如何从网络下载图片保存到SDCARD里面,直接看代码,这个通用,应该可以应用成从网络下载文件保存到SDCARD内。
package com.cts.testdwonloadimage.testdwonloadimage; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Environment; import android.os.Handler; import android.os.Message; import android.renderscript.ScriptGroup; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.widget.ImageView; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class MainActivity extends AppCompatActivity { private ImageView mImageView; private File cache; private String imgPath="https://www.cnblogs.com/images/logo_small.gif"; Handler handler=new Handler(new Handler.Callback() { @Override public boolean handleMessage(Message msg) { //显示 Bitmap b=(Bitmap)msg.obj; mImageView.setImageBitmap(b); //保存至本地 File imgFile=new File(cache,"woca.jpg"); try { BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(imgFile)); b.compress(Bitmap.CompressFormat.JPEG,80,bos); bos.flush(); bos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return false; } }); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mImageView=(ImageView)findViewById(R.id.mImageView); cache=new File(Environment.getExternalStorageDirectory(),"Test"); if(!cache.exists()){ cache.mkdirs(); } new Thread(){ @Override public void run() { super.run(); HttpURLConnection conn = null; InputStream is = null; try{ URL url = new URL(imgPath); conn=(HttpURLConnection) url.openConnection(); conn.setConnectTimeout(5000); conn.setRequestMethod("GET"); if(conn.getResponseCode()==200){ is=conn.getInputStream(); Bitmap b= BitmapFactory.decodeStream(is); //把输入流转化成bitmap格式,以msg形式发送至主线程 Message msg=new Message(); msg.obj=b; handler.sendMessage(msg); } }catch (Exception e){ String strEx = e.getMessage(); strEx = strEx + "111"; }finally { //conn.disconnect(); } } }.start(); } }
下载文件进一步
package com.cts.testdwonloadimage.testdwonloadimage; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Environment; import android.os.Handler; import android.os.Message; import android.renderscript.ScriptGroup; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ImageView; import android.widget.Toast; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.InputStream; import java.io.PrintStream; import java.net.HttpURLConnection; import java.net.URL; public class MainActivity extends AppCompatActivity { private ImageView mImageView; private File cache; private String imgPath = "https://www.cnblogs.com/images/logo_small.gif"; private PrintStream ps = null; private FileOutputStream os = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button btnTest = findViewById(R.id.btnTest); btnTest.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { btnTest(); } }); } public void btnTest() { cache = new File(Environment.getExternalStorageDirectory(), "Test"); if (!cache.exists()) { cache.mkdirs(); } new Thread() { @Override public void run() { super.run(); HttpURLConnection conn = null; InputStream is = null; try { URL url = new URL(imgPath); conn = (HttpURLConnection) url.openConnection(); conn.setConnectTimeout(5000); conn.setRequestMethod("GET"); if (conn.getResponseCode() == 200) { is = conn.getInputStream(); if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { Toast.makeText(getApplicationContext(), "读取失败,SD存储卡不存在!", Toast.LENGTH_LONG).show(); return; } /* Bitmap b= BitmapFactory.decodeStream(is); //把输入流转化成bitmap格式,以msg形式发送至主线程 Message msg=new Message(); msg.obj=b; handler.sendMessage(msg); */ //初始化File String FILENAME = "logo_smallaaa.gif"; String path = Environment.getExternalStorageDirectory().toString() + File.separator + "genwoxue" + File.separator + FILENAME; File file = new File(path); if (!file.getParentFile().exists()) file.getParentFile().mkdirs(); //ps = new PrintStream(new FileOutputStream(file)); os = new FileOutputStream(path); byte[] buff = new byte[1024]; int hasRead = 0; while ((hasRead = is.read(buff)) > 0) { os.write(buff); } } } catch (Exception e) { String strEx = e.getMessage(); strEx = strEx + "111"; } finally { //conn.disconnect(); } } }.start(); try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } Toast.makeText(MainActivity.this, "下载成功", Toast.LENGTH_LONG).show(); } }