Checks for plugin jar file corruption and logs if found.

Maintain existing "refuse to start" behaviour.

community/kernel/src/main/java/org/neo4j/kernel/impl/proc/ProcedureJarLoader.java

@@ -28,6 +28,7 @@
 import java.util.List;
 import java.util.stream.Stream;
 import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
 import java.util.zip.ZipInputStream;
 
 import org.neo4j.collection.PrefetchingRawIterator;
@@ -48,13 +49,14 @@ public class ProcedureJarLoader
     private final ReflectiveProcedureCompiler compiler;
     private final Log log;
 
-    public ProcedureJarLoader( ReflectiveProcedureCompiler compiler, Log log )
+    ProcedureJarLoader( ReflectiveProcedureCompiler compiler, Log log )
     {
         this.compiler = compiler;
         this.log = log;
     }
 
-    public Callables loadProcedures( URL jar ) throws Exception
+    // TODO: delete me and change the tests
+    Callables loadProcedures( URL jar ) throws Exception
     {
         return loadProcedures( jar, new URLClassLoader( new URL[]{jar}, this.getClass().getClassLoader() ),
                 new Callables() );
@@ -73,6 +75,8 @@ public Callables loadProceduresFromDir( File root ) throws IOException, KernelEx
                 .collect( toList() );
         URL[] jarFiles = list.toArray( new URL[list.size()] );
 
+        validateJarFiles( jarFiles );
+
         URLClassLoader loader = new URLClassLoader( jarFiles, this.getClass().getClassLoader() );
 
         for ( URL jarFile : jarFiles )
@@ -82,6 +86,22 @@ public Callables loadProceduresFromDir( File root ) throws IOException, KernelEx
         return out;
     }
 
+    private void validateJarFiles( URL[] jarFiles ) throws IOException
+    {
+        for ( URL jarFile : jarFiles )
+        {
+            try
+            {
+                new ZipFile( new File( jarFile.getFile() ) );
+            }
+            catch ( IOException e )
+            {
+                log.error( String.format( "Plugin jar file: %s corrupted. Please reinstall.", jarFile.getFile() ) );
+                throw e;
+            }
+        }
+    }
+
     private Callables loadProcedures( URL jar, ClassLoader loader, Callables target )
             throws IOException, KernelException
     {
@@ -185,12 +205,12 @@ public List<CallableUserFunction> functions()
             return functions;
         }
 
-        public void addAllProcedures( List<CallableProcedure> callableProcedures )
+        void addAllProcedures( List<CallableProcedure> callableProcedures )
         {
             procedures.addAll( callableProcedures );
         }
 
-        public void addAllFunctions( List<CallableUserFunction> callableFunctions )
+        void addAllFunctions( List<CallableUserFunction> callableFunctions )
         {
             functions.addAll( callableFunctions );
         }

community/kernel/src/test/java/org/neo4j/kernel/impl/proc/ProcedureJarLoaderTest.java

@@ -25,24 +25,31 @@
 import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
+import java.io.File;
 import java.io.IOException;
+import java.net.URISyntaxException;
 import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.Collections;
 import java.util.List;
 import java.util.Random;
 import java.util.stream.Stream;
+import java.util.zip.ZipException;
 
 import org.neo4j.kernel.api.ResourceTracker;
 import org.neo4j.kernel.api.StubResourceManager;
 import org.neo4j.kernel.api.exceptions.ProcedureException;
 import org.neo4j.kernel.api.proc.BasicContext;
 import org.neo4j.kernel.api.proc.CallableProcedure;
 import org.neo4j.kernel.api.proc.ProcedureSignature;
+import org.neo4j.logging.AssertableLogProvider;
 import org.neo4j.logging.NullLog;
 import org.neo4j.procedure.Name;
 import org.neo4j.procedure.Procedure;
 
 import static java.util.stream.Collectors.toList;
+import static junit.framework.TestCase.fail;
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.junit.Assert.assertThat;
@@ -202,14 +209,51 @@ public void shouldGiveHelpfulErrorOnGenericStreamProcedure() throws Throwable
         jarloader.loadProcedures( jar );
     }
 
-    public URL createJarFor( Class<?> ... targets ) throws IOException
+    @Test
+    public void shouldLogHelpfullyWhenPluginJarIsCorrupt() throws Exception
+    {
+        // given
+        URL theJar = createJarFor( ClassWithOneProcedure.class, ClassWithAnotherProcedure.class, ClassWithNoProcedureAtAll.class );
+        corruptJar( theJar );
+        AssertableLogProvider logProvider = new AssertableLogProvider( true );
+
+        ProcedureJarLoader jarloader = new ProcedureJarLoader(
+                new ReflectiveProcedureCompiler( new TypeMappers(), new ComponentRegistry(), NullLog.getInstance(), ProcedureAllowedConfig.DEFAULT ),
+                logProvider.getLog( ProcedureJarLoader.class ) );
+
+        // when
+        try
+        {
+            jarloader.loadProceduresFromDir( new File( theJar.getFile() ).getParentFile() );
+            fail("Should have logged and thrown exception.");
+        }
+        catch ( ZipException expected )
+        {
+            // then
+            logProvider.assertContainsLogCallContaining( String.format( "Plugin jar file: %s corrupted. Please reinstall.", theJar.getFile() ) );
+        }
+    }
+
+    private void corruptJar( URL jar ) throws IOException, URISyntaxException
+    {
+        long fileLength = new File( jar.getFile() ).length();
+        byte[] bytes = Files.readAllBytes( Paths.get( jar.toURI() ) );
+        for ( long i = fileLength/2; i < fileLength; i++ )
+        {
+            bytes[(int)i]= 0;
+        }
+
+        Files.write( Paths.get( jar.getPath() ), bytes );
+    }
+
+    private URL createJarFor( Class<?> ... targets ) throws IOException
     {
         return new JarBuilder().createJarFor( tmpdir.newFile( new Random().nextInt() + ".jar" ), targets );
     }
 
     public static class Output
     {
-        public long someNumber = 1337;
+        public long someNumber = 1337; // Public because needed by a mapper
 
         public Output()
         {