第一种方式使用httpclient-*.jar (需要在网上去下载httpclient-*.jar包)
把httpclient-4.5.jar/httpclient-4.4.1.jar包放入到libs里，然后点击sync project ...才能使用httpclient-4.5.jar包
httpclient-4.5.jar不好用，建议使用httpclient-4.4.1.jar
第二种方式：配置AndroidStudio 的方式获取 HttpClient
在相应的module下的build.gradle中加入：useLibrary 'org.apache.http.legacy'
这条语句一定要加在 android{ } 当中，然后rebulid
例如：
app/build.gradle android { useLibrary 'org.apache.http.legacy' }
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "liudeli.async"
minSdkVersion 21
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
useLibrary 'org.apache.http.legacy'
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
在AndroidManifest.xml加入权限：
<!-- 访问网络是危险的行为 所以需要权限 --> <uses-permission android:name="android.permission.INTERNET" /> <!-- 设置壁纸是危险的行为 所以需要权限 --> <uses-permission android:name="android.permission.SET_WALLPAPER" />
MainActivity5：
package liudeli.async; import android.app.Activity; import android.app.ProgressDialog; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.AsyncTask; import android.os.Bundle; import android.os.Handler; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.ImageView; import android.widget.Toast; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.HttpResponse; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; public class MainActivity5 extends Activity { private final static String TAG = MainActivity5.class.getSimpleName(); // 图片地址 private final String PATH = "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000" + "&sec=1544714792699&di=3c2de372608ed6323f583f1c1b445e51&imgtype=0&src=http%3A%2F%2Fp" + "2.qhimgs4.com%2Ft0105d27180a686e91f.jpg"; private ImageView imageView; private Button bt_set_wallpaper; private ProgressDialog progressDialog; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main4); imageView = findViewById(R.id.iv_image); bt_set_wallpaper = findViewById(R.id.bt_set_wallpaper); Button bt_get_image = findViewById(R.id.bt_get_image); bt_get_image.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // 让异步任务执行耗时操作 new DownloadImage().execute(PATH); } }); bt_set_wallpaper.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (null != bitmap) { try { setWallpaper(bitmap); Toast.makeText(MainActivity5.this, "壁纸设置成功", Toast.LENGTH_LONG).show(); } catch (IOException e) { e.printStackTrace(); Toast.makeText(MainActivity5.this, "壁纸设置失败", Toast.LENGTH_LONG).show(); } } } }); } private Bitmap bitmap; class DownloadImage extends AsyncTask<String, Void, Object> { /** * 执行耗时操作前执行 */ @Override protected void onPreExecute() { super.onPreExecute(); // 弹出进度条 progressDialog = new ProgressDialog(MainActivity5.this); progressDialog.setMessage("Download ..."); progressDialog.show(); } /** * 执行耗时操作 * @param strings * @return */ @Override protected Object doInBackground(String... strings) { try { /** * 第一步 * HttpClient是接口 不能直接实例化，需要通过HttpClient接口的子类 DefaultHttpClient来实例化 */ HttpClient httpClient = new DefaultHttpClient(); /** * 第三步 * 实例化HttpGet对象，Get请求方式，应该说是请求对象 */ HttpUriRequest getRequest = new HttpGet(PATH); /** * 第二步 * 执行任务 */ HttpResponse response = httpClient.execute(getRequest); /** * 第四步 * 判断请求码 是否请求成功 */ int responseCode = response.getStatusLine().getStatusCode(); Log.d(TAG, "responseCode:" + responseCode); if (HttpURLConnection.HTTP_OK == responseCode) { /** * 第五步 * 获取到服务区响应的字节流数据 然后转换成图片Bitmap数据 */ InputStream inputStream = response.getEntity().getContent(); bitmap = BitmapFactory.decodeStream(inputStream); return bitmap; } } catch (Exception e) { e.printStackTrace(); } return null; } /** * 耗时执行过程中 更新进度条刻度操作 * @param values */ @Override protected void onProgressUpdate(Void... values) { super.onProgressUpdate(values); } /** * 耗时操作执行完成，用于更新UI * @param o */ @Override protected void onPostExecute(Object o) { super.onPostExecute(o); if (o != null) { // 成功 bitmap = (Bitmap) o; // 故意放慢两秒，模仿网络差的效果 new Handler().postDelayed(new Runnable() { @Override public void run() { // 设置从网上下载的图片 imageView.setImageBitmap(bitmap); // 设置为可以点击 bt_set_wallpaper.setEnabled(true); // 关闭进度条 progressDialog.dismiss(); } }, 2000); } else { //失败 bt_set_wallpaper.setEnabled(false); Toast.makeText(MainActivity5.this, "下载失败,请检查原因", Toast.LENGTH_LONG).show(); // 关闭进度条 progressDialog.dismiss(); } } } }
activity_layout5.xml :
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/bt_get_image" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="获取图片" android:onClick="getImage" android:layout_marginLeft="20dp" /> <Button android:id="@+id/bt_set_wallpaper" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="设置壁纸" android:layout_alignParentRight="true" android:layout_marginRight="20dp" android:enabled="false" /> <ImageView android:id="@+id/iv_image" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/bt_get_image" /> </RelativeLayout>
操作结果：
