在使用okhttp库的时候忘记导入okio

今天调试《第一行代码》的HTTP访问网络部分，在使用okhttp库的时候，由于eclipse得手动导入包，结果出现错误。其实如果使用Android Studio, 就只要在gradle里面添加一句话，然后同步即可。真的是生产工具会大大提高生产力，不用再这种错误上浪费时间。

“Caused by: java.lang.ClassNotFoundException: Didn’t find class “okio.Buffer” on path: DexPathList[[zip file “/data/app/com.example.networktest-1/base.apk”],nativeLibraryDirectories=[/data/app/com.example.networktest-1/lib/arm64, /vendor/lib64, /system/lib64]]
”
后来才知道光导入okhttp包没有导入okio的包。
下载okio，导入，调试，ok

MainActivity.java

**public class MainActivity extends Activity implements OnClickListener{
    TextView responseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button sendRequest = (Button)findViewById(R.id.send_request);
        responseText = (TextView)findViewById(R.id.response_text);

        sendRequest.setOnClickListener(this);
    }
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        if(v.getId()==R.id.send_request){
//          sendRequestWithHttpURLConnection();
            sendRequestWithOkHttp();
        }
    }

    private void sendRequestWithOkHttp() {
        new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder()
                    .url("http://www.baidu.com")
                    .build();
                    //输入request执行，返回response
                    Response response = client.newCall(request).execute();
                    String responseData = response.body().string();
                    showResponse(responseData);
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }).start();

    }
    private void sendRequestWithHttpURLConnection() {
        new Thread(new Runnable() {

            @Override
            public void run() {
                HttpURLConnection connection = null;
                BufferedReader reader = null;
                try {
                    URL url = new URL("http://www.bing.com");
                    connection = (HttpURLConnection)url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    InputStream in = connection.getInputStream();
                    reader = new BufferedReader(new InputStreamReader(in));
                    StringBuilder response = new StringBuilder();
                    String line;
                    while ((line = reader.readLine())!=null) {
                        response.append(line);
                    }
                    showResponse(response.toString());
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }finally{
                    if(reader!=null){
                        try {
                            reader.close();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                    if (connection!=null) {
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }

    private void showResponse(final String response){
        runOnUiThread(new Runnable() {

            @Override
            public void run() {
                // 在这里进行UI操作，结果显示在界面上
                responseText.setText(response);
            }
        });
    }

}**

xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.networktest.MainActivity" >

    <Button
        android:id="@+id/send_request"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send Request" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView android:id="@+id/response_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
    </ScrollView>


</LinearLayout>