文章目录

SpringBoot使用RXTX连接串口教程及遇到的坑总结
- 一、所用环境及依赖
- 二、部署流程
- - 2.1 下载RXTXComm包
  - 2.2 部署RXTXComm包
- 三、编写串口使用程序
- - 3.1 编写RXTXConfig.java
  - 3.2 编写实体类SerialPortEntity
  - 3.3 编写监听器SerialPortListener
  - 3.4 编写工具类SerialPortUtil
  - 3.5 编写枚举类WarningLightEnum
  - 3.6 编写测试类TestController
- 四、所踩到的坑

SpringBoot使用RXTX连接串口教程及遇到的坑总结

本文主要记录了本人在近期使用串口操作设备时的流程以及踩到的坑，希望能够帮助到有需要运用JAVA去操作串口需求的朋友，避免像我一样踩了很多坑才成功连接上。

一、所用环境及依赖

java: jdk11
maven: apache-maven-3.5.3
sprintboot：2.7.6
rxtx: 2.1.7
operate system: windows10

二、部署流程

2.1 下载RXTXComm包

可以选择从官网下载
也直接下载我网盘的分享文件网盘文件，提取码：sjsf
下载完成后把压缩包里的RXTXcomm.jar、rxtxParallel.dll、rxtxSerial.dll复制出来

2.2 部署RXTXComm包

由于我的Springboot工程使用的是Maven仓库，因此需要通过命令先把RXTXcomm.jar导入到自己Maven的Repository里面（Maven的具体使用方式本文不做详解）
打开CMD，输入以下命令，导入RXTXcomm.jar

/** DgroupId: pom.xml中映射的groupId* DartifactId: pom.xml中映射的artifactId* Dversion: pom.xml中映射的version* Dpackaging: 加载的是jar包* Dfile: RXTXcomm.jar包的路径，建议使用绝对路径*/

mvn install:install-file-DgroupId=gnu.io -DartifactId=rxtx -Dversion=2.1.7 -Dpackaging=jar -Dfile="E:\RXTXcomm.jar"

运行后若在Maven的repository中存在下面的文件夹及文件，就代表导入成功了
RXTXcomm.jar导入成功后，需要把解压到的rxtxParallel.dll、rxtxSerial.dll文件复制到JAVA_HOME/bin路径下或者C:/Windows/System32/路径下（JAVA_HOME的配置方法很简单，自行百度即可）
最后在pom.xml中输入以下命令引用依赖即可完成RXTXcomm依赖导入到项目中

<dependency><groupId>gnu.io</groupId><artifactId>rxtx</artifactId><version>2.1.7</version></dependency>

三、编写串口使用程序

为了更有效、更清晰地使用RXTXcomm，我编写了以下几个文件，分享出来供参考
我的工程目录如下

3.1 编写RXTXConfig.java

首先在application.yml中添加下面的配置

rxtx-config:portName: COM13  # 串口名baudRate: 9600  # 波特率parityBit: EVEN  # 检验位dataBits: 8  # 数据位stopBits: 1  # 停止位

config目录下建立RXTXConfig.java，代码如下

package com.mbtxtq.app.config;import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;@Component
@ConfigurationProperties(prefix = "rxtx-config")
public class RXTXConfig {private String portName;private Integer baudRate;private String parityBit;private String dataBits;private String stopBits;public String getPortName() {return portName;}public void setPortName(String portName) {this.portName = portName;}public Integer getBaudRate() {return baudRate;}public void setBaudRate(Integer baudRate) {this.baudRate = baudRate;}public String getParityBit() {return parityBit;}public void setParityBit(String parityBit) {this.parityBit = parityBit;}public String getDataBits() {return dataBits;}public void setDataBits(String dataBits) {this.dataBits = dataBits;}public String getStopBits() {return stopBits;}public void setStopBits(String stopBits) {this.stopBits = stopBits;}}

3.2 编写实体类SerialPortEntity

在entity目录下建立SerialPortEntity.java，代码如下

package com.mbtxtq.app.entity;import com.mbtxtq.app.listener.SerialPortListener;
import com.mbtxtq.app.utils.SerialPortUtil;
import gnu.io.SerialPort;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;import java.util.List;@Slf4j
@Data
public class SerialPortEntity {private String portName;  //端口号private Integer baudRate;  //波特率private int dataBits;  //数据位private String dataBitsStr;  //数据位字符串private int stopBits;  //停止位private String stopBitsStr;  //停止位字符串private int parityBit;  //校验位private String parityBitStr;  //校验位字符串private SerialPort serialPort = null; //串口会话public SerialPortEntity(String portName, Integer baudRate, String parityBit, String dataBits, String stopBits){this.portName = portName;this.baudRate = baudRate;this.dataBitsStr = dataBits;this.stopBitsStr = stopBits;this.parityBitStr = parityBit;//校验位switch (parityBit) {case "NONE":this.parityBit = SerialPort.PARITY_NONE;break;case "ODD":this.parityBit = SerialPort.PARITY_ODD;break;case "EVEN":this.parityBit = SerialPort.PARITY_EVEN;break;case "MARK":this.parityBit = SerialPort.PARITY_MARK;break;case "SPACE":this.parityBit = SerialPort.PARITY_SPACE;break;}//数据位switch (dataBits) {case "5":this.dataBits = SerialPort.DATABITS_5;break;case "6":this.dataBits = SerialPort.DATABITS_6;break;case "7":this.dataBits = SerialPort.DATABITS_7;break;case "8":this.dataBits = SerialPort.DATABITS_8;break;}//停止位switch (stopBits) {case "1":this.stopBits = SerialPort.STOPBITS_1;break;case "1.5":this.stopBits = SerialPort.STOPBITS_1_5;break;case "2":this.stopBits = SerialPort.STOPBITS_2;break;}}// 连接串口public SerialPort connect(){// 查看所有串口SerialPortUtil serialPortUtil = SerialPortUtil.getSerialPortUtil();List<String> portList = serialPortUtil.findPort();log.info("发现全部端口: "+portList);log.info("尝试打开端口:"+portName+" ....");// 打开指定端口SerialPort serialPort = serialPortUtil.openPort(portName,baudRate,dataBits,parityBit,stopBits);SerialPortListener listener = new SerialPortListener();listener.setSerialPort(serialPort);setSerialPort(serialPort);serialPortUtil.addListener(serialPort, listener);return serialPort;}// 关闭串口public void close(){SerialPortUtil serialPortUtil = SerialPortUtil.getSerialPortUtil();if(serialPort != null) serialPortUtil.closePort(serialPort);else log.info("请先调用connect方法！");}// 发送指令public void send(byte[] code){SerialPortUtil serialPortUtil = SerialPortUtil.getSerialPortUtil();if (serialPort != null) serialPortUtil.sendToPort(serialPort,code);else log.info("请先调用connect方法！");}}

3.3 编写监听器SerialPortListener

在listener目录下建立SerialPortEntity.java，代码如下

package com.mbtxtq.app.listener;import com.mbtxtq.app.utils.SerialPortUtil;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;import java.util.Arrays;
import java.util.Date;@Slf4j
@Data
public class SerialPortListener implements SerialPortEventListener {private SerialPort serialPort = null;@Overridepublic void serialEvent(SerialPortEvent serialPortEvent) {switch (serialPortEvent.getEventType()){// 串口存在有效数据case SerialPortEvent.DATA_AVAILABLE:byte[] bytes = SerialPortUtil.getSerialPortUtil().readFromPort(serialPort);log.info("===========start===========");log.info(new Date() + "【读到的字符】：-----" + Arrays.toString(bytes));
//                log.info(new Date() + "【字节数组转16进制字符串】：-----" + ModBusUtils.bytes2HexString(bytes));log.info("===========end===========");break;// 2.输出缓冲区已清空case SerialPortEvent.OUTPUT_BUFFER_EMPTY:log.error("输出缓冲区已清空");break;// 3.清除待发送数据case SerialPortEvent.CTS:log.error("清除待发送数据");break;// 4.待发送数据准备好了case SerialPortEvent.DSR:log.error("待发送数据准备好了");break;// 10.通讯中断case SerialPortEvent.BI:log.error("与串口设备通讯中断");break;default:break;}}}

3.4 编写工具类SerialPortUtil

在utils目录下建立SerialPortUtil.java，代码如下

package com.mbtxtq.app.utils;import gnu.io.*;
import lombok.extern.slf4j.Slf4j;import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.TooManyListenersException;@Slf4j
public class SerialPortUtil {private static SerialPortUtil serialPortUtil = null;static {serialPortUtil = new SerialPortUtil();}private SerialPortUtil(){}/*** 获取提供服务的SerialTool对象* @return serialPortUtil*/public static SerialPortUtil getSerialPortUtil(){if(serialPortUtil == null){serialPortUtil = new SerialPortUtil();}return serialPortUtil;}/*** 查找所有可用端口* @return 可用端口名称列表*/public ArrayList<String> findPort() {// 获得当前所有可用串口Enumeration<CommPortIdentifier> portList = CommPortIdentifier.getPortIdentifiers();ArrayList<String> portNameList = new ArrayList<>();// 将可用串口名添加到List并返回该Listwhile (portList.hasMoreElements()) {String portName = portList.nextElement().getName();portNameList.add(portName);}return portNameList;}/*** 打开串口* @param portName 端口名称* @param baudrate 波特率  9600* @param databits 数据位  8* @param parity   校验位（奇偶位）  NONE ：0* @param stopbits 停止位 1* @return 串口对象*/public SerialPort openPort(String portName, int baudrate, int databits, int parity, int stopbits) {try {// 通过端口名识别端口CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);// 打开端口，并给端口名字和一个timeout（打开操作的超时时间）CommPort commPort = portIdentifier.open(portName, 5000);// 判断是不是串口if (commPort instanceof SerialPort) {SerialPort serialPort = (SerialPort) commPort;// 设置一下串口的波特率等参数serialPort.setSerialPortParams(baudrate, databits, stopbits, parity);log.info("打开串口 " + portName + " 成功 !");return serialPort;} else {log.error("不是串口");}} catch (NoSuchPortException e1) {log.error("没有找到端口");e1.printStackTrace();} catch (PortInUseException e2) {log.error("端口被占用");e2.printStackTrace();} catch (UnsupportedCommOperationException e) {e.printStackTrace();}return null;}/*** 关闭串口* @param serialPort 待关闭的串口对象*/public void closePort(SerialPort serialPort) {if (serialPort != null) {serialPort.close();}}/*** 往串口发送数据* @param serialPort 串口对象*/public void sendToPort(SerialPort serialPort, byte[] bytes) {OutputStream out = null;try {out = serialPort.getOutputStream();out.write(bytes);//            如果jdk大于1.8版本的话不要把out.flush()打开，会报错
//            out.flush();} catch (IOException e) {e.printStackTrace();} finally {try {if (out != null) {out.close();}} catch (IOException e) {e.printStackTrace();}}}/*** 从串口读取数据* @param serialPort 当前已建立连接的SerialPort对象* @return 读取到的数据*/public byte[] readFromPort(SerialPort serialPort) {InputStream in = null;byte[] bytes = null;try {Thread.sleep(500);} catch (InterruptedException e) {e.printStackTrace();}try {in = serialPort.getInputStream();// 获取buffer里的数据长度int bufferlength = in.available();while (bufferlength != 0) {// 初始化byte数组为buffer中数据的长度bytes = new byte[bufferlength];in.read(bytes);bufferlength = in.available();}} catch (IOException e) {e.printStackTrace();} finally {try {if (in != null) {in.close();}} catch (IOException e) {e.printStackTrace();}}return bytes;}/*** 添加监听器* @param port     串口对象* @param listener 串口监听器*/public void addListener(SerialPort port, SerialPortEventListener listener) {try {// 给串口添加监听器port.addEventListener(listener);// 设置当有数据到达时唤醒监听接收线程port.notifyOnDataAvailable(true);// 设置当通信中断时唤醒中断线程port.notifyOnBreakInterrupt(true);} catch (TooManyListenersException e) {log.error("太多监听器");e.printStackTrace();}}/*** 删除监听器** @param port     串口对象* @param listener 串口监听器*/public void removeListener(SerialPort port, SerialPortEventListener listener) {// 删除串口监听器port.removeEventListener();}/*** 设置串口的Listener** @param serialPort* @param listener*/public static void setListenerToSerialPort(SerialPort serialPort, SerialPortEventListener listener) {try {// 给串口添加事件监听serialPort.addEventListener(listener);} catch (TooManyListenersException e) {e.printStackTrace();}// 串口有数据监听serialPort.notifyOnDataAvailable(true);// 中断事件监听serialPort.notifyOnBreakInterrupt(true);}}

3.5 编写枚举类WarningLightEnum

在enums目录下建立WarningLightEnum.java，代码如下

package com.mbtxtq.app.enums;public enum WarningLightEnum {ALL_CLOSE("全关", new byte[]{1, 5, 0, 0, 0, 0, (byte) 205, (byte) 202}),RED_LIGHT_OPEN("红灯亮", new byte[]{1, 5, 0, 1, (byte) 255, 0, (byte) 221, (byte) 250});private String codeType;private byte[] codeList;private WarningLightEnum(String codeType, byte[] codeList) {this.codeType = codeType;this.codeList = codeList;}public String getCodeType() {return codeType;}public void setCodeType(String codeType) {this.codeType = codeType;}public byte[] getCodeList() {return codeList;}public void setCodeList(byte[] codeList) {this.codeList = codeList;}}

3.6 编写测试类TestController

在controller目录下建立TestController.java，代码如下

package com.mbtxtq.app.controller.test;import com.mbtxtq.app.config.RXTXConfig;
import com.mbtxtq.app.entity.main_scout_process.SerialPortEntity;
import com.mbtxtq.app.enums.WarningLightEnum;import gnu.io.SerialPort;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;import java.util.Map;@Controller
@CrossOrigin(origins = "*")
@ResponseBody
@RequestMapping("/target/feature/extract")
public class TestController {@Autowiredprivate RXTXConfig rxtxConfig;@PostMapping("test")public void test(@RequestBody Map<String, Object> params) {String useType = (String) params.get("use_type");byte[] codeList1 = warningLightEnum.ALL_CLOSE.getCodeList();byte[] codeList2 = WarningLightEnum.RED_LIGHT_OPEN.getCodeList();// 初始化实体类SerialPortEntity，参数使用RXTXConfig中的参数，可自行调整SerialPortEntity serialPortEntity = new SerialPortEntity(this.rxtxConfig.getPortName(), this.rxtxConfig.getBaudRate(),this.rxtxConfig.getParityBit(), this.rxtxConfig.getDataBits(), this.rxtxConfig.getStopBits());try {SerialPort serialPort = serialPortEntity.connect();System.out.println(serialPort);if (useType.equals("close")) {serialPortEntity.send(codeList1);} else if (useType.equals("start")) {serialPortEntity.send(codeList2);}//            Thread.sleep(10000);serialPortEntity.close();} catch (Exception e){e.printStackTrace();serialPortEntity.close();}}}

通过postman获取前端代码请求test的api即可调用串口的测试接口，成功连接！

四、所踩到的坑

复制rxtxParallel.dll、rxtxSerial.dll这两个文件很重要！没有复制或者复制错目录会导致报以下的错

java.lang.UnsatisfiedLinkError: no rxtxSerial64 in java.library.path thrown while loading gnu.io.RXTXCommDriver
Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: Could not initialize class gnu.io.RXTXVersionat gnu.io.CommPortIdentifier.<clinit>(CommPortIdentifier.java:123)