(Rest API)OkHttp

首先先在gradle裡面加入：

compile 'com.squareup.okhttp:okhttp:2.4.0'
compile 'com.squareup.okio:okio:1.4.0'

接著在AndroidManifest裡面加入下面兩段來獲取網路連線資源

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

GET

Request request = new Request.Builder()
      .url(url)
      .build();

POST

RequestBody formBody = new FormEncodingBuilder()
                .add("name", userName)
                .add("pass", passWord)
                .build();

Request request = new Request.Builder()
                .url(params[0]).post(formBody)
                .build();

SEND

try {
            Response response=client.newCall(request).execute();
            if (!response.isSuccessful())
                throw new IOException("Unexpected code " + response.toString());
            return response.body().string();
        } catch (IOException e) {
            e.printStackTrace();
        }

Http攜帶參數

RequestBody forBody=new FormEncodingBuilder()
                .add("name",UserName)
                .add("pass",UserPass)
                .build();
        Request request=new Request.Builder()
                .url(params[0]).post(forBody)
                .build();

下方實做圖片下載

在Layout的地方只需要加入一個按鈕跟一個ImageView就可以了

 <ImageView
        android:id="@+id/imageView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:visibility="invisible"
        android:src="@drawable/ic_launcher" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="Download Image" />

建立一個Class去繼承AsyncTesk之後實作OkHttpClient

public class OkHttpHandler extends AsyncTask<String, Void, byte[]> {

    OkHttpClient client = new OkHttpClient();

    @Override
    protected byte[] doInBackground(String... params) {

        Request.Builder builder = new Request.Builder();
        builder.url(params[0]);

        Request request = builder.build();

        try {

            Response response = client.newCall(request).execute();
            return response.body().bytes();

        } catch (Exception e) {
        }
        return null;

最後在Main裡面去實體化剛建立的Class

dowloadBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                dowloadBtn.setVisibility(View.INVISIBLE);
                OkHttpHandler handler = new OkHttpHandler();
                byte[] image = new byte[0];

                try {
                    image = handler.execute(URL).get();

                    if (image != null && image.length > 0) {

                        Bitmap bitmap = BitmapFactory.decodeByteArray(image, 0,
                                image.length);
                        mImage.setImageBitmap(bitmap);
                        mImage.setVisibility(View.VISIBLE);

就完成了！