java串口通讯分享
本文推荐一个简单好用java实现串口通讯方法
如果是非标准协议的串口通讯可以采用一下方法，如果是标准的modbus协议可以参考我的另外一篇博文：java实现modbus_rtu通讯
首先引入jar包
<dependency>
<groupId>com.github.purejavacomm</groupId>
<artifactId>purejavacomm</artifactId>
<version>1.0.1.RELEASE</version>
</dependency>
其他的jar包或多或少还有点坑，我这暂不推荐，有兴趣的同学可以自行尝试，使用方法大致相同
废话不多说，上代码：直接引入工具类
package com.yixinhong.util;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;
import purejavacomm.CommPortIdentifier;
import purejavacomm.SerialPort;
import purejavacomm.SerialPortEvent;
import purejavacomm.SerialPortEventListener;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* @Author：lpj
* @name：CommUtil
* @Date：2023/5/29 15:09
* @describe：
*/
@Slf4j
public class CommUtil implements SerialPortEventListener {
private String PORT_NAME ;
private static final int BIT_RATE = 9600;
public static final int DATA_BITS = SerialPort.DATABITS_8;
public static final int STOP_BIT = SerialPort.STOPBITS_1;
public static final int PARITY_BIT = SerialPort.PARITY_NONE;
public static SerialPort serialPort;
private static InputStream in;
private static OutputStream out;
private static CommUtil commUtil;
// 保存串口返回信息
public String data;
// 保存串口返回信息十六进制
public String dataHex;
private CommUtil(String PORT_NAME) {
this.PORT_NAME = PORT_NAME;
}
public static synchronized CommUtil getInstance(String PORT_NAME) {
if (commUtil == null) {
commUtil = new CommUtil(PORT_NAME);
commUtil.init();
}else if(!commUtil.PORT_NAME.equals(PORT_NAME))
{
commUtil = new CommUtil(PORT_NAME);
commUtil.init();
}
// commUtil = new CommUtil(PORT_NAME);
// commUtil.init();
return commUtil;
}
public void init( ) {
try {
if(StringUtils.isEmpty(PORT_NAME)){
log.error("init PORT_NAME is null");
}else {
log.info("init PORT_NAME is :{}",PORT_NAME);
}
CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(PORT_NAME);
if (portIdentifier.isCurrentlyOwned()) {
log.error("Port is currently in use");
} else if (portIdentifier.getPortType() == 1) {
serialPort = (SerialPort) portIdentifier.open(PORT_NAME, 1000);
serialPort.setSerialPortParams(BIT_RATE, DATA_BITS, STOP_BIT, PARITY_BIT);
in = serialPort.getInputStream();
out = serialPort.getOutputStream();
serialPort.addEventListener(this);
serialPort.notifyOnDataAvailable(true);
} else {
log.error("Error: Only serial ports are handled by this example.");
}
} catch (Exception e) {
log.error("init failed",e);
}
}
@Override
public void serialEvent(SerialPortEvent serialPortEvent) {
switch (serialPortEvent.getEventType()) {
case SerialPortEvent.DATA_AVAILABLE:
receive();
break;
}
}
public void send(String message) {
try {
log.info("sendmsg:{}",message);
byte[] bytes = hexStrToByteArray(message);
out.write(bytes);
// Thread.sleep(1000);
} catch (Exception e) {
log.error("send failed",e);
}
}
public void receive() {
try {
in = serialPort.getInputStream();
// 通过输入流对象的available方法获取数组字节长度
byte[] readBuffer = new byte[in.available()];
// 从线路上读取数据流
int len = 0;
// int read = in.read(readBuffer);
while ((len = in.read(readBuffer)) != -1) {
// 直接获取到的数据
data = new String(readBuffer, 0, len).trim();
// 转为十六进制数据
dataHex = bytesToHexString(readBuffer);
// System.out.println("data:" + data);
// System.out.println("dataHex:" + dataHex);// 读取后置空流对象
in.close();
in = null;
break;
}
} catch (IOException e) {
System.out.println(("读取串口数据时发生IO异常"));
}
}
public void close() {
try {
in.close();
out.close();
serialPort.notifyOnDataAvailable(false);
serialPort.removeEventListener();
serialPort.close();
} catch (Exception e) {
log.error("close",e);
}
}
//16进制转byte数组
public static byte[] hexStrToByteArray(String str) {
if (str == null) {
return null;
}
if (str.length() == 0) {
return new byte[0];
}
byte[] byteArray = new byte[str.length() / 2];
for (int i = 0; i < byteArray.length; i++) {
String subStr = str.substring(2 * i, 2 * i + 2);
byteArray[i] = ((byte) Integer.parseInt(subStr, 16));
}
return byteArray;
}
public static String ByteArrayToString(byte[] by) {
String str = "";
for (int i = 0; i < by.length; i++) {
String hex = Integer.toHexString(by[i] & 0xFF);
if (hex.length() == 1) {
hex = "0" + hex;
}
str += hex.toUpperCase();
}
return str;
}
/**
* 数组转换成十六进制字符串
* @param
* @return HexString
*/
public static final String bytesToHexString(byte[] bArray) {
StringBuffer sb = new StringBuffer(bArray.length);
String sTemp;
for (int i = 0; i < bArray.length; i++) {
sTemp = Integer.toHexString(0xFF & bArray[i]);
if (sTemp.length() < 2)
sb.append(0);
sb.append(sTemp.toUpperCase());
}
return sb.toString();
}
/**
* 获取源数据和验证码的组合byte数组
* @param aa 字节数组
* @return
*/
public static byte[] getData(byte[] aa) {
// byte[] bb = getCrc16(aa);
byte[] cc = new byte[aa.length];
System.arraycopy(aa,0,cc,0,aa.length);
return cc;
}
public static byte[] getData(String...strings) {
byte[] data = new byte[]{};
for (int i = 0; i<strings.length;i++) {
int x = Integer.parseInt(strings[i], 16);
byte n = (byte)x;
byte[] buffer = new byte[data.length+1];
byte[] aa = {n};
System.arraycopy( data,0,buffer,0,data.length);
System.arraycopy( aa,0,buffer,data.length,aa.length);
data = buffer;
}
return getData(data);
}
public static String byteTo16String(byte b) {
StringBuffer buffer = new StringBuffer();
int aa = (int)b;
if (aa<0) {
buffer.append(Integer.toString(aa+256, 16)+" ");
}else if (aa==0) {
buffer.append("00 ");
}else if (aa>0 && aa<=15) {
buffer.append("0"+Integer.toString(aa, 16)+" ");
}else if (aa>15) {
buffer.append(Integer.toString(aa, 16)+" ");
}
return buffer.toString();
}
}
解释：
在send方法中，发送数据后要等待1s的原因是，需要监听串口的应答数据，不等待应答数据就读取不到，如果是只考虑发送，不考虑应答的话可以不用等待。
调用代码示例
String dataHex = null;
try{
CommUtil util = CommUtil.getInstance(commPortId);
util.send("FF0101050F010118");
Thread.sleep(1000);
util.send("FF0101050F020119");
dataHex = util.dataHex;
CommUtil.serialPort.close();
}catch (Exception e)
{
log.error("指令发送失败~"+e.getMessage());
}
return dataHex;
