Refactor command line tests for CPD and create a BaseCPDCLITest class

pmd-test/src/main/java/net/sourceforge/pmd/cli/BaseCPDCLITest.java

@@ -0,0 +1,48 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+package net.sourceforge.pmd.cli;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.io.UnsupportedEncodingException;
+
+import net.sourceforge.pmd.cpd.CPD;
+import net.sourceforge.pmd.cpd.CPDCommandLineInterface;
+
+import org.junit.After;
+import org.junit.Before;
+
+public abstract class BaseCPDCLITest {
+    private ByteArrayOutputStream bufferStdout;
+    private PrintStream originalStdout;
+    private PrintStream originalStderr;
+
+    @Before
+    public void setup() throws UnsupportedEncodingException {
+        originalStdout = System.out;
+        originalStderr = System.err;
+        bufferStdout = new ByteArrayOutputStream();
+        System.setOut(new PrintStream(bufferStdout, false, "UTF-8"));
+        System.setErr(System.out);
+    }
+
+    @After
+    public void teardown() {
+        System.setOut(originalStdout);
+        System.setErr(originalStderr);
+    }
+
+    public final String getOutput() {
+        try {
+            return bufferStdout.toString("UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    protected void runCPD(String ... args) {
+        System.setProperty(CPDCommandLineInterface.NO_EXIT_AFTER_RUN, "true");
+        CPD.main(args);
+    }
+}