log4j

Redirect System.out and System.err to slf4j

由 六眼飞鱼酱① 提交于 2019-12-17 06:39:38
问题 I needed to redirect System.out/err.println outputs to slf4j. I know that this is not the way to do logging properly but there is an external library, which logs to System.out 回答1: You can use sysout-over-slf4j. The sysout-over-slf4j module allows a user to redirect all calls to System.out and System.err to an SLF4J defined logger with the name of the fully qualified class in which the System.out.println (or similar) call was made, at configurable levels. If you are not using Maven, download

How to configure log4j with a properties file

由 独自空忆成欢 提交于 2019-12-17 06:36:41
问题 How do I get log4j to pick up a properties file. I'm writing a Java desktop app which I want to use log4j. In my main method if have this: PropertyConfigurator.configure("log4j.properties"); The log4j.properties file sits in the same directory when I open the Jar. Yet I get this error: log4j:ERROR Could not read configuration file [log4j.properties]. java.io.FileNotFoundException: log4j.properties (The system cannot find the file specified) What am I doing wrong? 回答1: I believe that the

Conditional logging with log4j

由 微笑、不失礼 提交于 2019-12-17 06:36:12
问题 The web application on which I am working occasionally develops data integrity issues for some of the users. I'd like to turn on trace level logging, but since we are dealing with 100s of requests per second trace logging every single request is out of the question. Is there a way with log4j to be able to log conditionally? In other words, I would like to be able to get trace logs only when specific users make a request. Since I don't know beforehand which users will be affected, I cannot

Conditional logging with log4j

由 断了今生、忘了曾经 提交于 2019-12-17 06:36:11
问题 The web application on which I am working occasionally develops data integrity issues for some of the users. I'd like to turn on trace level logging, but since we are dealing with 100s of requests per second trace logging every single request is out of the question. Is there a way with log4j to be able to log conditionally? In other words, I would like to be able to get trace logs only when specific users make a request. Since I don't know beforehand which users will be affected, I cannot

Should new projects use logback instead of log4j? [closed]

由 こ雲淡風輕ζ 提交于 2019-12-17 06:25:22
问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 6 years ago . Should new projects use logback instead of log4j as a logging framework ? Or with other words :'Is logback better than log4j (leaving

How to customize log4j2 RollingFileAppender?

由 拟墨画扇 提交于 2019-12-17 06:16:32
问题 We use log4j 1.2.x for logging in our product and are looking to migrate to log4j 2.x in near future. One of the functionality we have implemented is to log the system information and other important parameters on every new roll-over logfile that gets generated. The way we implemented in log4j 1.2.x is that we have extended RollingFileAppender class of log4j and have overridden the rollOver() method, below is the part snippet of the implementation @Override public void rollOver() { super

PySpark logging from the executor

由 Deadly 提交于 2019-12-17 05:57:39
问题 What is the correct way to access the log4j logger of Spark using pyspark on an executor? It's easy to do so in the driver but I cannot seem to understand how to access the logging functionalities on the executor so that I can log locally and let YARN collect the local logs. Is there any way to access the local logger? The standard logging procedure is not enough because I cannot access the spark context from the executor. 回答1: You cannot use local log4j logger on executors. Python workers

PySpark logging from the executor

由 妖精的绣舞 提交于 2019-12-17 05:56:46
问题 What is the correct way to access the log4j logger of Spark using pyspark on an executor? It's easy to do so in the driver but I cannot seem to understand how to access the logging functionalities on the executor so that I can log locally and let YARN collect the local logs. Is there any way to access the local logger? The standard logging procedure is not enough because I cannot access the spark context from the executor. 回答1: You cannot use local log4j logger on executors. Python workers

Change location of log4j.properties

由 不羁岁月 提交于 2019-12-17 02:47:05
问题 I want to put all my config files in a /config subfolder of my application directory. Log4j is expecting the log4j.properties file in the root folder of my application. Is there a way to tell log4j where to look for the properties file? 回答1: Yes, define log4j.configuration property java -Dlog4j.configuration=file:/path/to/log4j.properties myApp Note, that property value must be a URL. For more read section 'Default Initialization Procedure' in Log4j manual. 回答2: You can use

2、slf4j、log4j 和 common-logging的关系

由 一世执手 提交于 2019-12-16 15:44:17
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 前面有一篇日志中简单的介绍了 log4j，同时也介绍了它与commons-logging的关系，但是突然冒出来一个slf4j，并且slf4j有取代commons-logging的趋势，所以，我们可以推知slf4j与commons-logging的作用应该 相差不大的。 好，下面开始先讲讲slf4j。 1.slf4j 他只提供一个核心slf4j api(就是slf4j-api.jar包)，这个包只有日志的接口，并没有实现，所以如果要使用就得再给它提供一个实现了些接口的日志包，比 如：log4j,common logging,jdk log日志实现包等，但是这些日志实现又不能通过接口直接调用，实现上他们根本就和slf4j-api不一致，因此slf4j又增加了一层来转换各日志实 现包的使用，当然slf4j-simple除外。 slf4j+log4j组合使用模式： 1. slf4j-api-1.5.11.jar 2. slf4j-log4j12-1.5.11.jar 3. log4j-1.2.15.jar 4. log4j.properties(也可以是 log4j.xml) JCL+Log4J组合使用模式（即commons-logging+log4j）： 1. commons-logging-1.1.jar 2.
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