Selenium webdriver JsonPrimitive.isPrimitiveOrString的Selenium集线器异常

Selenium独立服务器的实例该节点返回在com.google.gson.JsonPrimitive.isPrimitiveOrString上引发的500错误响应NullPointerException

任何解决此错误的提示都值得一提

启动Selenium服务器集线器和节点 检查该节点是否列在服务器控制台上

软件版本：

• ApacheMaven 3.5.0
• selenium-server-standalone-3.5.0
• ChromeDriver 2.31-geckodriver-v0.18.0-win64
• Chrome v 60.0.3112.101（64位）
• Firefox 55.0.2（64位）
• Java 1.8.0_92（64位）

服务器启动命令：

java -jar "selenium-server-standalone-3.5.0.jar" -role hub 
java -Dwebdriver.gecko.driver="C:/selenium/geckodriver.exe" -jar "selenium-server-standalone-3.5.0.jar" -role node -hub http://localhost:4444/grid/register 

Maven POM：

<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>

<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-java</artifactId>
<version>3.4.0</version>

错误堆栈：

Problem accessing /wd/hub/session. Reason:
Caused by: java.lang.NullPointerException **    at com.google.gson.JsonPrimitive.isPrimitiveOrString(JsonPrimitive.java:278)
at com.google.gson.JsonPrimitive.setValue(JsonPrimitive.java:101)
at com.google.gson.JsonPrimitive.<init>(JsonPrimitive.java:65)
at org.openqa.selenium.remote.server.ExceptionHandler.lambda$execute$0(ExceptionHandler.java:82)
at java.util.stream.ReferencePipeline$3$1.accept(Unknown Source)
at java.util.Spliterators$ArraySpliterator.forEachRemaining(Unknown Source)
at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source)
at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.util.stream.ReferencePipeline.collect(Unknown Source)

这个错误似乎发生在自动化测试的早期。我还没有答案的问题：发送的JSON有效负载是什么，是否需要配置其他功能

类似职位

Problem accessing /wd/hub/session. Reason:
Caused by: java.lang.NullPointerException **    at com.google.gson.JsonPrimitive.isPrimitiveOrString(JsonPrimitive.java:278)
at com.google.gson.JsonPrimitive.setValue(JsonPrimitive.java:101)
at com.google.gson.JsonPrimitive.<init>(JsonPrimitive.java:65)
at org.openqa.selenium.remote.server.ExceptionHandler.lambda$execute$0(ExceptionHandler.java:82)
at java.util.stream.ReferencePipeline$3$1.accept(Unknown Source)
at java.util.Spliterators$ArraySpliterator.forEachRemaining(Unknown Source)
at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source)
at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.util.stream.ReferencePipeline.collect(Unknown Source)