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import jdk.nashorn.api.scripting.ScriptObjectMirror; import
javax.script.Invocable; import javax.script.ScriptEngine; import
javax.script.ScriptEngineManager; import javax.script.SimpleBindings; import
java.io.FileReader; import java.util.Map; import java.util.TreeMap; public
class JSEngine{ public static ScriptEngine engine; public static String str;
public static void getValues() throws Exception{ str = " var msg='hello'; " + "
var number = 123; " + " var array=['A','B','C']; " + " var json={ " + "
'name':'pd', " + " 'subjson':{ " + " 'subname':'spd' " + " ,'id':123 " + " } " +
" }; "; engine.eval(str); str="msg+=' world';number+=5"; System.out.println(
engine.get("msg")); System.out.println(engine.get("number")); //获取数组
ScriptObjectMirror array= (ScriptObjectMirror) engine.get("array");
System.out.println(array.getSlot(0)); ScriptObjectMirror json = (
ScriptObjectMirror) engine.get("json"); System.out.println(json.get("name"));
//json嵌套 ScriptObjectMirror subjson= (ScriptObjectMirror) json.get("subjson");
System.out.println(subjson.get("subname")); } public static void getObject()
throws Exception{ str = " var obj=new Object(); " + " obj.info='hello world'; "
+" obj.getInfo=function(){ " + " return this.info; " + " }; "; engine.eval(str);
ScriptObjectMirror obj= (ScriptObjectMirror) engine.get("obj");
System.out.println(obj.get("info")); System.out.println(obj.get("getInfo")); str
= "obj.getInfo()"; System.out.println(engine.eval(str)); } //给js传递变量 public
static void putValue() throws Exception{ str = "Math.pow(a,b)"; Map<
String,Object> input = new TreeMap<>(); input.put("a",2); input.put("b",8);
System.out.println(engine.eval(str,new SimpleBindings(input))); } //调用js函数
public static void callJSFunction() throws Exception{ str = "function add (a,
b) {return a+b; }"; //执行js脚本定义函数 engine.eval(str); Invocable invocable = (
Invocable) engine; Object res = invocable.invokeFunction("add",new Object[]{2,3}
); System.out.println(res); } //读取js文件，执行函数;易变业务使用脚本编写，这样即使修改脚本，也不需重新部署java程序
public static void callJSFunctionFromFile() throws Exception{ //执行js while (true
){ //模拟执行期间add.js被修改 Thread.sleep(5000); engine.eval(new FileReader("e:\\add.js"
)); Invocable invocable = (Invocable) engine; Object res =
invocable.invokeFunction("add",new Object[]{2,3}); System.out.println(res); } }
public static void main(String[] args) throws Exception{ ScriptEngineManager
scriptEngineManager= new ScriptEngineManager(); engine =
scriptEngineManager.getEngineByName("javascript"); getValues(); getObject();
putValue(); callJSFunction(); callJSFunctionFromFile(); } } public static void
main(String[] args) { ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine= engine = manager.getEngineByName("JavaScript"); engine.put(
"result", null); engine.put("value", null); String script = "var citys=[\"西安市\",
\"北京市\",\"天津市\"];var result=\"\"
;if(null!=value){for(i=0;i<citys.length;i++){if(value.indexOf(citys[i])!=-1){result=citys[i];}}}"
; try { engine.eval(script); System.out.println(engine.get("result")); } catch (
ScriptException e) { e.printStackTrace(); } } public static void main(String[]
args) { try { ScriptEngine engine = new ScriptEngineManager().getEngineByName(
"javascript"); Compilable compilable = (Compilable) engine; Bindings bindings =
engine.createBindings(); String script = "function cityContains(str){citys=[\"
西安市\",\"北京市\",\"天津市\"
];for(i=0;i<citys.length;i++){if(str.indexOf(citys[i])!=-1){return
citys[i];}}return\"\";} cityContains(city)"; CompiledScript JSFunction =
compilable.compile(script); //解析编译脚本函数 bindings.put("city", "天津市"); Object
result= JSFunction.eval(bindings); System.out.println(result);
//调用缓存着的脚本函数对象，Bindings作为参数容器传入} catch (ScriptException e) { log.error(
"执行JS函数发生异常", e); } }