APK:SerialPortFinder,显示串口列表

百分之50 

SerialPortFinder 方法 有点意思 这个方法是不涉及底层的，没有native方法，也不需要c和h文件 就能识别串口

MainActivity.java

package com.gatsby.serialport;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import android_serialport_api.SerialPort;
import android_serialport_api.SerialPortFinder;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    SerialPortFinder mSerialPortFinder;

    final String[] devices = new SerialPortFinder().getAllDevicesPath();
    final List data = new ArrayList<>();


    protected SerialPort mSerialPort;
    protected InputStream mInputStream;
    protected OutputStream mOutputStream;

    private String prot = "/dev/ttyS3";
    private int baudrate = 9600;
    //数据
    private static long i = 0;

    private Toast mToast;

    private Thread receiveThread;
    private Thread sendThread;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView listView = findViewById(R.id.id_list);
        listView.setAdapter(bA);

        getSerialPortPression();

        initLayout();

        mToast = Toast.makeText(this, "", Toast.LENGTH_SHORT);

    }

    private void initLayout() {
        findViewById(R.id.btn_open).setOnClickListener(MainActivity.this);
        findViewById(R.id.btn_send).setOnClickListener(MainActivity.this);
        findViewById(R.id.btn_close).setOnClickListener(MainActivity.this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_open:
                showTip("btn_open");

                // 打开
                try {
                    mSerialPort = new SerialPort(new File(prot), baudrate,8,1,'N');
                    mInputStream = mSerialPort.getInputStream();
                    mOutputStream = mSerialPort.getOutputStream();
                    receiveThread();
                } catch (SecurityException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    //打开失败
                    Log.e("gatsby", "open serialport default");
                    e.printStackTrace();
                }

                break;
            case R.id.btn_send:
                showTip("btn_send");
                // 发送
                sendThread = new Thread() {
                    @Override
                    public void run() {
                        while (true) {
                            try {
                                i++;
                                mOutputStream.write((String.valueOf(i)).getBytes());
                                //发送成功
                                Log.i("gatsby", "send serialport sucess!" + i);
                                Thread.sleep(50);
                            } catch (Exception e) {
                                //发送失败
                                Log.i("gatsby", "send serialport default!");
                                e.printStackTrace();
                            }
                        }

                    }
                };
                sendThread.start();

                break;
            case R.id.btn_close:
                showTip("btn_close");

                closeSerialPort();

                break;
            default:
                break;
        }
    }

    private void receiveThread() {
        // 接收
        receiveThread = new Thread() {
            @Override
            public void run() {
                while (true) {
                    int size;
                    try {
                        byte[] buffer = new byte[512];
                        if (mInputStream == null)
                            return;
                        size = mInputStream.read(buffer);
                        if (size > 0) {
                            String recinfo = new String(buffer, 0,
                                    size);
                            Log.i("gatsby", "recevier serialport info :" + recinfo);
//                            sb = recinfo;
//                            handler.sendEmptyMessage(1);
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        };//111
        receiveThread.start();
    }

    /**
     * 关闭串口
     */
    public void closeSerialPort() {

        if (mSerialPort != null) {
            mSerialPort.close();
        }
        if (mInputStream != null) {
            try {
                mInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (mOutputStream != null) {
            try {
                mOutputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

    private void showTip(final String str) {
        mToast.setText(str);
        mToast.show();
    }

    public void getSerialPortPression() {
        if (devices.length > 0) {
            for (String device : devices) {

                File file = new File(device);
                String path = file.getAbsolutePath();

                StringBuilder permission = new StringBuilder();
                permission.append("[");
                permission.append(file.canRead() ? " 可读" : "不可读");
                permission.append(file.canWrite() ? "  可写 " : " 不可写 ");
                permission.append(file.canExecute() ? "可执行" : "不可执行");
                permission.append("]");

                String msg = "(" + path + ")" + " 权限:" + permission;
                data.add(msg);
            }
        }
    }

    BaseAdapter bA = new BaseAdapter() {
        @Override
        public int getCount() {
            return devices.length;
        }

        @Override
        public Object getItem(int position) {
            return devices[position];
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            if (convertView == null)
                convertView = getLayoutInflater().inflate(R.layout.item_layout, null);
            TextView textView = convertView.findViewById(R.id.id_item_text);
            textView.setText(data.get(position));

            return convertView;
        }
    };
}