通过输入流来诸葛获取text文件内容，再返回输入流的内容
public String getStringFromInputStream(InputStream inputStream){
byte[] buffer=new byte[1024];
int hasRead=0;
//创建一个字节数组用于存储获取的text内的内容；
StringBuilder result=new StringBuilder("");try{
while((hasRead=inputStream.read(buffer))!=-1){
result.append(new String(buffer,0,hasRead,"GBK"));
}
}catch(Exception e){
e.printStackTrace();
}
return result.toString();
}