SU and SH in Java/Android

CMDProcessor.java

package com.com.com;

import android.util.Log;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;

public class CMDProcessor {

    private final String TAG = getClass().getSimpleName();
    private static final boolean DEBUG = false;
    private Boolean can_su;
    public SH sh;
    public SH su;

    public CMDProcessor() {
        sh = new SH("sh");
        su = new SH("su");
    }

    public SH suOrSH() {
        return canSU() ? su : sh;
    }

    public boolean canSU() {
        return canSU(false);
    }

    public class CommandResult {
        private final String resultTag = TAG + '.' + getClass().getSimpleName();
        public final String stdout;
        public final String stderr;
        public final Integer exit_value;

        CommandResult(final Integer exit_value_in) {
            this(exit_value_in, null, null);
        }

        CommandResult(final Integer exit_value_in, final String stdout_in,
                      final String stderr_in) {
            exit_value = exit_value_in;
            stdout = stdout_in;
            stderr = stderr_in;
            if (DEBUG)
                Log.d(TAG, resultTag + "( exit_value=" + exit_value
                        + ", stdout=" + stdout + ", stderr=" + stderr + " )");
        }

        public boolean success() {
            return exit_value != null && exit_value == 0;
        }

    }

    public class SH {
        private String SHELL = "sh";

        public SH(final String SHELL_in) {
            SHELL = SHELL_in;
        }

        private String getStreamLines(final InputStream is) {
            String out = null;
            StringBuffer buffer = null;
            final DataInputStream dis = new DataInputStream(is);
            try {
                if (dis.available() > 0) {
                    buffer = new StringBuffer(dis.readLine());
                    while (dis.available() > 0) {
                        buffer.append("\n").append(dis.readLine());
                    }
                }
                dis.close();
            } catch (final Exception ex) {
                Log.e(TAG, ex.getMessage());
            }
            if (buffer != null) {
                out = buffer.toString();
            }
            return out;
        }

        public Process run(final String s) {
            Process process = null;
            try {
                process = Runtime.getRuntime().exec(SHELL);
                final DataOutputStream toProcess = new DataOutputStream(
                        process.getOutputStream());
                toProcess.writeBytes("exec " + s + "\n");
                toProcess.flush();
            } catch (final Exception e) {
                Log.e(TAG,
                        "Exception while trying to run: '" + s + "' "
                                + e.getMessage());
                process = null;
            }
            return process;
        }

        public CommandResult runWaitFor(final String s) {
            if (DEBUG)
                Log.d(TAG, "runWaitFor( " + s + " )");
            final Process process = run(s);
            Integer exit_value = null;
            String stdout = null;
            String stderr = null;
            if (process != null) {
                try {
                    exit_value = process.waitFor();
                    stdout = getStreamLines(process.getInputStream());
                    stderr = getStreamLines(process.getErrorStream());
                } catch (final InterruptedException e) {
                    Log.e(TAG, "runWaitFor " + e.toString());
                } catch (final NullPointerException e) {
                    Log.e(TAG, "runWaitFor " + e.toString());
                }
            }
            return new CommandResult(exit_value, stdout, stderr);
        }
    }

    public boolean canSU(final boolean force_check) {
        if (can_su == null || force_check) {
            final CommandResult r = su.runWaitFor("id");
            final StringBuilder out = new StringBuilder();
            if (r.stdout != null) {
                out.append(r.stdout).append(" ; ");
            }
            if (r.stderr != null) {
                out.append(r.stderr);
            }
            Log.d(TAG, "canSU() su[" + r.exit_value + "]: " + out);
            can_su = r.success();
        }
        return can_su;
    }
}