Object Storage Service:ContentMD5 Object Storage Service (OSS) using JAVA SDK prompts "log4j" error

Problem description

The following error message appears when you use ContentMD5 of the JAVA SDK.

log4j:WARN No appenders could be found for logger (org.apache.http.impl.conn.PoolingHttpClientConnectionManager). 
log4j:WARN Please initialize the log4j system properly. 
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.: 

Solutions

1. log4j is an Apache service. You can create a log4j.properties file under the src folder of the project. The content is as follows:

   # Configure logging for testing: optionally with log file
   log4j.rootLogger=WARN, stdout
   # log4j.rootLogger=WARN, stdout, logfile
   
   log4j.appender.stdout=org.apache.log4j.ConsoleAppender
   log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
   log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n
   
   log4j.appender.logfile=org.apache.log4j.FileAppender
   log4j.appender.logfile.File=target/spring.log
   log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
   log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n
   
   ===============================

2. After adding this configuration file, running the program again will not cause an error message.

Applicable scope

• Object Storage Service (OSS)