这里展示两种方法，以top命令为例，需要注意的是top命令返回的结果只包含当前用户id对应的进程相关的process信息。
在adb shell直接执行命令获取的是以root进行的，所以可以查看所有进程。

    public void execShellCommand(int tmp) {
        try {
            String prop = SystemProperties.get("sys.top.debug");
            StringBuilder mStringResult = new StringBuilder();
            // 查询某一个进程的信息
            List<String> cmds = new ArrayList<>();
            if (prop != null && prop.length() > 0) {
                Collections.addAll(cmds, prop.split(" "));
            } else {
                cmds.add("top");
                cmds.add("-b");
                cmds.add("-m");//10 tasks to show
                cmds.add("10");
                cmds.add("-n");//Exit after 1 iteration
                cmds.add("1");
                cmds.add("-H");
                cmds.add("-s");
                cmds.add("4");
                cmds.add("-o");
                cmds.add("pid,tid,user,%cpu,virt,res,name");
            }

            ProcessBuilder pb = new ProcessBuilder(cmds);
            Process p = pb.start();

            BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = br.readLine()) != null){
                mStringResult.append(line).append("\n");
            }
            mResultList.add(mStringResult.toString());
            mHandler.sendEmptyMessage(0);

            Iterator i = cmds.iterator();
            StringBuilder s = new StringBuilder();
            while (i.hasNext()) {
                s.append(i.next());
            }
            Log.d(TAG,"CMDS : " + s.toString());
            Log.d(TAG,"results : " + mStringResult.toString());

            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        } catch (Exception ex){
            ex.printStackTrace();
            Log.e(TAG,"Exception : " + ex.toString());
        }
    }

    public void execShellCommand() {
        Process p = null;
        String cmd = SystemProperties.get("sys.top.debug");
        StringBuilder mStringResult = new StringBuilder();

        if (cmd == null || cmd.length() <= 0) {
            cmd = "top -b -m 10 -n 1 -H -s 4 -o pid,tid,user,%cpu,virt,res,name";
        }
        try {
            p = Runtime.getRuntime().exec("su -c " + cmd);

            p.waitFor(5, TimeUnit.SECONDS);

            BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = br.readLine()) != null){
                mStringResult.append(line).append("\n");
            }
            mResultList.add(mStringResult.toString());
            mHandler.sendEmptyMessage(0);

            Log.d(TAG,"CMDS : " + cmd);
            Log.d(TAG,"results : " + mStringResult.toString());
        } catch (Exception e) {
            Log.e(TAG, "// Exception from " + cmd + " : " + e.getMessage());
        } finally {
            if (p != null) {
                p.destroy();
            }
        }
    }