spring 或者 java执行JavaScript脚本方式
作者:互联网
简单示例
public static void test10(){ // 创建JavaScript引擎 ScriptEngine jsEngine = new ScriptEngineManager().getEngineByName("js"); // ScriptEngine jsEngine = new ScriptEngineManager().getEngineByExtension("js"); // ScriptEngine jsEngine = new ScriptEngineManager().getEngineByMimeType("text/javascript"); // 方式一,默认设置变量 jsEngine.put("hello", "jack"); // 方式二,使用binding设置变量 SimpleBindings bindings = new SimpleBindings(); bindings.put("hello","world"); jsEngine.setBindings(bindings, ScriptContext.GLOBAL_SCOPE); // 方式三,使用Context设置变量 ScriptContext scriptContext = jsEngine.getContext(); scriptContext.setAttribute("hello", "polo", ScriptContext.ENGINE_SCOPE); try { // 方式一,直接调用 jsEngine.eval("print(hello)"); // 方式二,编译调用(需要重复调用,建议先编译后调用) if (jsEngine instanceof Compilable){ CompiledScript compileScript = ((Compilable) jsEngine).compile("print(hello)"); if (compileScript != null){ for (int i = 0; i < 10; i++) { compileScript.eval(); } } } Invocable invocable = ((Invocable)jsEngine); // 方式三,使用JavaScript中的顶层方法 jsEngine.eval("function greet(name) { print('Hello, ' + name); } "); invocable.invokeFunction("greet", "tom"); // 方式四,使用某个对象的方法 jsEngine.eval("var obj = { getGreeting: function(name){ return 'hello, ' + name; } } "); Object obj = jsEngine.get("obj"); Object result = invocable.invokeMethod(obj, "getGreeting", "kitty"); System.out.println(result); // 方法五, 指定脚本中的方法为Java接口的实现 jsEngine.eval("function getGreeting(name) { return 'Hello, ' + name; } "); Greet greet = invocable.getInterface(Greet.class); String result2 = greet.getGreeting("Alex"); System.out.println(result2); } catch (ScriptException | NoSuchMethodException e) { e.printStackTrace(); } }
相关测试Demo
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); } } }View Code
常见问题
- Nashorn engine is planned to be removed from a future JDK release
pom依赖
<properties> <graalvm.version>21.1.0</graalvm.version> </properties> <dependencies> <!--javascript运行环境--> <dependency> <groupId>org.graalvm.sdk</groupId> <artifactId>graal-sdk</artifactId> <version>${graalvm.version}</version> </dependency> <dependency> <groupId>org.graalvm.js</groupId> <artifactId>js</artifactId> <version>${graalvm.version}</version> <scope>runtime</scope> </dependency> <dependency> <groupId>org.graalvm.js</groupId> <artifactId>js-scriptengine</artifactId> <version>${graalvm.version}</version> </dependency> <!--javascript end--> </dependencies>
使用方法
ScriptEngineManager manager = new ScriptEngineManager(); ScriptEngine engine = manager.getEngineByName("graal.js");
标签:engine,java,script,spring,JavaScript,manager,obj,new,ScriptEngineManager 来源: https://www.cnblogs.com/qianxiaoPro/p/16356130.html