NullPointerException in Experiment overview if an extract is missing a sample

[Nicklas Nordborg]

The original error was reported in #1217. Below is the relevant stack trace. The same error can also happen if the logged in user doesn't has access to the sample.

java.lang.NullPointerException on page /base2/views/experiments/overview/tree.jsp
	
Version	BASE 2.9.0 (build #4667; schema #65)
Web server	Apache Tomcat/6.0.18
Database Server	MySQL 5.0.45-log
Database Dialect	org.hibernate.dialect.MySQLInnoDBDialect
JDBC Driver	com.mysql.jdbc.Driver (version 5.1)
Java runtime	Java(TM) SE Runtime Environment (1.6.0_07-b06-153), Apple Inc.
Operating system	Mac OS X x86_64 10.5.5
Memory	Total: 180.0 MB
Free: 58.4 MB
Max: 479.2 MB
Browser	Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_5; en-us) AppleWebKit/525.18 (KHTML, like Gecko) Version/3.1.2 Safari/525.20.1
Error message	
Stack trace	
java.lang.NullPointerException
...at net.sf.basedb.util.overview.ExperimentOverview.addSample(ExperimentOverview.java:1223)
...at net.sf.basedb.util.overview.ExperimentOverview.addExtract(ExperimentOverview.java:1137)
...at net.sf.basedb.util.overview.ExperimentOverview.addLabeledExtract(ExperimentOverview.java:1012)
...at net.sf.basedb.util.overview.ExperimentOverview.addLabeledExtracts(ExperimentOverview.java:934)
...at net.sf.basedb.util.overview.ExperimentOverview.addHybridization(ExperimentOverview.java:839)
...at net.sf.basedb.util.overview.ExperimentOverview.addScan(ExperimentOverview.java:805)
...at net.sf.basedb.util.overview.ExperimentOverview.addRawBioAssay(ExperimentOverview.java:654)
...at net.sf.basedb.util.overview.ExperimentOverview.addRawBioAssays(ExperimentOverview.java:629)
...at net.sf.basedb.util.overview.ExperimentOverview.generateOverview(ExperimentOverview.java:336)
...at net.sf.basedb.util.overview.ExperimentOverview.<init>(ExperimentOverview.java:276)
...at net.sf.basedb.util.overview.ExperimentOverview.getOverview(ExperimentOverview.java:206)
...at org.apache.jsp.views.experiments.overview.tree_jsp._jspService(tree_jsp.java:164)

[Nicklas Nordborg]

(In [4707]) Fixes #1220: NullPointerException in Experiment overview if an extract is missing a sample