12文件下载

来源：互联网发布：财经网数据编辑：程序博客网时间：2024/06/05 08:57

1、DDMS
2、文件下载
a、创建一个HttpURLConnection对象
HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
b、获得一个InputStream对象
urlConn.getInputStream()
c、访问网络的权限
android.permission.INTERNET
3、访问SD-CARD
a、得到当前设备SD卡的目录
Environment.getExternalStorageDirectory()
b、访问SD卡的权限
android.permission.WRITE_EXTERNAL_STORAGE

//////////////////////////////////////////////
HttpDownloader.java
public class HttpDownloader {
private URL url = null;

public String download(String urlStr){
  StringBuffer sb = new StringBuffer();
  String line = null;
  BufferedReader buffer = null;
  try{
   url = new URL(urlStr);
   HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
   buffer = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
   while ((line =buffer.readLine())!=null){
    sb.append(line);
   }
  }catch(Exception e){
   e.printStackTrace();
  }finally{
   try{
    buffer.close();
   }catch(Exception e){
    e.printStackTrace();
   }
  }
  return sb.toString();
}

public int downFile(String urlStr, String path, String fileName){
  InputStream inputStream = null;
  try{
   FileUtils fileUtils = new FileUtils();
   if(fileUtils.isFileExist(path+fileName)){
    return 1;
   }else{
    inputStream = getInputStreamFromUrl(urlStr);
    File resultFile = fileUtils.write2SDFromInput(path,fileName,inputStream);
    if(resultFile == null){
     return -1;
    }
   }
  }catch(Exception e){
   e.printStackTrace();
   return -1;
  }finally{
   try{
    inputStream.close();
   }catch(Exception e){
    e.printStackTrace();
   }
  }
  return 0;
}

public InputStream getInputStreamFromUrl(String urlStr)throws IOException{
  url = new URL(urlStr);
  HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
  InputStream inputStream = urlConn.getInputStream();
  return inputStream;
}
}
//////////////////////////////////////////////
FileUtils.java
package hy.com;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.os.Environment;

public class FileUtils {
private String SDPATH;

public String getSDPATH(){
  return SDPATH;
}

public FileUtils(){
  SDPATH = Environment.getExternalStorageState()+"/";
}

public File createSDFile(String fileName)throws IOException{
  File file = new File(SDPATH+fileName);
  file.createNewFile();
  return file;
}

public File createSDDir(String dirName){
  File dir = new File(SDPATH+dirName);
  dir.mkdir();
  return dir;
}

public boolean isFileExist(String fileName){
  File file = new File(SDPATH+fileName);
  return file.exists();
}

public File write2SDFromInput(String path, String fileName, InputStream input){
  File file = null;
  OutputStream output = null;
  try{
   createSDDir(path);
   file = createSDFile(path+fileName);
   output = new FileOutputStream(file);
   byte buffer[] = new byte[4*1024];
   while((input.read(buffer))!=-1){
    output.write(buffer);
   }
   output.flush();
  }catch(Exception e){
   e.printStackTrace();
  }finally{
   try{
    output.close();
   }catch(Exception e){
    e.printStackTrace();
   }
  }
  return file;
}
}
///////////////////////////////////////
//下载text
HttpDownloader httpDownloader = new HttpDownloader();
String lrc = httpDownloader.download("http://127.0.0.1:80/test.txt");
//下载MP3
HttpDownloader httpDownloader = new HttpDownloader();
int result = httpDownloader.downFile("http://127.0.0.1:80/test.mp3", "music/", "test.mp3");

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