英文:
Kafka tutorial: java.lang.Object cannot be resolved
问题
我试图遵循 https://kafka.apache.org/25/documentation/streams/tutorial 进行操作,但是编译失败,出现了一堆错误。这是第一个错误:
The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
我删除了所有源文件,然后放入一个仅包含以下内容的 Pipe.java:
package myapps;
public class Pipe {
public static void main(String[] args) throws Exception {
}
}
但它仍然无法编译:
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project streams.examples: Compilation failure: Compilation failure:
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[1]
[ERROR] package myapps;
[ERROR] ^
[ERROR] The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[3]
[ERROR] public class Pipe {
[ERROR] ^^^^
[ERROR] Implicit super constructor Object() is undefined for default constructor. Must define an explicit constructor
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[5]
[ERROR] public static void main(String[] args) throws Exception {
[ERROR] ^^^^^^
[ERROR] String cannot be resolved to a type
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[5]
[ERROR] public static void main(String[] args) throws Exception {
[ERROR] ^^^^^^^^^
[ERROR] Exception cannot be resolved to a type
[ERROR] 4 problems (4 errors)
我正在使用 Debian Linux 映像运行,Java 版本如下:
$ java -version
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_242-b08)
OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.242-b08, mixed mode)
英文:
I'm trying to follow https://kafka.apache.org/25/documentation/streams/tutorial
But it failed compilation with a bunch of errors. This is the first one:
The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
I removed all source files and put in a barebone Pipe.java with the following content:
package myapps;
public class Pipe {
public static void main(String[] args) throws Exception {
}
}
And it's still not compiling:
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project streams.examples: Compilation failure: Compilation failure:
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[1]
[ERROR] package myapps;
[ERROR] ^
[ERROR] The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[3]
[ERROR] public class Pipe {
[ERROR] ^^^^
[ERROR] Implicit super constructor Object() is undefined for default constructor. Must define an explicit constructor
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[5]
[ERROR] public static void main(String[] args) throws Exception {
[ERROR] ^^^^^^
[ERROR] String cannot be resolved to a type
[ERROR] /home/fatdragon/Play/kafka/streaming/streams.examples/src/main/java/myapps/Pipe.java:[5]
[ERROR] public static void main(String[] args) throws Exception {
[ERROR] ^^^^^^^^^
[ERROR] Exception cannot be resolved to a type
[ERROR] 4 problems (4 errors)
I'm running from a Debian Linux image with this version:
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_242-b08)
OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.242-b08, mixed mode)
</details>
# 答案1
**得分**: 0
你的类路径中没有运行时库。<br>
请检查你的设置。
<details>
<summary>英文:</summary>
There is no runtime library in your classpath.<br>
Check your settings.
</details>
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