migration and tests of TeeFilter

src/main/java/kieker/analysis/plugin/filter/forward/TeeFilter.java

+package kieker.analysis.plugin.filter.forward;
+
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.PrintStream;
+import java.io.UnsupportedEncodingException;
+
+import teetime.stage.basic.AbstractFilter;
+
+/**
+ * This filter has exactly one input port and one output port.
+ *
+ * A simple message is printed to a configurable stream and all objects are forwarded to the output port.
+ *
+ * @author Matthias Rohr, Jan Waller, Lars Erik Bluemke
+ *
+ * @since 1.2
+ */
+public class TeeFilter extends AbstractFilter<Object> {
+
+	/** The default value of the encoding property which determines that the filter uses utf-8. */
+	public static final String DEFAULT_ENCODING = "UTF-8";
+	/** The default value of the stream property which determines that the filter appends or overwrites a file. */
+	public static final boolean DEFAULT_STREAM_APPEND = true;
+
+	private final PrintStream printStream;
+	private final String printStreamName;
+	private final boolean active;
+
+	private final boolean append;
+	private final String encoding;
+
+	/**
+	 * Predefined types of streams for the {@link TeeFilter}.<br>
+	 * <b>STDLOG</b> = standard log<br>
+	 * <b>STDOUT</b> = standard output<br>
+	 * <b>STDERR</b> = standard error output<br>
+	 * <b>NULL</b> = filter doesn't print anything
+	 */
+	public enum TeeFilterStreamType {
+		STDLOG, STDOUT, STDERR, NULL
+	}
+
+	/**
+	 * Creates a new instance of this class using the given parameters. Uses one of the predefined {@link TeeFilterStreamType}s.
+	 *
+	 * @param streamType
+	 *            Determines which of the predefined {@link TeeFilterStreamType}s the filter uses.
+	 * @param encoding
+	 *            Determines which encoding the filter uses. Pass null for default encoding {@value #DEFAULT_ENCODING}.
+	 */
+	public TeeFilter(final TeeFilterStreamType streamType, final String encoding) {
+
+		// Get the encoding.
+		if (encoding != null) {
+			this.encoding = encoding;
+		} else {
+			this.encoding = DEFAULT_ENCODING;
+		}
+
+		this.printStreamName = null; // NOPMD (null)
+		this.append = false;
+
+		// Decide which stream to be used
+		if (streamType.equals(TeeFilterStreamType.STDLOG)) {
+			this.printStream = null; // NOPMD (null)
+			this.active = true;
+		} else if (streamType.equals(TeeFilterStreamType.STDOUT)) {
+			this.printStream = System.out;
+			this.active = true;
+		} else if (streamType.equals(TeeFilterStreamType.STDERR)) {
+			this.printStream = System.err;
+			this.active = true;
+		} else {
+			this.printStream = null; // NOPMD (null)
+			this.active = false;
+		}
+	}
+
+	/**
+	 * Creates a new instance of this class using the given parameters. Uses a {@link FileOutputStream}.
+	 *
+	 * @param fileName
+	 *            The system dependent file name for the {@link FileOutputStream}.
+	 * @param encoding
+	 *            Determines which encoding the filter uses. Pass null for default encoding {@value #DEFAULT_ENCODING}.
+	 * @param append
+	 *            Determines whether the filter appends or overwrites a file.
+	 */
+	public TeeFilter(final String fileName, final String encoding, final boolean append) {
+
+		// Get the encoding.
+		if (encoding != null) {
+			this.encoding = encoding;
+		} else {
+			this.encoding = DEFAULT_ENCODING;
+		}
+
+		this.append = append;
+		PrintStream tmpPrintStream;
+		try {
+			tmpPrintStream = new PrintStream(new FileOutputStream(fileName, this.append), false, this.encoding);
+		} catch (final UnsupportedEncodingException ex) {
+			this.logger.error("Failed to initialize " + fileName, ex);
+			tmpPrintStream = null; // NOPMD (null)
+		} catch (final FileNotFoundException ex) {
+			this.logger.error("Failed to initialize " + fileName, ex);
+			tmpPrintStream = null; // NOPMD (null)
+		}
+		this.printStream = tmpPrintStream;
+		this.printStreamName = fileName;
+		this.active = true;
+	}
+
+	@Override
+	public void onTerminating() throws Exception {
+		if ((this.printStream != null) && (this.printStream != System.out) && (this.printStream != System.err)) {
+			this.printStream.close();
+		}
+		super.onTerminating();
+	}
+
+	/**
+	 * This method receives incoming objects from the filter's input port. Every object will be printed into a stream (based on the configuration) before the
+	 * filter sends it to the output port.
+	 *
+	 * @param object
+	 *            The new object.
+	 */
+	@Override
+	protected void execute(final Object object) {
+		if (this.active) {
+			final StringBuilder sb = new StringBuilder(128);
+			sb.append(this.getId());
+			sb.append('(').append(object.getClass().getSimpleName()).append(") ").append(object.toString());
+			final String record = sb.toString();
+			if (this.printStream != null) {
+				this.printStream.println(record);
+			} else {
+				this.logger.info(record);
+			}
+		}
+		this.outputPort.send(object);
+	}
+
+	public String getPrintStreamName() {
+		return printStreamName;
+	}
+}

src/test/java/kieker/analysis/plugin/filter/forward/TeeFilterTest.java

+package kieker.analysis.plugin.filter.forward;
+
+import static teetime.framework.test.StageTester.test;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Scanner;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import kieker.analysis.exception.AnalysisConfigurationException;
+
+/**
+ * This test makes sure that the {@link TeeFilter} writes (with regard to the append property) correctly into files.
+ *
+ * @author Nils Christian Ehmke, Lars Erik Bluemke
+ *
+ * @since 1.10
+ */
+public class TeeFilterTest {
+
+	public TeeFilterTest() {
+		// empty default constructor
+	}
+
+	@Test
+	public void testFileAppend() throws IOException {
+		final File tempFile = File.createTempFile("kieker", ".tmp");
+
+		this.executeAnalysis(tempFile, false, Arrays.asList(1, 2, 3));
+		this.executeAnalysis(tempFile, true, Arrays.asList(4, 5, 6));
+
+		final List<Integer> contentOfFile = this.readFromFile(tempFile);
+		Assert.assertEquals(Arrays.asList(1, 2, 3, 4, 5, 6), contentOfFile);
+	}
+
+	@Test
+	public void testFileOverwrite() throws IOException, IllegalStateException, AnalysisConfigurationException {
+		final File tempFile = File.createTempFile("kieker", ".tmp");
+
+		this.executeAnalysis(tempFile, false, Arrays.asList(1, 2, 3));
+		this.executeAnalysis(tempFile, false, Arrays.asList(4, 5, 6));
+
+		final List<Integer> contentOfFile = this.readFromFile(tempFile);
+		Assert.assertEquals(Arrays.asList(4, 5, 6), contentOfFile);
+	}
+
+	private void executeAnalysis(final File tempFile, final boolean append, final List<Integer> objectsToWrite) {
+		final TeeFilter teeFilter = new TeeFilter(tempFile.getAbsolutePath(), null, append);
+
+		test(teeFilter).and().send(objectsToWrite).to(teeFilter.getInputPort()).start();
+	}
+
+	private List<Integer> readFromFile(final File tempFile) throws FileNotFoundException {
+		final List<Integer> result = new ArrayList<Integer>();
+		Scanner scanner = null;
+
+		try {
+			scanner = new Scanner(tempFile, TeeFilter.DEFAULT_ENCODING);
+			// The tee filter writes something like "TeeFilter-3(Integer) 4" - therefore we have to parse this String a little bit.
+			while (scanner.hasNextLine()) {
+				final String line = scanner.nextLine();
+				result.add(Integer.parseInt(line.split(" ")[1]));
+			}
+		} finally {
+			if (scanner != null) {
+				scanner.close();
+			}
+		}
+
+		return result;
+	}
+}