Volley的Get、Post方式（JsonObjectRequest、StringRequest）以及Volley获取图片的3种方式
activity_main.xml 里面什么也没有
AndroidManifest.xml（重点是android:name="com.example.volley.MyApplication"）
MyApplication
package com.example.volley;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.Volley;
import android.app.Application;
public class MyApplication extends Application {
public static RequestQueue queue;
/** 一旦创建就创建RequestQueue请求队列 */
@Override
public void onCreate() {
super.onCreate();
queue = Volley.newRequestQueue(getApplicationContext());
}
/** 对外提供静态的方法 */
public static RequestQueue getHttpRequestQueue() {
return queue;
}
}
MainActivity
package com.example.volley;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import org.json.JSONObject;
import com.android.volley.Request.Method;
import com.android.volley.AuthFailureError;
import com.android.volley.Response;
import com.android.volley.Response.Listener;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.StringRequest;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
public class MainActivity extends Activity {
/**
* 关联activity，退出之后取消所有的网络请求，释放资源
*/
@Override
protected void onStop() {
super.onStop();
MyApplication.getHttpRequestQueue().cancelAll("abcGet");
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// volley_get();
volley_post();
}
/**
* get请求方式
*/
private void volley_get() {
/**
* String类型
*/
String url = "http://www.imooc.com/api/teacher?type=4&num=30";
StringRequest request = new StringRequest(Method.GET, url,
new Listener() {
@Override
public void onResponse(String arg0) {
//返回正确后的操作
Log.e("TAG", ""+arg0);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError arg0) {
}
});
// 设置标签
request.setTag("abcGet");
MyApplication.getHttpRequestQueue().add(request);
MyApplication.getHttpRequestQueue().start();
/**
* JsonObjectRequest类型 因为get参数已经在url写好了，所以传空即可
*/
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Method.GET,
url, null, new Listener() {
@Override
public void onResponse(JSONObject arg0) {
Toast.makeText(MainActivity.this, arg0.toString(), 0)
.show();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError arg0) {
}
});
// 设置标签
jsonObjectRequest.setTag("bcdGet");
MyApplication.getHttpRequestQueue().add(jsonObjectRequest);
MyApplication.getHttpRequestQueue().start();
/**
* 还有jsonArray方式,这里省略了。。。
*/
}
/**
* post请求方式
*/
private void volley_post() {
/**
* StringRequest---post方式
*/
String url = "http://www.imooc.com/api/teacher?";
StringRequest request = new StringRequest(Method.POST, url,
new Listener() {
@Override
public void onResponse(String arg0) {
Log.e("TAG", ""+arg0);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError arg0) {
}
}) {
@Override
protected Map getParams() throws AuthFailureError {
//传递参数
Map map = new HashMap();
map.put("type", "4");
map.put("num", "30");
return map;
}
};
// 设置标签
request.setTag("abcPost");
MyApplication.getHttpRequestQueue().add(request);
MyApplication.getHttpRequestQueue().start();
/**
* jsonObject--post方式
*/
HashMap map = new HashMap();
map.put("type", "4");
map.put("num", "30");
// 将map转为jsonObject对象
JSONObject object = new JSONObject(map);
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Method.POST, url,
object, new Listener() {
@Override
public void onResponse(JSONObject arg0) {
Log.e("TAG", arg0.toString());
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError arg0) {
}
});
// 设置标签
jsonObjectRequest.setTag("bcdPost");
MyApplication.getHttpRequestQueue().add(jsonObjectRequest);
MyApplication.getHttpRequestQueue().start();
}
}
*************************************************下载网络图片**********************************************
AndroidManifest.xml（重点是 android:name="com.example.volleyimagedemo.MyApplication"）
MyApplication
package com.example.volleyimagedemo;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.Volley;
import android.app.Application;
public class MyApplication extends Application {
public static RequestQueue queue;
@Override
public void onCreate() {
super.onCreate();
queue = Volley.newRequestQueue(getApplicationContext());
}
public static RequestQueue getHttpRequestQueue() {
return queue;
}
}
BitMapCache
package com.example.volleyimagedemo;
import android.graphics.Bitmap;
import android.util.LruCache;
import com.android.volley.toolbox.ImageLoader.ImageCache;
public class BitMapCache implements ImageCache{
public LruCache cache;
//超过10兆，自动回收
public int max = 10*1024*1024;
public BitMapCache(){
cache = new LruCache(max){
@Override
protected int sizeOf(String key, Bitmap value) {
return value.getRowBytes()*value.getHeight();
}
};
}
@Override
public Bitmap getBitmap(String arg0) {
return cache.get(arg0);
}
@Override
public void putBitmap(String arg0, Bitmap arg1) {
cache.put(arg0, arg1);
}
}
MainActivity
package com.example.volleyimagedemo;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.os.Bundle;
import android.widget.ImageView;
import com.android.volley.Response;
import com.android.volley.Response.Listener;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.ImageLoader.ImageListener;
import com.android.volley.toolbox.ImageRequest;
import com.android.volley.toolbox.NetworkImageView;
public class MainActivity extends Activity {
private ImageView imageview1;
private ImageView imageview2;
private NetworkImageView networkImageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/** 获取控件、图片url地址 */
imageview1 = (ImageView) findViewById(R.id.imageview1);
imageview2 = (ImageView) findViewById(R.id.imageview2);
networkImageView = (NetworkImageView) findViewById(R.id.networkImageview);
String url = "http://img.mukewang.com/55237dcc0001128c06000338-300-170.jpg";
/**
* 下载图片的第二种方式ImageLoader+BitMapCache
*/
// imageCache单肚使用是不到缓存效果，需要结合lruCache
ImageLoader imageLoader1 = new ImageLoader(
MyApplication.getHttpRequestQueue(), new BitMapCache());
networkImageView.setDefaultImageResId(R.drawable.ic_launcher);
networkImageView.setErrorImageResId(R.drawable.ic_launcher);
networkImageView.setImageUrl(url, imageLoader1);
/**
* 下载图片的第三种种方式
*/
ImageLoader imageLoader2 = new ImageLoader(
MyApplication.getHttpRequestQueue(), new BitMapCache());
// view视图，默认的图片，错误的图片
ImageListener listener = imageLoader1.getImageListener(imageview2,
R.drawable.ic_launcher, R.drawable.ic_launcher);
imageLoader2.get(url, listener);
/**
* 下载网络图片的第一种方式ImageRequest
*/
// // 0 是原图的方式加载--Config.RGB_565原图
ImageRequest imageRequest = new ImageRequest(url,
new Listener() {
//
@Override
public void onResponse(Bitmap arg0) {
imageview1.setImageBitmap(arg0);
}
}, 0, 0, Config.RGB_565, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError arg0) {
imageview1
.setBackgroundResource(R.drawable.ic_launcher);
}
});
MyApplication.getHttpRequestQueue().add(imageRequest);
MyApplication.getHttpRequestQueue().start();
}
}