无法编译Eclipse中的任何Java代码

Question

I'm new to the world of java and have been following a few online tutorials to get started. Everything was going great and the programs were compiling perfectly and then all of a sudden, without me seemingly changing anything, as far as preferences directly attributing to Eclipse, it stopped compiling any code at all. Even the simple Hello World code will not compile. All I get in the console line for any code is:

Usage: javaw [-options] class [args...]
       (to execute a class)
or  javaw [-options] -jar jarfile [args...]
       (to execute a jar file)
where options include:
-d32      use a 32-bit data model if available
-d64      use a 64-bit data model if available
-server   to select the "server" VM
-hotspot      is a synonym for the "server" VM  [deprecated]
              The default VM is server.

-cp <class search path of directories and zip/jar files>
-classpath <class search path of directories and zip/jar files>
              A ; separated list of directories, JAR archives,
              and ZIP archives to search for class files.
-D<name>=<value>
              set a system property
-verbose[:class|gc|jni]
              enable verbose output
-version      print product version and exit
-version:<value>
              require the specified version to run
-showversion  print product version and continue
-jre-restrict-search | -no-jre-restrict-search
              include/exclude user private JREs in the version search
-? -help      print this help message
-X            print help on non-standard options
-ea[:<packagename>...|:<classname>]
-enableassertions[:<packagename>...|:<classname>]
              enable assertions with specified granularity
-da[:<packagename>...|:<classname>]
-disableassertions[:<packagename>...|:<classname>]
              disable assertions with specified granularity
-esa | -enablesystemassertions
              enable system assertions
-dsa | -disablesystemassertions
              disable system assertions
-agentlib:<libname>[=<options>]
              load native agent library <libname>, e.g. -agentlib:hprof
              see also, -agentlib:jdwp=help and -agentlib:hprof=help
-agentpath:<pathname>[=<options>]
              load native agent library by full pathname
-javaagent:<jarpath>[=<options>]
              load Java programming language agent, see java.lang.instrument
-splash:<imagepath>
              show splash screen with specified image

See http://www.oracle.com/technetwork/java/javase/documentation/index.html for more details.

I'm not exactly sure of what this is or why it started doing it. How do I go about in fixing the compiler so I can continue to learn?

Answer 1

That happens because you haven't installed JDK but only JRE. Install JDK to make it work.

Source

Answer 2

I too have had this problem. Try restarting Eclipse. If that doesn't work, restart your computer. If even that doesn't work, re-install Java. Its an annoying bug that usually occurs when your computer goes into standby while a program is running on Eclipse.

EDIT: If the problem persists, you can make a small javac program that would compile any code in a given directory.

Hope I helped!