title: java.lang.NoClassDefFoundError: Could not initialize class com.google.api.client.util.Data
body: <p>When I programming, an error occured:</p>
  <pre><code>&quot;java.lang.NoClassDefFoundError: Could not initialize class com.google.api.client.util.Data&quot;
  </code></pre>
  <p>How to resolve it?</p>
  <hr />
  <blockquote>
  <p>java.lang.NoClassDefFoundError: Could not initialize class
  com.google.api.client.util.Data at
  com.google.api.client.util.FieldInfo.(FieldInfo.java:131) at
  com.google.api.client.util.FieldInfo.of(FieldInfo.java:104) at
  com.google.api.client.util.ClassInfo.(ClassInfo.java:181) at
  com.google.api.client.util.ClassInfo.of(ClassInfo.java:92) at
  com.google.api.client.util.GenericData.(GenericData.java:79) at
  com.google.api.client.http.HttpHeaders.(HttpHeaders.java:59) at
  com.google.api.client.http.HttpRequest.(HttpRequest.java:65)</p>
  </blockquote>
  <hr />
  <blockquote>
  <p>at
  com.google.api.client.http.HttpTransport.buildRequest(HttpTransport.java:98)
  at
  com.google.api.client.http.HttpRequestFactory.buildRequest(HttpRequestFactory.java:89)
  at
  com.google.api.client.http.HttpRequestFactory.buildGetRequest(HttpRequestFactory.java:120)</p>
  </blockquote>