I got this exception when I run my class in Eclipse:
log = LoggerFactory.getLogger(SilenceInstall.class);

Exception in thread "main" java.lang.NullPointerException
at org.slf4j.LoggerFactory.singleImplementationSanityCheck(LoggerFactory.java:192)
at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:113)
at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:269)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:242)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:255)
at
com.foo.installation.SilenceInstall.main(SilenceInstall.java:99)

It is due to LoggerFactory.class.getClassLoader() returns null in:

private static void singleImplementationSanityCheck() {
try {
Enumeration paths = LoggerFactory.class.getClassLoader().getResources(
STATIC_LOGGER_BINDER_PATH);
....

According to JavaDoc, getClassLoader() can be null: "Some implementations may use null to represent the bootstrap class loader. "