INT-3764: LastModifiedFileListFilter

JIRA: https://jira.spring.io/browse/INT-3764

* Add JavaDocs to the `LastModifiedFileListFilter`
* Add `Namespace Support` to the `file.adoc`

spring-integration-file/src/main/java/org/springframework/integration/file/filters/LastModifiedFileListFilter.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed 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.
+ */
+package org.springframework.integration.file.filters;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * The {@link FileListFilter} implementation to filter those files which
+ * {@link File#lastModified()} is less than the {@link #age} in comparison
+ * with the current time.
+ * <p>
+ * The resolution is done in seconds.
+ *
+ * @author Gary Russell
+ * @since 4.2
+ *
+ */
+public class LastModifiedFileListFilter implements FileListFilter<File> {
+
+	private static final long DEFAULT_AGE = 60;
+
+	private volatile long age = DEFAULT_AGE;
+
+	public long getAge() {
+		return age;
+	}
+
+	/**
+	 * Set the age that files have to be before being passed by this filter.
+	 * If {@link File#lastModified()} plus age is greater than the current time, the file
+	 * is filtered. The resolution is seconds.
+	 * Defaults to 60 seconds.
+	 * @param age the age
+	 */
+	public void setAge(long age) {
+		setAge(age, TimeUnit.SECONDS);
+	}
+
+	/**
+	 * Set the age that files have to be before being passed by this filter.
+	 * If {@link File#lastModified()} plus age is greater than the current time, the file
+	 * is filtered. The resolution is seconds.
+	 * Defaults to 60 seconds.
+	 * @param age the age
+	 * @param unit the timeUnit.
+	 */
+	public void setAge(long age, TimeUnit unit) {
+		this.age = unit.toSeconds(age);
+	}
+
+	@Override
+	public List<File> filterFiles(File[] files) {
+		List<File> list = new ArrayList<File>();
+		long now = System.currentTimeMillis() / 1000;
+		for (File file : files) {
+			if (file.lastModified() / 1000 + this.age <= now) {
+				list.add(file);
+			}
+		}
+		return list;
+	}
+
+}

spring-integration-file/src/test/java/org/springframework/integration/file/filters/LastModifiedFileListFilterTests.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed 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.
+ */
+package org.springframework.integration.file.filters;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+/**
+ * @author Gary Russell
+ * @since 4.2
+ *
+ */
+public class LastModifiedFileListFilterTests {
+
+	@Rule
+	public TemporaryFolder folder = new TemporaryFolder();
+
+	@Test
+	public void testAge() throws Exception {
+		LastModifiedFileListFilter filter = new LastModifiedFileListFilter();
+		filter.setAge(1, TimeUnit.SECONDS);
+		File foo = this.folder.newFile();
+		FileOutputStream fileOutputStream = new FileOutputStream(foo);
+		fileOutputStream.write("x".getBytes());
+		fileOutputStream.close();
+		assertEquals(0, filter.filterFiles(new File[] { foo }).size());
+		Thread.sleep(2000);
+		assertEquals(1, filter.filterFiles(new File[] { foo }).size());
+	}
+
+}

src/reference/asciidoc/file.adoc

@@ -90,7 +90,24 @@ The `CompositeFileListFilter` enables the composition.
 </bean>
 ----
 
-The configuration can be simplified using the file specific namespace.
+If it is not possible to create the file with a temporary name and rename to the final name, another alternative is
+provided.
+The `LastModifiedFileListFilter` was added in _version 4.2_.
+This filter can be configured with an `age` property and only files older than this will be passed by the filter.
+The age defaults to 60 seconds, but you should choose an age that is large enough to avoid picking up a file early, due
+to, say, network glitches.
+
+[source, xml]
+----
+<bean id="filter" class="org.springframework.integration.file.filters.LastModifiedFileListFilter">
+    <property name="age" value="120" />
+</bean>
+----
+
+[[file-namespace-support]]
+==== Namespace Support
+
+The configuration for file reading can be simplified using the file specific namespace.
 To do this use the following template.
 [source,xml]
 ----

src/reference/asciidoc/whats-new.adoc

@@ -58,19 +58,31 @@ As an alternative to the existing `selector` attribute, the `<wire-tap/>` now su
 [[x4.2-file-changes]]
 ==== File Changes
 
+See <<files>> for more information about these changes.
+
+===== Appending NewLines
+
 The `<int-file:outbound-channel-adapter>` and `<int-file:outbound-gateway>` now support an `append-new-line` attribute.
 If set to `true`, a new line is appended to the file after a message is written.
 The default attribute value is `false`.
 
+===== Ignoring Hidden Files
+
 The `ignore-hidden` attribute has been introduced for the `<int-file:inbound-channel-adapter>` to pick up or not
 the _hidden_ files from the source directory.
 It is `true` by default.
 
+===== Writing InputStream Payloads
+
 The `FileWritingMessageHandler` now also accepts `InputStream` as a valid message payload type.
 
+===== HeadDirectoryScanner
+
 The `HeadDirectoryScanner` can now be used with other `FileListFilter` s.
 
-See <<files>> for more information.
+===== Last Modified Filter
+
+The `LastModifiedFileListFilter` has been added.
 
 [[x4.2-class-package-change]]
 ==== Class Package Change