Clear lock cache in NioFileLocker (#2998)

Fixes #2980
# Conflicts:
#	spring-integration-file/src/test/java/org/springframework/integration/file/locking/NioFileLockerTests.java

# Conflicts:
#	spring-integration-file/src/main/java/org/springframework/integration/file/locking/NioFileLocker.java
#	spring-integration-file/src/test/java/org/springframework/integration/file/locking/NioFileLockerTests.java

Author: garyrussell

spring-integration-file/src/main/java/org/springframework/integration/file/locking/NioFileLocker.java

@@ -16,15 +16,15 @@
 
 package org.springframework.integration.file.locking;
 
-import org.springframework.messaging.MessagingException;
-import org.springframework.integration.file.FileReadingMessageSource;
-
 import java.io.File;
 import java.io.IOException;
 import java.nio.channels.FileLock;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
+import org.springframework.integration.file.FileReadingMessageSource;
+import org.springframework.messaging.MessagingException;
+
 /**
  * File locking strategy that uses java.nio. The locks taken by FileChannel are shared with all the threads in a single
  * JVM, so this locking strategy <b>does not</b> prevent files being picked up multiple times within the same JVM.
@@ -39,45 +39,46 @@
  */
 public class NioFileLocker extends AbstractFileLockerFilter {
 
-    private final ConcurrentMap<File, FileLock> lockCache = new ConcurrentHashMap<File, FileLock>();
+	private final ConcurrentMap<File, FileLock> lockCache = new ConcurrentHashMap<File, FileLock>();
 
-    /**
-     * {@inheritDoc}
-     */
-    public boolean lock(File fileToLock) {
-        FileLock lock = this.lockCache.get(fileToLock);
-        if (lock == null) {
-            FileLock newLock = null;
-            try {
-                newLock = FileChannelCache.tryLockFor(fileToLock);
-            }
-catch (IOException e) {
-                throw new MessagingException("Failed to lock file: "
-                        + fileToLock, e);
-            }
-            if (newLock != null) {
-                FileLock original = this.lockCache.putIfAbsent(fileToLock, newLock);
-                lock = original != null ? original : newLock;
-            }
-        }
-        return lock != null;
-    }
+	/**
+	 * {@inheritDoc}
+	 */
+	public boolean lock(File fileToLock) {
+		FileLock lock = this.lockCache.get(fileToLock);
+		if (lock == null) {
+			FileLock newLock;
+			try {
+				newLock = FileChannelCache.tryLockFor(fileToLock);
+			}
+			catch (IOException e) {
+				throw new MessagingException("Failed to lock file: "
+						+ fileToLock, e);
+			}
+			if (newLock != null) {
+				FileLock original = this.lockCache.putIfAbsent(fileToLock, newLock);
+				lock = original != null ? original : newLock;
+			}
+		}
+		return lock != null;
+	}
 
-    public boolean isLockable(File file) {
-        return this.lockCache.containsKey(file) || !FileChannelCache.isLocked(file);
-    }
+	public boolean isLockable(File file) {
+		return this.lockCache.containsKey(file) || !FileChannelCache.isLocked(file);
+	}
 
-    public void unlock(File fileToUnlock) {
-        FileLock fileLock = this.lockCache.get(fileToUnlock);
-        try {
-            if (fileLock != null) {
-                fileLock.release();
-            }
-            FileChannelCache.closeChannelFor(fileToUnlock);
-        }
-catch (IOException e) {
-            throw new MessagingException("Failed to unlock file: "
-                    + fileToUnlock, e);
-        }
+	@Override
+	public void unlock(File fileToUnlock) {
+		FileLock fileLock = this.lockCache.remove(fileToUnlock);
+		try {
+			if (fileLock != null) {
+				fileLock.release();
+			}
+			FileChannelCache.closeChannelFor(fileToUnlock);
+		}
+		catch (IOException e) {
+			throw new MessagingException("Failed to unlock file: " + fileToUnlock, e);
+		}
 	}
+
 }

spring-integration-file/src/test/java/org/springframework/integration/file/locking/NioFileLockerTests.java

@@ -18,20 +18,24 @@
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.io.IOException;
+import java.lang.reflect.Field;
 import java.util.ArrayList;
-import java.util.List;
+import java.util.Map;
 
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.integration.file.filters.FileListFilter;
+import org.springframework.integration.test.util.TestUtils;
 
 /**
  * @author Iwein Fuld
+ * @author Gary Russell
  */
 public class NioFileLockerTests {
 
@@ -46,25 +50,31 @@ public void create() throws IOException {
 		}
 	};
 
-    @Test
-    public void fileListedByFirstFilter() throws IOException {
-        NioFileLocker filter = new NioFileLocker();
-        File testFile = new File(workdir, "test0");
-        testFile.createNewFile();
-        assertThat(filter.filterFiles(workdir.listFiles()).get(0), is(testFile));
-        filter.lock(testFile);
-        assertThat(filter.filterFiles(workdir.listFiles()).get(0), is(testFile));
-    }
+	@Test
+	public void fileListedByFirstFilter() throws Exception {
+		NioFileLocker filter = new NioFileLocker();
+		File testFile = new File(workdir, "test0");
+		testFile.createNewFile();
+		assertThat(filter.filterFiles(workdir.listFiles()).get(0), is(testFile));
+		filter.lock(testFile);
+		assertThat(filter.filterFiles(workdir.listFiles()).get(0), is(testFile));
+		filter.unlock(testFile);
+		Field channelCache = FileChannelCache.class.getDeclaredField("channelCache");
+		channelCache.setAccessible(true);
+		assertTrue(((Map<?, ?>) channelCache.get(null)).isEmpty());
+		assertTrue(TestUtils.getPropertyValue(filter, "lockCache", Map.class).isEmpty());
+	}
 
-    @Test
-    public void fileNotListedWhenLockedByOtherFilter() throws IOException {
-        NioFileLocker filter1 = new NioFileLocker();
-        FileListFilter<File> filter2 = new NioFileLocker();
-        File testFile = new File(workdir, "test1");
-        testFile.createNewFile();
-        assertThat(filter1.filterFiles(workdir.listFiles()).get(0), is(testFile));
-        filter1.lock(testFile);
-        assertThat(filter2.filterFiles(workdir.listFiles()), is((List<File>) new ArrayList<File>()));
-    }
+	@Test
+	public void fileNotListedWhenLockedByOtherFilter() throws IOException {
+		NioFileLocker filter1 = new NioFileLocker();
+		FileListFilter<File> filter2 = new NioFileLocker();
+		File testFile = new File(workdir, "test1");
+		testFile.createNewFile();
+		assertThat(filter1.filterFiles(workdir.listFiles()).get(0), is(testFile));
+		filter1.lock(testFile);
+		assertThat(filter2.filterFiles(workdir.listFiles()), is(new ArrayList<File>()));
+		filter1.unlock(testFile);
+	}
 
 }