ScriptEngineManager class (Java and JS call each other)

Calls between Java and Js based ScriptEngineManager class, this class is jdk8 added:

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.script.Bindings;
import javax.script.Invocable;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.SimpleScriptContext;

import org.junit.Test;


public class JavaScriptFunction {

    @Test
    public void print() throws Exception{
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        engine.eval("print('hello word!!')");
    }
    
    @Test
    public void obj() throws Exception {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        StringBuffer script = new StringBuffer();
        script.append("var obj = new Object();");
        script.append ( "obj.hello = function (name) {Print ( 'Hello,' + name);}" );
         // implementation of this script script 
        engine.eval (script.toString ());
         // the javax. script.Invocable is an optional interface
         // check your script engine interface is realized!
         // Note: JavaScript engine implements the interface Invocable 
        Invocable inv = (Invocable) Engine;
         // get js we want to call that method belongs object 
        object obj = engine.get ( "obj" );
         // method called hello execution object obj 
        inv.invokeMethod (obj, "hello", "Script method, !!" );
    }
    
    @Test
    public void file() throws Exception{
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        engine.eval(new java.io.FileReader(new File("F:/test/test.js")));
        Invocable inv = (Invocable) engine;
        Object obj = engine.get("obj");
        inv.invokeMethod (obj, "name", "know" );
    }
    
    
    /**
     * Script variables
     * @throws Exception 
     */
    @Test
    public void scriptVar() throws Exception{
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        File File = new new File ( "F.: /Test/test.txt" );
         // File object f js injected directly into the script and can be used as a global variable 
        engine.put ( "Files" , File);
        engine.eval("print(files.getPath());print(files.getName());");
    }
    
    /**
     * Use Script achieve java interfaces
     * @throws Exception 
     */
    public void runnableImpl() throws Exception{
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        
        // String script defined in JavaScript code 
        String = Script "RUN function () {Print ( 'RUN Called');}" ;
         // implementation of the script 
        engine.eval (script);
        
        // Get Runnable interface object (instance) from the script engine. The interface method implemented by the script function with a matching name. 
        Inv = Invocable (Invocable) Engine;
         // In the above script, we have implemented the Runnable interface run () method 
        Runnable Runnable = inv.getInterface (Runnable. Class );
        
        // start a thread to run a script to achieve the above script runnable interfaces of 
        the Thread the Thread = new new the Thread (runnable);
        thread.start();
    }
    
    /**
     * Script engine more scope
     * @throws Exception 
     */
    @Test
    public void multiScopes() throws Exception{
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("nashorn");
        // 打印全局变量 "x"
        engine.put("x", "hello word!!");
        engine.eval ( "Print (X);" );
         // The above code will print "hello word !!"
        
        // now, passing a different context Script 
        ScriptContext context = new new SimpleScriptContext ();
         // New Script context of binding ScriptContext the ENGINE_SCOPE of 
        Bindings Bindings = context.getBindings (ScriptContext.ENGINE_SCOPE);
        
        // add a new face changing to a new range engineScope in 
        bindings.put ( "the X-", "Word the Hello !!" );
         // execute the same script - but this time passing in a different context Script 
        engine.eval ( " Print (X); " , Bindings);
        engine.eval("print(x);");
    }
    
    
    
    public static void main(String[] args) throws Exception {
        new JavaScriptFunction().runnableImpl();
        
        List list = new ArrayList();
        list.add("1");
        list.add("1");
        list.add("1");
        
        for (Object object : list) {
            System.out.println(object);
        }
        
    }
}

 

The use packaging technology in Java will run js script encapsulation:

import java.io.FileNotFoundException;
import java.io.FileReader;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

/**
 * Run the script
 * @author Ruby
 *
 */
public class RunScript {

    private ScriptEngineManager manager = new ScriptEngineManager();
    private ScriptEngine engine;
    private String fileName;
    
    public RunScript(String fileName){
        engine = manager.getEngineByName("JavaScript");
        this.fileName = fileName;
    }
    
    /**
     * Set the variable
     * @param varName
     * @Param obj
      * / 
    public  void setVar (String to varName, the Object obj) {
        engine.put(varName, obj);
    }
    
    /**
     * Startup script
     * @throws FileNotFoundException
     * @throws ScriptException
     */
    public void start() throws FileNotFoundException, ScriptException{
        engine.eval(new FileReader(fileName));
    }
}

 

test

The Logger object is injected into the js object, then you can use java in the Logger object in the js file:

public static void main(String[] args) throws Exception {
    RunScript rs = new RunScript("D:\test.js");
    rs.setVar("Logger", Logger.getLogger(ConsoleListener.class));
    rs.start();
}

 

Extended:

Use ScriptEngineManager JSON string class is determined whether valid:

ScriptEngineManager sem = new ScriptEngineManager ();
        ScriptEngine se = sem.getEngineByName ("js");
        String jsonstr = "({name: 1, obj: 3,[dd]})";
        try
        {
            System.out.println (se.eval (jsonstr));
        }
        catch (ScriptException e)
        {
            System.out.println ( "malformed json" );
        }

other methods:

package util;

import com.alibaba.fastjson.JSONException;
import com.alibaba.fastjson.JSONObject;

public class Test {

    public static void main(String[] args) {
        try {
            JSONObject.parse("{'a':1 'b':1}");
        } catch (JSONException e) {
            System.out.println ( "Error the JSON String" );
        }
    }

}