flink程序本地运行报： A JNI error has occurred和java.lang.NoClassDefFoundError

1.问题描述

        在idea中运行flink job程序出现如下错误：

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/flink/api/common/io/FileInputFormat
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
    at java.lang.Class.getMethod0(Class.java:3018)
    at java.lang.Class.getMethod(Class.java:1784)
    at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:650)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:632)
Caused by: java.lang.ClassNotFoundException: org.apache.flink.api.common.io.FileInputFormat
    at java.net.URLClassLoader.findClass(URLClassLoader.java:387)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    ... 7 more

2.问题分析

2.1代码问题分析

package test;import org.apache.flink.api.java.io.TextInputFormat;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;/*** @Description* @Author * @Date 2024/5/23* @Version 1.0*/
public class ReadTextDemo {public static void main(String[] args) throws Exception {StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();TextInputFormat textInputFormat = new TextInputFormat(null);DataStreamSource<String> source = env.readFile(textInputFormat, "D:\\datatest\\readtext.txt");source.print();env.execute("readText test");}
}

        代码编译没有问题，但是却报类无法加载的异常，而且报错信息出现A JNI error has occurred，因此，猜测大概率和JDK有关，网上查了下解决方案：解决Java编译时错误:A JNI error has occurred,please check your installation and try again_java_脚本之家

        但是通过验证，本地的JDK环境配置没有问题：

        因此排除JDK问题的猜想。

2.2 pom配置问题分析

        类无法正常加载还一种可能是pom依赖出现了问题，pom配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.example</groupId><artifactId>xxx-flink</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><flink.version>1.15.0</flink.version><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>org.apache.flink</groupId><artifactId>flink-streaming-java</artifactId><version>${flink.version}</version><scope>provided</scope></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-clients</artifactId><version>${flink.version}</version><scope>provided</scope></dependency></dependency></dependencies><build><plugins><plugin><!--<groupId>org.apache.maven.plugins</groupId>--><artifactId>maven-compiler-plugin</artifactId><version>3.8.1</version><configuration><source>1.8</source><target>1.8</target></configuration></plugin><plugin><artifactId>maven-assembly-plugin </artifactId><configuration><descriptorRefs><!-- 此处填写打包后jar包后添加的标识 --><descriptorRef>jar-with-dependencies</descriptorRef></descriptorRefs><archive><manifest><!-- 此处填写程序的主入口(main方法) --><mainClass>cn.xxx.Main</mainClass></manifest></archive></configuration><executions><execution><id>make-assembly</id><phase>package</phase><goals><goal>single</goal></goals></execution></executions></plugin></plugins></build></project>

        对pom内容进行分析，发现flink jar依赖多了一行：

        <scope>provided</scope>表示为当前依赖在打包过程中，不需要打进去，需要由运行的环境来提供，因此怀疑是它导致的，然后就将它注解掉，再次运行，发现程序正常执行。