Android 从网上获取图片

时间 2020-05-08 标签 android 网上获取图片

<?xml version= "1.0" encoding= "utf-8"?>
<LinearLayout xmlns:android= "http://schemas.android.com/apk/res/android"
  android:orientation="vertical" android:layout_width="fill_parent"
  android:layout_height="fill_parent">
  <TextView android:id="@+id/textView1" android:layout_width="wrap_content"
    android:layout_height="wrap_content" android:text="请输入图片网址"></TextView>
  <EditText android:layout_height="wrap_content"
    android:layout_width="fill_parent" android:id="@+id/editText_url"></EditText>
  <Button android:layout_width="wrap_content"
    android:layout_height="wrap_content" android:text="获取" android:id="@+id/button_get"></Button>
  <ImageView android:layout_height="wrap_content"
    android:layout_width="wrap_content" android:layout_gravity="center"
    android:id="@+id/p_w_picpathView"></ImageView>
</LinearLayout>

package com.yanjun;

import com.yanjun.getImage.GetImage;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
/**
* 经过网络获取图片
* @author YanJun
*<uses-permission android:name="android.permission.INTERNET"></uses-permission>
*/
public class MainActivity extends Activity {


   private static final String TAG = "MainActivity";
  EditText p_w_picpathEditText = null ;
  Button button ;
  ImageView p_w_picpathView ;
        @Override
         public void onCreate(Bundle savedInstanceState) {
                 super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                p_w_picpathEditText = (EditText) findViewById(R.id.editText_url);
                p_w_picpathView = (ImageView) findViewById(R.id.p_w_picpathView);
                button = (Button) findViewById(R.id.button_get);
                button.setOnClickListener( new OnClickListener() {

       public void onClick(View v) {
         // TODO Auto-generated method stub
        String Url = p_w_picpathEditText.getText().toString();
         try {
           //获得图片二进制数据
           byte[] data = GetImage.getImage(Url);
           //将二进制数据转换成位图
          Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
           //显示图片
          p_w_picpathView.setImageBitmap(bitmap);
        } catch (Exception e) {

          Toast.makeText(MainActivity. this, "连接延时", Toast.LENGTH_LONG).show();
          Log.e(TAG, e.toString());
        }
      }
    });
        }

}

package com.yanjun.getImage;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class GetImage {
   /**
    * 获取路径方法
    * @param path 路径
    * @return
    * @throws Exception
    */
         public static byte[]getImage(String path) throws Exception {
     // 从网络上获取图片--UUL对象用来封装路径
    URL url = new URL(path);
     // 打开路径连接---获得HttpURLConnection对象
    HttpURLConnection httpURLConnection = (HttpURLConnection) url
        .openConnection();
     // 经过HTTP协议请求网络图片---设置请求方式：get/post
    httpURLConnection.setRequestMethod( "GET");
     // 设置链接超时
    httpURLConnection.setConnectTimeout(5*1000);
     // 从外界想手机应用内传递数据----经过输入流获取图片数据
    InputStream inputStream = httpURLConnection.getInputStream();
     // 从输入流中获取图片的二进制数据----readInputStream()
     return StreamTool.readInputStream(inputStream);

  }
}

package com.yanjun.getImage;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class StreamTool {

   /**从输入流获取数据
    * @param inSream 输入流
    * @return
    * @throws Exception
    */

     public static byte[] readInputStream(InputStream inSream) throws Exception {
      ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
       // 定义一个缓冲区
       byte[] buffer = new byte[1024];
       int len = 0;
       // 不断的从流里读取数据---while循环---nSream.read(buffer)表示从流里读取数据到缓冲区
       // 读取到末尾时，返回值是-1；
       while ((len = inSream.read(buffer)) != -1) {
         // 将缓冲区的数据写到输出流中
        byteArrayOutputStream.write(buffer, 0, len);
      }
      inSream.close();
       return byteArrayOutputStream.toByteArray();     } }