Merge pull request scala#4561 from jdevelop/io-source-fromclasspath-2.12

SI-7514 Introduce Source.fromResource(...) method

Author: adriaanm

src/library/scala/io/Source.scala

@@ -167,6 +167,16 @@ object Source {
 
   def fromInputStream(is: InputStream)(implicit codec: Codec): BufferedSource =
     createBufferedSource(is, reset = () => fromInputStream(is)(codec), close = () => is.close())(codec)
+
+  /** Reads data from a classpath resource, using either a context classloader (default) or a passed one.
+   *
+   *  @param  resource     name of the resource to load from the classpath
+   *  @param  classLoader  classloader to be used, or context classloader if not specified
+   *  @return              the buffered source
+   */
+  def fromResource(resource: String, classLoader: ClassLoader = Thread.currentThread().getContextClassLoader())(implicit codec: Codec): BufferedSource =
+    fromInputStream(classLoader.getResourceAsStream(resource))
+
 }
 
 /** An iterable representation of source data.

test/junit/scala/io/SourceTest.scala

@@ -28,6 +28,10 @@ class SourceTest {
   @Test def canIterateLines() = {
     assertEquals(sampler.lines.size, (Source fromString sampler).getLines.size)
   }
+  @Test def loadFromResource() = {
+    val res = Source.fromResource("rootdoc.txt")
+    assertTrue("No classpath resource found", res.getLines().size > 5)
+  }
   @Test def canCustomizeReporting() = {
     class CapitalReporting(is: InputStream) extends BufferedSource(is) {
       override def report(pos: Int, msg: String, out: PrintStream): Unit = {