HtmlUnit .setText（）はnullポインタ例外をスローしていますが、要素はnullではありません。

Question

HtmlUnitで要素のテキストを設定しようとしていますが、何らかの理由でNullPointerExceptionがスローされていることを理解できません。明らかに要素はページ上に存在し、htmlunitによって見つけられます！なぜsetTextはエラーを投げるのでしょうか？何か案は？

コード：

String code = "123"; 

HtmlTextInput textElem = (HtmlTextInput)page.getHtmlElementById("gc-redemption-input"); 
System.out.println(textElem); 
textElem.setText(code); 

出力：

HtmlTextInput[<input type="text" required="" id="gc-redemption-input" name="claimCode" class="gc-redemption-input a-input-text a-span12 a-form-selected" autofocus="autofocus" value="">] 

エラー：Unclosed character literal：それは私のIDE内で次のエラーを示しているため

Exception in thread "main" 
java.lang.NullPointerException 
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.hasTopCall(ScriptRuntime.java:3241) 
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:102) 
    at com.gargoylesoftware.htmlunit.javascript.host.dom.MutationObserver.attributeReplaced(MutationObserver.java:165) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:348) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.fireHtmlAttributeReplaced(HtmlElement.java:353) 
    at com.gargoylesoftware.htmlunit.html.HtmlElement.setAttributeNS(HtmlElement.java:209) 
    at com.gargoylesoftware.htmlunit.html.HtmlInput.setAttributeNS(HtmlInput.java:538) 
    at com.gargoylesoftware.htmlunit.html.HtmlTextInput.setAttributeNS(HtmlTextInput.java:164) 
    at com.gargoylesoftware.htmlunit.html.DomElement.setAttribute(DomElement.java:331) 
    at com.gargoylesoftware.htmlunit.html.HtmlInput.setValueAttribute(HtmlInput.java:94) 
    at com.gargoylesoftware.htmlunit.html.HtmlTextInput.setText(HtmlTextInput.java:124) 

Answer 1

問題は、String code = '123';かもしれません。代わりに二重引用符を使用してください：String code = "123";。