Andriod- 从网络下载文件保存到SDCARD里

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。

 

 

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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();
    }

}