Merge pull request #64 from amihaiemil/60

SwitchableCrawl + unit tests

src/main/java/com/amihaiemil/charles/SwitchableCrawl.java

@@ -0,0 +1,72 @@
+/*
+ Copyright (c) 2016, Mihai Emil Andronache
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+ * Neither the name of charles nor the names of its
+ contributors may be used to endorse or promote products derived from
+ this software without specific prior written permission.
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+package com.amihaiemil.charles;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A crawl that switches to a new one if it fails with RuntimeException.
+ * @author Mihai Andronache (amihaiemil@gmail.com)
+ * @version $Id$
+ * @since 1.0.0
+ *
+ */
+public final class SwitchableCrawl implements WebCrawl {
+
+    private static final Logger LOG = LoggerFactory.getLogger(SwitchableCrawl.class);
+
+    /**
+     * Initial crawl.
+     */
+    private WebCrawl initial;
+
+    /**
+     * Failsafe. Run in case the initial crawl fails.
+     */
+    private WebCrawl failsafe;
+
+    /**
+     * Ctor.
+     * @param initial WebCrawl performed.
+     * @param failsafe WebCrawl performed in case the initial one fails with RuntimeException.
+     */
+    public SwitchableCrawl(WebCrawl initial, WebCrawl failsafe) {
+        this.initial = initial;
+        this.failsafe = failsafe;
+    }
+
+    @Override
+    public void crawl() throws DataExportException {
+        try {
+            this.initial.crawl();
+        } catch (RuntimeException ex) {
+            LOG.error("The initial crawl failed. Running the failsafe crawl...", ex);
+            this.failsafe.crawl();
+        }
+    }
+
+}

src/test/java/com/amihaiemil/charles/RetriableCrawlTestCase.java

@@ -86,6 +86,28 @@ public void crawlSuccessfulAtLastTrial() throws Exception {
         rc.crawl();
         Mockito.verify(mc, Mockito.times(5)).crawl();
     }
+
+    /**
+     * RetriableCrawl fails with RE the first time, then throws DataExportException
+     * the second time (thus not retrying the 3rd time) 
+     * @throws Exception If something goes wrong.
+     */
+    @Test
+    public void crawlThrowsDeeSecondTime() throws Exception {
+        WebCrawl mc = Mockito.mock(WebCrawl.class);
+        Mockito
+            .doThrow(new RuntimeException("Test runtime exception 1"))
+            .doThrow(new DataExportException("Test dee exception 2"))
+            .doNothing()
+            .when(mc).crawl();
+        RetriableCrawl rc = new RetriableCrawl(mc);
+        try {
+            rc.crawl();
+        } catch (DataExportException ex) {
+            assertTrue(ex.getMessage().equals("Test dee exception 2"));
+            Mockito.verify(mc, Mockito.times(2)).crawl();
+        }
+    }
 
     /**
      * RetriableCrawl fails after all retrials

src/test/java/com/amihaiemil/charles/SwitchableCrawlTestCase.java

@@ -0,0 +1,120 @@
+/*
+ Copyright (c) 2016, Mihai Emil Andronache
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+ * Neither the name of charles nor the names of its
+ contributors may be used to endorse or promote products derived from
+ this software without specific prior written permission.
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+package com.amihaiemil.charles;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import org.mockito.Mockito;
+
+/**
+ * Unit tests for {@link SwitchableCrawl}
+ * @author Mihai Andronache (amihaiemil@gmail.com)
+ * @version $Id$
+ * @since 1.0.0
+ *
+ */
+public final class SwitchableCrawlTestCase {
+
+    /**
+     * {@link SwitchableCrawl} performs the initial crawl without problems.
+     * @throws Exception If something goes wrong.
+     */
+    @Test
+    public void initialCrawlWorksFine() throws Exception {
+        WebCrawl initial = Mockito.mock(WebCrawl.class);
+        WebCrawl failsafe = Mockito.mock(WebCrawl.class);
+        Mockito.doNothing().when(initial).crawl();
+        SwitchableCrawl sc = new SwitchableCrawl(initial, failsafe);
+        sc.crawl();
+        Mockito.verify(initial, Mockito.times(1)).crawl();
+        Mockito.verify(failsafe, Mockito.times(0)).crawl();
+    }
+
+    /**
+     * {@link SwitchableCrawl} performs the initial crawl, which throws DataExportException
+     * @throws Exception If something goes wrong.
+     */
+    @Test
+    public void initialCrawlThrowsDee() throws Exception {
+        WebCrawl initial = Mockito.mock(WebCrawl.class);
+        WebCrawl failsafe = Mockito.mock(WebCrawl.class);
+        Mockito
+            .doThrow(new DataExportException("Dee on initial crawl!"))
+            .when(initial).crawl();
+        SwitchableCrawl sc = new SwitchableCrawl(initial, failsafe);
+        try {
+            sc.crawl();
+        } catch (DataExportException ex) {
+            assertTrue(ex.getMessage().equals("Dee on initial crawl!"));
+            Mockito.verify(initial, Mockito.times(1)).crawl();
+            Mockito.verify(failsafe, Mockito.times(0)).crawl();
+        }
+    }
+
+    /**
+     * {@link SwitchableCrawl} performs the failsafe crawl without problems, after
+     * the initial one failed
+     * @throws Exception If something goes wrong.
+     */
+    @Test
+    public void failsafeWorksFine() throws Exception {
+        WebCrawl initial = Mockito.mock(WebCrawl.class);
+        WebCrawl failsafe = Mockito.mock(WebCrawl.class);
+        Mockito
+            .doThrow(new RuntimeException("Fail initial crawl!"))
+            .when(initial).crawl();
+        Mockito.doNothing().when(failsafe).crawl();
+        SwitchableCrawl sc = new SwitchableCrawl(initial, failsafe);
+        sc.crawl();
+        Mockito.verify(initial, Mockito.times(1)).crawl();
+        Mockito.verify(failsafe, Mockito.times(1)).crawl();
+    }
+
+    /**
+     * {@link SwitchableCrawl} throws RE after both crawls fail.
+     * @throws Exception If something goes wrong.
+     */
+    @Test
+    public void bothCrawlsFail() throws Exception {
+        WebCrawl initial = Mockito.mock(WebCrawl.class);
+        WebCrawl failsafe = Mockito.mock(WebCrawl.class);
+        Mockito
+            .doThrow(new RuntimeException("Fail initial crawl!"))
+            .when(initial).crawl();
+        Mockito
+            .doThrow(new RuntimeException("Fail failsafe crawl!"))
+            .when(failsafe).crawl();
+        SwitchableCrawl sc = new SwitchableCrawl(initial, failsafe);
+        try {
+            sc.crawl();
+        } catch (RuntimeException ex) {
+            assertTrue(ex.getMessage().equals("Fail failsafe crawl!"));
+            Mockito.verify(initial, Mockito.times(1)).crawl();
+            Mockito.verify(failsafe, Mockito.times(1)).crawl();
+        }
+    }
+}