It’s correct and there’s no requirement for catch clause. Oracle java 7 doc says the resource will be closed regardless of whether an exception is actually thrown or not. You should use a catch clause only if you want to react upon the exception. The catch clause will be executed after the resource is closed. … Read more
Java 7 introduced stricter verification and changed the class format a bit—to contain a stack map used to verify that code is correct. The exception you see means that some method doesn’t have a valid stack map. Java version or bytecode instrumentation could both be to blame. Usually this means that a library used by … Read more
I’ve been testing it out with a heavy application: 60-70GB allocated to heap, with 20-50GB in use at any time. With these sorts of applications, it’s an understatement to say that your mileage may vary. I’m running JDK 1.6_22 on Linux. The minor versions are important– before about 1.6_20, there were bugs in G1 that … Read more
Java NIO’s PathMatcher provides FileSystem.getPathMatcher(String syntaxAndPattern): PathMatcher matcher = FileSystems.getDefault().getPathMatcher(“glob:*.java”); Path filename = …; if (matcher.matches(filename)) { System.out.println(filename); } See the Finding Files tutorial for details.
Java SE 7 Features and Enhancements from JDK 7 Release Notes This is the Java 7 new features summary from the OpenJDK 7 features page: vm JSR 292: Support for dynamically-typed languages (InvokeDynamic) Strict class-file checking lang JSR 334: Small language enhancements (Project Coin) core Upgrade class-loader architecture Method to close a URLClassLoader Concurrency and … Read more
It looks like the language in section 5.5 Casting Conversion of Java 7 JLS was updated in comparison to the same section in the Java 5/6 JLS, probably to clarify the allowed conversions. Java 7 JLS says An expression of a reference type may undergo casting conversion to a primitive type without error, by unboxing … Read more
This is how I got 1.7 to work with Eclipse. I hope it helps. I Downloaded the latest OpenJDK 1.7 universal (32/64 bits) JDK from Mac OS/X branch from http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html copied the jdk to /Library/Java/JavaVirtualMachines/ next to the default 1.6.0 one In Eclipse > Preferences > Java > Installed JREs you add a new one, … Read more
The exception message is actually pretty descriptive. The contract it mentions is transitivity: if A > B and B > C then for any A, B and C: A > C. I checked it with paper and pencil and your code seems to have few holes: if (card1.getRarity() < card2.getRarity()) { return 1; you do … Read more
Technical differences are a consequence of the goal of each one (OpenJDK is meant to be the reference implementation, open to the community, while Oracle is meant to be a commercial one) They both have “almost” the same code of the classes in the Java API; but the code for the virtual machine itself is … Read more
Finally found the answer here: http://www.adam-bien.com/roller/abien/entry/java_se_development_kit_7 You should use JAVA_HOME=$(/usr/libexec/java_home) instead on a Mac and then set the current jdk via “Java Preferences.app”. Set JAVA_HOME in ~/.profile