java中調用JavaScript進階應用程式（在JavaScript中調用Java中對象的方法）

        前面我們已經看到來在java中呼叫指令碼引擎執行JavaScript，現在我們看下將對象綁定到指令碼引擎後，怎麼在JavaScript中調用Java中對象的方法。

使用執行個體如下：

import java.util.HashMap; import java.util.Map; import java.util.logging.Level; import java.util.logging.Logger; import javax.script.Bindings; import javax.script.Invocable; import javax.script.ScriptContext; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; /** * * @author zcb */ public class SuperTest { public static void main(String[] args) { ScriptEngineManager sem = new ScriptEngineManager(); ScriptEngine se = null; se = sem.getEngineByExtension("js"); //se=sem.getEngineByMimeType("text/javascript"); //se=sem.getEngineByName("javascript"); String jsscript = "function mytest(){" + "println(ContextProperties);" + "ContextProperties.remove('three');" + "println(ContextProperties);" + "println('1:'+ContextProperties.containsKey('one'));" + "println('2:'+ContextProperties.containsKey('four'));" + "println('size:'+ContextProperties.size());" + "println(ContextProperties.get('one'));" + "return (ContextProperties.get('one')>ContextProperties.get('two'))?true:false;}";//也可以調用綁定對象的別的方法，如自訂對象的方法等 Bindings bindings = se.getBindings(ScriptContext.ENGINE_SCOPE); Map map = new HashMap(); map.put("one", 1); map.put("two", 5); map.put("three", 5); // bindings.putAll(map); // System.out.println("one:"+bindings.get("one")); // System.out.println("two:"+bindings.get("two")); //綁定Map對象，也可以綁定自訂的Java對象 bindings.put("ContextProperties",map); try { Object flag = null; se.eval(jsscript, bindings); if (se instanceof Invocable) { Invocable invoke = (Invocable) se; flag = invoke.invokeFunction("mytest"); System.out.println("flag:" + flag); } //輸出經過JavaScript修改後的map對象 System.out.println("map:"+map); } catch (NoSuchMethodException ex) { Logger.getLogger(SuperTest.class.getName()).log(Level.SEVERE, null, ex); } catch (ScriptException ex) { Logger.getLogger(SuperTest.class.getName()).log(Level.SEVERE, null, ex); } } }

輸出結果如下：

{two=5, one=1, three=5}
{two=5, one=1}
1:true
2:false
size:2
1
flag:false
map:{two=5, one=1} 注意：在js中對Java對象的更改也生效來哦~
這樣，我們就實現來Java調用JavaScript，而JavaScript又調用了Java，實現了迴圈調用。