//下载apk程序代码
protected File downLoadFile(String httpUrl) {
// TODO Auto-generated method stub
final String fileName = "updata.apk";
File tmpFile = new File("/sdcard/update");
if (!tmpFile.exists()) {
tmpFile.mkdir();
}
final File file = new File("/sdcard/update/" + fileName);
try {
URL url = new URL(httpUrl);
try {
HttpURLConnection conn = (HttpURLConnection) url
.openConnection();
InputStream is = conn.getInputStream();
FileOutputStream fos = new FileOutputStream(file);
byte[] buf = new byte[256];
conn.connect();
double count = 0;
if (conn.getResponseCode() >= 400) {
Toast.makeText(Main.this, "连接超时", Toast.LENGTH_SHORT)
.show();
} else {
while (count <= 100) {
if (is != null) {
int numRead = is.read(buf);
if (numRead <= 0) {
break;
} else {
fos.write(buf, 0, numRead);
}
} else {
break;
}
}
}
conn.disconnect();
fos.close();
is.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return file;
}
Java代码 /**
* 打开文件
* @param file
*/
private void openFile(File file){
Intent intent = new Intent();
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
//设置intent的Action属性
intent.setAction(Intent.ACTION_VIEW);
//获取文件file的MIME类型
String type = getMIMEType(file);
//设置intent的data和Type属性。
intent.setDataAndType(/*uri*/Uri.fromFile(file), type);
//跳转
startActivity(intent); //这里最好try一下，有可能会报错。 //比如说你的MIME类型是打开邮箱，但是你手机里面没装邮箱客户端，就会报错。
}
/**
* 根据文件后缀名获得对应的MIME类型。
* @param file
*/
private String getMIMEType(File file) {
String type="*/*";
String fName = file.getName();
//获取后缀名前的分隔符"."在fName中的位置。
int dotIndex = fName.lastIndexOf(".");
if(dotIndex < 0){
return type;
}
/* 获取文件的后缀名*/
String end=fName.substring(dotIndex,fName.length()).toLowerCase();
if(end=="")return type;
//在MIME和文件类型的匹配表中找到对应的MIME类型。
for(int i=0;i<MIME_MapTable.length;i++){ //MIME_MapTable??在这里你一定有疑问，这个MIME_MapTable是什么？
if(end.equals(MIME_MapTable[i][0]))
type = MIME_MapTable[i][1];
}
return type;
}
MIME_MapTable是所有文件的后缀名所对应的MIME类型的一个String数组：
Java代码 <span style="white-space: pre;"> </span>private final String[][] MIME_MapTable={
//{后缀名，MIME类型}
{".3gp", "video/3gpp"},
{".apk", "application/vnd.android.package-archive"},
{".asf", "video/x-ms-asf"},
{".avi", "video/x-msvideo"},
{".bin", "application/octet-stream"},
{".bmp", "image/bmp"},
{".c", "text/plain"},
{".class", "application/octet-stream"},
{".conf", "text/plain"},
{".cpp", "text/plain"},
{".doc", "application/msword"},
{".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
{".xls", "application/vnd.ms-excel"},
{".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
{".exe", "application/octet-stream"},
{".gif", "image/gif"},
{".gtar", "application/x-gtar"},
{".gz", "application/x-gzip"},
{".h", "text/plain"},
{".htm", "text/html"},
{".html", "text/html"},
{".jar", "application/java-archive"},
{".java", "text/plain"},
{".jpeg", "image/jpeg"},
{".jpg", "image/jpeg"},
{".js", "application/x-javascript"},
{".log", "text/plain"},
{".m3u", "audio/x-mpegurl"},
{".m4a", "audio/mp4a-latm"},
{".m4b", "audio/mp4a-latm"},
{".m4p", "audio/mp4a-latm"},
{".m4u", "video/vnd.mpegurl"},
{".m4v", "video/x-m4v"},
{".mov", "video/quicktime"},
{".mp2", "audio/x-mpeg"},
{".mp3", "audio/x-mpeg"},
{".mp4", "video/mp4"},
{".mpc", "application/vnd.mpohun.certificate"},
{".mpe", "video/mpeg"},
{".mpeg", "video/mpeg"},
{".mpg", "video/mpeg"},
{".mpg4", "video/mp4"},
{".mpga", "audio/mpeg"},
{".msg", "application/vnd.ms-outlook"},
{".ogg", "audio/ogg"},
{".pdf", "application/pdf"},
{".png", "image/png"},
{".pps", "application/vnd.ms-powerpoint"},
{".ppt", "application/vnd.ms-powerpoint"},
{".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
{".prop", "text/plain"},
{".rc", "text/plain"},
{".rmvb", "audio/x-pn-realaudio"},
{".rtf", "application/rtf"},
{".sh", "text/plain"},
{".tar", "application/x-tar"},
{".tgz", "application/x-compressed"},
{".txt", "text/plain"},
{".wav", "audio/x-wav"},
{".wma", "audio/x-ms-wma"},
{".wmv", "audio/x-ms-wmv"},
{".wps", "application/vnd.ms-works"},
{".xml", "text/plain"},
{".z", "application/x-compress"},
{".zip", "application/x-zip-compressed"},
{"", "*/*"}
};
这个MIME类型可能不够完整，你有要补充的吗？