hide exception

Item.java

package com.company;

import java.util.logging.Level;
import java.util.logging.Logger;

public class Item {

    Logger log = Logger.getLogger("ItemLogger");

    public boolean function(String param) {
        if (param==null) {
            log.log(Level.SEVERE,"error", new IllegalArgumentException("boom"));
            return false;
        }
        return true;
    }
}

ItemTest.java

package com.company;

import org.junit.Rule;
import org.junit.Test;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

public class ItemTest {

    @Rule
    public org.junit.rules.TestRule watcher = new TestWatcherLoggingRule("testFunction","ItemLogger");

    @Test
    public void testFunction()  {
        assertThat(new Item().function(null),is(false));
    }
}

TestWatcherLoggingRule.java

package com.company;

import org.junit.rules.TestWatcher;
import org.junit.runner.Description;

import java.util.logging.Level;
import java.util.logging.Logger;

public class TestWatcherLoggingRule extends TestWatcher {

    //name of the method to suspend logging for
    private final String methodName;

    private Level loggingLevel;

    private Logger logger;

    public TestWatcherLoggingRule(String methodName, String loggerName) {

        this.methodName = methodName;
        this.logger = Logger.getLogger(loggerName);
        this.loggingLevel = logger.getLevel();
    }

    @Override
    public void starting(Description desc) {

        if (desc.getMethodName().equals(methodName))
            logger.setLevel(Level.OFF);
    }

    @Override
    public void finished(Description desc) {
        logger.setLevel(loggingLevel);
    }
}