文件存储的基本思路：
写入：
String data = "this is the data";
FileOutputStream out =null;
BufferedWriter writer = null;
try
{
out = openFileOutput("content_path",MODE_PRIVATE/MODE_APPEND);
writer = new BufferedWriter(new OutputStreamWriter（out）);
writer.write(data);
}
catch(IOException e)
{
e.printStackTrace();
}
finally
{
try
{
if(writer!=null)
{
writer.close();
}
catch(IOException e)
{
e.printStackTrace();
}
}
}
读取：
FileInputStream in =null;
BufferedReader reader =null;
StringBuilder builder = new StringBuilder();
try
{
in = openFileInput("content_path");
reader = new BufferedReader(new InputStreamReader(in));
String line="";
while(line=reader.readLine()!=null)
{
builder.append(line);
}
}
catch(IOException e)
{
e.printStackTrace();
}
finally
{
try
{
if(reader!=null)
{
reader.close();
}
}
catch(IOException e)
{
e.printStackTrace();
}
}