android 读取串口数据的服务

2016-09-1813:10:03

继承Service，定义抽象方法onDataReceived，子类通过实现抽象方法获取接收到数据的回调。

package com.zrsoft.liftad.serialport;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.app.Service;
import android_serialport_api.SerialPort;

import com.zrsoft.liftad.MyApp;
import com.zrsoft.liftad.utils.Logger;

public abstract class SerialPortService extends Service {
 
    protected SerialPort mSerialPort;
    protected OutputStream mOutputStream;
    private InputStream mInputStream;
    private ReadThread mReadThread;

    private class ReadThread extends Thread {
        byte[] buffer = new byte[128];

        @Override
        public void run() {
            super.run();
            while (!isInterrupted()) {
                int size;
                try {

                    if (mInputStream == null)
                        return;
                    size = mInputStream.read(buffer);
                    if (size > 0) {
                        onDataReceived(buffer, size); 
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                    return;
                }
            }
        }
    }

    @Override
    public void onCreate() { 
        try { 
            mSerialPort = new SerialPort(new File("/dev/ttyS3"), 9600, 0);
            mOutputStream = mSerialPort.getOutputStream();
            mInputStream = mSerialPort.getInputStream();

            mReadThread = new ReadThread();
            mReadThread.start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    protected abstract void onDataReceived(final byte[] buffer, final int size);

    @Override
    public void onDestroy() {
        if (mReadThread != null){
            mReadThread.interrupt();
        }
        if (mSerialPort != null) {
            mSerialPort.close();
            mSerialPort = null;
        } 
        mSerialPort = null;
        super.onDestroy();
    }
}

SerialPort 类：

/*
 * Copyright 2009 Cedric Priscal
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License. 
 */

package android_serialport_api;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.util.Log;

public class SerialPort {
    private static final String TAG = "SerialPort";

    /*
     * Do not remove or rename the field mFd: it is used by native method
     * close();
     */
    private FileDescriptor mFd;
    private FileInputStream mFileInputStream;
    private FileOutputStream mFileOutputStream;

    public SerialPort(File device, int baudrate, int flags) throws SecurityException, IOException {
        try {
            System.loadLibrary("serial_port");
        } catch (Exception ex) {
            Log.d("asdf", ex.getMessage());
        }
        /* Check access permission */
        if (!device.canRead() || !device.canWrite()) {
            try {
                /* Missing read/write permission, trying to chmod the file */
                Process su;
                su = Runtime.getRuntime().exec("/system/bin/su");
                String cmd = "chmod 666 " + device.getAbsolutePath() + "
" + "exit
";
                su.getOutputStream().write(cmd.getBytes());
                if ((su.waitFor() != 0) || !device.canRead() || !device.canWrite()) {
                    throw new SecurityException();
                }
            } catch (Exception e) {
                e.printStackTrace();
                throw new SecurityException();
            }
        }
        Log.d("port", "open ready");
        mFd = open(device.getAbsolutePath(), baudrate, flags);
        if (mFd == null) {
            Log.e(TAG, "native open returns null");
            throw new IOException();
        }
        mFileInputStream = new FileInputStream(mFd);
        mFileOutputStream = new FileOutputStream(mFd);
    }

    // Getters and setters
    public InputStream getInputStream() {
        return mFileInputStream;
    }

    public OutputStream getOutputStream() {
        return mFileOutputStream;
    }

    // JNI
    private native static FileDescriptor open(String path, int baudrate, int flags);

    public native void close();

    static {
        System.loadLibrary("serial_port");
    }
}