在JRuby中导入java类

时间:2014-03-09 01:02:27

标签: java classpath jruby load-path jruby-java-interop

我正在尝试在Jruby中导入Java类

$ 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)'

我在这里做错了什么?

1 个答案:

答案 0 :(得分:3)

你有很多问题:

  1. 您在irb:java_import 'com.pratice.Test'
  2. 中拼错了“练习”
  3. 您的课程实际上并不在正确的课程中。您需要将package com.practice;添加到Java代码中。
  4. 您需要在类路径中添加“bin”,以便JVM可以找到类:$CLASSPATH << 'bin'
  5. 总而言之,我能够在IRB中运行它:

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

    编辑:我没有复制你的package行,这是我的错,不是你的。 : - )