Okhttp的简单介绍和使用(一)
16lz
2021-01-26
前言:
通过本篇,可以了解一下几点:
- Android中网络请求进化
- okhttp是什么
- okhttp的简单使用
如果有兴趣,可以看下我的另一篇,okhttp的简单封装:
- http://blog.csdn.net/wuyinlei/article/details/50598783
网络请求发展:
- HttpURLConnection—>Apache HTTP Client—>Volley—->okHttp
OkHttp是什么:
- 项目开源地址 :https://github.com/square/okhttp
- 项目使用:在build.gradle中加入依赖
compile 'com.squareup.okhttp3:okhttp:3.0.1'
OkHttp是一个高效的HTTP库:
- 1.支持 SPDY ,共享同一个Socket来处理同一个服务器的所有请求
- 2.如果SPDY不可用,则通过连接池来减少请求延时
- 3.无缝的支持GZIP来减少数据流量
- 4.缓存响应数据来减少重复的网络请求
优点:
- OkHttp会从很多常用的连接问题中自动恢复。如果您的服务器配置了多个IP地址,当第一个IP连接失败的时候,会自动尝试下一个IP。OkHttp还处理了代理服务器问题和SSL握手失败问题。
- 使用 OkHttp 无需重写您程序中的网络代码。OkHttp实现了几乎和java.net.HttpURLConnection一样的API。如果您用了 Apache HttpClient,则OkHttp也提供了一个对应的okhttp-apache 模块
Okhttp的基本使用,从以下五方面讲解:
- 1.Get请求(同步和异步)
- 2.POST请求表单(key-value)
- 3.POST请求提交(JSON/String/文件等)(这个有待研究)
- 4.文件下载
- 5.请求超时设置
GET请求同步方法
OkHttpClient client=new OkHttpClient(); Request request = new Request.Builder().url(url) .build(); Response response= client.newCall(request).execute(); String message=response.body().string();
GET请求异步方法
OkHttpClient client=new OkHttpClient(); Request request = new Request.Builder().url(url).build(); client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Request request, IOException e) { } @Override public void onResponse(Response response) throws IOException { } });
POST请求提交
在这里解释一下,我在用3.0的时候,去找FormEncodingBuilder(),这个方法,找不到了,就去了他的官网查看了信息,找到了一下一段解释:
- We’ve replaced the opaque FormEncodingBuilder with the more powerful FormBody and FormBody.Builder combo. Similarly we’ve upgraded MultipartBuilder into MultipartBody, MultipartBody.Part, and MultipartBody.Builder.
okhttp3.0之前:
OkHttpClient client = new OkHttpClient(); RequestBody forBody = new FormEncodingBuilder().add("username","tom").add("password", "1110").build(); Request request=new Request.Builder().url(url).post(forBody).build(); client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Request request, IOException e) { } @Override public void onResponse(Response response) throws IOException { Log.d("xiaoming",response.body().string()); } });
okhttp3.0之后
OkHttpClient client = new OkHttpClient(); FormBody formBody = new FormBody.Builder() .add("type", "1") .build(); Request request=new Request.Builder().url(url).post(forBody).build(); client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Request request, IOException e) { } @Override public void onResponse(Response response) throws IOException { Log.d("xiaoming",response.body().string()); } });
文件下载
String url = "http://www.0551fangchan.com/images/keupload/20120917171535_49309.jpg"; //构建request对象 Request request = new Request.Builder().url(url).build(); OkHttpClient client = new OkHttpClient(); client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { } @Override public void onResponse(Call call, Response response) throws IOException { InputStream inputStream = response.body().byteStream(); FileOutputStream fileOutputStream = new FileOutputStream(new File("/sdcard/logo.jpg")); byte[] buffer = new byte[2048]; int len = 0; while ((len = inputStream.read(buffer)) != -1) { fileOutputStream.write(buffer, 0, len); } fileOutputStream.flush(); Log.d("wuyinlei", "文件下载成功..."); } });
超时设置:
okhttp3.0之前:
client.setConnectTimeout(10, TimeUnit.SECONDS); client.setWriteTimeout(10, TimeUnit.SECONDS); client.setReadTimeout(30, TimeUnit.SECONDS);
okhttp3.0之后:
client.newBuilder().connectTimeout(10, TimeUnit.SECONDS); client.newBuilder().readTimeout(10,TimeUnit.SECONDS); client.newBuilder().writeTimeout(10,TimeUnit.SECONDS);
下面看下结果演示:
注:不知道为什么,我的写入sdcard的权限也加了,就是提示我下载的时候没有权限,我只能用真机了,这里通过log日志来反馈下载成功:
下面来看下代码,布局很简单,四个按钮,一个textview,这里就不解释了
package com.example.okhttpdemo;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.TextView;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.util.concurrent.TimeUnit;import okhttp3.Call;import okhttp3.Callback;import okhttp3.FormBody;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.Response;public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button syncGet; private Button asyncget; private Button post; private Button fileDownload,fengzhuang; private TextView tvtext; private String result; private static OkHttpClient client = new OkHttpClient(); /** * 在这里直接设置连接超时,静态方法内,在构造方法被调用前就已经初始话了 */ static { client.newBuilder().connectTimeout(10, TimeUnit.SECONDS); client.newBuilder().readTimeout(10, TimeUnit.SECONDS); client.newBuilder().writeTimeout(10, TimeUnit.SECONDS); } private Request request; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initialize(); initListener(); } /** * 事件监听 */ private void initListener() { syncGet.setOnClickListener(this); asyncget.setOnClickListener(this); post.setOnClickListener(this); fileDownload.setOnClickListener(this); fengzhuang.setOnClickListener(this); } /** * 初始化布局控件 */ private void initialize() { syncGet = (Button) findViewById(R.id.syncGet); asyncget = (Button) findViewById(R.id.asyncget); post = (Button) findViewById(R.id.post); tvtext = (TextView) findViewById(R.id.tv_text); fileDownload = (Button) findViewById(R.id.fileDownload); fengzhuang = (Button) findViewById(R.id.fengzhuang); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.syncGet: initSyncData(); break; case R.id.asyncget: initAsyncGet(); break; case R.id.post: initPost(); break; case R.id.fileDownload: downLoadFile(); break; case R.id.fengzhuang: break; } } /** * get请求同步方法 */ private void initSyncData() { new Thread(new Runnable() { @Override public void run() { try { request = new Request.Builder().url(Contants.SYNC_URL).build(); Response response = client.newCall(request).execute(); result = response.body().string(); runOnUiThread(new Runnable() { @Override public void run() { tvtext.setText(result); Log.d("MainActivity", "hello"); } }); } catch (Exception e) { e.printStackTrace(); } } }).start(); } /** * 异步请求 */ private void initAsyncGet() { new Thread(new Runnable() { @Override public void run() { request = new Request.Builder().url(Contants.ASYNC_URL).build(); client.newCall(request).enqueue(new Callback() { /** * A call is a request that has been prepared for execution. A call can be canceled. As this object * represents a single request/response pair (stream), it cannot be executed twice. * * * @param call 是一个接口, 是一个准备好的可以执行的request * 可以取消,对位一个请求对象,只能单个请求 * @param e */ @Override public void onFailure(Call call, IOException e) { Log.d("MainActivity", "请求失败"); } /** * * @param call * @param response 是一个响应请求 * @throws IOException */ @Override public void onResponse(Call call, Response response) throws IOException { /** * 通过拿到response这个响应请求,然后通过body().string(),拿到请求到的数据 * 这里最好用string() 而不要用toString() * toString()每个类都有的,是把对象转换为字符串 * string()是把流转为字符串 */ result = response.body().string(); runOnUiThread(new Runnable() { @Override public void run() { tvtext.setText(result); } }); } }); } }).start(); } /** * 表单提交 */ private void initPost() { String url = "http://112.124.22.238:8081/course_api/banner/query"; FormBody formBody = new FormBody.Builder() .add("type", "1") .build(); request = new Request.Builder().url(url) .post(formBody).build(); new Thread(new Runnable() { @Override public void run() { client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { } @Override public void onResponse(Call call, final Response response) throws IOException { runOnUiThread(new Runnable() { @Override public void run() { tvtext.setText("提交成功"); } }); } }); } }).start(); } /** * 文件下载地址 */ private void downLoadFile() { String url = "http://www.0551fangchan.com/images/keupload/20120917171535_49309.jpg"; request = new Request.Builder().url(url).build(); OkHttpClient client = new OkHttpClient(); client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { } @Override public void onResponse(Call call, Response response) throws IOException { //把请求成功的response转为字节流 InputStream inputStream = response.body().byteStream(); /** * 在这里要加上权限 在mainfests文件中 * <uses-permission android:name="android.permission.INTERNET"/> * <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> */ //在这里用到了文件输出流 FileOutputStream fileOutputStream = new FileOutputStream(new File("/sdcard/logo.jpg")); //定义一个字节数组 byte[] buffer = new byte[2048]; int len = 0; while ((len = inputStream.read(buffer)) != -1) { //写出到文件 fileOutputStream.write(buffer, 0, len); } //关闭输出流 fileOutputStream.flush(); Log.d("wuyinlei", "文件下载成功..."); } }); }}
好了,简单的okhttp使用就介绍到这里了,接下来会对其完成以下简单的封装。
由于okhttp3.0较于之前的有些变化,大家使用的时候可以去看下他们官方的说明,这样在使用中就会少了不必要的麻烦了。
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