Volley網絡請求

第一步：導依賴

dependencies { 
compile 'eu.the4thfloor.volley:com.android.volley:2015.05.28' 
}

第二步代碼實現

1. 建立一個RequestQueue對象。

2. 建立一個StringRequest對象。

3. 將StringRequest對象添加到RequestQueue裏面。

package com.example.myvolley;

import android.graphics.Bitmap;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.ImageRequest;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button but1;
    private Button but2;
    private ImageView img1;
    private Button but3;
    private ImageView img2;
    private Button but4;
    public static final String URLPOSTSTRING = "http://172.16.45.49:8080/day13/servlet/demo";
    public static final String URLIMG = "http://img.my.csdn.net/uploads/201403/03/1393854083_6511.jpg";
    public static final String URLSTRING = "http://112.124.22.238:8081/course_api/cniaoplay/featured2?p={%22page%22:0}";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        but1 = (Button) findViewById(R.id.but1);
        but2 = (Button) findViewById(R.id.but2);
        img1 = (ImageView) findViewById(R.id.img1);
        but3 = (Button) findViewById(R.id.but3);
        img2 = (ImageView) findViewById(R.id.img2);
        but4 = (Button) findViewById(R.id.but4);

        but1.setOnClickListener(this);
        but2.setOnClickListener(this);
        but3.setOnClickListener(this);
        but4.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.but1:
                requestStringGet();
                break;
            case R.id.but2:
                requsetImgGet();
                break;
            case R.id.but3:
                requsetImgLoaderGet();
                break;
            case R.id.but4:
                requsetPost();
                break;
        }
    }
    //POST請求字符串
    private void requsetPost() {
        RequestQueue requestQueue = Volley.newRequestQueue(this);
        StringRequest stringRequest = new StringRequest(Request.Method.POST, URLPOSTSTRING, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                Toast.makeText(MainActivity.this, response, Toast.LENGTH_SHORT).show();
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                HashMap<String,String> map = new HashMap<>();
                map.put("username", "abc");
                map.put("password", "123");
                return map;
            }
        };
        requestQueue.add(stringRequest);
    }
    //Get請求圖片--縮放模式
    private void requsetImgLoaderGet() {
        RequestQueue requestQueue = Volley.newRequestQueue(this);
        ImageLoader imageLoader = new ImageLoader(requestQueue, new ImageLoader.ImageCache() {
            @Override
            public Bitmap getBitmap(String url) {
                return null;
            }
            @Override
            public void putBitmap(String url, Bitmap bitmap) {
            }
        });
        ImageLoader.ImageListener imageListener = ImageLoader.getImageListener(img2,R.mipmap.ic_launcher, R.mipmap.ic_launcher);
        imageLoader.get(URLIMG,imageListener);
    }
    //Get請求圖片
    private void requsetImgGet() {
        RequestQueue requestQueue =Volley.newRequestQueue(this);
        ImageRequest imageRequest = new ImageRequest(URLIMG, new Response.Listener<Bitmap>() {
            @Override
            public void onResponse(Bitmap response) {
                img1.setImageBitmap(response);
            }
        }, 0, 0, Bitmap.Config.RGB_565, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        });
        requestQueue.add(imageRequest);
    }
    //Get請求字符串
    private void requestStringGet() {
        RequestQueue requestqueue = Volley.newRequestQueue(this);
        StringRequest stringRequest =   new StringRequest(Request.Method.GET,URLSTRING,
        new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                Toast.makeText(MainActivity.this, response, Toast.LENGTH_SHORT).show();
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        });
        requestqueue.add(stringRequest);
    }
}