android网络请求库volley方法详解 _Android网络

【android网络请求库volley方法详解】不飞则已，一飞冲天；不鸣则已，一鸣惊人。这篇文章主要讲述android网络请求库volley方法详解相关的知识，希望能为你提供帮助。
使用volley进行网络请求：需先将volley包导入androidstudio中
File下的Project Structrue，点加号导包

文章图片

volley网络请求步骤：
1. 创建请求队列 RequestQueue queue = Volley.newRequestQueue(this);
2.创建请求对象（3种）
StringRequest request = new StringRequest（“ 请求方法” ，“ 请求的网络地址” ，“ 成功的网络回调” ，“ 失败的网络回调” ）；
ImageRequest request = new ImageRequest（“ 图片路径” ，“ 成功的回调函数” ，“ 图片宽度” ，“ 图片高度” ，“ 图片的颜色属性” ，“ 失败的网络回调” ）；
Jsonrequest request = new Jsonrequest（）；
3.把请求对象放入请求队列 queue.add(request);
注销请求：重写onstop方法

@Override
protected void onStop() {
super.onStop();
/*取消当前请求队列的所有请求*/
queue.cancelAll(this);
/*取消当前请求队列tag为get的请求*/
queue.cancelAll("get");
/*取消当前请求队列tag为post的请求*/
queue.cancelAll("post");
}

设置当前请求的优先级：重写getPriority方法

@Override
public Priority getPriority() {
return Priority.LOW;
}

设置请求头：重写GetHeader方法

@Override
public Map< String, String> getHeaders() throws AuthFailureError {
Map< String,String> map = new HashMap< String, String> ();
map.put("apikey","fc642e216cd19906f642ee930ce28174");
return map;
}

传递参数：重写GetParams方法

@Override
protected Map< String, String> getParams() throws AuthFailureError {
Map< String,String> map = new HashMap< String, String> ();
map.put("num","10");
map.put("page","1");
map.put("word","%E6%9E%97%E4%B8%B9");
return map;
}

代码部分：
xml文件：

< ?xml version="1.0" encoding="utf-8"?> < 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:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:orientation="vertical" tools:context="com.jredu.helloworld.activity.VolleyActivity"> < WebView android:id="@+id/volleyWebView" android:layout_width="match_parent" android:layout_height="300dp"> < /WebView> < ImageView android:id="@+id/img" android:layout_width="match_parent" android:layout_height="wrap_content" /> < Button android:id="@+id/volleyButton" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:textAllCaps="false" android:text="Volley"/> < Button android:id="@+id/imgButton" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:textAllCaps="false" android:text="Volley获取图片"/> < /LinearLayout>

activity文件：

package com.jredu.helloworld.activity; import android.graphics.Bitmap; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.webkit.WebView; import android.widget.Button; import android.widget.ImageView; import com.android.volley.AuthFailureError; import com.android.volley.NetworkResponse; import com.android.volley.ParseError; 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.HttpHeaderParser; import com.android.volley.toolbox.ImageRequest; import com.android.volley.toolbox.StringRequest; import com.android.volley.toolbox.Volley; import com.jredu.helloworld.R; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Map; public class VolleyActivity extends AppCompatActivity { WebView webView; Button button; Button imgButton; ImageView img; RequestQueue queue = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_volley); queue = Volley.newRequestQueue(this); webView = (WebView) findViewById(R.id.volleyWebView); img = (ImageView) findViewById(R.id.img); button = (Button) findViewById(R.id.volleyButton); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { doStringVolley2(); doStringVolley(); } }); imgButton = (Button) findViewById(R.id.imgButton); imgButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { GetImg(); } }); } /*get方法*/ public void doStringVolley(){ /*创建请求队列*/ //RequestQueue queue = Volley.newRequestQueue(this); /*创建请求对象*/ StringRequest request = new StringRequest( Request.Method.GET, "http://apis.baidu.com/txapi/tiyu/tiyu?num=10& page=1& word=%E6%9E%97%E4%B8%B9", /*"http://www.baidu.com",*/ new Response.Listener< String> () { @Override public void onResponse(String response) { String s = response; webView.getSettings().setDefaultTextEncodingName("utf-8"); webView.getSettings().setjavascriptEnabled(true); webView.loadDataWithBaseURL(null,s,"text/html","utf-8",null); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { webView.loadDataWithBaseURL(null,"网络连接失败!!!","text/html","utf-8",null); } } ){ /*设置请求头*/ @Override public Map< String, String> getHeaders() throws AuthFailureError { Map< String,String> map = new HashMap< String, String> (); map.put("apikey","fc642e216cd19906f642ee930ce28174"); return map; } /*解析网络请求结果的方法*/ @Override protected Response< String> parseNetworkResponse( NetworkResponse response) { try { String jsonObject = new String( new String(response.data, "UTF-8")); returnResponse.success(jsonObject, HttpHeaderParser.parseCacheHeaders(response)); } catch (UnsupportedEncodingException e) { return Response.error(new ParseError(e)); } catch (Exception je) { return Response.error(new ParseError(je)); } } /*设置当前请求的优先级*/ @Override public Priority getPriority() { return Priority.LOW; } }; request.setTag("get"); /*把请求对象放入请求队列*/ queue.add(request); } /*post方法*/ public void doStringVolley2(){ /*创建请求队列*/ //RequestQueue queue = Volley.newRequestQueue(this); /*创建请求对象*/ StringRequest request = new StringRequest( Request.Method.POST, "http://www.baidu.com", new Response.Listener< String> () { @Override public void onResponse(String response) { String s = response; webView.getSettings().setDefaultTextEncodingName("utf-8"); webView.getSettings().setJavaScriptEnabled(true); webView.loadDataWithBaseURL(null,s,"text/html","utf-8",null); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { webView.loadDataWithBaseURL(null,"网络连接失败!!!","text/html","utf-8",null); } } ){ /*重写params方法写参数*/ @Override protected Map< String, String> getParams() throws AuthFailureError { Map< String,String> map = new HashMap< String, String> (); map.put("num","10"); map.put("page","1"); map.put("word","%E6%9E%97%E4%B8%B9"); return map; } /*设置请求对象优先级*/ @Override public Priority getPriority() { return Priority.HIGH; } }; request.setTag("post"); /*把请求对象放入请求队列*/ queue.add(request); } /*获取图片*/ public void GetImg(){ ImageRequest request = new ImageRequest( "https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/bd_logo1_31bdc765.png", new Response.Listener< Bitmap> () { @Override public void onResponse(Bitmap response) { img.setImageBitmap(response); } }, 5000, 5000, Bitmap.Config.ARGB_8888, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { img.setImageResource(R.drawable.first5); } } ); queue.add(request); } /*重写onStop方法，用来注销请求*/ @Override protected void onStop() { super.onStop(); /*取消当前请求队列的所有请求*/ queue.cancelAll(this); /*取消当前请求队列tag为get的请求*/ queue.cancelAll("get"); /*取消当前请求队列tag为post的请求*/ queue.cancelAll("post"); } }