created PluginClasspathLoader to dynamically add jars in the plugins …

…folder to the classpath at runtime (Lighthouse unclebob#63)

plugins/testJar1.jar

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+not really a jar, just a file for the PluginsClasspathLoaderTest.java

plugins/testJar2.jar

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+not really a jar, just a file for the PluginsClasspathLoaderTest.java

src/fitnesse/components/PluginClasspathLoader.java

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+package fitnesse.components;
+
+import java.io.File;
+
+
+public class PluginClasspathLoader {
+
+    private String pluginsDirecory = "./plugins";
+
+    public void addPluginsToClasspath() {
+        File pluginsDir = new File(pluginsDirecory);
+        File[] plugins = pluginsDir.listFiles();
+        for (File plugin : plugins) {
+            if (plugin.getName().endsWith("jar")) {
+                System.setProperty("java.class.path", getClasspath() + getPathSeperator() + plugin.getAbsolutePath());
+            }
+        }
+    }
+
+    protected String getClasspath() {
+        return System.getProperty("java.class.path");
+    }
+
+
+    protected String getPathSeperator() {
+        return System.getProperty("path.separator");
+    }
+
+}

src/fitnesse/components/PluginClasspathLoaderTest.java

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+package fitnesse.components;
+
+import static org.junit.Assert.*;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+
+public class PluginClasspathLoaderTest {
+
+    private PluginClasspathLoader loader;
+
+    @Before
+    public void setUp() throws Exception {
+        loader = new PluginClasspathLoader();
+    }
+
+
+    @Test
+    public void loadClassPath() {
+        List<String> jars = listOfJarsInClasspath();
+        assertFalse(jars.contains("testJar1.jar"));
+        assertFalse(jars.contains("testJar2.jar"));
+        int originalJarCount = jars.size();
+
+        loader.addPluginsToClasspath();
+
+        List<String> newListOfJars = listOfJarsInClasspath();
+        assertEquals(originalJarCount + 2, newListOfJars.size());
+        assertTrue(newListOfJars.contains("testJar1.jar"));
+        assertTrue(newListOfJars.contains("testJar2.jar"));
+    }
+
+    private List<String> listOfJarsInClasspath() {
+        List<String> classpathElements = Arrays.asList(loader.getClasspath().split(loader.getPathSeperator()));
+        List<String> jars = new ArrayList<String>();
+        for (String classpathElement : classpathElements) {
+            int slashPosition = classpathElement.lastIndexOf(System.getProperty("file.separator"));
+            String jarName = classpathElement.substring(slashPosition + 1);
+            jars.add(jarName);
+        }
+        return jars;
+    }
+}