diff --git a/RCaller/.classpath b/RCaller/.classpath
deleted file mode 100644
index f362f73..0000000
--- a/RCaller/.classpath
+++ /dev/null
@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<classpath>
-	<classpathentry kind="src" output="target/classes" path="src/main/java"/>
-	<classpathentry kind="src" output="target/test-classes" path="src/test/java"/>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/J2SE-1.5"/>
-	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER"/>
-	<classpathentry kind="output" path="target/classes"/>
-</classpath>
diff --git a/RCaller/src/main/java/com/github/rcaller/JavaObject.java b/RCaller/src/main/java/com/github/rcaller/JavaObject.java
index 0255f64..6a875ba 100644
--- a/RCaller/src/main/java/com/github/rcaller/JavaObject.java
+++ b/RCaller/src/main/java/com/github/rcaller/JavaObject.java
@@ -57,7 +57,7 @@ public void setName(String name) {
 
     public static String ConvertToRCode(String name, Object javaobject, boolean useList, boolean useEquals) throws IllegalAccessException {
         StringBuilder builder = new StringBuilder();
-        StringBuffer tempbuffer = new StringBuffer();
+        StringBuilder tempbuffer = new StringBuilder();
         String className, varName;
         Object o;
         Field f;
diff --git a/RCaller/src/main/java/com/github/rcaller/rstuff/RCode.java b/RCaller/src/main/java/com/github/rcaller/rstuff/RCode.java
index 66dc5dd..1775a17 100644
--- a/RCaller/src/main/java/com/github/rcaller/rstuff/RCode.java
+++ b/RCaller/src/main/java/com/github/rcaller/rstuff/RCode.java
@@ -39,12 +39,12 @@
 
 public class RCode {
 
-    private StringBuffer code;
+    private StringBuilder code;
     private TempFileService tempFileService = null;
 
 
     private RCode() {
-        this.code = new StringBuffer();
+        this.code = new StringBuilder();
     }
 
     public static RCode create() {
@@ -56,17 +56,23 @@ public static RCode create() {
     public static RCode create(StringBuffer stringBuffer) {
         RCode rCode = RCode.create();
         rCode.clear();
-        rCode.getCode().append(stringBuffer);
+        rCode.getCode().append(stringBuffer.toString());
         return rCode;
     }
 
     public void setCode(StringBuffer sb) {
-        this.code = new StringBuffer();
+        this.code = new StringBuilder();
+        clear();
+        this.code.append(sb.toString());
+    }
+
+    public void setCode(StringBuilder sb) {
+        this.code = new StringBuilder();
         clear();
         this.code.append(sb);
     }
 
-    public StringBuffer getCode() {
+    public StringBuilder getCode() {
         return (this.code);
     }
 
diff --git a/RCaller/src/main/java/com/github/rcaller/scriptengine/RCallerScriptEngine.java b/RCaller/src/main/java/com/github/rcaller/scriptengine/RCallerScriptEngine.java
index a39901c..c21d06a 100644
--- a/RCaller/src/main/java/com/github/rcaller/scriptengine/RCallerScriptEngine.java
+++ b/RCaller/src/main/java/com/github/rcaller/scriptengine/RCallerScriptEngine.java
@@ -109,7 +109,7 @@ public Object eval(Reader reader, Bindings bindings) throws ScriptException {
     @Override
     public void put(String name, Object o) {
         rcode.clearOnline();
-        StringBuffer code = new StringBuffer();
+        StringBuilder code = new StringBuilder();
         RCodeUtils.addRespectToType(code, name, o, false);
         rcode.addRCode("result <- list(a=0)");
         rcode.setCode(code);
diff --git a/RCaller/src/main/java/com/github/rcaller/util/RCodeUtils.java b/RCaller/src/main/java/com/github/rcaller/util/RCodeUtils.java
index 57fc24a..c6ff345 100644
--- a/RCaller/src/main/java/com/github/rcaller/util/RCodeUtils.java
+++ b/RCaller/src/main/java/com/github/rcaller/util/RCodeUtils.java
@@ -39,31 +39,31 @@
 
 public class RCodeUtils {
 
-    public static void addIntArray(StringBuffer rCode, String name, int[] arr, boolean useEquals) {
+    public static void addIntArray(StringBuilder rCode, String name, int[] arr, boolean useEquals) {
         addArray(rCode, name, ArrayUtils.toObject(arr), useEquals, false);
     }
 
-    public static void addLongArray(StringBuffer rCode, String name, long[] arr, boolean useEquals) {
+    public static void addLongArray(StringBuilder rCode, String name, long[] arr, boolean useEquals) {
         addArray(rCode, name, ArrayUtils.toObject(arr), useEquals, false);
     }
 
-    public static void addFloatArray(StringBuffer rCode, String name, float[] arr, boolean useEquals) {
+    public static void addFloatArray(StringBuilder rCode, String name, float[] arr, boolean useEquals) {
         addArray(rCode, name, ArrayUtils.toObject(arr), useEquals, false);
     }
 
-    public static void addDoubleArray(StringBuffer rCode, String name, double[] arr, boolean useEquals) {
+    public static void addDoubleArray(StringBuilder rCode, String name, double[] arr, boolean useEquals) {
         addArray(rCode, name, ArrayUtils.toObject(arr), useEquals, false);
     }
 
-    public static void addStringArray(StringBuffer rCode, String name, String[] arr, boolean useEquals) {
+    public static void addStringArray(StringBuilder rCode, String name, String[] arr, boolean useEquals) {
         addArray(rCode, name, arr, useEquals, true);
     }
 
-    public static void addShortArray(StringBuffer rCode, String name, short[] arr, boolean useEquals) {
+    public static void addShortArray(StringBuilder rCode, String name, short[] arr, boolean useEquals) {
         addArray(rCode, name, ArrayUtils.toObject(arr), useEquals, false);
     }
 
-    public static void addLogicalArray(StringBuffer rCode, String name, boolean[] arr, boolean useEquals) {
+    public static void addLogicalArray(StringBuilder rCode, String name, boolean[] arr, boolean useEquals) {
         String[] stringArray = new String[arr.length];
         for (int i = 0; i < arr.length; i++) {
             stringArray[i] = String.valueOf(arr[i]).toUpperCase();
@@ -71,7 +71,7 @@ public static void addLogicalArray(StringBuffer rCode, String name, boolean[] ar
         addArray(rCode, name, stringArray, useEquals, false);
     }
 
-    public static <T> void addArray(StringBuffer rCode, String name, T[] array, boolean useEquals, boolean isString) {
+    public static <T> void addArray(StringBuilder rCode, String name, T[] array, boolean useEquals, boolean isString) {
         if (!name.equals("")) {
             if (useEquals) {
                 rCode.append(name).append("=");
@@ -98,14 +98,14 @@ public static <T> void addArray(StringBuffer rCode, String name, T[] array, bool
         }
     }
 
-    public static void addJavaObject(StringBuffer rCode, Object o, boolean useEquals) throws IllegalAccessException {
+    public static void addJavaObject(StringBuilder rCode, Object o, boolean useEquals) throws IllegalAccessException {
         rCode.append(((JavaObject) o).produceRCode(useEquals));
         if (!useEquals) {
             rCode.append("\n");
         }
     }
 
-    public static void addDoubleMatrix(StringBuffer rCode, String name, double[][] matrix, boolean useEquals) {
+    public static void addDoubleMatrix(StringBuilder rCode, String name, double[][] matrix, boolean useEquals) {
         int dim2 = matrix[0].length;
         int counter = 0;
         if (!name.equals("")) {
@@ -131,31 +131,31 @@ public static void addDoubleMatrix(StringBuffer rCode, String name, double[][] m
         }
     }
 
-    public static void addDouble(StringBuffer rCode, String name, double d, boolean useEquals) {
+    public static void addDouble(StringBuilder rCode, String name, double d, boolean useEquals) {
         addValue(rCode, name, d, useEquals);
     }
 
-    public static void addInt(StringBuffer rCode, String name, int i, boolean useEquals) {
+    public static void addInt(StringBuilder rCode, String name, int i, boolean useEquals) {
         addValue(rCode, name, i, useEquals);
     }
 
-    public static void addLong(StringBuffer rCode, String name, long l, boolean useEquals) {
+    public static void addLong(StringBuilder rCode, String name, long l, boolean useEquals) {
         addValue(rCode, name, l, useEquals);
     }
 
-    public static void addFloat(StringBuffer rCode, String name, float f, boolean useEquals) {
+    public static void addFloat(StringBuilder rCode, String name, float f, boolean useEquals) {
         addValue(rCode, name, String.valueOf(f).toUpperCase(), useEquals);
     }
 
-    public static void addShort(StringBuffer rCode, String name, short s, boolean useEquals) {
+    public static void addShort(StringBuilder rCode, String name, short s, boolean useEquals) {
         addValue(rCode, name, s, useEquals);
     }
 
-    public static void addBoolean(StringBuffer rCode, String name, boolean b, boolean useEquals) {
+    public static void addBoolean(StringBuilder rCode, String name, boolean b, boolean useEquals) {
         addValue(rCode, name, String.valueOf(b).toUpperCase(), useEquals);
     }
 
-    public static void addString(StringBuffer rCode, String name, String value, boolean useEquals) {
+    public static void addString(StringBuilder rCode, String name, String value, boolean useEquals) {
         if (!name.equals("")) {
             if (useEquals) {
                 rCode.append(name).append("=");
@@ -173,7 +173,7 @@ public static void addString(StringBuffer rCode, String name, String value, bool
         }
     }
 
-    private static void addValue(StringBuffer rCode, String name, Object value, boolean useEquals) {
+    private static void addValue(StringBuilder rCode, String name, Object value, boolean useEquals) {
         if (!name.equals("")) {
             if (useEquals) {
                 rCode.append(name).append("=").append(value);
@@ -189,7 +189,7 @@ private static void addValue(StringBuffer rCode, String name, Object value, bool
         }
     }
 
-    public static void addRespectToType(StringBuffer rCode, String name, Object o, boolean useEquals) {
+    public static void addRespectToType(StringBuilder rCode, String name, Object o, boolean useEquals) {
         if (o instanceof double[]) {
             RCodeUtils.addDoubleArray(rCode, name, (double[]) o, useEquals);
         } else if (o instanceof int[]) {
@@ -230,7 +230,7 @@ public static void addRespectToType(StringBuffer rCode, String name, Object o, b
 
     }
 
-    public static void addDataFrame(StringBuffer rCode, String name, DataFrame dataFrame) {
+    public static void addDataFrame(StringBuilder rCode, String name, DataFrame dataFrame) {
         try {
             File file = File.createTempFile("dataFrame", ".csv");
             CSVFileWriter csvFileWriter = CSVFileWriter.create(file.getAbsolutePath());
diff --git a/RCaller/src/test/java/com/github/rcaller/RunOnlineTest.java b/RCaller/src/test/java/com/github/rcaller/RunOnlineTest.java
index f6fe7b8..d0a210f 100644
--- a/RCaller/src/test/java/com/github/rcaller/RunOnlineTest.java
+++ b/RCaller/src/test/java/com/github/rcaller/RunOnlineTest.java
@@ -146,6 +146,7 @@ public void errorHandlerTest() {
     @Test
     public void timeoutTest() {
         System.out.println("TIMEOUT TEST");
+        System.out.println("*** This must throw an exception:");
         RCaller rcaller = RCaller.create(RCallerOptions.create(FailurePolicy.CONTINUE, 100)); //don't retry
         RCode code = RCode.create();