Continuous Error 404 in servlet operation [How to Solve]

When writing the project, the servlet has been unable to work normally. After consulting the data for many times, we found the following possibilities.

First, automatic editing is not turned on

In the top project option, check build automatically from the drop-down list

Second: the version of the top header in web.xml is too low

The author uses @ webservlet (urlpatterns =/xxservlet) mode, which does not need to configure servlet file in web.xml, but only version 3.0 or above supports this mode. Therefore, in web.xml, there must be version = 3.1.

You can directly copy the following code to use.

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <display-name>Project Name</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

Third: Tomcat configuration problems

Remove Tomcat from the server and install Tomcat again according to the process.

1. Delete Tomcat

2. Select preference in the top window option. In the pop-up box, select server — runtime environment — and select the original Tomcat — remove

3. Then click Add to configure the Tomcat you downloaded.

I hope eclipse will work properly.

‘webpack dev server’ is not an internal or external command, nor is it a runnable program or batch file. Solution: error in cnpm run dev:

‘webpack dev server’ is not an internal or external command, nor is it a runnable program or batch file. Solution
error report when executing cnpm run dev:

resolvent:

Now to use webpack you have to install both the package webpack-cli to be able to invoke the commands webpack and webpack-dev-server.
cnpm install webpack webpack-dev-server webpack-cli --save-dev

JMeter can’t open and save files [How to Solve]

The first time I found this problem was when I wrote the test data and was ready to execute it, I clicked save and found no response.
Then I restarted the software and found that not only saving but also opening did not work

2021-06-02 19:43:57,757 ERROR o.a.j.JMeter: Uncaught exception in thread Thread[AWT-EventQueue-0,6,main]
java.lang.IllegalAccessError: class com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge$DetailsTableModel (in unnamed module @0xf2f2cc1) cannot access class sun.awt.shell.ShellFolder (in module java.desktop) because module java.desktop does not export sun.awt.shell to unnamed module @0xf2f2cc1
at com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge$DetailsTableModel.updateColumnInfo(DarkFilePaneUIBridge.java:1128) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge$DetailsTableModel.<init>(DarkFilePaneUIBridge.java:1115) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge.getDetailsTableModel(DarkFilePaneUIBridge.java:576) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge$SortableListModel.<init>(DarkFilePaneUIBridge.java:1079) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFilePane.createList(DarkFilePane.java:137) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFileChooserUIBridge.createList(DarkFileChooserUIBridge.java:585) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFileChooserUIBridge$MetalFileChooserUIAccessor.createList(DarkFileChooserUIBridge.java:750) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge.setViewType(DarkFilePaneUIBridge.java:376) ~[darklaf-core-2.5.4.jar:2.5.4]
at com.github.weisj.darklaf.ui.filechooser.DarkFilePaneUIBridge.propertyChange(DarkFilePaneUIBridge.java:890) ~[darklaf-core-2.5.4.jar:2.5.4]
at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:342) ~[?:?]
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:334) ~[?:?]
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:267) ~[?:?]
at java.awt.Component.f

Solution: just change a theme …. Is it very joyful
It is very helpless, but the truth is this

Vue require Error: node_modules/babel-loader/lib

vue require reports node_modules/babel-loader/lib error
This error is reported in the vue project.
…/…/assets/images/11.png in ./node_modules/cache-loader/dist/cjs.js??ref–12-0!./node_modules/babel-loader/lib!./node_modules/cache-loader/dist/cjs.js??ref–0-0!./node_modules/vue-loader/lib??vue-loader-options!./src/components/HouseManage/EmergencyPlan.vue?vue&type=script&lang=js&
Most of them are due to problems with the path of the file.
A good check can check out

CUDA error: CUBLAS_STATUS_NOT_INITIALIZED when calling `cublasCreate(handle)`

RuntimeError: [enforce fail at …\c10\core\CPUAllocator.cpp:75] data. DefaultCPUAllocator: not enough memory: you tried to allocate 50331648 bytes. Buy new RAM!
pytorch:RuntimeError: CUDA error: CUBLAS_STATUS_ALLOC_FAILED when calling cublasCreate(handle)
The batchsize is too big, not enough memory, changed from 64 to 8, the device is too bad.

[solution] warning: this statement may fall through [- wimplicit fallthrough]) encountered during GCC compilation

When practicing the switch statement in Ubuntu, if break is not added in the case statement, the warning message will pop up, causing the program to fail to compile,

root@root:~/code$ g++ -Wall -W test_switch.c -o test_switch 
test_switch.c: In function ‘int main()’:
test_switch.c:13:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
   13 |    printf("1\n");
      |    ~~~~~~^~~~~~~~~~~~~
test_switch.c:15:3: note: here
   15 |   case 3:
      |   ^~~~
test_switch.c:16:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
   16 |    printf("3\n");
      |    ~~~~~~^~~~~~~~~~~~~
test_switch.c:18:3: note: here
   18 |   case 5:
      |   ^~~~

At this time, adding – W when compiling the code can shield the alarm, and the code can be compiled normally

root@root:~/code$ g++ -Wall -W test_switch.c -o test_switch -w

[Solved] Mybatis:Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance.

Error note – M ybatis:Cause : org.apache.ibatis.builder.BuilderException: Error creating document instance.

Project scenario: Problem Description: Cause Analysis: solution:

Project scenario:

prompt: when testing mybatis project, an error is reported: cause: org.apache.ibatis.builder.builderexception: error creating document instance. Cause: com.sun.org.apache.xerces.internal.impl.io.malformedbytesequenceexception: byte 2 of 2-byte UTF-8 sequence is invalid</ font>

Problem Description:

when running mybatis project, the following error will be reported: </ font>

org.apache.ibatis.exceptions.PersistenceException: 
### Error building SqlSession.
### Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: 2 字节的 UTF-8 序列的字节 2 无效。

	at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:64)
	at MyTest.test(MyTest.java:22)
	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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)
Caused by: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: 2 字节的 UTF-8 序列的字节 2 无效。
	at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:263)
	at org.apache.ibatis.parsing.XPathParser.<init>(XPathParser.java:127)
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.<init>(XMLConfigBuilder.java:81)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:77)
	... 24 more

Cause analysis:

analysis: the main reason for this problem is that the code declared in the XML file is inconsistent with the code saved in the XML file itself
for example, your statement is & lt;?xml version=”1.0″ encoding=”UTF-8″?& gt;<However, it is encoded in ANSI format. Although there is no garbled code, the XML parser cannot parse it
the solution is to reset the consistency between the encoding and declaration when saving XML files</ font>

Solution:

Configure in pom.xml file

	<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

[Solved] Django.core.exceptions.ImproperlyConfigured: SQLite 3.9.0 or later is required (found 3.7.17).

CentOS comes with 3.7.17 Django, which is not supported. It must be above 3.9.0. If you want to use SQLite3 as a database, there is no way to upgrade it. If it is me, I will not use SQLite3, but use mysql

The upgrade is simple:

1. Download the latest package of SQLite3

https://www.sqlite.org/download.html

wget https://www.sqlite.org/2021/sqlite-autoconf-3350500.tar.gz

2. Compile and install

tar xf https://www.sqlite.org/2021/sqlite-autoconf-3350500.tar.gz
cd sqlite-autoconf-3350500
./configure --prefix=/usr/local/ && make && make install

3. Change the original SQLite3 command

First check which directory SQLite3 has executable files in

(python36) [root@george servermonitor]# whereis sqlite3
 sqlite3: /usr/bin/sqlite3 /usr/local/bin/sqlite3 /usr/include/sqlite3.h /usr/share/man/man1/sqlite3.1.gz (python36) [root@george servermonitor]#

It is found that/usr/bin/SQLite3 is old, 3.7.17. If you are not sure, just execute it

/usr/bin/sqlite3 –verssion

Then replace the old version

mv /usr/bin/sqlite3 /usr/bin/sqlite3_3.7.17
 ln -s /usr/local/bin/sqlite3 /usr/bin/sqlite3

4. Change the library path

Many small partners went to the above and tested it. They found that the same error was still reported when executing Python manage.py runserver 8080. The reason is that Django read the old library, and you can verify it yourself

(python36) [root@george servermonitor]# python 
Python 3.6.8 (default, Nov 16 2020, 16:55:22) [GCC 4.8.5 20150623 
(Red Hat 4.8.5-44)] on linux Type "help", "copyright", "credits" or "license" for more information.
 >>> import sqlite3
 > >>> sqlite3.sqlite_version 
 > '3.7.17'      
>>> .exit

Modifying library variables

export LD_LIBRARY_PATH="/usr/local/lib/"

Retest

(python36) [root@george servermonitor]# python Python 3.6.8
 (default, Nov 16 2020, 16:55:22) [GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux Type "help", "copyright", "credits" or "license" for more information.
  >>> import sqlite3
  > >>> sqlite3.sqlite_version
  '3.35.5'          
  >>> exit()

Execution returned to normal

(python36) [root@george servermonitor]# python manage.py runserver 8080
 Django version 3.2.4, using settings 'servermonitor.settings' Starting development server at
http://127.0.0.1:8080/ Quit the server with CONTROL-C.

[Solved] CUDA fails to compile in visual studio and throws error msb3721 and nvcc fatal

Platform: VS2013+CUDA 8.0
Executing “Compile” will pass, but “Executing “Recompile” or “Clean” will report an error.

nvcc fatal : Could not set up the environment for Microsoft Visual Studio using ‘C:/Program Files (x86)/Microsoft Visual Studio 12.0/VC/bin/x86_amd64/…/…/…/VC/bin/amd64/vcvars64.bat’
error MSB3721: 命令““C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\bin\nvcc.exe” -ccbin “C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\x86_amd64” -I”C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\include” -I”C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\include” –keep-dir x64\Release -maxrregcount=0 –machine 64 –compile -DWIN32 -DNDEBUG -D_CONSOLE -D_LIB -D_UNICODE -DUNICODE -Xcompiler “/EHsc /W3 /nologo /O2 /FS /Zi /MD ” -clean”已退出，返回代码为 1。

Guess the reason may be the computer installed at the same time vs2017, vs2019, cuda 10.1 multiple versions caused by the previous only vs2013 and cuda 8.0 when there is no problem
Solution.
Find vcvars64.bat under C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\amd64 and modify this sentence inside.

@if not “%WindowsSDK_ExecutablePath_x64%” == “” (
@set “PATH=%WindowsSDK_ExecutablePath_x64%;%PATH%”
)

to

@if not “%WindowsSDK_ExecutablePath_x64%” == “” (
@set “PATH=!WindowsSDK_ExecutablePath_x64!;!PATH!”
)