NoClassDefFoundError: com/pi4j/config/Config when running the java code om pi

[peterivarsson]

Hi,

Why does it complaining about NoClassDefFoundError
Is some dependencies missing?

/ Peter

****************** my java file
package se.peter.ivarsson.raspberry.gpio;

import com.pi4j.Pi4J;
import com.pi4j.context.Context;
import com.pi4j.io.i2c.I2C;
import com.pi4j.io.i2c.I2CConfig;
import com.pi4j.io.i2c.I2CProvider;

public class testGpio {

private static final byte TCA9534_REG_ADDR_OUT_PORT = 0x01;
private static final byte TCA9534_REG_ADDR_CFG = 0x03;

public static void main(String[] args) throws InterruptedException {

    Context pi4j = Pi4J.newAutoContext();
    I2CProvider i2CProvider = pi4j.provider("linuxfs-i2c");
    I2CConfig i2cConfig = I2C.newConfigBuilder(pi4j).id("TCA9534").bus(1).device(0x70).build();

    try (I2C tca9534Dev = i2CProvider.create(i2cConfig)) {

		int config = tca9534Dev.readRegister(TCA9534_REG_ADDR_CFG);

        if (config < 0)
			throw new IllegalStateException(
					"Failed to read configuration from address 0x" + String.format("%02x", TCA9534_REG_ADDR_CFG));

		byte currentState = (byte) tca9534Dev.readRegister(TCA9534_REG_ADDR_OUT_PORT);

		if (config != 0x00) {

            System.out.println("TCA9534 is not configured as OUTPUT, setting register 0x" + String
					.format("%02x", TCA9534_REG_ADDR_CFG) + " to 0x00");

			tca9534Dev.writeRegister(TCA9534_REG_ADDR_CFG, (byte) 0x5a);
        }
    }
    
    pi4j.shutdown();
}

}
********************** pom.xml file

4.0.0 se.peter.ivarsson raspberry-gpio-test 1.0.0-SNAPSHOT jar UTF-8 11 11 2.0.0-alpha5 2.0

<dependencies>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>${slf4j.version}</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>${slf4j.version}</version>
    </dependency>

    <!-- include Pi4J Core -->
    <dependency>
        <groupId>com.pi4j</groupId>
        <artifactId>pi4j-core</artifactId>
        <version>${pi4j.version}</version>
    </dependency>

    <!-- include Pi4J Plugins (Platforms and I/O Providers) -->
    <dependency>
        <groupId>com.pi4j</groupId>
        <artifactId>pi4j-plugin-raspberrypi</artifactId>
        <version>${pi4j.version}</version>
    </dependency>
    <dependency>
        <groupId>com.pi4j</groupId>
        <artifactId>pi4j-plugin-pigpio</artifactId>
        <version>${pi4j.version}</version>
    </dependency>
    <dependency>
        <groupId>com.pi4j</groupId>
        <artifactId>pi4j-plugin-linuxfs</artifactId>
        <version>${pi4j.version}</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.2.0</version>
            <configuration>
                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <mainClass>se.peter.ivarsson.raspberry.gpio.testGpio</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>    

[eitch]

@peterivarsson On first glance all looks well. Do yo have the stack trace as well?

[peterivarsson]

This is the only trace I get.

pi@raspberrypi:~/pi-camera/bright_test $ !!
java -jar raspberry-gpio-test-1.0.0-SNAPSHOT.jar
Error: Unable to initialize main class se.peter.ivarsson.raspberry.gpio.testGpio
Caused by: java.lang.NoClassDefFoundError: com/pi4j/config/Config

[peterivarsson]

I have sript out everything except the row below.
It seems that the java code below doesn´t load the Pi4J dependecis

Context pi4j = Pi4J.newAutoContext();

I get this result:
ava -jar raspberry-gpio-test-1.0.0-SNAPSHOT.jar
Exception in thread "main" java.lang.NoClassDefFoundError: com/pi4j/Pi4J
at se.peter.ivarsson.raspberry.gpio.testGpio.main(testGpio.java:29)
Caused by: java.lang.ClassNotFoundException: com.pi4j.Pi4J
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 1 more

---

/*

• DEVELOPER: Peter Ivarsson
• PROJECT : Pi4J Test
• FILENAME : module-info.java

*/

module se.peter.ivarsson.raspberry.gpio {

requires com.pi4j;

}

[eitch]

Looking at your command, i think the pi4j library is missing in the classpath, which explains the ClassNotFoundException