如何解决使用JVM Nashorn播放框架渲染React.js时出错我得到“空不是函数”
来自这里的答案：https : //groups.google.com/forum/#!topic/play- framework/Oz8OC_fPdx8
“显然是8u25。使用最新版本的Nashorn的结果：在8u40中引发另一个异常；在8u60早期访问版本中完全可以正常工作。”
我验证了更新到8u60可以解决本地计算机上的问题。
解决方法
我正在阅读本教程：http : //tylermcginnis.com/reactjs-tutorial-a-
comprehensive-guide-to-building-apps-with-
react/，在使用JVM渲染React时遇到问题纳斯霍恩。
我的App.js文件如下。在客户端上运行时，它可以正常工作。仅在使用Nashorn / JVM时给出错误：
var App = React.createClass({
getInitialState: function(){
return {
name: 'Tyler McGinnis',friends: ['Jake Lingwall','Murphy Randall','Merrick Christensen'],}
},addFriend: function(friend){
this.setState({
friends: this.state.friends.concat([friend])
});
},render: function(){
return (
<div>
<h3> Name: {this.state.name} </h3>
<AddFriend addNew={this.addFriend} />
<ShowList names={this.state.friends} />
</div>
)
}
});
var AddFriend = React.createClass({
getInitialState: function(){
return {
newFriend: ''
}
},updateNewFriend: function(e){
this.setState({
newFriend: e.target.value
});
},handleAddNew: function(){
this.props.addNew(this.state.newFriend);
this.setState({
newFriend: ''
});
},render: function(){
return (
<div>
<input type="text" value={this.state.newFriend} onChange={this.updateNewFriend} />
<button onClick={this.handleAddNew}> Add Friend </button>
</div>
);
}
});
var ShowList = React.createClass({
render: function(){
var listItems = this.props.names.map(function(friend){
return <li> {friend} </li>;
});
return (
<div>
<h3> Friends </h3>
<ul>
{listItems}
</ul>
</div>
)
}
});
我的JVM代码：
ScriptEngine engine = new ScriptEngineManager(null).getEngineByName("nashorn");
String script = "var global = this;" +
"console = {log: print,warn: print,error: print};";
engine.eval (script);
// Evaluate React and the application code.
engine.eval(new FileReader("target/web/web-modules/main/webjars/lib/react/react-with-addons.js"));
engine.eval(new FileReader("target/web/public/main/javascripts/components/App.js"));
html = engine.eval("React.renderToString(React.createElement(App));").toString();
运行此代码时，出现以下堆栈跟踪错误：
Warning: ReactDOMButton(...): No `render` method found on the returned component instance: you may have forgotten to define `render` in your component or you may have accidentally tried to render an element whose type is a function that isn't a React component.
Warning: getInitialState was defined on ReactDOMButton,a plain JavaScript class. This is only supported for classes created using React.createClass. Did you mean to define a state property instead?
javax.script.ScriptException: TypeError: null is not a function in <eval> at line number 7395
at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:586)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:570)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:525)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:521)
at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:192)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
at controllers.Application.index(Application.java:50)
at Routes$$anonfun$routes$1$$anonfun$applyOrElse$1$$anonfun$apply$1.apply(routes_routing.scala:80)
at Routes$$anonfun$routes$1$$anonfun$applyOrElse$1$$anonfun$apply$1.apply(routes_routing.scala:80)
at play.core.Router$HandlerInvokerFactory$$anon$4.resultCall(Router.scala:264)
at play.core.Router$HandlerInvokerFactory$JavaActionInvokerFactory$$anon$15$$anon$1.invocation(Router.scala:255)
at play.core.j.JavaAction$$anon$1.call(JavaAction.scala:55)
at play.core.j.JavaAction$$anonfun$11.apply(JavaAction.scala:82)
at play.core.j.JavaAction$$anonfun$11.apply(JavaAction.scala:82)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at play.core.j.HttpExecutionContext$$anon$2.run(HttpExecutionContext.scala:40)
at play.api.libs.iteratee.Execution$trampoline$.execute(Execution.scala:46)
at play.core.j.HttpExecutionContext.execute(HttpExecutionContext.scala:32)
at scala.concurrent.impl.Future$.apply(Future.scala:31)
at scala.concurrent.Future$.apply(Future.scala:485)
at play.core.j.JavaAction$class.apply(JavaAction.scala:82)
at play.core.Router$HandlerInvokerFactory$JavaActionInvokerFactory$$anon$15$$anon$1.apply(Router.scala:252)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:130)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:130)
at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:129)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:128)
at scala.Option.map(Option.scala:145)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:128)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:121)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:483)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:483)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:519)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:519)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$14.apply(Iteratee.scala:496)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$14.apply(Iteratee.scala:496)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:41)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: <eval>:7395 TypeError: null is not a function
at jdk.nashorn.internal.runtime.ECMAErrors.error(ECMAErrors.java:58)
at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:214)
at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:186)
at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:173)
at jdk.nashorn.internal.runtime.linker.NashornBottomLinker.linkNull(NashornBottomLinker.java:176)
at jdk.nashorn.internal.runtime.linker.NashornBottomLinker.getGuardedInvocation(NashornBottomLinker.java:66)
at jdk.internal.dynalink.support.CompositeGuardingDynamicLinker.getGuardedInvocation(CompositeGuardingDynamicLinker.java:124)
at jdk.internal.dynalink.support.LinkerServicesImpl.getGuardedInvocation(LinkerServicesImpl.java:144)
at jdk.internal.dynalink.DynamicLinker.relink(DynamicLinker.java:232)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:7393(<eval>:7395)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:7412(<eval>:7421)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:535)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6855)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$14.L:4-1$L:13161$L:13341(<eval>:13353)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8127(<eval>:8153)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8057(<eval>:8063)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$14.L:4-1$L:13161$L:13341(<eval>:13353)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8127(<eval>:8153)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8057(<eval>:8063)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$16.L:4-1$L:14906$renderToString$L:14945(<eval>:14948)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:535)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.call(NativeFunction.java:162)
at jdk.nashorn.internal.scripts.Script$\^eval\_$19.L:4-1$L:18201$L:18319(<eval>:18335)
at jdk.nashorn.internal.scripts.Script$\^eval\_$16.L:4-1$L:14906$renderToString(<eval>:14945)
at jdk.nashorn.internal.scripts.Script$\^eval\_.runScript(<eval>:1)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:535)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:568)
... 43 more
如果我删除此行：
<button onClick={this.handleAddNew}> Add Friend </button>
从AddFriend渲染函数，然后错误消失。
编辑
如果我尝试通过执行以下操作来打印上面的button元素的结果：
function makeString(button){
var objStr = '';
for (var member in button) {
objStr += (objStr ? ',\n': '')+
member + ':' + button[member] + '';
}
return objStr;
}
var button = React.createElement("button",{onClick: this.handleAddNew}," Add Friend ")
var bs = makeString(button);
bs += '\n\n*****_owner:\n\n';
bs += makeString(button['_owner']);
bs += '\n\n*****_context:\n\n';
bs += makeString(button['_context']);
bs += '\n\n*****_store:\n\n';
bs += makeString(button['_store']);
bs += '\n\n*****props:\n\n';
bs += makeString(button['props']);
console.log(bs);
我得到以下打印输出：http :
//pastebin.com/raw.php?i=hEMkN8UP
版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。
