我使用汇合的人工制品开始了一个简单的项目。但是，当我尝试使用mvn clean install或mvn clean package编译项目时，会收到类似消息
[ERROR] C:\Users\its\git\datakmu\service-stack\stream-data-preprocessor\src\main\java\at\ac\fhsalzburg\datakmu\service\DataPreProcessor.java:[1]
package at.ac.fhsalzburg.datakmu.service;
^
The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
[ERROR] C:\Users\its\git\datakmu\service-stack\stream-data-preprocessor\src\main\java\at\ac\fhsalzburg\datakmu\service\DataPreProcessor.java:[3]
public class DataPreProcessor {
^^^^^^^^^^^^^^^^
Implicit super constructor Object() is undefined for default constructor. Must define an explicit constructor
[ERROR] C:\Users\its\git\datakmu\service-stack\stream-data-preprocessor\src\main\java\at\ac\fhsalzburg\datakmu\service\DataPreProcessor.java:[4]
public static void main(String[] args) {
^^^^^^
String cannot be resolved to a type
表示未找到基本的SDK类，例如“无法解析类型 java.lang.Object ”。我正在与其他几个Maven项目一起工作，并且它们工作正常。我不明白，那一定是一个愚蠢的错误。
在这里您可以找到pom.xml文件：
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<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>stream-data-preprocessor</groupId>
<artifactId>stream-data-preprocessor</artifactId>
<version>0.1</version>
<packaging>jar</packaging>
<name>Kafka Streams Quickstart :: Java</name>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<slf4j.version>1.7.7</slf4j.version>
<log4j.version>1.2.17</log4j.version>
<java.version>8</java.version>
<avro.version>1.9.1</avro.version>
<gson.version>2.2.4</gson.version>
<kafka.version>2.5.0</kafka.version>
<confluent.version>5.5.1</confluent.version>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<repositories>
<repository>
<id>apache.snapshots</id>
<name>Apache Development Snapshot Repository</name>
<url>https://repository.apache.org/content/repositories/snapshots/</url>
<releases>
<enabled>false</enabled>
</releases>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
<repository>
<id>confluent</id>
<name>Confluent</name>
<url>https://packages.confluent.io/maven/</url>
</repository>
</repositories>
<!--
Execute "mvn clean package -Pbuild-jar"
to build a jar file out of this project!
-->
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.avro</groupId>
<artifactId>avro-maven-plugin</artifactId>
<version>${avro.version}</version>
<executions>
<execution>
<phase>generate-sources</phase>
<goals>
<goal>schema</goal>
</goals>
<configuration>
<sourceDirectory>${project.basedir}/src/main/resources/avro/</sourceDirectory>
<includes>
<include>SensorValue.avsc</include>
</includes>
<outputDirectory>${project.build.directory}/generated-sources</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>io.confluent</groupId>
<artifactId>kafka-schema-registry-maven-plugin</artifactId>
<version>${confluent.version}</version>
<configuration>
<schemaRegistryUrls>
<param>http://localhost:28081</param>
</schemaRegistryUrls>
<subjects>
<transactions-value>src/main/resources/avro/Sentence.avsc</transactions-value>
</subjects>
<outputDirectory/>
</configuration>
<goals>
<goal>test-compatibility</goal>
</goals>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
<compilerId>jdt</compilerId>
</configuration>
<dependencies>
<dependency>
<groupId>org.eclipse.tycho</groupId>
<artifactId>tycho-compiler-jdt</artifactId>
<version>0.21.0</version>
</dependency>
</dependencies>
</plugin>
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<versionRange>[2.4,)</versionRange>
<goals>
<goal>single</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore/>
</action>
</pluginExecution>
<pluginExecution>
<pluginExecutionFilter>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<versionRange>[3.1,)</versionRange>
<goals>
<goal>testCompile</goal>
<goal>compile</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore/>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<dependencies>
<!-- Apache Kafka dependencies -->
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-streams</artifactId>
<version>${kafka.version}</version>
</dependency>
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>${kafka.version}</version>
</dependency>
<!-- Dependencies below are required/recommended only when using Apache Avro. -->
<dependency>
<groupId>io.confluent</groupId>
<artifactId>kafka-avro-serializer</artifactId>
<version>${confluent.version}</version>
</dependency>
<dependency>
<groupId>org.apache.avro</groupId>
<artifactId>avro</artifactId>
<version>${avro.version}</version>
</dependency>
</dependencies>
</project>
据我所知，还正确配置了maven：
Maven home: C:\Users\its\scoop\apps\maven\current
Java version: 11.0.2, vendor: Oracle Corporation, runtime: C:\Program Files\Java\jdk-11.0.2
Default locale: de_AT, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"
为完整起见，主要的Java类。我从原型中删除了所有其他代码段：
package at.ac.fhsalzburg.datakmu.service;
public class DataPreProcessor {
public static void main(String[] args) {
//TODO
}
}
有人可以帮忙吗？如果您需要其他任何输入，请告诉我！ 谢谢
答案 0 :(得分：0)
在您的pom.xml中，您具有以下片段。在src / main / resources中创建avro文件夹，或删除avro部件。然后执行mvn clean验证，以确保您的项目已构建
<execution>
<phase>generate-sources</phase>
<goals>
<goal>schema</goal>
</goals>
<configuration>
<sourceDirectory>${project.basedir}/src/main/resources/avro/</sourceDirectory>
<includes>
<include>SensorValue.avsc</include>
</includes>
<outputDirectory>${project.build.directory}/generated-sources</outputDirectory>
</configuration>
</execution>