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);}");
//执行这段script脚本
engine.eval(script.toString());
// javax.script.Invocable 是一个可选的接口
// 检查你的script engine 接口是否已实现!
// 注意：JavaScript engine实现了Invocable接口
Invocable inv = (Invocable) engine;
// 获取我们想调用那个方法所属的js对象
Object obj = engine.get("obj");
// 执行obj对象的名为hello的方法
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", "知道了" );
}
/**
* 脚本变量
* @throws Exception
*/
@Test
public void scriptVar() throws Exception{
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
File file = new File("F:/test/test.txt");
//将File对象f直接注入到js脚本中并可以作为全局变量使用
engine.put("files", file);
engine.eval("print(files.getPath());print(files.getName());");
}
/**
* 使用Script实现java接口
* @throws Exception
*/
public void runnableImpl() throws Exception{
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
// String里定义一段JavaScript代码脚本
String script = "function run() { print('run called'); }";
// 执行这个脚本
engine.eval(script);
// 从脚本引擎中获取Runnable接口对象（实例）. 该接口方法由具有相匹配名称的脚本函数实现。
Invocable inv = (Invocable) engine;
// 在上面的脚本中，我们已经实现了Runnable接口的run()方法
Runnable runnable = inv.getInterface(Runnable.class);
// 启动一个线程运行上面的实现了runnable接口的script脚本
Thread thread = new Thread(runnable);
thread.start();
}
/**
* 脚本引擎的多个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);");
// 上面的代码会打印"hello word！！"
// 现在，传入另一个不同的script context
ScriptContext context = new SimpleScriptContext();
//新的Script context绑定ScriptContext的ENGINE_SCOPE
Bindings bindings = context.getBindings(ScriptContext.ENGINE_SCOPE);
// 增加一个新变脸到新的范围 engineScope 中
bindings.put("x", "word hello!!");
// 执行同一个脚本 - 但这次传入一个不同的script context
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);
}
}
}
