android平台上对文件的操作和java基本上是相同的
注意用Environment.getExternalStorageDirectory()+"/"获得的SD目录最好
package duohuo.teng.net;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 FileUtil { private String SDPATH; public FileUtil() { //获得SD卡的路劲 SDPATH=Environment.getExternalStorageDirectory()+"/"; } /*创建文件 * * */ public File createFile(String fileName) throws IOException{ File file=new File(SDPATH+fileName); file.createNewFile(); return file; } /*创建文件夹 * * */ public File createDirs(String dirName){ File file=new File(SDPATH+dirName); Boolean b=file.mkdirs(); System.out.println(b); return file; } /*判断文件(夹)是否存在 * * */ public boolean isFileExist(String path){ return new File(SDPATH+path).exists(); } public File writeToSDFromInputStream(String path,String fileName,InputStream in){ File file=null; OutputStream out = null; createDirs(path); try { path=path+"/"+fileName; System.out.println(path); file=createFile(path); out=new FileOutputStream(file); byte[] buffer=new byte[4*1024]; while(in.read(buffer)!=-1){ out.write(buffer); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(out!=null) out.close(); if(in!=null) in.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return file; } /*delete file * @return 0 文件不存在 1删除成功 * */ public int deleteFile(String fileAllName){ File file=new File(SDPATH+fileAllName); if(isFileExist(file.getPath())){ return 0; } file.delete(); return 1; } }下面是下载?
package duohuo.teng.net;import java.io.BufferedReader;import java.io.File;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.net.URLConnection;public class HttpDownloadUtil { /*将文件保存为String * @param urlStr 本机测试是不是ip不是localhost和127.0.0.1,这是指android的IP,电脑是10.0.2.2 * */ public String downloadString(String urlStr){ StringBuffer result=new StringBuffer();; URL url; InputStream in = null; BufferedReader reader=null; try { url=new URL(urlStr); HttpURLConnection con=(HttpURLConnection)url.openConnection(); in=con.getInputStream(); reader=new BufferedReader(new InputStreamReader(in)); String line; while((line=reader.readLine())!=null){ result.append(line); } } catch (MalformedURLException e) { e.printStackTrace(); }catch (IOException e) { e.printStackTrace(); }finally{ try { if(reader!=null) reader.close(); if(in!=null) in.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return result.toString(); } /*将文件写入SD卡 * @return -1 写入失败 0存在 1写入成功 * @param urlStr 本机测试是不是ip不是localhost和127.0.0.1,这是指android的IP,电脑是10.0.2.2 * */ public int downloadFile(String urlStr,String toPath,String fileName){ try { URL url=new URL(urlStr); URLConnection con=url.openConnection(); InputStream in=con.getInputStream(); FileUtil fileUtil=new FileUtil(); if(fileUtil.isFileExist(toPath+fileName)){ return 0; } File file=fileUtil.writeToSDFromInputStream(toPath, fileName, in); if(file==null){ return -1; } } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); return -1; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); return -1; } return 1; } }?