eclipse 使用 Google Gson 库时出现 java.lang.NoClassDefFoundError
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/12792551/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Getting java.lang.NoClassDefFoundError while using Google Gson library
提问by Rajath
I am using Gson libraryto convert objects to Jsonand vice versa. I have copied the jarsof that library into a new folder liband added it to the build path for the project in my Eclipse IDE.
我正在使用Gson library将对象转换为对象，Json反之亦然。我已jars将该库的复制到一个新文件夹中lib，并将其添加到我的Eclipse IDE.
I have one main class where I convert an object into Json using toJson()shown below and send it to a servletusing Apache HttpClient's HttpPost().
我有一个主类，我使用toJson()如下所示将对象转换为 Json并将其发送到servletusing Apache HttpClient's HttpPost()。
Gson gson= new Gson();
String json = gson.toJson(names);
But in the servletI am not able to convert the Jsoninto Objectusing fromJson()when I execute the following code.
但是在执行以下代码时，我servlet无法将其转换Json为Objectusing fromJson()。
Gson gson = new Gson();
Names names = gson.fromJson(s, Names.class);
It is throwing the following exception:
它抛出以下异常：
java.lang.NoClassDefFoundError: com/google/gson/Gson
Any idea why that could be happening? Should I have copied the jarsinto the WebContent/WEB-INF/libfolder instead of a new folder called lib?
知道为什么会发生这种情况吗？我应该将 复制jars到WebContent/WEB-INF/lib文件夹而不是一个名为 的新文件夹中lib吗？
采纳答案by Rajath
Okay, I figured out the answer using this post. Please read the comments in the first answer.
好的，我用这篇文章找到了答案。请阅读第一个答案中的评论。
我收到“java.lang.ClassNotFoundException: com.google.gson.Gson”错误，即使它是在我的类路径中定义的
I just had to place the external jarsinto my WebContent/WEB-INF/libfolder and Eclipsewould take care of the build pathitself.
我不得不外部放置jars到我的WebContent/WEB-INF/lib文件夹，并Eclipse会采取照顾build path自己。
