swap out System.out and System.err in a way that affects JDK and Scala

Before it only affected jdk, because scala.Console captures our and err
before the swap.

This is needed when running main classes like Scaladoc or the compiler
and wanting to redirect output to standard error

1 files changed, 30 insertions, 0 deletions

diff --git a/nailgun_launcher/ThreadLocalOutputStream.java b/nailgun_launcher/ThreadLocalOutputStream.java
new file mode 100644
index 0000000..c12b775
--- /dev/null
+++ b/nailgun_launcher/ThreadLocalOutputStream.java
@@ -0,0 +1,30 @@
+package cbt;
+import java.io.*;
+
+public class ThreadLocalOutputStream extends OutputStream{
+  final public ThreadLocal<OutputStream> threadLocal; 
+  final private OutputStream initialValue;
+
+  public ThreadLocalOutputStream( OutputStream initialValue ){
+    this.initialValue = initialValue;
+    threadLocal = new ThreadLocal<OutputStream>() {
+      @Override protected OutputStream initialValue() {
+        return ThreadLocalOutputStream.this.initialValue;
+      }
+    };
+  }
+  
+  public OutputStream get(){
+    return threadLocal.get();
+  }
+  
+  public void set( OutputStream outputStream ){
+    threadLocal.set( outputStream );
+  }
+  
+  public void write( int b ) throws IOException{
+    // after implementing this I realized NailgunLauncher uses the same hack,
+    // so probably this is not a problem performance
+    get().write(b);
+  }
+}