diff --git a/classpath/java/lang/String.java b/classpath/java/lang/String.java
index 7eb33fa104..921522a34e 100644
--- a/classpath/java/lang/String.java
+++ b/classpath/java/lang/String.java
@@ -228,6 +228,33 @@ public final class String implements Comparable<String> {
     return -1;
   }
 
+  public String replace(char oldChar, char newChar) {
+    if (data instanceof char[]) {
+      char[] buf = new char[length];
+      for (int i=0; i < length; i++) {
+	if (charAt(i) == oldChar) {
+	  buf[i] = newChar;
+	} else {
+	  buf[i] = charAt(i);
+	}
+      }
+      return new String(buf, 0, length, false);
+    } else {
+      byte[] buf = new byte[length];
+      byte[] orig = (byte[])data;
+      byte oldByte = (byte)oldChar;
+      byte newByte = (byte)newChar;
+      for (int i=0; i < length; i++) {
+	if (orig[i+offset] == oldByte) {
+	  buf[i] = newByte;
+	} else {
+	  buf[i] = orig[i+offset];
+	}
+      }
+      return new String(buf, 0, length, false);
+    }
+  }
+
   public String substring(int start) {
     return substring(start, length);
   }
diff --git a/classpath/java/lang/StringBuffer.java b/classpath/java/lang/StringBuffer.java
index d216370464..66780d24c7 100644
--- a/classpath/java/lang/StringBuffer.java
+++ b/classpath/java/lang/StringBuffer.java
@@ -60,6 +60,11 @@ public class StringBuffer {
     return this;
   }
 
+  public synchronized StringBuffer delete(int start, int end) {
+    sb.delete(start, end);
+    return this;
+  }
+
   public synchronized StringBuffer deleteCharAt(int i) {
     sb.deleteCharAt(i);
     return this;
@@ -73,6 +78,11 @@ public class StringBuffer {
     return sb.length();
   }
 
+  public synchronized StringBuffer replace(int start, int end, String str) {
+    sb.replace(start, end, str);
+    return this;
+  }
+
   public synchronized void setLength(int v) {
     sb.setLength(v);
   }
diff --git a/classpath/java/lang/StringBuilder.java b/classpath/java/lang/StringBuilder.java
index 731da9169d..02e8510c52 100644
--- a/classpath/java/lang/StringBuilder.java
+++ b/classpath/java/lang/StringBuilder.java
@@ -148,6 +148,15 @@ public class StringBuilder {
     return insert(i, new String(new char[] { c }, 0, 1, false));
   }
 
+  public StringBuilder delete(int start, int end) {
+    int numChars = end - start; // Do not delete end itself
+    while (numChars > 0) {
+      deleteCharAt(start);
+      numChars--;
+    }
+    return this;
+  }
+
   public StringBuilder deleteCharAt(int i) {
     if (i < 0 || i >= length) {
       throw new IndexOutOfBoundsException();
@@ -185,6 +194,12 @@ public class StringBuilder {
     return this;
   }
 
+  public StringBuilder replace(int start, int end, String str) {
+    delete(start, end);
+    insert(start, str);
+    return this;
+  }
+
   public int length() {
     return length;
   }