安卓學習----使用okHttp(get方式)---下載圖片，

安卓學習----使用okHttp(get方式)---下載圖片，
一首先下載Jar包

https://github.com/square/okhttp

 

如果使用android studio只需要加入依賴

compile 'com.squareup.okhttp3:okhttp:3.2.0'

 

二--下載一張圖片並顯示

使用的是hanlder的方式

package com.liunan.okhttpdemo2;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.ImageView;import android.widget.Toast;import java.io.IOException;import java.io.InputStream;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.Response;import okhttp3.ResponseBody;public class MainActivity extends AppCompatActivity {    private static final int ERROR = 1;    private static final int SUCCESS = 2 ;    private String url = "http://192.168.1.102:8080/img/a.jpg";    private ImageView mIv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();    }    private Handler handler = new Handler(){        @Override        public void handleMessage(Message msg) {            switch (msg.what){                case SUCCESS:                    mIv.setImageBitmap((Bitmap) msg.obj);                    break;                case ERROR:                    Toast.makeText(MainActivity.this, "請求逾時", Toast.LENGTH_SHORT).show();                    break;            }        }    };    /**     * 初始化 組件     */    private void initView() {        mIv = (ImageView) findViewById(R.id.main_iv);    }    /**     * 點擊擷取圖片     */    public void getPic(View v){        new Thread(){            @Override            public void run() {                //擷取okHttp對象get請求,                try {                    OkHttpClient client = new OkHttpClient();                    //擷取請求對象                    Request request = new Request.Builder().url(url).build();                    //擷取響應體                    ResponseBody body = client.newCall(request).execute().body();                    //擷取流                    InputStream in = body.byteStream();                    //轉化為bitmap                    Bitmap bitmap = BitmapFactory.decodeStream(in);                    //使用Hanlder發送訊息                    Message msg = Message.obtain();                    msg.what = SUCCESS;                    msg.obj = bitmap;                    handler.sendMessage(msg);                } catch (IOException e) {                    e.printStackTrace();                    //失敗                    Message msg = Message.obtain();                    msg.what = ERROR;                    handler.sendMessage(msg);                }            }        }.start();    }}

也可以把網路請求寫為一個工具類,

package com.liunan.okhttpdemo2;import java.io.IOException;import java.io.InputStream;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.Response;/** * Created by 劉楠 on 2016-03-27. */public class OkHttpUtils {    OkHttpClient client = new OkHttpClient();    /**     * 擷取流     * @param url  請求地址     * @return  輸入資料流     */    public InputStream getInpuStream(String url) throws IOException {        //設定 請求        Request request = new Request.Builder()                .url(url).build();        //擷取行響應        InputStream in = client.newCall(request).execute().body().byteStream();        return in;    }    /**     * 返回字串     * @param url     * @return   返回字串     * @throws IOException     */  public String getString(String url) throws IOException {        //設定 請求        Request request = new Request.Builder()                .url(url).build();        //擷取行響應      Response response = client.newCall(request).execute();      return response.body().string();    }}

 

get方式