Groovy 從應用程序訪問腳本變量

Question

需要訪問groovy腳本文件中定義的變量
在使用GroovyShell執行腳本之前
但是，我收到錯誤：

groovy.lang.MissingPropertyException: No such property: _THREADS for class: Test1

//Test1.groovy

_THREADS=10;
println("Hello from the script test ")

//scriptRunner.groovy

File scriptFile = new File("Test1.groovy");
def sharedData = new Binding()
def shell = new GroovyShell(sharedData)
def script = shell.parse (scriptFile);

def thread = script.getProperty('_THREADS'); // getting ERROR --
// No such property: _THREADS for class: Test1
//-------

//now run the threads
script.run()

Answer 1

您必須在獲取屬性/綁定之前運行腳本

def sharedData = new Binding()
def shell = new GroovyShell(sharedData)
def script = shell.parse (''' _THREADS=10 ''')
script.run()

println script.getProperty('_THREADS')

嘗試在 groovy 控制台中打開AST Browser (Ctrl+T)以獲取此代碼：

_THREADS=10

您將看到大約以下生成的 class：

public class script1663101205410 extends groovy.lang.Script { 
    public java.lang.Object run() {
        _THREADS = 10
    }
}

其中_THREADS = 10將屬性分配給綁定

但是，可以將 _THREADS 定義為 function，然后無需運行腳本即可訪問它。

def sharedData = new Binding()
def shell = new GroovyShell(sharedData)
def script = shell.parse (''' def get_THREADS(){ 11 } ''')

println script.getProperty('_THREADS')

Answer 2

解析后可以訪問使用@Field修飾符值的解決方案

import groovy.transform.Field
@Field _THREADS=10

File scriptFile = new File("Test1.groovy");
def sharedData = new Binding()
def shell = new GroovyShell(sharedData)
def script = shell.parse (scriptFile);

def thread = script.getProperty('_THREADS'); //value is accessible