Made format compatibkle with JDK 1.4. Fixed #197

1 files changed, 16 insertions, 2 deletions

diff --git a/src/library/scala/runtime/StringAdd.scala b/src/library/scala/runtime/StringAdd.scala
index 2ca64538d9..8591ae3313 100644
--- a/src/library/scala/runtime/StringAdd.scala
+++ b/src/library/scala/runtime/StringAdd.scala
@@ -14,6 +14,13 @@ package scala.runtime
 
 import Predef._
 
+object StringAdd {
+  // Needed for the format hack. Can be removed once we drop 1.4
+  lazy val formatMethod: java.lang.reflect.Method = {
+    val paramTypes = Array(classOf[String], classOf[Array[Object]])
+    classOf[String].getDeclaredMethod("format", paramTypes)
+  }
+}
 final class StringAdd(self: Any) {
 
   def +(other: String) = self.toString + other
@@ -21,7 +28,14 @@ final class StringAdd(self: Any) {
   /** Formats string according to given <code>format</code> string.
    *  Format strings are as for <code>String.format</code>
    *  (@see java.lang.String.format).
+   *  Only works on Java 1.5 or higher!
    */
-  def format(format: String): String =
-    String.format(format, Array(self.asInstanceOf[Object]))
+  def format(format: String): String = {
+    // This should be:
+    // String.format(format, Array(self.asInstanceOf[Object]))
+    // However, the line above does not compile on Java 1.4 because String.format exists only in 1.5
+    // Therefore, we do the following hack:
+    val args = Array(self.asInstanceOf[Object])
+    StringAdd.formatMethod.invoke(null, Array[Object](format, args)).asInstanceOf[String]
+  }
 }