Author Archives: Robins

[Solved] VirtualBox + Vagrant Error: VirtualBox host only Ethernet adapter

VirtualBox and vagrant are installed in the win10 system, but the virtual machine cannot be started when it is started later. The error code “VirtualBox host only Ethernet adapter” appears

Solution:

In the control panel = => network and Internet = => network and sharing center = => change adapter settings = => there is a VirtualBox host only Ethernet adapter inside. After finding it, disable it first, and then right-click the properties to find the VirtualBox ndis6 bridged networking driver, uncheck it, highlight it, enable it again, check it, and then exit.

[Solved] Maven executes servlet error: HTTP Status 500

An error is reported when the servlet executes and the dependency range is not written

Solution:

add the following code to pom.xml, mainly the dependency range provided

<dependencies>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

Tinyint error: java.lang.NullPointerException… [How to Solve]

Tinyint error reporting record
I wrote the wrong set before, which is easy to use when it is written as setid, and then I changed it to setType to report an error, and then I transformed it down to byte. After the change, it will be null pointer. Below are the error reporting information and error reporting line position




Finally, change the position as follows. Change the type from integer to string to solve the problem
the specific principle is not clear. For the time being, record it first. A great God who knows the principle can leave a message. Thank you

[Solved] Jxls error: Cannot load XLS transformer. Please make sure a Transformer implementation is in classpath

Note the problems encountered in using Jxls in the project

Cannot load XLS transformer. Please make sure a Transformer implementation is in classpath

Check whether components such as easyexcel are introduced into the project
if so, it needs to be excluded

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>easyexcel</artifactId>
      <version>2.2.10</version>
      <exclusions>
        <exclusion>
          <artifactId>poi</artifactId>
          <groupId>org.apache.poi</groupId>
        </exclusion>
        <exclusion>
          <artifactId>poi-ooxml</artifactId>
          <groupId>org.apache.poi</groupId>
        </exclusion>
        <exclusion>
          <artifactId>poi-ooxml-schemas</artifactId>
          <groupId>org.apache.poi</groupId>
        </exclusion>
      </exclusions>
    </dependency>

Then
the POI component 4 version is introduced

    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi</artifactId>
      <version>4.1.2</version>
    </dependency>
    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml</artifactId>
      <version>4.1.2</version>
    </dependency>
    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml-schemas</artifactId>
      <version>4.1.2</version>
    </dependency>

Because the project is iterative, complex excel is exported. Easyexcel can not meet the requirements. You can consider processing complex logic in the form of Jxls template.
it can solve the function of Excel processing by block, horizontal and column
official website: http://jxls.sourceforge.net/

In theory, it is not recommended to use several excel components at the same time. The idea plug-in Maven helper is recommended here to facilitate conflict handling.

When a problem is inexplicable and can not be solved by how to change it, see if there is a package conflict and if there is a problem with the network itself.

[Solved] java.lang.reflect.InaccessibleObjectException: Unable to make protected java.net.http.HttpRequest()…

Error message:

Page:

Back end:

java.lang.reflect.InaccessibleObjectException: Unable to make protected java.net.http.HttpRequest() accessible: module java.net.http does not "opens java.net.http" to unnamed module @621f89b8

Solution:

Change the parameters passed in the controller:   HttpRequest   ——》  HttpServletRequest

[Solved] Vue package error: Syntax Error: Error: Cannot find module ‘mozjpeg’ 

Syntax Error: Error: Cannot find module 'mozjpeg'

The main reason is that some dependencies of image webpack loader are not installed successfully, which makes the processing of pictures report errors

Attempting to install dependencies:

npm install mozjpeg

report errors:

connect ECONNREFUSED 0.0.0.0:443
mozjpeg pre-build test failed

You can solve this problem by modifying hosts.

Modify hosts for MAC system

https://github.com/googlehosts/hosts
Go to this website to download files
open the terminal, enter open/etc
and paste the hosts into the etc folder to replace the original hosts file.

The reinstallation was successful and the packaging was successful.

[Solved] Android gradle Error: gradle project sync failed. Please fix your project and try again

Another error was reported during Android development. This is a version error. The first step is to synchronize the versions
error message:
Android studio error: gradle project sync failed. Please fix your project and try again

1. Version synchronization:

1.1 file> sync project with android gradle

If you succeed, you don’t have to look at the following

1.2 error reporting:

It can be seen or not solved:

It should be the version problem. If we can’t download it, we can download it directly manually (check the network first, and the agent has no problem, but it still can’t be solved)

2. Modify proxy parameters:

Agent:

2.1 open file> setting> Search proxy

2.2 configuration information

The address and port of the agent shall be filled in as follows:

URL: http://127.0.0.1:1080/pac

2.3 check whether the Ping is connected

    1. use check connection

      1. enter a website to test: www.baidu.com, and then test: </ OL>

Still not!

3. Manual Download

So let’s continue:

3.1 open the gradle wrapper properties file

3.2 download

Download the gradle in the last line of the website. Note that the version must be consistent. Download whatever he puts down.

3.3 modifying environment variables

Remember to modify the gradle environment variable in the computer:

        1. system environment variable:

          1. path:

3.4 modify the compilation environment configuration

Then unzip it, modify the gradle configuration in the environment, and it’s OK.

You can see that my environment is OK now:

Appium Top 10 Common Error [How to Solve]

(1) Appium service is not started

[error message] urllib.error.urlerror: & lt; Urlopen error [winerror 10061] unable to connect because the target computer actively refused.

[solution] after clicking the start appium button, the [appium] welcome to appium v1.7.2 prompt appears, and then run the script

(2) Session conflict

Error: failed to start an appium session, err was: error: requested a new session but one was in progress

[solution] restart the appium service, start the appium service, check the allow session override option in the advanced interface, restart the appium test, and add driver. Quit() in afterclass at the end of the test

(3) Device not connected

[error message] selenium. Common. Exceptions. Webdriverexception: Message: an unknown server side error occurred while processing the command. Original error: could not find a connected Android device

[solution] ADB ensure that the device is connected

(4) Java not installed or version problem

[error message] selenium.common.exceptions.webdriverexception: Message: a new session could not be created. (original error: ‘Java – version’ failed. Error: command failed: C: \ windows \ system32 \ cmd.exe/S/C “Java – version”“

[solution] check Java environment variables

(5) The launchable activity value is written incorrectly

[error message] activity used to start app doesn’t exist or cannot be launched! Make sure it exists and is a launching activity

[solution]  correct the misspelling of launch activity.

(6) System permission problem

[error message] failure [install_failed_user_restricted])

[solution] 1. USB installation management permission limit. Just close it. 2. Turn on the option to allow unknown source app installation

(7) Appium service exception

[error message] an unknown server side error occurred while processing the command “while opening the app

[solution] restart appium service

(8) JRE environmental issues

[error message] are you sure you have installed JDK/JRE?

[solution] check whether there is JRE in the same level directory of JDK, and check the environment variable configuration of JDK

(9) Android SDK environment

[error message] no such file or directory “E: \ android_sdk”

[solution] check the environment variable configuration of Android SDK, especially android_home

(10) Uiautomator error

[error message] uiautomator version is too low/high

[solution] add “automationname”: “uiautomator2” to the capability configuration information

[Solved] Flink1.12 integrate Hadoop 3.X error: java.lang.RuntimeException…

Flink1.12 integration Hadoop 3. X error reporting

Due to the needs of the project, it is necessary to carry out rule early warning for a period of time, so first install the Flink cluster and Hadoop on the alicloud server of the project, but when running the official website example, an error is directly reported. The specific information is as follows:

Caused by: java.lang.RuntimeException: org.apache.flink.runtime.client.JobInitializationException: Could not instantiate JobManager.
	at org.apache.flink.util.ExceptionUtils.rethrow(ExceptionUtils.java:309)
	at org.apache.flink.util.function.FunctionUtils.lambda$uncheckedFunction$2(FunctionUtils.java:76)
	at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:616)
	at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:591)
	at java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:457)
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1067)
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1703)
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:172)
Caused by: org.apache.flink.runtime.client.JobInitializationException: Could not instantiate JobManager.
	at org.apache.flink.runtime.dispatcher.Dispatcher.lambda$createJobManagerRunner$5(Dispatcher.java:463)
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1604)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.flink.util.FlinkRuntimeException: Failed to create checkpoint storage at checkpoint coordinator side.
	at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.<init>(CheckpointCoordinator.java:316)
	at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.<init>(CheckpointCoordinator.java:231)
	at org.apache.flink.runtime.executiongraph.ExecutionGraph.enableCheckpointing(ExecutionGraph.java:495)
	at org.apache.flink.runtime.executiongraph.ExecutionGraphBuilder.buildGraph(ExecutionGraphBuilder.java:347)
	at org.apache.flink.runtime.scheduler.SchedulerBase.createExecutionGraph(SchedulerBase.java:291)
	at org.apache.flink.runtime.scheduler.SchedulerBase.createAndRestoreExecutionGraph(SchedulerBase.java:256)
	at org.apache.flink.runtime.scheduler.SchedulerBase.<init>(SchedulerBase.java:238)
	at org.apache.flink.runtime.scheduler.DefaultScheduler.<init>(DefaultScheduler.java:134)
	at org.apache.flink.runtime.scheduler.DefaultSchedulerFactory.createInstance(DefaultSchedulerFactory.java:108)
	at org.apache.flink.runtime.jobmaster.JobMaster.createScheduler(JobMaster.java:323)
	at org.apache.flink.runtime.jobmaster.JobMaster.<init>(JobMaster.java:310)
	at org.apache.flink.runtime.jobmaster.factories.DefaultJobMasterServiceFactory.createJobMasterService(DefaultJobMasterServiceFactory.java:96)
	at org.apache.flink.runtime.jobmaster.factories.DefaultJobMasterServiceFactory.createJobMasterService(DefaultJobMasterServiceFactory.java:41)
	at org.apache.flink.runtime.jobmaster.JobManagerRunnerImpl.<init>(JobManagerRunnerImpl.java:141)
	at org.apache.flink.runtime.dispatcher.DefaultJobManagerRunnerFactory.createJobManagerRunner(DefaultJobManagerRunnerFactory.java:80)
	at org.apache.flink.runtime.dispatcher.Dispatcher.lambda$createJobManagerRunner$5(Dispatcher.java:450)
	... 4 more
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Could not find a file system implementation for scheme 'hdfs'. The scheme is not directly supported by Flink and no Hadoop file system to support this scheme could be loaded. For a full list of supported file systems, please see https://ci.apache.org/projects/flink/flink-docs-stable/ops/filesystems/.
	at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:491)
	at org.apache.flink.core.fs.FileSystem.get(FileSystem.java:389)
	at org.apache.flink.core.fs.Path.getFileSystem(Path.java:292)
	at org.apache.flink.runtime.state.filesystem.FsCheckpointStorageAccess.<init>(FsCheckpointStorageAccess.java:64)
	at org.apache.flink.runtime.state.filesystem.FsStateBackend.createCheckpointStorage(FsStateBackend.java:501)
	at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.<init>(CheckpointCoordinator.java:313)
	... 19 more
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Hadoop is not in the classpath/dependencies.
	at org.apache.flink.core.fs.UnsupportedSchemeFactory.create(UnsupportedSchemeFactory.java:58)
	at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:487)
	... 24 more

Only later did Baidu find that it needed a jar package to bridge Flink and HDFS, so it put the two jar packages into the Lib of Flink.

Then, when starting, an error will still be reported, and the information is as follows:

[root@k8s-master flink-1.12.0]# bin/flink run  examples/batch/WordCount.jar --input hdfs://k8s-master:9000/test/word.txt --output hdfs://k8s-master:9000/test/result.txt  --parallelism 2
Job has been submitted with JobID 058a2b79197c7cdb1dd04269fcc2a0b6

------------------------------------------------------------
 The program finished with the following exception:

org.apache.flink.client.program.ProgramInvocationException: The main method caused an error: org.apache.flink.client.program.ProgramInvocationException: Job failed (JobID: 058a2b79197c7cdb1dd04269fcc2a0b6)
        at org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:330)
        at org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:198)
        at org.apache.flink.client.ClientUtils.executeProgram(ClientUtils.java:114)
        at org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:743)
        at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:242)
        at org.apache.flink.client.cli.CliFrontend.parseAndRun(CliFrontend.java:971)
        at org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:1047)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1876)
        at org.apache.flink.runtime.security.contexts.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41)
        at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:1047)
Caused by: java.util.concurrent.ExecutionException: org.apache.flink.client.program.ProgramInvocationException: Job failed (JobID: 058a2b79197c7cdb1dd04269fcc2a0b6)
        at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
        at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1908)
        at org.apache.flink.client.program.ContextEnvironment.getJobExecutionResult(ContextEnvironment.java:112)
        at org.apache.flink.client.program.ContextEnvironment.execute(ContextEnvironment.java:76)
        at org.apache.flink.examples.java.wordcount.WordCount.main(WordCount.java:93)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:316)
        ... 11 more
Caused by: org.apache.flink.client.program.ProgramInvocationException: Job failed (JobID: 058a2b79197c7cdb1dd04269fcc2a0b6)
        at org.apache.flink.client.deployment.ClusterClientJobClientAdapter.lambda$null$6(ClusterClientJobClientAdapter.java:119)
        at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:616)
        at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:591)
        at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
        at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
        at org.apache.flink.client.program.rest.RestClusterClient.lambda$pollResourceAsync$22(RestClusterClient.java:602)
        at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
        at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
        at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
        at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
        at org.apache.flink.runtime.concurrent.FutureUtils.lambda$retryOperationWithDelay$9(FutureUtils.java:379)
        at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
        at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
        at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
        at java.util.concurrent.CompletableFuture.postFire(CompletableFuture.java:575)
        at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:943)
        at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:456)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.flink.runtime.client.JobExecutionException: Job execution failed.
        at org.apache.flink.runtime.jobmaster.JobResult.toJobExecutionResult(JobResult.java:147)
        at org.apache.flink.client.deployment.ClusterClientJobClientAdapter.lambda$null$6(ClusterClientJobClientAdapter.java:117)
        ... 19 more
Caused by: org.apache.flink.runtime.JobException: Recovery is suppressed by NoRestartBackoffTimeStrategy
        at org.apache.flink.runtime.executiongraph.failover.flip1.ExecutionFailureHandler.handleFailure(ExecutionFailureHandler.java:116)
        at org.apache.flink.runtime.executiongraph.failover.flip1.ExecutionFailureHandler.getFailureHandlingResult(ExecutionFailureHandler.java:78)
        at org.apache.flink.runtime.scheduler.DefaultScheduler.handleTaskFailure(DefaultScheduler.java:224)
        at org.apache.flink.runtime.scheduler.DefaultScheduler.maybeHandleTaskFailure(DefaultScheduler.java:217)
        at org.apache.flink.runtime.scheduler.DefaultScheduler.updateTaskExecutionStateInternal(DefaultScheduler.java:208)
        at org.apache.flink.runtime.scheduler.SchedulerBase.updateTaskExecutionState(SchedulerBase.java:610)
        at org.apache.flink.runtime.scheduler.SchedulerNG.updateTaskExecutionState(SchedulerNG.java:89)
        at org.apache.flink.runtime.jobmaster.JobMaster.updateTaskExecutionState(JobMaster.java:419)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcInvocation(AkkaRpcActor.java:286)
        at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcMessage(AkkaRpcActor.java:201)
        at org.apache.flink.runtime.rpc.akka.FencedAkkaRpcActor.handleRpcMessage(FencedAkkaRpcActor.java:74)
        at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleMessage(AkkaRpcActor.java:154)
        at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26)
        at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21)
        at scala.PartialFunction.applyOrElse(PartialFunction.scala:123)
        at scala.PartialFunction.applyOrElse$(PartialFunction.scala:122)
        at akka.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:21)
        at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171)
        at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:172)
        at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:172)
        at akka.actor.Actor.aroundReceive(Actor.scala:517)
        at akka.actor.Actor.aroundReceive$(Actor.scala:515)
        at akka.actor.AbstractActor.aroundReceive(AbstractActor.scala:225)
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:592)
        at akka.actor.ActorCell.invoke(ActorCell.scala:561)
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258)
        at akka.dispatch.Mailbox.run(Mailbox.scala:225)
        at akka.dispatch.Mailbox.exec(Mailbox.scala:235)
        at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
        at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
        at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Could not find a file system implementation for scheme 'hdfs'. The scheme is not directly supported by Flink and no Hadoop file system to support this scheme could be loaded. For a full list of supported file systems, please see https://ci.apache.org/projects/flink/flink-docs-stable/ops/filesystems/.
        at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:491)
        at org.apache.flink.core.fs.FileSystem.get(FileSystem.java:389)
        at org.apache.flink.core.fs.Path.getFileSystem(Path.java:292)
        at org.apache.flink.api.common.io.FileOutputFormat.open(FileOutputFormat.java:218)
        at org.apache.flink.api.java.io.CsvOutputFormat.open(CsvOutputFormat.java:161)
        at org.apache.flink.runtime.operators.DataSinkTask.invoke(DataSinkTask.java:209)
        at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:722)
        at org.apache.flink.runtime.taskmanager.Task.run(Task.java:547)
        at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Hadoop is not in the classpath/dependencies.
        at org.apache.flink.core.fs.UnsupportedSchemeFactory.create(UnsupportedSchemeFactory.java:58)
        at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:487)
        ... 8 more

Since I install the Flink cluster here, I can package the two jars in SCP to the other two nodes and they can run normally.

[Solved] ESLint error: Newline required at end of file but not found (eol-last)

When verifying Vue projects with eslint, the following warnings were found:

error: Newline required at end of file but not found (eol-last)

The results are as follows:

I found that the online solution is to insert a blank line after the warning code. I think this is very bad.

[solution]
1. Insert a configuration file .Editorconfig , in the project_final_Newline = true is changed to false

2. Cancel the verification of the last rule in . Eslintrc. JS

recompile without warning.