Turning HtmlUnit Warnings off

Do you know how can I turn Warnings, Notes, Errors in HtmlUnit off?

Put this somewhere around the start of your code; it will shut its dirty mouth:

LogFactory.getFactory().setAttribute("org.apache.commons.logging.Log", "org.apache.commons.logging.impl.NoOpLog");
    
java.util.logging.Logger.getLogger("com.gargoylesoftware.htmlunit").setLevel(Level.OFF); 
java.util.logging.Logger.getLogger("org.apache.commons.httpclient").setLevel(Level.OFF);

webClient = new WebClient(bv);
webClient.setCssEnabled(false);

webClient.setIncorrectnessListener(new IncorrectnessListener() {
	
	@Override
	public void notify(String arg0, Object arg1) {
		// TODO Auto-generated method stub
		
	}
});
webClient.setCssErrorHandler(new ErrorHandler() {
	
	@Override
	public void warning(CSSParseException exception) throws CSSException {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void fatalError(CSSParseException exception) throws CSSException {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void error(CSSParseException exception) throws CSSException {
		// TODO Auto-generated method stub
		
	}
});
webClient.setJavaScriptErrorListener(new JavaScriptErrorListener() {
	
	@Override
	public void timeoutError(HtmlPage arg0, long arg1, long arg2) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void scriptException(HtmlPage arg0, ScriptException arg1) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void malformedScriptURL(HtmlPage arg0, String arg1, MalformedURLException arg2) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void loadScriptError(HtmlPage arg0, URL arg1, Exception arg2) {
		// TODO Auto-generated method stub
		
	}
});
webClient.setHTMLParserListener(new HTMLParserListener() {
	
	@Override
	public void warning(String arg0, URL arg1, int arg2, int arg3, String arg4) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void error(String arg0, URL arg1, int arg2, int arg3, String arg4) {
		// TODO Auto-generated method stub
		
	}
});

webClient.setThrowExceptionOnFailingStatusCode(false);
webClient.setThrowExceptionOnScriptError(false);

The code in Arsen Zahray's answer helped in removing almost all the logs generated by HtmlUnit.

But one edit helps to remove them all. Use:

java.util.logging.Logger.getLogger("com.gargoylesoftware").setLevel(Level.OFF); 

instead of:

java.util.logging.Logger.getLogger("com.gargoylesoftware.htmlunit").setLevel(Level.OFF);

To remove all output from the latest version of HtmlUnit you just have to add these lines in a static block or in your main class:

java.util.logging.Logger.getLogger("com.gargoylesoftware").setLevel(Level.OFF); 
System.setProperty("org.apache.commons.logging.Log", "org.apache.commons.logging.impl.NoOpLog");

It is NOT needed to override any method as some other answers state.

Try the following code to turn the logging level down to off:

java.util.logging.Logger.getLogger("com.gargoylesoftware").setLevel(Level.OFF);

Here you can get info on how to manipulate logging of HtmlUnit.

This is what I added to my log4j.properties in order to disable verbose debugging messages from HtmlUnit components:

# Set specific logger levels.
log4j.logger.org.mortbay.log=fatal
log4j.logger.org.apache.http=fatal
log4j.logger.org.apache.http.headers=fatal
log4j.logger.org.apache.http.wire=fatal
# For HttpClient 3, which is used by FirefoxDriver
log4j.logger.httpclient.wire=fatal
log4j.logger.org.apache.commons=fatal
log4j.logger.com.gargoylesoftware.htmlunit=fatal
log4j.logger.com.gargoylesoftware.htmlunit.WebTestCase=fatal
# Change this to TRACE when enabling the debugger.
log4j.logger.com.gargoylesoftware.htmlunit.javascript.DebugFrameImpl=fatal

I am using the code below and it works perfectly:

LogFactory.getFactory().setAttribute("org.apache.commons.logging.Log", "org.apache.commons.logging.impl.NoOpLog");

java.util.logging.Logger.getLogger("com.gargoylesoftware.htmlunit").setLevel(Level.OFF);
java.util.logging.Logger.getLogger("org.apache.commons.httpclient").setLevel(Level.OFF);

Turn the loggers off. But that is not a good solution, since you might want to have some uncommon issues in the logs.

I know HtmlUnit produces a lot of unimportant exceptions, warnings, etc. You can suppress of few of those using:

client.getOptions().setThrowExceptionOnFailingStatusCode(false);
client.getOptions().setThrowExceptionOnScriptError(false);
client.getOptions().setPrintContentOnFailingStatusCode(false);

Just add this string to your log4.properties:

log4j.logger.com.gargoylesoftware.htmlunit=fatal

Now in HtmlUnit 2.9, WebClient.setCssErrorHandler(new SilentCssErrorHandler()) can conveniently ignore the warnings and errors. For example:

@Override
protected WebClient modifyWebClient(WebClient client) {
	// currently does nothing, but may be changed in future versions
	WebClient modifiedClient = super.modifyWebClient(client);

	modifiedClient.getOptions().setThrowExceptionOnScriptError(false);
	modifiedClient.setCssErrorHandler(new SilentCssErrorHandler());

	return modifiedClient;
}

Have a look at the docs.

There is a sample log4 file used by the test suite, you can find it here, you can disable everything if you wish.

This worked for me:

@Test
	public void homePage() throws Exception {
	    final WebClient webClient = new WebClient();   
 webClient.setThrowExceptionOnScriptError(false);
    final HtmlPage page = webClient.getPage("http://localhost:8080/web/guest/home");

Try adding this to your code:

LogFactory.getFactory().setAttribute("org.apache.commons.logging.Log", "org.apache.commons.logging.impl.NoOpLog");

Basically, this makes the logger log to NoOpLog, which doesn't write the log information anywhere.

I must be doing something different to everyone above. I have htmlunit set up as a Spring project currently and removing the logs required adding a logback.xml to my resources dir. Add the following as logback.xml to your main/java/resources dir - this will only output INFO level log statements and nothing below (https://stackoverflow.com/questions/2031163/when-to-use-the-different-log-levels)

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <!--<include resource="org/springframework/boot/logging/logback/base.xml"/>-->
    <!--<logger name="org.springframework.web" level="INFO"/>-->

    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] [%logger{20}] %-5level - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="FILE" class="ch.qos.logback.core.FileAppender">
        <file>gdaxDesktop.log</file>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %logger{20} %-5level - %msg%n</pattern>
        </encoder>
    </appender>

    <root level="info">
        <!--<appender-ref ref="FILE"/>-->
        <appender-ref ref="CONSOLE"/>
    </root>
</configuration>

One option which worked well for me is to change the HtmlUnit logger to log to a different file just so that I have those errors in case I need to refer it some time and it also doesn't clutter up my main logs. Below is the log4j change I made to log4j.properties:

log4j.logger.com.gargoylesoftware.htmlunit=ERROR, HTMLUNIT
log4j.additivity.com.gargoylesoftware.htmlunit=false
log4j.appender.HTMLUNIT = org.apache.log4j.RollingFileAppender
log4j.appender.HTMLUNIT.layout=org.apache.log4j.PatternLayout
log4j.appender.HTMLUNIT.layout.ConversionPattern=%m%n
log4j.appender.HTMLUNIT.File=logs/HtmlUnitLog4j.log
log4j.appender.HTMLUNIT.MaxFileSize=5MB
log4j.appender.HTMLUNIT.MaxBackupIndex=5

If you don't need JavaScript support, it is the easiest way to disable it:

WebClient client = new WebClient(BrowserVersion.BEST_SUPPORTED);
client.getOptions().setThrowExceptionOnFailingStatusCode(false);
client.getOptions().setPrintContentOnFailingStatusCode(false);
client.getOptions().setThrowExceptionOnScriptError(false);
client.getOptions().setJavaScriptEnabled(false);
client.setCssErrorHandler(new SilentCssErrorHandler());
client.setHTMLParserListener(new HTMLParserListener() {
    @Override
    public void error(String message, URL url, String html, int line, int column, String key) {
    }

    @Override
    public void warning(String message, URL url, String html, int line, int column, String key) {
    }
});

You also disable exceptions and log on failing status codes, JavaScript, CSS errors and HTML parse errors.

If you need JavaScript support you can use a custom implementation for JavaScript errors:

client.setJavaScriptErrorListener(new JavaScriptErrorListener() {
    @Override
    public void timeoutError(HtmlPage arg0, long arg1, long arg2) {
    }

    @Override
    public void scriptException(HtmlPage arg0, ScriptException arg1) {
    }

    @Override
    public void malformedScriptURL(HtmlPage arg0, String arg1, MalformedURLException arg2) {
    }

    @Override
    public void loadScriptError(HtmlPage arg0, URL arg1, Exception arg2) {
    }
});

If you don't need you also can just disable it:

client.getOptions().setCssEnabled(false);

So there is no need to configure any other Logger.

I am using spring-boot, only solved with this:

import com.gargoylesoftware.htmlunit.SilentCssErrorHandler;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.javascript.SilentJavaScriptErrorListener;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class HtmlUnitConfiguration {

    @Bean
    public WebClient webClient() {
        WebClient webClient = new WebClient();
        webClient.getOptions().setThrowExceptionOnScriptError(false);
        webClient.setJavaScriptErrorListener(new SilentJavaScriptErrorListener());
        webClient.setCssErrorHandler(new SilentCssErrorHandler());

        return webClient;
    }
}

And then calling the bean with @Autowired or in class constructor. And without this line:

webClient.getOptions().setThrowExceptionOnScriptError(false);

The two lines under it will throw a bizarre error. This line has the magic.

Try this, it worked for me.

WebClient webClient = new WebClient();
webClient.getOptions().setJavaScriptEnabled(false);
webClient.getOptions().setCssEnabled(false);