在Android Studio中找不到Java类

Question

I am building an app which has to log in on a server, once logged in it will show a webview.

This is my first time programming in Android, i managed to get all pieces i need for the app working. But when i am trying to put my code together in Android Studio, i get some Java errors.

I didn't get these errors when i was testing my code in Eclipse IDE, it ran perfect.

At first Android Studio couldn't find some classes, so i added the jar i needed (httpclient-4.3.5.jar) to the app/src/lib folder. The errors went away, and i could compile and start the app.

However when my sendPost() method is called, my app crashes and gives me errors in my console. The method tries to do a simple HTTP request which works perfectly in Eclipse. This is the error I get:

Caused by: java.lang.NoClassDefFoundError: org.apache.http.util.TextUtils
at org.apache.http.impl.client.HttpClientBuilder.split(HttpClientBuilder.java:686)
at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:702)
at org.apache.http.impl.client.HttpClients.createSystem(HttpClients.java:66)
at com.example.loginscreen2.MainActivity.sendPost(MainActivity.java:106)
at com.example.loginscreen2.MainActivity.login(MainActivity.java:52)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at android.view.View$1.onClick(View.java:3818)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)

The line causing this error is : CloseableHttpClient client = HttpClients.createSystem(); I am puzzled, i added the library, Android Studio put the import lines in for me, still it cant find the class?

Does anyone know what might be the problem?

EDIT: these are my apps dependencies in the app's build.gradle dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) }

I installed ADT Bundle for Eclipse, within Android project i'm getting the same error there....

Answer 1

我使用了构建路径选项来导入库，将其删除并将库文件复制到“ libs”文件夹似乎可以解决问题。