Category Archives: How to Fix

Error: could not create the Java virtual machine. Error: a fatal exception has occurred

Error message:
java hotspot ™ 64-Bit Server VM warning: ignoring option PermSize=128M; support was removed in 8.0
Java HotSpot ™ 64-Bit Server VM warning: ignoring option MaxPermSize=256M; support was removed in 8.0
MaxTenuringThreshold of 31 is invalid; must be between 0 and 15
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.**

The reason for the above error is that the memory allocated to the Java virtual machine (JVM) is larger than the available memory of the system, and there is not enough memory space allocated to the JVM to create objects

Go to/opt/avcon/Tomcat/bin in the Tomcat bin directory. There is a catalina.sh File
modify the value as small as possible

Modify save restart!

Error starting ApplicationContext. To display the conditions report re run

When we create a springboot project, it pom.xml This place in is like this: as shown in the figure

 

If there is no comment point in the red box, an error will be reported as soon as the project is run, as shown in the following picture:

There is also a warning as shown in the figure below:

After some time, baidu also did not find a similar error situation, do not know how to solve.

Only will pom.xml Note out this in, as shown in the figure below:

Then click Import changes. After compiling, it will run normally.

Solution to error 2002 (HY000) in MySQL login startup

Error information

Login database error:`

ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/lib/mysql/ mysql.sock ‘ (2 “No such file or directory”)`

Service restart error: job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service " and "journalctl -xe" for details.

View service status information: ` systemctl status mariadb.service

● mariadb.service – MariaDB 10.1 database server
Loaded: loaded (/usr/lib/systemd/system/ mariadb.service ; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Mon 2019-04-15 17:16:38 UTC; 4s ago
Process: 2864 ExecStartPre=/usr/libexec/mysql-prepare-db-dir %n (code=exited, status=1/FAILURE)
Process: 2841 ExecStartPre=/usr/libexec/mysql-check-socket (code=exited, status=0/SUCCESS)

Apr 15 17:16:37 xiandian systemd[1]: Starting MariaDB 10.1 database server…
Apr 15 17:16:38 xiandian mysql-prepare-db-dir[2864]: Database MariaDB is not initialized, but the directory /var/lib/mysql is not empty…e done.
Apr 15 17:16:38 xiandian mysql-prepare-db-dir[2864]: Make sure the /var/lib/mysql is empty before running mysql-prepare-db-dir.
Apr 15 17:16:38 xiandian systemd[1]: mariadb.service : control process exited, code=exited status=1
Apr 15 17:16:38 xiandian systemd[1]: Failed to start MariaDB 10.1 database server.
Apr 15 17:16:38 xiandian systemd[1]: Unit mariadb.service entered failed state.
Apr 15 17:16:38 xiandian systemd[1]: mariadb.service failed.
Hint: Some lines were ellipsized, use -l to show in full.`

The error message of restart service log: ` APR 15 17:16:21 Xiandian MySQL prepare DB dir: database MariaDB is not initialized, but the directory/var/lib/MySQL is not empty, so initialization cannot be done

Apr 15 17:16:21 mysql-prepare-db-dir: Make sure the /var/lib/mysql is empty before running mysql-prepare-db-dir.
Apr 15 17:16:21 systemd: mariadb.service : control process exited, code=exited status=1
Apr 15 17:16:21 systemd: Failed to start MariaDB 10.1 database server.
Apr 15 17:16:21 systemd: Unit mariadb.service entered failed state.
Apr 15 17:16:21 systemd: mariadb.service failed.`

You can see that the error message indicates that the database is not initialized, but/var/lib/MySQL is not empty, so it cannot be initialized.

Take a look at the directory permissions

 ll /var/lib/
 d---------. 11 mysql      mysql      4096 May  4  2018 mysql

The MySQL permission is 0, which causes the startup file sock file cannot be written in
Restart, give the directory permission 755
Chmod 755/var/lib/MySQL/
and then restart the MySQL service
systemctl restart mariadb.service
PS - e | grep - I MySQL
3191?00:00:02 mysqld
starts normally

Reproduced in: https://blog.51cto.com/9103824/2378808

Error creating Django application: error on Python side.Exit code:1.

Due to the need of work, I recently learned Django based web program, but in the actual development, I also encountered a series of problems:
New Django project based on pychar compiler, and the following errors appeared:

the solution given:
1. Django 1.11 above does not seem to support Python 2.7, change to Django 1.10 version
1 2. It’s better to set up the project directory of Django in Chinese
3. It’s better to re install Django in the same directory as Python
PS: it’s just a problem you encounter in your study. You are welcome to give us some advice

Error: [1] bootstrap checks failed…

Referring to other blogs, it is verified to be completely correct

ERROR: [1] bootstrap checks failed
[1]: the default discovery settings are unsuitable for production use; at least one of [ discovery.seed_ hosts, discovery.seed_ providers, cluster.initial_ master_ Nodes] must be configured
this is due to elasticsearch.yml The following parameters are set in

The solution: to elasticsearch.yml In# cluster.initial_ master_ Nodes: [“node-1”, “node-2”] comment is removed, and “node-2” is removed. Restart

Note: modified in Notepad + + elasticsearch.yml To save in UTF-8 format.

Solution to error 2002 (HY000) in MySQL

ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/lib/mysql/ mysql.sock ‘ (111)

Troubleshooting:

1. Start the service: Service mysqld status
2. Open the port: lsof – I: 3306
3. Determine the correct location of the “socket” file: lsof – C mysqld | grep socket $
find/- name “*. Socket”

Idea community version starts Tomcat to report error running ‘XXXXXX’: java.lang.NullPointerException

catalog

 

1、 Idea version

2、 Error information

3、 Solutions

1、 Idea version

2、 Error information

Error running ‘XXXXXX’: java.lang.NullPointerException

3、 Solutions

Modify the port number of Tomcat and restart Tomcat

 

I don’t know why it’s OK to change the port. Port is not occupied, online check again, no result, is worried about how to solve the time, changed the next port on the line.

 

Error code 1045, state 28000, Java sql.SQLException :Access denied for user ‘root’@’localhost’

Using druid to connect to MySQL and report errors: errorcode 1045, state 28000, Java sql.SQLException :Access denied for user ‘root’@’localhost’ using password:yes

At first, we checked the account password or permissions. However, we found that all the configurations were correct. As a result, we found that db.properties There are a few more spaces in the user and password , for a long time, take warning, later configuration must pay attention to the space

Error creating bean with name ‘xxcontroller’

Today, when we learn to integrate SSM projects to test whether the framework is available, we will report the above error as soon as we run Maven’s Tomcat,

At the beginning, I thought it was because the service layer annotation was not well written. After checking, I found that there was no error. Finally, in the web.xml It is found that the following param value is wrongly written in the file, and the application in ApplicationContext – *. XML is missing an n.

≪! — load the spring container — & gt;
& lt; context param & gt;
& lt; param name & gt; contextconfiglocation & lt; & param name & gt;
& lt; param value & gt; classpath:spring/applicationContext- *.xml</param-value>
  </context-param>

And less in the transaction aspect

< aop:config>
< aop:advisor advice-ref= “txAdvice”
pointcut=”execution(* cn.itcast .e3 mall.service ..*.*(..))” />
</ aop:config>

Spent a lot of time, finally solved, hope to help you!