调用Java方法从Groovy

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英文:

Invoke java method from Groovy

问题

我正在研究Groovy,并且尝试在Groovy中绑定Java对象并从脚本中运行方法。

示例:

public class Toaster {
    private int toasted = 0;
    
    public Toaster() {
        super();
    }
    
    public void toast() {
        System.out.println(++toasted);
    }
}

在Java的主程序中:

Toaster toaster = new Toaster();
Binding binding = new Binding();
binding.setVariable("toaster", toaster);
GroovyShell shell = new GroovyShell(binding);
shell.evaluate("toaster.toast();");

这显然无法正常工作,那么我需要在这里做些什么才能够在Groovy中使用Java的烤面包机对象呢?

英文:

I'm looking into Groovy, and I'm trying to bind java objects in groovy and run methods from the script.

Example:

public class Toaster{
private int toasted=0;
public Toaster() {
		super();
	}
public void toast(){
     System.out.println(++toasted);
  }
}

And in the java main I have:

Toaster toaster = new Toaster();
Binding binding = new Binding();
binding.setVariable("toaster", toaster);
GroovyShell shell = new GroovyShell(binding);
shell.evaluate("toaster.toast();");

This obviously doesn't work, so what do I need to do here to be able to use the java toaster object from groovy?

答案1

得分: 2

以下是你提供的代码的翻译部分:

A.java:

import groovy.lang.GroovyShell;
import groovy.lang.Binding;

public class A{
    public static class Toaster{
        private int toasted=0;
        public void toast(){
            System.out.println(++toasted);
        }
    }
    
    public static void main(String[] arg){
        Toaster toaster = new Toaster();
        Binding binding = new Binding();
        binding.setVariable("toaster", toaster);
        GroovyShell shell = new GroovyShell(binding);
        shell.evaluate("toaster.toast();");   // < prints 1
        shell.evaluate("toaster.toast();");   // < prints 2
        shell.evaluate("toaster.toast();");   // < prints 3
        shell.evaluate("toaster.toast();");   // < prints 4
    }
}

编译:

javac -cp %GROOVY_HOME%/lib/* A.java

运行:

java -cp %GROOVY_HOME%/lib/*;. A
英文:

your code works fine if you remove all typos...

A.java:

import groovy.lang.GroovyShell;
import groovy.lang.Binding;


public class A{
	public static class Toaster{
		private int toasted=0;
		public void toast(){
			System.out.println(++toasted);
		}
	}
	
	public static void main(String[] arg){
		Toaster toaster = new Toaster();
		Binding binding = new Binding();
		binding.setVariable(&quot;toaster&quot;, toaster);
		GroovyShell shell = new GroovyShell(binding);
		shell.evaluate(&quot;toaster.toast();&quot;);   // &lt; prints 1
		shell.evaluate(&quot;toaster.toast();&quot;);   // &lt; prints 2
		shell.evaluate(&quot;toaster.toast();&quot;);   // &lt; prints 3
		shell.evaluate(&quot;toaster.toast();&quot;);   // &lt; prints 4
	}
}

compile:

javac -cp %GROOVY_HOME%/lib/* A.java

run:

java -cp %GROOVY_HOME%/lib/*;. A 

答案2

得分: 0

Groovy和Java将被编译成相同的字节码,保存为.class文件。因此,您不需要Groovy shell。我不确定您在这里的具体安排。但如果它们需要同时编译,我建议您使用Groovy的编译器groovyc进行编译,以便它可以识别Java代码的一侧。

英文:

Groovy and java will be compiled to the same bytecode as .class file. So, you don't need groovy shell. I am not sure what your arrangement here. But if they both need to be compiled at the same time, I suggest you use Groovy's compiler groovyc to compile, so it can recognize Java side of the code.

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  • 本文由 发表于 2020年9月18日 01:04:17
  • 转载请务必保留本文链接:https://go.coder-hub.com/63942931.html
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