1.首先下载一个libserial_port.so，新建目录libs/armeabi,将so文件放到该目录下。

2.定义串口类，在类的构建函数中修改权限，打开设备，创建输入流和输出流，通过native接口访问串口打开关闭函数

public class SerialPort {

/*Do not remove or rename the field mFd: it is used by native method close();*/

public SerialPort(File device, int baudrate, int flags) throws SecurityException, IOException, InvalidParameterException{

//如果串口权限不够，改变权限

/* 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() + "\n"

+ "exit\n";

su.getOutputStream().write(cmd.getBytes());

if ((su.waitFor() != 0) || !device.canRead()

|| !device.canWrite()) {

throw new SecurityException();

}

} catch (Exception e) {

e.printStackTrace();

throw new SecurityException();

}

}

mFd = open(device.getAbsolutePath(), baudrate, flags);//打开串口

if (mFd == null) {

Log.e(TAG, "native open returns null");

throw new IOException();

}

mFileInputStream = new FileInputStream(mFd);//串口输入流

mFileOutputStream = new FileOutputStream(mFd);//串口输出流

}

// 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);//c文件中的串口open()函数

public native void close();//c文件中的串口close()函数

static {

System.loadLibrary("serial_port");//加载串口库

}

}

}

3.定义抽象类ServerData

public abstract class ServerData {

protected SerialPort mSerialPort;

protected OutputStream mOutputStream;

private InputStream mInputStream;

private ReadThread mReadThread;

private class ReadThread extends Thread {

@Override

//在线程中读取数据并处理数据

public void run() {

super.run();

byte[] buffer = new byte[128];

int size;

while(true) {

try {

if (mInputStream == null) return;

size = mInputStream.read(buffer);//读取数据

if (size > 0) {

onDataReceived(buffer, size);//处理数据

}

} catch (IOException e) {

e.printStackTrace();

return;

}

}

}

}

4.实例化串口类，输出流和输入流，实例化读取线程并开始执行该线程

[code]

public ServerData(String path, int baudrate){

try {

mSerialPort = new SerialPort(new File(path), baudrate, 0);

mOutputStream = mSerialPort.getOutputStream();

mInputStream = mSerialPort.getInputStream();

/* Create a receiving thread */

mReadThread = new ReadThread();

mReadThread.start();

} catch (SecurityException e) {

} catch (IOException e) {

} catch (InvalidParameterException e) {

}

}

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

}

[/code]

5.然后再新建一个类，在新建的类中实现上面的抽象函数，并写一个函数返回读取到的数据。

package View;

//导入R类，所在包不同，不能直接饮用，需要导入才可以使用

import android_serialport_api.sample.R;

/* EtcView类，Etc界面管理 */

public class SerialView {

private Activity context = null;

private Serial mEtcServer = null;

/* Etc界面构造函数 */

public SerialView(Activity context) {

this.context = context;

}

public void EtcInitView() {

//这样才可以找到android_serialport_api.sample包下的id

TextView mytext=(TextView)context.findViewById(R.id.mytext);

mEtcServer = new Serial("/dev/s3c2410_serial3", 9600);

}

public void EtcRefresh() {

//返回串口线程读取的数据

byte[] buffer = mEtcServer.getdata();

String recString=new String(buffer);//将byte[]的数组转换成字符串string

mytext.setText(recString);//设置字符文本

buffer = null;

}

}