrayList<Pair<VersionNumber, VersionNumber>>(1);
+            StringTokenizer rangesTokenizer = new StringTokenizer(versionStr, ",");
+            while (rangesTokenizer.hasMoreTokens())
+            {
+                String range = rangesTokenizer.nextToken().trim();
+                // Handle the * special case
+                if (range.equals("*"))
+                {
+                    range = "*-*";
+                }
+                if (range.startsWith("-"))
+                {
+                    range = "*" + range;
+                }
+                if (range.endsWith("-"))
+                {
+                    range = range + "*";
+                }
+                // The range must have at least one version in it
+                StringTokenizer rangeTokenizer = new StringTokenizer(range, "-", false);
+                VersionNumber versionLower = null;
+                VersionNumber versionUpper = null;
+                while (rangeTokenizer.hasMoreTokens())
+                {
+                    String version = rangeTokenizer.nextToken();
+                    version = version.trim();
+                    if (versionLower == null)
+                    {
+                        if (version.equals("*"))
+                        {
+                            // Unbounded lower version
+                            versionLower = VersionNumber.VERSION_ZERO;
+                        }
+                        else
+                        {
+                            // Explicit lower bound
+                            versionLower = new VersionNumber(version);
+                        }
+                    }
+                    else if (versionUpper == null)
+                    {
+                        if (version.equals("*"))
+                        {
+                            // Unbounded upper version
+                            versionUpper = VersionNumber.VERSION_BIG;
+                        }
+                        else
+                        {
+                            // Explicit upper bound
+                            versionUpper = new VersionNumber(version);
+                        }
+                    }
+                }
+                // Check
+                if (versionUpper == null && versionLower == null)
+                {
+                    throw new AlfrescoRuntimeException(
+                            "Valid dependency version ranges are: \n" +
+                            "   LOW  - HIGH \n" +
+                            "   *    - HIGH \n" +
+                            "   LOW  - *    \n" +
+                            "   *       ");
+                }
+                else if (versionUpper == null && versionLower != null)
+                {
+                    versionUpper = versionLower;
+                }
+                else if (versionLower == null && versionUpper != null)
+                {
+                    versionLower = versionUpper;
+                }
+                // Create the range pair
+                Pair<VersionNumber, VersionNumber> rangePair = new Pair<VersionNumber, VersionNumber>(versionLower, versionUpper);
+                versionRanges.add(rangePair);
+            }
+            return versionRanges;
+        }
+        
+        public String getDependencyId()
+        {
+            return dependencyId;
+        }
+
+        public String getVersionString()
+        {
+            return versionStr;
+        }
+
+        public boolean isValidDependency(ModuleDetails moduleDetails)
+        {
+            // Nothing to compare to
+            if (moduleDetails == null)
+            {
+                return false;
+            }
+            // Check the ID
+            if (!moduleDetails.getId().equals(dependencyId))
+            {
+                return false;
+            }
+            // Check the version number
+            VersionNumber checkVersion = moduleDetails.getVersion();
+            boolean matched = false;
+            for (Pair<VersionNumber, VersionNumber> versionRange : versionRanges)
+            {
+                VersionNumber versionLower = versionRange.getFirst();
+                VersionNumber versionUpper = versionRange.getSecond();
+                if (checkVersion.compareTo(versionLower) < 0)
+                {
+                    // The version is too low
+                    continue; 
+                }
+                if (checkVersion.compareTo(versionUpper) > 0)
+                {
+                    // The version is too high
+                    continue;
+                }
+                // It is a match
+                matched = true;
+                break;
+            }
+            return matched;
+        }
+    }
 }

source/java/org/alfresco/repo/module/ModuleDetailsImplTest.java

@@ -24,9 +24,11 @@
  */
 package org.alfresco.repo.module;
 
+import java.util.List;
 import java.util.Properties;
 
 import org.alfresco.error.AlfrescoRuntimeException;
+import org.alfresco.service.cmr.module.ModuleDependency;
 import org.alfresco.service.cmr.module.ModuleDetails;
 import org.alfresco.service.cmr.module.ModuleInstallState;
 import org.alfresco.util.VersionNumber;
@@ -53,6 +55,14 @@ public class ModuleDetailsImplTest extends TestCase
         defaultProperties.setProperty(ModuleDetails.PROP_VERSION, "1.0.0");
         defaultProperties.setProperty(ModuleDetails.PROP_REPO_VERSION_MIN, new VersionNumber("1.2").toString());
         defaultProperties.setProperty(ModuleDetails.PROP_REPO_VERSION_MAX, new VersionNumber("1.4.3").toString());
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "a", "1.2.3");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "b", "*");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "c", "- 1.2");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "d", "1.2 -");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "e", "* - 1.2");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "f", "1.2 - *");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "g", "0.5, 0.6");
+        defaultProperties.setProperty(ModuleDetails.PROP_DEPENDS_PREFIX + "h", "0.5 - 0.6, 0.9 - *");
         defaultProperties.setProperty(ModuleDetails.PROP_INSTALL_STATE, ModuleInstallState.INSTALLED.toString());
     }
 
@@ -71,6 +81,29 @@ public class ModuleDetailsImplTest extends TestCase
         assertEquals("The properties are different", defaultProperties, processedProperties);
     }
     
+    public void testDependencyChecks()
+    {
+        ModuleDetails details = new ModuleDetailsImpl(defaultProperties);
+        
+        Properties tempProperties = new Properties();
+        tempProperties.setProperty(ModuleDetails.PROP_ID, "a");
+        tempProperties.setProperty(ModuleDetails.PROP_TITLE, "A");
+        tempProperties.setProperty(ModuleDetails.PROP_DESCRIPTION, "A description");
+        tempProperties.setProperty(ModuleDetails.PROP_VERSION, "1.0.0");
+        ModuleDetails tempDetails = new ModuleDetailsImpl(tempProperties);
+        
+        List<ModuleDependency> dependencies = details.getDependencies();
+        assertEquals("Incorrect number of dependencies", 8, dependencies.size());
+        for (ModuleDependency dependency : dependencies)
+        {
+            if (dependency.getDependencyId().equals(tempDetails.getId()))
+            {
+                // It should not match
+                assertFalse("No match expected", dependency.isValidDependency(tempDetails));
+            }
+        }
+    }
+    
     public void testTrimming() throws Exception
     {
         defaultProperties.setProperty(ModuleDetails.PROP_INSTALL_STATE, "    ");

source/java/org/alfresco/repo/module/tool/ModuleManagementTool.java

@@ -30,12 +30,14 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 
 import org.alfresco.error.AlfrescoRuntimeException;
+import org.alfresco.service.cmr.module.ModuleDependency;
 import org.alfresco.service.cmr.module.ModuleDetails;
 import org.alfresco.service.cmr.module.ModuleInstallState;
 import org.alfresco.util.VersionNumber;
@@ -127,25 +129,17 @@ public class ModuleManagementTool
     {
         this.verbose = verbose;
     }
-    
+
     /**
+     * Installs all modules within a folder into the given WAR file.
      * 
-     * @param directory
+     * @see #installModule(String, String, boolean, boolean, boolean)
-     * @param warFileLocation
      */
     public void installModules(String directory, String warFileLocation)
     {
         installModules(directory, warFileLocation, false, false, true);
     }
     
-    /**
-     * 
-     * @param directoryLocation
-     * @param warFileLocation
-     * @param preview
-     * @param forceInstall
-     * @param backupWAR
-     */
     public void installModules(String directoryLocation, String warFileLocation, boolean preview, boolean forceInstall, boolean backupWAR)
     {
         java.io.File dir = new java.io.File(directoryLocation);
@@ -159,14 +153,6 @@ public class ModuleManagementTool
         }
     }
     
-    /**
-     * 
-     * @param dir
-     * @param warFileLocation
-     * @param preview
-     * @param forceInstall
-     * @param backupWAR
-     */
     private void installModules(java.io.File dir, String warFileLocation, boolean preview, boolean forceInstall, boolean backupWAR)
     {
         java.io.File[] children =  dir.listFiles();
@@ -256,6 +242,25 @@ public class ModuleManagementTool
             String installingId = installingModuleDetails.getId();
             VersionNumber installingVersion = installingModuleDetails.getVersion();
             
+            // Check that the target war has the necessary dependencies for this install
+            List<ModuleDependency> installingModuleDependencies = installingModuleDetails.getDependencies();
+            List<ModuleDependency> missingDependencies = new ArrayList<ModuleDependency>(0);
+            for (ModuleDependency dependency : installingModuleDependencies)
+            {
+                String dependencyId = dependency.getDependencyId();
+                ModuleDetails dependencyModuleDetails = ModuleDetailsHelper.createModuleDetailsFromWarAndId(warFileLocation, dependencyId);
+                // Check the dependency.  The API specifies that a null returns false, so no null check is required
+                if (!dependency.isValidDependency(dependencyModuleDetails))
+                {
+                    missingDependencies.add(dependency);
+                    continue;
+                }
+            }
+            if (missingDependencies.size() > 0)
+            {
+                throw new ModuleManagementToolException("The following modules must first be installed: " + missingDependencies);
+            }
+            
             // Try to find an installed module by the ID
             ModuleDetails installedModuleDetails = ModuleDetailsHelper.createModuleDetailsFromWarAndId(warFileLocation, installingId);
             if (installedModuleDetails == null)
@@ -716,71 +721,69 @@ public class ModuleManagementTool
      */
     public static void main(String[] args)
     {
-        if (args.length >= 1)
+        if (args.length <= 1)
         {
-            ModuleManagementTool manager = new ModuleManagementTool();
+            outputUsage();
+            return;
+        }
+        ModuleManagementTool manager = new ModuleManagementTool();
+        
+        String operation = args[0];
+        if (operation.equals(OP_INSTALL) == true && args.length >= 3)
+        {            
+            String aepFileLocation = args[1];
+            String warFileLocation = args[2];
+            boolean forceInstall = false;
+            boolean previewInstall = false;
+            boolean backup = true;
+            boolean directory = false;
             
-            String operation = args[0];
+            if (args.length > 3)
-            if (operation.equals(OP_INSTALL) == true && args.length >= 3)
+            {
-            {            
+                for (int i = 3; i < args.length; i++)
-                String aepFileLocation = args[1];
-                String warFileLocation = args[2];
-                boolean forceInstall = false;
-                boolean previewInstall = false;
-                boolean backup = true;
-                boolean directory = false;
-                
-                if (args.length > 3)
                 {
-                    for (int i = 3; i < args.length; i++)
+                    String option = args[i];
+                    if (OPTION_VERBOSE.equals(option) == true)
                     {
-                        String option = args[i];
+                        manager.setVerbose(true);
-                        if (OPTION_VERBOSE.equals(option) == true)
+                    }
-                        {
+                    else if (OPTION_FORCE.equals(option) == true)
-                            manager.setVerbose(true);
+                    {
-                        }
+                        forceInstall = true;
-                        else if (OPTION_FORCE.equals(option) == true)
+                    }
-                        {
+                    else if (OPTION_PREVIEW.equals(option) == true)
-                            forceInstall = true;
+                    {
-                        }
+                        previewInstall = true;
-                        else if (OPTION_PREVIEW.equals(option) == true)
+                        manager.setVerbose(true);
-                        {
+                    }
-                            previewInstall = true;
+                    else if (OPTION_NOBACKUP.equals(option) == true)
-                            manager.setVerbose(true);
+                    {
-                        }
+                        backup = false;
-                        else if (OPTION_NOBACKUP.equals(option) == true)
+                    }
-                        {
+                    else if (OPTION_DIRECTORY.equals(option) == true)
-                            backup = false;
+                    {
-                        }
+                        directory = true;
-                        else if (OPTION_DIRECTORY.equals(option) == true)
-                        {
-                            directory = true;
-                        }
                     }
                 }
-                      
-                if (directory == false)
-                {
-                    // Install the module
-                    manager.installModule(aepFileLocation, warFileLocation, previewInstall, forceInstall, backup);
-                }
-                else
-                {
-                    // Install the modules from the directory
-                    manager.installModules(aepFileLocation, warFileLocation, previewInstall, forceInstall, backup);
-                }
             }
-            else if (OP_LIST.equals(operation) == true && args.length == 2)
+                  
+            if (directory == false)
             {
-                // List the installed modules
+                // Install the module
-                String warFileLocation = args[1];
+                manager.installModule(aepFileLocation, warFileLocation, previewInstall, forceInstall, backup);
-                manager.listModules(warFileLocation);                
             }
             else
             {
-                outputUsage();
+                // Install the modules from the directory
+                manager.installModules(aepFileLocation, warFileLocation, previewInstall, forceInstall, backup);
             }
         }
+        else if (OP_LIST.equals(operation) == true && args.length == 2)
+        {
+            // List the installed modules
+            String warFileLocation = args[1];
+            manager.listModules(warFileLocation);                
+        }
         else
         {
             outputUsage();

source/java/org/alfresco/repo/module/tool/ModuleManagementToolTest.java

@@ -45,9 +45,10 @@ import de.schlichtherle.io.FileOutputStream;
 import de.schlichtherle.io.ZipDetector;
 
 /**
- * Module management tool unit test
+ * @see org.alfresco.repo.module.tool.ModuleManagementTool
  * 
  * @author Roy Wetherall
+ * @author Derek Hulley
  */
 public class ModuleManagementToolTest extends TestCase
 {
@@ -61,11 +62,9 @@ public class ModuleManagementToolTest extends TestCase
         manager.setVerbose(true);
         
         String warLocation = getFileLocation(".war", "module/test.war");
-        String ampLocation = getFileLocation(".amp", "module/test.amp");
+        String ampLocation = getFileLocation(".amp", "module/test_v1.amp");
         String ampV2Location = getFileLocation(".amp", "module/test_v2.amp");
         
-        System.out.println(warLocation);
-        
         // Initial install of module
         this.manager.installModule(ampLocation, warLocation);
         
@@ -161,15 +160,47 @@ public class ModuleManagementToolTest extends TestCase
         }        
     }
     
+    public void testDependencySuccess() throws Exception
+    {
+        manager.setVerbose(true);
+        
+        String warLocation = getFileLocation(".war", "module/test.war");
+        String testAmpV1Location = getFileLocation(".amp", "module/test_v1.amp");
+        String testAmpV2Location = getFileLocation(".amp", "module/test_v2.amp");
+        String testAmpDepV1Location = getFileLocation(".amp", "module/dependent_on_test_v1.amp");
+        String testAmpDepV2Location = getFileLocation(".amp", "module/dependent_on_test_v2.amp");
+        
+        // Install V1
+        this.manager.installModule(testAmpV1Location, warLocation, false, false, false);
+        
+        // Install the module dependent on test_v1
+        this.manager.installModule(testAmpDepV1Location, warLocation, false, false, false);
+        
+        try
+        {
+            // Attempt to upgrade the dependent module
+            this.manager.installModule(testAmpDepV2Location, warLocation, false, false, false);
+            fail("Failed to detect inadequate dependency on the test amp");
+        }
+        catch (ModuleManagementToolException e)
+        {
+            System.out.println("Expected: " + e.getMessage());
+        }
+        
+        // Install the test_v2
+        this.manager.installModule(testAmpV2Location, warLocation, false, false, false);
+        
+        // The dependent module should now go in
+        this.manager.installModule(testAmpDepV2Location, warLocation, false, false, false);
+    }
+
     public void testPreviewInstall()
         throws Exception
     {
         manager.setVerbose(true);
         
         String warLocation = getFileLocation(".war", "module/test.war");
-        String ampLocation = getFileLocation(".amp", "module/test.amp");
+        String ampLocation = getFileLocation(".amp", "module/test_v1.amp");
-        
-        System.out.println(warLocation);
         
         // Initial install of module
         this.manager.installModule(ampLocation, warLocation, true, false, true);
@@ -183,9 +214,7 @@ public class ModuleManagementToolTest extends TestCase
         manager.setVerbose(true);
         
         String warLocation = getFileLocation(".war", "module/test.war");
-        String ampLocation = getFileLocation(".amp", "module/test.amp");
+        String ampLocation = getFileLocation(".amp", "module/test_v1.amp");
-        
-        System.out.println(warLocation);
         
         // Initial install of module
         this.manager.installModule(ampLocation, warLocation, false, false, false);
@@ -198,15 +227,13 @@ public class ModuleManagementToolTest extends TestCase
         manager.setVerbose(true);
         
         String warLocation = getFileLocation(".war", "module/test.war");
-        String ampLocation = getFileLocation(".amp", "module/test.amp");
+        String ampLocation = getFileLocation(".amp", "module/test_v1.amp");
         String ampV2Location = getFileLocation(".amp", "module/test_v2.amp");
 
         int index = ampV2Location.lastIndexOf(File.separator);
         System.out.println(index);
         String directoryLocation = ampV2Location.substring(0, index);
         
-        System.out.println(warLocation);
-        System.out.println(directoryLocation);
         try
         {
             this.manager.installModules(directoryLocation, warLocation);
@@ -222,7 +249,7 @@ public class ModuleManagementToolTest extends TestCase
         throws Exception
     {
         String warLocation = getFileLocation(".war", "module/test.war");
-        String ampLocation = getFileLocation(".amp", "module/test.amp");
+        String ampLocation = getFileLocation(".amp", "module/test_v1.amp");
         
         this.manager.listModules(warLocation);
         
@@ -230,7 +257,7 @@ public class ModuleManagementToolTest extends TestCase
         
         this.manager.listModules(warLocation);        
     }
-
+    
     private String getFileLocation(String extension, String location)
         throws IOException
     {

source/java/org/alfresco/service/cmr/module/ModuleDependency.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2005-2007 Alfresco Software Limited.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+ * As a special exception to the terms and conditions of version 2.0 of 
+ * the GPL, you may redistribute this Program in connection with Free/Libre 
+ * and Open Source Software ("FLOSS") applications as described in Alfresco's 
+ * FLOSS exception.  You should have recieved a copy of the text describing 
+ * the FLOSS exception, and it is also available here: 
+ * http://www.alfresco.com/legal/licensing"
+ */
+package org.alfresco.service.cmr.module;
+
+import java.io.Serializable;
+
+/**
+ * An ensapsulated module dependency.  Since module dependencies may be range based and even
+ * unbounded, it is not possible to describe a dependency using a list of module version numbers.
+ * This class answers the 
+ * 
+ * @author Derek Hulley
+ */
+public interface ModuleDependency extends Serializable
+{
+    /**
+     * Get the ID of the module that this dependency describes.  The dependency
+     * may be upon specific versions or a range of versions.  Nevertheless, the
+     * module given by the returned ID will be required in one version or another.
+     * 
+     * @return      Returns the ID of the module that this depends on
+     */
+    public String getDependencyId();
+    
+    /**
+     * @return      Returns a string representation of the versions supported
+     */
+    public String getVersionString();
+
+    /**
+     * Check if a module satisfies the dependency requirements.
+     * 
+     * @param moduleDetails     the module details of the dependency.  This must be
+     *                          the details of the module with the correct
+     *                          {@link #getDependencyId() ID}.  This may be <tt>null</tt>
+     *                          in which case <tt>false</tt> will always be returned.
+     * @return                  Returns true if the module satisfies the dependency
+     *                          requirements.
+     */
+    public boolean isValidDependency(ModuleDetails moduleDetails);
+}

source/java/org/alfresco/service/cmr/module/ModuleDetails.java

@@ -24,6 +24,7 @@
  */
 package org.alfresco.service.cmr.module;
 
+import java.io.Serializable;
 import java.util.Date;
 import java.util.List;
 import java.util.Properties;
@@ -36,7 +37,7 @@ import org.alfresco.util.VersionNumber;
  * @author Roy Wetherall
  * @since 2.0
  */
-public interface ModuleDetails
+public interface ModuleDetails extends Serializable
 {
     static final String PROP_ID = "module.id";
     static final String PROP_ALIASES = "module.aliases";
@@ -45,6 +46,7 @@ public interface ModuleDetails
     static final String PROP_DESCRIPTION = "module.description";
     static final String PROP_REPO_VERSION_MIN = "module.repo.version.min";
     static final String PROP_REPO_VERSION_MAX = "module.repo.version.max";
+    static final String PROP_DEPENDS_PREFIX = "module.depends.";
     static final String PROP_INSTALL_DATE = "module.installDate";
     static final String PROP_INSTALL_STATE = "module.installState";
     
@@ -110,6 +112,11 @@ public interface ModuleDetails
      */
     void setRepoVersionMax(VersionNumber repoVersionMax);
     
+    /**
+     * @return  Returns a list of module dependencies that must be present for this module
+     */
+    List<ModuleDependency> getDependencies();
+    
     /**
      * Get the modules install date
      *