Android self-study course-basic use of OkHttp and android course okhttp

Android self-study course-basic use of OkHttp and android course okhttp

Some time ago, I learned how to use a subthread to obtain network images and update the main UI. I found that most of the demos are based on HttpClient, but google seems to have weakened HttpClient. I can only find the related classes of HttpURLConnection. No way, you can only find new ways. This is the source of this translation.

　　

Before:

1. download the latest OKHttp Jar package and Okio Jar package.

2. Import the Jar package in Android studio.

The quickest way is: (but sometimes I do not know what to do, and then download and import the Jar package)

compile 'com.squareup.okhttp:okhttp:2.5.0'compile 'com.squareup.okio:okio:1.6.0'

 

 

1. Get An URlStep 1 :Select File-> New-> Project-> Android Application Project. Fill the forms, create "Blank Activity" and click "Finish" button. Step 2 :Open res-> layout-> activity_main.xml and add following code:

<RelativeLayout 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"    tools:context=".MainActivity">    <LinearLayout        android:id="@+id/linearLayout1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_alignParentTop="true"        android:layout_centerHorizontal="true"        android:weightSum="1">        <EditText            android:id="@+id/editText1"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_weight=".2" />        <Button            android:id="@+id/button1"            style="?android:attr/buttonStyleSmall"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_weight=".8"            android:onClick="downloadUrl"            android:text="Go" />    </LinearLayout>    <TextView        android:id="@+id/textView1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_below="@+id/linearLayout1"        android:layout_centerHorizontal="true"        android:layout_marginTop="35dp"        android:text=""        android:textAppearance="?android:attr/textAppearanceSmall" /></RelativeLayout>

 

 

Step 3: Open src-> package-> MainActivity. java and add following code:

package com.ryan.handler_messagedemo;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.EditText;import android.widget.TextView;import com.squareup.okhttp.OkHttpClient;import java.util.concurrent.ExecutionException;public class MainActivity extends AppCompatActivity {    private EditText edtText;    private TextView outputText;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        edtText = (EditText) findViewById(R.id.editText1);        outputText = (TextView) findViewById(R.id.textView1);    }    public void downloadUrl(View view) {        String url = "http://" + edtText.getText().toString();        OkHttpHandler handler = new OkHttpHandler();        String result = null;        try {            result = (String) handler.execute(url).get();        } catch (InterruptedException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (ExecutionException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        outputText.append(result + "\n");    }}

 

 

Step 4: Open src-> package-> Create new class OkHttpHandler. java and add following code:

package com.ryan.handler_messagedemo;import android.os.AsyncTask;import com.squareup.okhttp.OkHttpClient;import com.squareup.okhttp.Request;import com.squareup.okhttp.Response;/** * Created by air on 15-9-1. */public class OkHttpHandler extends AsyncTask {    OkHttpClient client = new OkHttpClient();    @Override    protected Object doInBackground(Object[] params) {        Request.Builder builder = new Request.Builder();        builder.url((String) params[0]);        Request request = builder.build();        try {            Response response = client.newCall(request).execute();            return response.body().string();        } catch (Exception e) {        }        return null;    }}

 

 

Step 5 :Open AndroidManifest. xml and add following code:

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.ryan.handler_messagedemo" >    <uses-permission android:name="android.permission.INTERNET" />    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

 

 

ScreenShot:

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

 

 

2. Get An ImageStep 1 :Select File-> New-> Project-> Android Application Project. Fill the forms, create "Blank Activity" and click "Finish" button. Step 2 :Open res-> layout-> activity_main.xml and add following code:

<RelativeLayout 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"    tools:context="com.skholingua.android.okhttp_getanimage.MainActivity" >     <ImageView        android:id="@+id/imageView1"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_centerHorizontal="true"        android:layout_centerVertical="true"        android:visibility="invisible"        android:src="@drawable/ic_launcher" />     <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_centerHorizontal="true"        android:layout_centerVertical="true"        android:text="Download Image" /> </RelativeLayout>

 

Step 3: Open src-> package-> MainActivity. java and add following code:

package com.ryan.okhttp_getimagedemo01;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.ImageView;public class MainActivity extends AppCompatActivity {    Button downloadBtn;    ImageView mImage;    private final String URL = "http://pic.cnblogs.com/avatar/790633/20150727124352.png";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        downloadBtn = (Button) findViewById(R.id.button1);        mImage = (ImageView) findViewById(R.id.imageView1);        downloadBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                downloadBtn.setVisibility(View.INVISIBLE);                OkHttpHandler handler = new OkHttpHandler();                byte[] image = new byte[0];                try {                    image = (byte[]) handler.execute(URL).get();                    if (image != null && image.length > 0) {                        Bitmap bitmap = BitmapFactory.decodeByteArray(image, 0,                                image.length);                        mImage.setImageBitmap(bitmap);                        mImage.setVisibility(View.VISIBLE);                    }                } catch (Exception e) {                }            }        });    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.menu_main, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // Handle action bar item clicks here. The action bar will        // automatically handle clicks on the Home/Up button, so long        // as you specify a parent activity in AndroidManifest.xml.        int id = item.getItemId();        //noinspection SimplifiableIfStatement        if (id == R.id.action_settings) {            return true;        }        return super.onOptionsItemSelected(item);    }}

 

 

Step 4: Open src-> package-> Create new class. java and add following code:

package com.ryan.okhttp_getimagedemo01;import android.os.AsyncTask;import com.squareup.okhttp.OkHttpClient;import com.squareup.okhttp.Request;import com.squareup.okhttp.Response;/** * Created by air on 15-9-1. */public class OkHttpHandler extends AsyncTask {    OkHttpClient client = new OkHttpClient();    @Override    protected Object doInBackground(Object[] params) {        Request.Builder builder = new Request.Builder();        builder.url((String) params[0]);        Request request = builder.build();        try {            Response response = client.newCall(request).execute();            return response.body().bytes();        } catch (Exception e) {        }        return null;    }}

 

 

Step 5 :Open AndroidManifest. xml and add following code:

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.ryan.okhttp_getimagedemo01" >    <uses-permission android:name="android.permission.INTERNET" />    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

ScreenShot:

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

So far, simple use has been completed. In the future, we will learn more about OkHttp content and threads.

 

About 3. Post To Server 4. Authentication,

For more information, see my source: http://www.skholingua.com/android-basic/other-sdk-n-libs/okhttp #