android创建目录和文件和安装其它apk

一、android下创建目录

File sd=Environment.getExternalStorageDirectory();
String path=sd.getPath()+"/notes";
File file=new File(path);
if(!file.exists())
file.mkdir();

二、android下创建文件

HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet= new HttpGet("http://img3.3lian.com/2006/016/09/031.jpg");
HttpResponse httpResponse = httpClient.execute(httpGet);
if(httpResponse.getStatusLine().getStatusCode() == 200){
total_length = httpResponse.getEntity().getContentLength();
is = httpResponse.getEntity().getContent() ;
File file = new File(Environment.getExternalStorageDirectory(), "aupdata.jpg");
fos = new FileOutputStream(file);
bis = new BufferedInputStream(is);
byte[] buffer = new byte[1024];
byte [] result_two = new byte [(int) total_length];
int len = 0;
int total=0;
while((len = bis.read(buffer)) > -1){
System.arraycopy(buffer, 0, result_two, total, len); fos.write(buffer, 0, len);
total = total + len ; }
}

FileOutputStream定义文件后。用.write方法写入内容，就能够创建相应文件了。

三、android安装其它apk

Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
File install_file = new File(Environment.getExternalStorageDirectory() , "MyWeb.apk");
intent.setDataAndType(Uri.fromFile(install_file), "application/vnd.android.package-archive");
startActivity(intent);