I have a Hashmap in Java like this: private Map<String, Integer> team1 = new HashMap<String, Integer>(); Then I fill it like this: team1.put(“United”, 5); How can I get the keys? Something like: team1.getKey() to return “United”. 15 Answers 15
Is it possible to get a Path object from a java.io.File? I know you can convert a path to a file using toFile() method, but I couldn’t find the opposite conversion. Is there a way to do this in Java 6 or lower? 4 Answers 4
On my machine I have two Java versions installed: (1.6 and 1.7 installed manually by me). I need both of them for different projects. But for Maven I need 1.7, but my Maven uses the 1.6 Java version. How can I set Maven to use 1.7? 25 Answers 25
Recently I ran into this error in my web application: java.lang.OutOfMemoryError: PermGen space It’s a typical Hibernate/JPA + IceFaces/JSF application running on Tomcat 6 and JDK 1.6. Apparently this can occur after redeploying an application a few times. What causes it and what can be done to avoid it? How do I fix the problem? … Read more
A HashMap contains more than one key. You can use keySet() to get the set of all keys. team1.put(“foo”, 1); team1.put(“bar”, 2); will store 1 with key “foo” and 2 with key “bar”. To iterate over all the keys: for ( String key : team1.keySet() ) { System.out.println( key ); } will print “foo” and … Read more
