Android 从服务器下载文件保存到sd卡

不念不忘少年蓝@ 2024-02-17 14:05 75阅读 0赞

本代码是通过http协议实现文件下载，记得在配置文件中加入对SD卡的读写权限和联网权限

先来Activity代码

import android.app.Activity;
    import android.app.ProgressDialog;
    import android.os.Bundle;
    import android.os.Environment;
    import android.os.Handler;
    import android.os.Message;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.Toast;
    
    public class AndroidTestActivity extends Activity {
        /** Called when the activity is first created. */
    	private Button down;
    	private HttpDown http;
    	private String msg;
    	//下载进度条
    	private ProgressDialog mSaveDialog = null; 
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            down = (Button) findViewById(R.id.down);
            down.setOnClickListener(new OnClickListener() {
    			
    			@Override
    			public void onClick(View arg0) {
    				
    				mSaveDialog = ProgressDialog.show(AndroidTestActivity.this, "下载文件", "文件正在保存中，请稍等...", true);  
    				//开启一个新的线程执行下载任务
    				new Thread(
    						new Runnable() {
    							
    							@Override
    							public void run() {
    								// TODO Auto-generated method stub
    								http = new HttpDown();
    								//获得SD卡路径
    								String sdpath = Environment.getExternalStorageDirectory()+"/DRMP/";
    								String str = "http://music.baidu.com/data/music/file?link=http://zhangmenshiting.baidu.com/data2/music/106150597/10090002354000128.mp3?xcode=56ea6c3d5f9b569dfbe9ff93fd6d8248075fef7b4684889d&song_id=100900023";								
    								msg = http.download(str, sdpath, "1234.mp3");
    								messageHandler.sendMessage(messageHandler.obtainMessage());
    							}
    						}
    					).start();
    			}
    		});
        }
        
        private Handler messageHandler = new Handler(){
        	public void handleMessage(Message me){
        		mSaveDialog.dismiss();
        		Toast.makeText(AndroidTestActivity.this, msg, Toast.LENGTH_SHORT).show();
        	}
        };
    }

file工具类

/**
     * 
     */
    package com.wu;
    
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.HttpURLConnection;
    import java.net.URL;
    
    /**
     * @author wu
     *
     */
    public class HttpDown {
    
    	/**
    	 * 
    	 * @param strurl 文件url地址
    	 * @param path 需要保存文件的路径
    	 * @param fileName 保存到本地的文件名
    	 * @return
    	 */
    	public String download(String strurl,String path,String fileName){
    		
    		InputStream is = null;
    		OutputStream os = null;
    		URL url = null;
    		try {
    			//创建文件夹
    			File f = new File(path);
    			if(!f.exists()){
    				f.mkdir();
    			}
    			//创建文件
    			File file = new File(path+fileName);
    			//判断是否存在文件
    			if(file.exists()){
    				//创建新文件
    				file.createNewFile();
    			}else{
    				file.delete();
    				file.createNewFile();
    			}
    			//创建并打开连接
    			url = new URL(strurl);
    			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    			//文件输入流
    			is = conn.getInputStream();			
    			//输出流
    			os = new FileOutputStream(file);
    			byte buffer[] = new byte[1024];
    			int len =0 ;
    			while( (len = is.read(buffer))!= -1){
    				os.write(buffer,0,len);
    			}
    			os.flush();
    			return "success";
    		} catch (IOException e) {
    				// TODO Auto-generated catch block
    			e.printStackTrace();
    			return "failure";
    		}finally{
    			try{
    			    os.close();
    			    is.close();
    			}
    			catch(Exception e){
    			    e.printStackTrace();
    			}
    		}
    		
    	}
    }

如有问题不正 请大家多多指出，共同学习