我一直在努力将类转换为C#( DataInputStream 和 DataOutputStream ),我已经完成了DataOutputStream类,现在问题都在于InputStream类 .
Note: The reason that I'm not using the Encoding class in C# is because DataInput/DataOutputStream in Java use a custom UTF-8 Encoding.
基本上,我有这个代码:( C# ),它使用 BinaryReader 类
public String ReadUTF()
{
int utflen = this.ReadUnsignedShort ();
byte[] bytearr = null;
char[] chararr = null;
if(bytearr.Length < utflen)
{
bytearr = new byte[utflen * 2];
chararr = new char[utflen * 2];
}
int c, char2, char3;
int count = 0;
int chararr_count=0;
this.ReadFully(bytearr, 0, utflen);
while (count < utflen) {
c = (int) bytearr[count] & 0xff;
if (c > 127) break;
count++;
chararr[chararr_count++]=(char)c;
}
while (count < utflen) {
c = (int) bytearr[count] & 0xff;
switch (c >> 4) {
case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
/* 0xxxxxxx*/
count++;
chararr[chararr_count++]=(char)c;
break;
case 12: case 13:
/* 110x xxxx 10xx xxxx*/
count += 2;
if (count > utflen)
throw new Exception(
"malformed input: partial character at end");
char2 = (int) bytearr[count-1];
if ((char2 & 0xC0) != 0x80)
throw new Exception(
"malformed input around byte " + count);
chararr[chararr_count++]=(char)(((c & 0x1F) << 6) |
(char2 & 0x3F));
break;
case 14:
/* 1110 xxxx 10xx xxxx 10xx xxxx */
count += 3;
if (count > utflen)
throw new Exception(
"malformed input: partial character at end");
char2 = (int) bytearr[count-2];
char3 = (int) bytearr[count-1];
if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80))
throw new Exception(
"malformed input around byte " + (count-1));
chararr[chararr_count++]=(char)(((c & 0x0F) << 12) |
((char2 & 0x3F) << 6) |
((char3 & 0x3F) << 0));
break;
default:
/* 10xx xxxx, 1111 xxxx */
throw new Exception(
"malformed input around byte " + count);
}
}
// The number of chars produced may be less than utflen
return new String(chararr, 0, chararr_count);
}
这是我的 ReadUnsignedShort 方法
public int ReadUnsignedShort()
{
int ch1 = BinaryReader.Read();
int ch2 = BinaryReader.Read();
if ((ch1 | ch2) < 0)
{
throw new EndOfStreamException(); // Temp- To be changed
}
return (ch1 << 8) + (ch2 << 0);
}
Here's the Readfully method too that's used:
public void ReadFully(byte[] b, int off, int len)
{
if(len < 0)
{
throw new IndexOutOfRangeException();
}
int n = 0;
while(n < len)
{
int count = ClientInput.Read(b, off + n, len - n);
if(count < 0)
{
throw new EndOfStreamException(); // Temp - to be changed
}
n += count;
}
}
使用OutputStream的问题是我使用的是Write(int)而不是Write(byte)函数,但我不认为这是这种情况,或者我必须是盲目的 .
如果您对如何发送UTF字符串感兴趣,请参阅以下C#转换:
public int WriteUTF(string str)
{
int strlen = str.Length;
int utflen = 0;
int c, count = 0;
for(int i = 0; i < strlen; i++)
{
c = str.ToCharArray()[i];
if((c >= 0x0001) && (c <= 0x007F))
{
utflen++;
}
else if(c > 0x07FF)
{
utflen += 3;
}
else
{
utflen += 2;
}
}
if(utflen > 65535)
{
throw new Exception("Encoded string is too long: " + utflen + " bytes");
}
byte[] bytearr = null;
bytearr = new byte[(utflen*2) + 2];
bytearr[count++] = (byte) (((uint)utflen >> 8) & 0xFF);
bytearr[count++] = (byte) (((uint)utflen >> 0) & 0xFF);
int x = 0;
for(x = 0; x < strlen; x++)
{
c = str.ToCharArray()[x];
if (!((c >= 0x0001) && (c <= 0x007F))) break;
bytearr[count++] = (byte)c;
}
for(;x < strlen; x++)
{
c = str.ToCharArray()[x];
if ((c >= 0x0001) && (c <= 0x007F))
{
bytearr[count++] = (byte)c;
}
else if (c > 0x07FF)
{
bytearr[count++] = (byte) (0xE0 | ((c >> 12) & 0x0F));
bytearr[count++] = (byte) (0x80 | ((c >> 6) & 0x3F));
bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F));
}
else
{
bytearr[count++] = (byte) (0xC0 | ((c >> 6) & 0x1F));
bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F));
}
}
ClientOutput.Write (bytearr, 0, utflen+2);
return utflen + 2;
}
希望我已经提供了足够的信息来帮助您阅读UTF值,这实际上为我的项目进度提供了一个障碍 .
2 回答
如果我正确地理解了“问题”(例如它 - 你说有一个“障碍”,但你没有解释究竟是什么“障碍”),你试图在C#中实现从中读取和写入文本的代码流 . 如果是这样,那么(我知道你是否是.NET的新手,这并不是很明显),自己明确处理文本编码是疯了 .
BinaryReader和BinaryWriter都有处理这个问题的方法 . 创建对象时,可以传递Encoding实例(例如System.Text.Encoding.UTF8,System.Text.Encoding.Unicode等),该实例用于解释或创建文本的二进制数据 . 您可以使用BinaryReader.ReadChars(int)读取文本,使用BinaryWriter.Write(char [])来写入文本 .
如果由于某种原因不起作用,您至少可以直接使用Encoding实例来解释或创建某些文本的二进制数据 . Encoding.GetString(byte [])将二进制转换为文本,Encoding.GetBytes(string)将文本转换为二进制 . 同样,使用特定的Encoding实例来处理您正在处理的实际文本编码 .
已经写了一个C#转换的Java的 DataInputStream 和 DataOutputStream 你可以在这里收集它们 .
https://bitbucket.org/CTucker1327/c-datastreams/src
要构造这些类,您可以将BinaryWriter或BinaryReader传递给构造函数 .
构造DataOutputStream
构造DataInputStream