Add enforcer rule for valid Classpath Entries in EAR modules' manifest

src/main/java/org/apache/maven/plugins/enforcer/EarModuleClasspath.java

@@ -0,0 +1,226 @@
+package org.apache.maven.plugins.enforcer;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.Stack;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+import java.util.zip.ZipInputStream;
+
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.parsers.SAXParser;
+import javax.xml.parsers.SAXParserFactory;
+
+import org.apache.maven.enforcer.rule.api.EnforcerRule;
+import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
+import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;
+import org.apache.maven.project.MavenProject;
+import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
+import org.xml.sax.Attributes;
+import org.xml.sax.SAXException;
+import org.xml.sax.helpers.DefaultHandler;
+
+/**
+ * This rule verifies that the EJB's Classpath entry in the manifest refers to a libray in the shared library path.
+ * 
+ * The rule assumes that all EJB are located at the root of the EAR and the lib folder contains all shared libraries.
+ *  
+ * @author Martin Goldhahn <[email protected]>
+ * @author Stig Tore Johannesen <[email protected]>
+ */
+public class EarModuleClasspath implements EnforcerRule {
+
+    public void execute(EnforcerRuleHelper helper) throws EnforcerRuleException {
+
+        try {
+            MavenProject project = (MavenProject) helper.evaluate("${project}");
+            String projectType = project.getArtifact().getType();
+            if (!"ear".equals(projectType)) { 
+                throw new EnforcerRuleException("EarModuleClasspath rule can only be applied in EAR projects"); 
+            }
+            File outputDir = new File(project.getBuild().getDirectory());
+            String finalName = project.getBuild().getFinalName();
+            File earFile = new File(outputDir, finalName + '.' + projectType);
+
+            verifyManifests(earFile);
+        } catch (ExpressionEvaluationException e) {
+            throw new EnforcerRuleException("Unable to lookup expression " + e.getLocalizedMessage(), e);
+        } catch (IOException ex) {
+            throw new EnforcerRuleException(ex.getMessage(), ex);
+        }
+    }
+
+    public boolean isCacheable() {
+        return false;
+    }
+
+    public boolean isResultValid(EnforcerRule cachedRule) {
+        return false;
+    }
+
+    public String getCacheId() {
+        return "";
+    }
+
+    private void verifyManifests(File earFile) throws EnforcerRuleException, IOException {
+        Set<String> sharedLibs = new HashSet<String>();
+        Map<String, Set<String>> ejbClasspaths = new HashMap<String, Set<String>>();
+
+        ApplicationXmlHandler appXml = readApplicationXml(earFile);
+
+        extractSharedLibsAndEjbClasspath(earFile, appXml, sharedLibs, ejbClasspaths);
+
+        checkClassPaths(sharedLibs, ejbClasspaths, appXml);
+    }
+
+    private void extractSharedLibsAndEjbClasspath(File earFile, ApplicationXmlHandler appXml, Set<String> sharedLibs,
+        Map<String, Set<String>> ejbClasspaths) throws IOException {
+
+        String libFolderName = appXml.getLibDir() + '/';
+        ZipFile ear = null;
+        try {
+            ear = new ZipFile(earFile);
+            Enumeration<? extends ZipEntry> entries = ear.entries();
+            while (entries.hasMoreElements()) {
+                ZipEntry entry = entries.nextElement();
+                String entryName = entry.getName();
+                if (appXml.getEjbModules().contains(entryName)) {
+                    Set<String> cl = extractClassPathFromManifest(ear, entry);
+                    ejbClasspaths.put(entryName, cl);
+                } else if (appXml.getWebModules().contains(entryName)) {
+                    // web modules are ignored
+                } else if (entryName.startsWith(libFolderName) && entryName.endsWith(".jar")) {
+                    // this must be a shared library
+                    sharedLibs.add(entryName);
+                }
+            }
+        } finally {
+            if (ear != null) {
+                ear.close();
+            }
+        }
+    }
+
+    private Set<String> extractClassPathFromManifest(ZipFile ear, ZipEntry entry) throws IOException {
+
+        ZipInputStream zipStream = null;
+        Set<String> classPath = new HashSet<String>();
+        try {
+            zipStream = new ZipInputStream(ear.getInputStream(entry));
+
+            ZipEntry moduleEntry;
+            while ((moduleEntry = zipStream.getNextEntry()) != null) {
+                if (moduleEntry.getName().equals(JarFile.MANIFEST_NAME)) {
+                    ByteArrayOutputStream sb = new ByteArrayOutputStream();
+                    byte[] buffer = new byte[0xFFFF];
+                    int read;
+                    while ((read = zipStream.read(buffer)) >= 0) {
+                        sb.write(buffer, 0, read);
+                    }
+                    Manifest mf = new Manifest(new ByteArrayInputStream(sb.toByteArray()));
+                    String cl = mf.getMainAttributes().getValue("Class-Path");
+                    if (cl != null) {
+                        for (String clEntry : cl.split(" ")) {
+                            classPath.add(clEntry);
+                        }
+                    }
+                    break;
+                }
+            }
+            return classPath;
+        } finally {
+            if (zipStream != null) {
+                zipStream.close();
+            }
+        }
+    }
+
+    /**
+     * Read the META-INF/application.xml from the EAR.
+     */
+    private ApplicationXmlHandler readApplicationXml(File earFile) throws IOException {
+        ZipFile ear = null;
+        try {
+            ear = new ZipFile(earFile);
+            ApplicationXmlHandler appXml = new ApplicationXmlHandler();
+            ZipEntry applicationXmlEntry = ear.getEntry("META-INF/application.xml");
+            SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
+            parser.parse(ear.getInputStream(applicationXmlEntry), appXml);
+            return appXml;
+        } catch (ParserConfigurationException e) {
+            throw new RuntimeException(e);
+        } catch (SAXException e) {
+            throw new RuntimeException(e);
+        } finally {
+            if (ear != null) {
+                ear.close();
+            }
+        }
+    }
+
+    /**
+     * The libraries in the classpath entry of the manifest can include the library path or not. 
+     */
+    private void checkClassPaths(Set<String> sharedLibs, Map<String, Set<String>> ejbClasspaths, ApplicationXmlHandler appXml) throws EnforcerRuleException {
+        for (Map.Entry<String, Set<String>> entry : ejbClasspaths.entrySet()) {
+            for (String clEntry : entry.getValue()) {
+                if (!sharedLibs.contains(clEntry) && !sharedLibs.contains(appXml.getLibDir() + '/' + clEntry)) {
+                    throw new EnforcerRuleException("Did not find shared library " + clEntry + " in manifest of " + entry.getKey());
+                }
+            }
+        }
+    }
+
+    private static class ApplicationXmlHandler extends DefaultHandler {
+        private Set<String> ejbModules = new HashSet<String>();
+        private Set<String> webModules = new HashSet<String>();
+        private String libDir;
+
+        private Stack<String> elementStack = new Stack<String>();
+
+        @Override
+        public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
+            elementStack.push(qName);
+        }
+
+        @Override
+        public void endElement(String uri, String localName, String qName) throws SAXException {
+            elementStack.pop();
+        }
+
+        @Override
+        public void characters(char[] ch, int start, int length) throws SAXException {
+            String value = new String(ch, start, length).trim();
+
+            String currentElement = elementStack.peek();
+            if ("ejb".equals(currentElement)) {
+                ejbModules.add(value);
+            } else if ("web-uri".equals(currentElement)) {
+                webModules.add(value);
+            } else if ("library-directory".equals(currentElement)) {
+                libDir = value;
+            }
+        }
+
+        public Set<String> getEjbModules() {
+            return ejbModules;
+        }
+
+        public Set<String> getWebModules() {
+            return webModules;
+        }
+
+        public String getLibDir() {
+            return libDir;
+        }
+    }
+}

src/site/apt/earModuleClasspath.apt.vm

@@ -0,0 +1,126 @@
+~~ Licensed to the Apache Software Foundation (ASF) under one
+~~ or more contributor license agreements.  See the NOTICE file
+~~ distributed with this work for additional information
+~~ regarding copyright ownership.  The ASF licenses this file
+~~ to you under the Apache License, Version 2.0 (the
+~~ "License"); you may not use this file except in compliance
+~~ with the License.  You may obtain a copy of the License 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.
+
+  ------
+  EAR module classpath
+  ------
+  Martin Goldhahn
+  ------
+  April 2015
+  ------
+
+EAR module classpath
+
+  This rule checks that the classpath manifest entry for Enterprise Java Bean (EJB) in an Enterprise ARchive (EAR) project refers to 
+  existing libraries in the EAR's shared lib folder.
+
+  The Manifest of an EJB might have a manifest entry:
+  <<<Class-Path: commons-beanutils-1.8.3.jar>>>
+
+  This rule verifies that the EAR actually contains a commons-beanutils-1.8.3.jar in the EAR's lib folder.
+
+  As the EAR's lib folder can be configured, its actual value is read from META-INF/application.xml. 
+  This file is also read to get the list of EJBs in the EAR.
+
+Sample configuration:
+
++---+
+<project>
+  <groupId>com.company</groupId>
+  <artifactId>product</artifactId>
+  <version>1.0</version>
+  <url>http://company/wiki/product</url>
+  <packaging>ear</packaging>
+  [...]
+  <dependencies>
+    <dependency>
+      <groupId>com.company</groupId>
+      <artifactId>ejb1</artifactId>
+      <version>1.0</version>
+      <type>ejb</type>
+    </dependency>
+    <dependency>
+      <groupId>com.company</groupId>
+      <artifactId>webapp1</artifactId>
+      <version>1.0</version>
+      <type>war</type>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <version>${enforcerApiVersion}</version> <!-- find the latest version at http://maven.apache.org/plugins/maven-enforcer-plugin/ -->
+        <executions>
+          <execution>
+            <id>validate-ear</id>
+            <goals>
+              <goal>enforce</goal>
+            </goals>
+            <phase>package</phase>
+            <configuration>
+              <rules>
+                <earModuleClasspath/>
+              </rules>
+            </configuration>
+          </execution>
+        </executions>
+        <dependencies>
+          <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>${project.artifactId}</artifactId>
+            <version>${project.version}</version>
+          </dependency>
+        </dependencies>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-ear-plugin</artifactId>
+        <configuration>
+            <version>7</version>
+            <defaultLibBundleDir>lib</defaultLibBundleDir>
+            <applicationName>product-app</applicationName>
+            <archive>
+              <manifestEntries>
+                <Dependencies>com.oracle.jdbc7_g</Dependencies>
+              </manifestEntries>
+            </archive>
+
+            <modules>
+                <webModule>
+                    <groupId>com.company</groupId>
+                    <artifactId>webapp1</artifactId>
+                    <contextRoot>/webapp</contextRoot>
+                </webModule>
+
+                <ejbModule>
+                    <groupId>com.company</groupId>
+                    <artifactId>ejb1</artifactId>
+                </ejbModule>
+            </modules>
+        </configuration>
+    </plugin>
+    </plugins>
+  </build>
+  [...]
+</project>
++---+
+
+* Trademarks
+
+  Apache, Apache Maven, Maven and the Apache feather logo are trademarks of The Apache Software Foundation.

src/site/apt/index.apt

@@ -48,6 +48,8 @@ Extra Enforcer Rules
 
   * {{{./requireEncoding.html}requireEncoding}} - verifies that source files have a required encoding.
 
+  * {{{./earModuleClasspath.html}earModuleClasspath}} - verifies that Class-Path manifest entries in EJBs inside a EAR are valid.
+
   []
 
   <<NOTE: When using the Apache Maven Enforcer Plugin version 1.3 or later, be sure to use at least extra-enforcer-rules 1.0-beta-1>>

src/site/site.xml

@@ -32,6 +32,7 @@ under the License.
       <item name="Enforce Bytecode Version" href="enforceBytecodeVersion.html"/>
       <item name="Ban Circular Dependencies" href="banCircularDependencies.html"/>
       <item name="Require Encoding" href="requireEncoding.html"/>
+      <item name="Ear Module Classpath" href="earModuleClasspath.html"/>
     </menu>
   </body>
 </project>