java Runtime.getRuntime().exec using cat and piping

Question

I'm trying to run the following command through java to show the current wifi signal strenght :

cat /proc/net/wireless | awk 'END { print $4 }' | sed 's/\.$//'

In the terminal this command works fine.

The function I use to run the commands is like :

public static String[] executeNativeCommand(String[] commands, String friendlyErrorMessage, String... arguments) throws RuntimeException {
        if (commands == null || commands.length == 0)
            return new String[]{};

        Process listSSIDProcess = null;
        try {
            String[] replacedCommands = new String[commands.length];
            for (int t = 0; t < commands.length; t++) {
                replacedCommands[t] = MessageFormat.format(commands[t], (Object[])arguments);
            }
            listSSIDProcess = Runtime.getRuntime().exec(replacedCommands);
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            IOUtils.copy(listSSIDProcess.getInputStream(), output);
            return new String(output.toString()).split("\r?\n");
        } catch (IOException e) {
            if (friendlyErrorMessage == null) {
                logger.error("Error masked due to the friendly error message not being set", e);
                return new String[]{};
            }

            throw new RuntimeException(friendlyErrorMessage, e);
        } finally {
            if (listSSIDProcess != null) {
                listSSIDProcess.destroy();
            }
        }
    }

I tried to call it with :

public String getCurrentWiFiStrength(){
        String[] output = IOUtilities.executeNativeCommand(new String[]{"cat /proc/net/wireless | awk 'END { print $4 }' | sed 's/.$//'"}, null);
        if (output.length > 0) {
            logger.info("Wireless strength :" + output);
            return output[0];
        }
        else {
            return null;
        }
    }

This didn't work so after some stackoverflow research I added /bin/sh and -c like this :

public String getCurrentWiFiStrength(){
        String[] output = IOUtilities.executeNativeCommand(new String[]{"/bin/sh", "-c", "cat /proc/net/wireless | awk 'END { print $4 }' | sed 's/.$//'"}, null);
        if (output.length > 0) {
            logger.info("Wireless strength :" + output);
            return output[0];
        }
        else {
            return null;
        }
    }

This didn't work either. So I tried to run through terminal /bin/sh -c cat /proc/net/wireless | awk 'END { print $4 }' | sed 's/\.$//'

Which just keeps hanging and doesn't return anything... So I'm not sure what is going on and how to fix this... Any suggestions? I use tinkerOS (a debian based distro)

thanks in advance!

EDIT :

So I found out why it didn't work in shell, it was my escaping... The correct syntax is :

/bin/bash -c "cat /proc/net/wireless | awk 'END {print \$4;}' | sed 's/.$//'"

So I tried :

public String getCurrentWiFiStrength(){
        String[] output = IOUtilities.executeNativeCommand(new String[]{"/bin/sh", "-c", "\"cat /proc/net/wireless | awk 'END {print \\$4;}' | sed 's/.$//'\""}, null);
        if (output.length > 0) {
            return output[0];
        }
        else {
            return null;
        }
    }

Without too much luck... Any suggestions?