Debug:
I reported this error when I was a beginner of mybatis
Error building SqlSession.
Cause: org.apache.ibatis.builder.BuilderException: Error creating do
Caused by: org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 6; Processing instruction targets matching ‘[XX] [mm] [ll]’ are not allowed.
Finally, it is found that one line is left blank at the beginning of the SQL mapping file, but it is required that one line cannot be left blank. Just remove the blank line
This may occur when HDFS and yarn services are turned on, and when HDFS and yarn services are turned off using scripts, the
solution may also occur
Add the following parameters to the top of start-dfs.sh and stop-dfs.sh (in SBIN of Hadoop installation directory)
HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root
HDFS_SECONDARYNAMENODE_USER=root
Add the following parameters to the top of start-yarn.sh and stop-yarn.sh (in SBIN of Hadoop installation directory)
YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root
Successfully solved the problem
Select Manage Jenkins
Click global tool configuration to set the path of GIT
remarks:
To view the GIT path method, enter which git at the terminal
I wrote an executable jar package to execute on Linux, connected to Oracle 11g database and obtained database data. It was always the card owner. When it timed out, it ran out with an error message. The server could be restarted several times, and it was stuck later.
Execute jar package statement
/root/jdk1.8.0_ 181/bin/java -jar GetJdbc-1.0-SNAPSHOT.jar
java.sql.SQLRecoverableException: IO Error: Connection reset
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:421)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at com.iwhalecloud.jdbc.utils.GetDataSource.getConnection(GetDataSource.java:27)
at com.iwhalecloud.jdbc.execute.DistinguishDataSource.oracleQuery(DistinguishDataSource.java:78)
at com.iwhalecloud.jdbc.execute.DistinguishDataSource.dataHandle(DistinguishDataSource.java:34)
at com.iwhalecloud.jdbc.main.MainProgram.main(MainProgram.java:26)
Caused by: java.net.SocketException: Connection reset
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:115)
at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
at oracle.net.ns.DataPacket.send(DataPacket.java:199)
at oracle.net.ns.NetOutputStream.flush(NetOutputStream.java:211)
at oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:227)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:175)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:100)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:85)
at oracle.jdbc.driver.T4CSocketInputStreamWrapper.readNextPacket(T4CSocketInputStreamWrapper.java:122)
at oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:78)
at oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:1179)
at oracle.jdbc.driver.T4CMAREngine.unmarshalSB1(T4CMAREngine.java:1155)
at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:279)
at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:186)
at oracle.jdbc.driver.T4CTTIoauthenticate.doOAUTH(T4CTTIoauthenticate.java:366)
at oracle.jdbc.driver.T4CTTIoauthenticate.doOAUTH(T4CTTIoauthenticate.java:752)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:359)
... 10 more
close
Exception in thread "main" java.lang.NullPointerException
at com.iwhalecloud.jdbc.execute.DistinguishDataSource.oracleQuery(DistinguishDataSource.java:80)
at com.iwhalecloud.jdbc.execute.DistinguishDataSource.dataHandle(DistinguishDataSource.java:34)
at com.iwhalecloud.jdbc.main.MainProgram.main(MainProgram.java:26)Find an effective solution on the Internet and add a parameter – DJava. Security. EGD = file:/dev /../dev/urandom
The execution statement is as follows
/root/jdk1.8.0_ 181/bin/java -jar -Djava.security.egd=file:/dev/../dev/urandom GetJdbc-1.0-SNAPSHOT.jar
[problem description]: when starting the springboot project, the following stack error is reported
32.014 ERROR c.z.hikari.pool.HikariPool :594 restartedMain HikariPool-1 - Exception during pool initialization.
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:833)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:453)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198)
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138)
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:364)
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206)
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:476)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115)
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112)
at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:158)
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:116)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:330)
at org.springframework.boot.jdbc.EmbeddedDatabaseConnection.isEmbedded(EmbeddedDatabaseConnection.java:184)
at org.springframework.boot.jdbc.init.DataSourceScriptDatabaseInitializer.isEmbeddedDatabase(DataSourceScriptDatabaseInitializer.java:64)
at org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer.isEnabled(AbstractScriptDatabaseInitializer.java:87)
at org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer.initializeDatabase(AbstractScriptDatabaseInitializer.java:74)
at org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer.afterPropertiesSet(AbstractScriptDatabaseInitializer.java:65)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1845)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:338)
at com.abc.wiki.WikiApplication.main(WikiApplication.java:19)
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.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:89)
at com.mysql.cj.NativeSession.connect(NativeSession.java:144)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:953)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:823)
... 42 common frames omitted
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:63)
... 45 common frames omitted[cause of problem]: when debugging the project locally today, the WiFi connected to the computer changed, resulting in the change of IP, which finally led to this problem.
[solution]: modify the configuration of the project connection database to a new IP address.
Error reporting reason
Java compiler setting error in project structure or setting
resolvent
1. Project structure
Click f I l e → P R O j e c t s t r u c t u r e file \ rightarrow project structurefile → projectstructure
Ensure that the SDK versions under project are the same
2、Preferences
1. Problem phenomenon
The workbench that is normally used on weekdays finds that it cannot connect to the corresponding database after restarting the computer, and the workbench log displays
SSH tunnel]: Authentication error opening SSH tunnel: Authentication error, unhandled exception caught in tunnel manager, please refer to logs for details
Check the complete log and find the following:
$ tail -f ~/.mysql/workbench/log/wb.log
File "/usr/share/mysql-workbench/sshtunnel.py", line 303, in _connect_ssh
look_for_keys=has_key, allow_agent=has_key, timeout=SSH_CONNECTION_TIMEOUT)
File "/usr/lib/python2.7/dist-packages/paramiko/client.py", line 325, in connect
t.start_client()
File "/usr/lib/python2.7/dist-packages/paramiko/transport.py", line 492, in start_client
raise e
NotImplementedError: Use module Crypto.Signature.pkcs1_15 instead
14:17:14 [INF][ SSH tunnel]: TunnelManager.wait_connection authentication error: Authentication error, unhandled exception caught in tunnel manager, please refer to logs for details
14:17:14 [ERR][ SSH tunnel]: Authentication error opening SSH tunnel: Authentication error, unhandled exception caught in tunnel manager, please refer to logs for details
14:18:24 [INF][ WBContext]: Connection to XinJangCityWolMart cancelled by user: Tunnel connection cancelled
The point is
NotImplementedError: Use module Crypto.Signature.pkcs1_15 instead
Found after querying with PIP list
$ pip2 list | grep crypto
asn1crypto (1.4.0)
cryptography (2.7)
pycrypto (2.6.1)
pycryptodome (3.11.0)
There is a pycryptodome , which may be installed when installing other tools later
2. Solutions
Uninstall pycryptodome
sudo pip2 uninstall pycryptodome
Then reopen the workbench to connect to the database and return to normal.
import requests
url=['www....','www.....',...]
for i in range(0,len(url)):
linkhtml = requests.get(url[i])The crawler reported the following error:
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 247, in urlretrieve
with contextlib.closing(urlopen(url, data)) as fp:
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 222, in urlopen
return opener.open(url, data, timeout)
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 531, in open
response = meth(req, response)
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 640, in http_response
response = self.parent.error(
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 569, in error
return self._call_chain(*args)
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 502, in _call_chain
result = func(*args)
File "C:\Users\lenovo7\AppData\Local\Programs\Python\Python38\lib\urllib\request.py", line 649, in http_error_default
raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 404: Not FoundRefer to an article on stack overflow
Python: urllib.error.HTTPError: HTTP Error 404: Not Found – Stack Overflow
In the crawler scenario, the original link may not open. Naturally, it will prompt HTTP Error 404. What you need to do is skip this link and then crawl to the following page
Correction code
import requests
url=['www....','www.....',...]
for i in range(0,len(url)):
try:
linkhtml = requests.get(url[i])
except:
passProblem Description
Execute statementbin/sqoop import --connect jdbc:mysql://localhost:3306/gdcmxy --username root --password root --table 2019bigdata --fields-terminated-by '\t' --delete-target-dir --num-mappers 1 --hive-import --hive-database gdcmxy --hive-table 2019bigdata
Error: java.lang.RuntimeException: java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
After seeing the error report, it was preliminarily judged that the main problem was the database connection problem. At first, I thought the firewall was not turned off, but considering that hadoo had certainly turned off the firewall before, it should have nothing to do with the firewall.
Cluster environment:
Solution:
Change the localhost of the execution statement to the IP address of the local machine bin/sqoop import -- connect JDBC: mysql://192.168.112.81:3306/gdcmxy --Username root -- password root -- table 2019bigdata -- fields terminated by '\ t' -- delete target dir -- num mappers 1 -- hive import -- hive database gdcmxy -- hive table 2019bigdata
successfully imported
Article catalog
Error reporting screenshot reference: self inspection modification
Error reporting screenshot reference:
Self inspection
As soon as a new Eureka project was established, an error was reported. After checking the startup class and YML configuration file, it was found that the format of YML configuration file was wrong. The error is as follows:
Modification
There is an obvious indentation error in the screenshot, which makes Eureka unable to start normally. After modifying the indentation, it is as follows:
Screenshot of successful startup of Eureka server:
If the configuration file in YML format is prone to errors, we recommend that you use the configuration file in properties format; As follows:
The problem of ie11 is the biggest problem. At this time, you should check the most likely place of the problem step by step
I make this error because I use the following code when making type judgment:
toString. Call (svalue)==‘ [object date] ‘
such a writing method is not recognized in ie, and an unhandled promise rejection typeerror will be reported: the object does not support it, so it is necessary to change the writing method
Object.prototype.toString.call(sValue) !== ‘ [object date] ‘
this way of writing is recognized by ie
Problem phenomenon
$ sudo dnf update
EPOL
Errors during downloading metadata for repository 'EPOL':
-Status code: 404 for htpp://repo.openeuler.org/openEuler-21.09/EPOL/repomd.xml (IP: 159.138.**.***)
Error: Failed to download metadata for repo 'EPOL': Cannot download repodata/repomd.xml: All mirrors were tried
solve
Method 1.
the official has pushed the update. The updated file is located in
/etc/yum.repos.d/openeuler.repo.rpmnew ,
it needs to be manually compared and updated to the original
/etc/yum.repos.d/openeuler.repo
for the differences between the two files, see baseurl Path Method 2 in method 2 below.
directly manually modify the baseurl address of epol
baseurl= http://repo.openeuler.org/openEuler-21.09/EPOL/ $basearch/
is modified to
baseurl= http://repo.openeuler.org/openEuler-21.09/EPOL/main/ $basearch/