在JRuby中導入java類

Question

我正在嘗試在Jruby中導入Java類

$ ls
bin src

$ ls bin/com/practice
Test.class

$ ls src/com/practice
Test.java

$ cat src/com/practice/Test.java
package com.practice;

public class Test {
    public static String foo(){
        return "Java!!";
    }

    public static void main(String args[]){
        System.out.println(Test.foo());
    }
}
$ jirb -Ibin
jruby-1.7.10 :001 > java_import 'com.pratice.Test'
NameError: cannot load Java class com.pratice.Test
    from org/jruby/javasupport/JavaClass.java:1250:in `for_name'
    from org/jruby/javasupport/JavaUtilities.java:34:in `get_proxy_class'
    from file:/Users/gaurish/.rvm/rubies/jruby-1.7.10/lib/jruby.jar!/jruby/java/core_ext/object.rb:26:in `java_import'
    from org/jruby/RubyArray.java:2409:in `map'
    from file:/Users/gaurish/.rvm/rubies/jruby-1.7.10/lib/jruby.jar!/jruby/java/core_ext/object.rb:22:in `java_import'
    from (irb):1:in `evaluate'
    from org/jruby/RubyKernel.java:1119:in `eval'
    from org/jruby/RubyKernel.java:1519:in `loop'
    from org/jruby/RubyKernel.java:1282:in `catch'
    from org/jruby/RubyKernel.java:1282:in `catch'
    from /Users/gaurish/.rvm/rubies/jruby-1.7.10/bin/jirb:13:in `(root)'

我在這做錯了什么？

Answer 1

你有很多問題：

1. 你在irb中拼錯了“練習”： java_import 'com.pratice.Test'
2. 你的班級實際上並沒有正確的包裹。 你需要添加 package com.practice; 到Java代碼。
3. 您需要在類路徑中添加“bin”，以便JVM可以找到類： $CLASSPATH << 'bin'

總而言之，我能夠在IRB中運行它：

$CLASSPATH << 'bin'
com.practice.Test.foo
# => "Java!!"

編輯：我沒有復制你的package線，這是我的錯，不是你的。 :-)