另一个Delphi到Java的移植问题
我正在将一个用Delphi编写的旧应用程序移植到Java。 我在使用这个函数时遇到了一些问题,它计算传输消息的CRC 以下是原始代码:另一个Delphi到Java的移植问题,java,delphi,binary,porting,Java,Delphi,Binary,Porting,我正在将一个用Delphi编写的旧应用程序移植到Java。 我在使用这个函数时遇到了一些问题,它计算传输消息的CRC 以下是原始代码: if(ReceivedMessage[slot].Message[1] = $FD) and (ReceivedMessage[slot].MessageLength in [1..16]) and (ReceivedMessage[slot].Message[counter] = $FF) then
if(ReceivedMessage[slot].Message[1] = $FD) and
(ReceivedMessage[slot].MessageLength in [1..16]) and
(ReceivedMessage[slot].Message[counter] = $FF) then
begin
index := 2;
ReceivedMessage[slot].DataReady := TRUE;
for counter := 1 to ReceivedMessage[slot].MessageLength do
begin
Inc(index);
if ReceivedMessage[slot].Message[index] < $F8 then
ReceivedMessage[slot].Data[counter] := ReceivedMessage[slot].Message[index]
else
if ReceivedMessage[slot].Message[index] = $F8 then
begin
Inc(index);
ReceivedMessage[slot].Data[counter] := ReceivedMessage[slot].Message[index] or $F0;
end
else
ReceivedMessage[slot].DataReady := FALSE; // Invalid data
end;
if ReceivedMessage[slot].DataReady = TRUE then
begin
Inc(index);
if ReceivedMessage[slot].Message[index] < $F8 then
ReceivedMessage[slot].CRC := ReceivedMessage[slot].Message[index] shl 8
else
if ReceivedMessage[slot].Message[index] = $F8 then
begin
Inc(index);
ReceivedMessage[slot].CRC := (ReceivedMessage[slot].Message[index] or $F0) shl 8;
end;
Inc(index);
if ReceivedMessage[slot].Message[index] < $F8 then
ReceivedMessage[slot].CRC := ReceivedMessage[slot].CRC or ReceivedMessage[slot].Message[index]
else
if ReceivedMessage[slot].Message[index] = $F8 then
begin
Inc(index);
ReceivedMessage[slot].CRC := ReceivedMessage[slot].CRC or ReceivedMessage[slot].Message[index] or $F0;
end;
if(ReceivedMessage[slot]。消息[1]=$FD)和
(ReceivedMessage[slot].MessageLength在[1..16]中)和
(ReceivedMessage[slot]。Message[counter]=$FF)然后
开始
指数:=2;
ReceivedMessage[slot].DataReady:=TRUE;
对于计数器:=1以接收消息[slot]。消息长度do
开始
公司(指数),;
如果ReceivedMessage[slot]。Message[index]<$F8,则
ReceivedMessage[slot]。数据[计数器]:=ReceivedMessage[slot]。消息[索引]
其他的
如果ReceivedMessage[slot].Message[index]=$F8,则
开始
公司(指数),;
ReceivedMessage[slot]。数据[counter]:=ReceivedMessage[slot]。消息[index]或$F0;
结束
其他的
ReceivedMessage[slot]。DataReady:=FALSE;//无效数据
结束;
如果ReceivedMessage[slot].DataReady=TRUE,则
开始
公司(指数),;
如果ReceivedMessage[slot]。Message[index]<$F8,则
ReceivedMessage[slot]。CRC:=ReceivedMessage[slot]。消息[index]shl 8
其他的
如果ReceivedMessage[slot].Message[index]=$F8,则
开始
公司(指数),;
ReceivedMessage[slot]。CRC:=(ReceivedMessage[slot]。Message[index]或$F0)shl 8;
结束;
公司(指数),;
如果ReceivedMessage[slot]。Message[index]<$F8,则
ReceivedMessage[slot]。CRC:=ReceivedMessage[slot]。CRC或ReceivedMessage[slot]。消息[index]
其他的
如果ReceivedMessage[slot].Message[index]=$F8,则
开始
公司(指数),;
ReceivedMessage[slot]。CRC:=ReceivedMessage[slot]。CRC或ReceivedMessage[slot]。消息[index]或$F0;
结束;
下面是我的Java代码:
if(array[1]==0xFD && (array[2]>0 && array[2]<17) && array[pos]==(byte)0xFF)
{
index=2;
for(int counter=1;counter<splMsg.nbytes+1;counter++)
{
index++;
if(array[index]<0xF8)
data[counter]=array[index];
else
if(array[index]==0xF8)
{
index++;
data[counter]=(byte)(array[index] | 0xF0);
}
else
return 0xFC;
}
index++;
short crc=0x0000;
if(array[index]<0xF8)
crc=(short) (array[index]<<8);
else
if(array[index]==0xF8)
{
index++;
crc=(short)((array[index] | 0xF0) << 8);
}
index++;
if(array[index]<0xF8)
crc=(short) (crc | array[index]);
else
if(array[index]==0xF8)
{
index++;
crc=(short)(crc | array[index] | 0xF0);
}
msgcrc=new byte[] {(byte)(crc >> 8 & 0xff),(byte)(crc & 0xff)};
if(数组[1]==0xFD&&(数组[2]>0&&array[2]记住:
Java字节是有符号的。因此:
将输出:-1
及
将打印false
,但
byte test = (byte)255;
System.out.println((test & 255) == 255);
将执行我认为您希望实现的操作(在本例中,打印true
)
要获取无符号(字节)值,请使用(数组[索引]&255)
您必须在所有位置使用0xff进行掩蔽,否则将得到大于127的字节值的符号扩展整数
对于比较,您也可以对byte
(例如if(test==(byte)255)
)进行转换,但我认为应该坚持单一转换,因此我建议使用&0xff
掩蔽。是byte
类型的“数组”吗?嗨,不是,数组是字节[]@Pedro除了另一个Delphi to Java移植问题
,你能为你的问题想出一个更具描述性的标题吗?谢谢你,Neet。我已经在每个数组[索引]中添加了掩码,它成功了!
byte test = (byte)255;
System.out.println(test == 255);
byte test = (byte)255;
System.out.println((test & 255) == 255);