我必须向java发送一个文件，java必须接收该文件并通过tcp/ip将其发送回C。我能够发送文件，但在接收时我无法接收任何数据。我给出代码供引用。
int send_text(int socket)
{
FILE *text;
char a[50];
int size, read_size, stat, packet_index;
char send_buffer[8008], read_buffer[8008];
int wrt = 0, sock_fd, tsize = 0;
packet_index = 1;
int i = 0;
text = fopen("/home/sosdt009/Desktop/character3.txt", "r");
if (text == NULL)
{
printf("Error Opening text File:");
exit(-1);
}
printf("Getting text Size:\n");
gets(a);
fseek(text, 0, SEEK_END);
size = ftell(text);
fseek(text, 0, SEEK_SET);
printf("Total text size: %d \n", size);
gets(a);
//Send text Size
printf("Sending text Size:\n");
gets(a);
send(socket, (void *) &size, sizeof(size), 0);
while (size > tsize)
{
//Read from the file into our send buffer
printf("Ready for sending:\n");
gets(a);
read_size = fread(send_buffer, 1, sizeof(send_buffer), text);
printf("The size of send buffer:%c \n", sizeof(send_buffer));
gets(a);
printf("The read size value is :%d \n", read_size);
gets(a);
//Send data through our socket
for (i = 0; i < read_size; i++)
{
printf("Send value: %c \n", send_buffer[i]);
gets(a);
}
do
{
stat = send(socket, send_buffer, read_size, 0);
printf("The send size value is: %d \n", size);
gets(a);
printf("The read size value is: %d \n", read_size);
gets(a);
}
while (stat < 0);
printf("Packet %d, sent %d bytes.\n", packet_index, read_size);
gets(a);
//packet_index++;
//Zero out our send buffer
tsize = tsize + read_size;
printf("The tsize value is:%d \n", tsize);
gets(a);
memset(send_buffer, 0, sizeof(send_buffer));
if (read_size <= NULL)
{
printf("The connection is transferred to received text: \n");
gets(a);
}
}
fclose(text);
printf("Text successfully send:\n");
gets(a);
return 0;
}
int receive_text(int socket)
{
int buffersize, recv_size = 0, read_size = 1, write_size, size, stat;
char *pBuf, a[50];
int errno,i;
FILE *text;
text = fopen("/home/sosdt009/Desktop/receivednew.txt", "a");
if (text == NULL)
{
printf("Error has occurred, text file could not be opened \n");
return -1;
}
//Loop while we have not received the entire file yet
while (read_size > 0)
{
ioctl(socket, FIONREAD, &buffersize);
printf("The Buffersize is :%d\n", buffersize);
gets(a);
printf("The size of socket is:%d\n", socket);
gets(a);
//We check to see if there is data to be read from the socket
if (buffersize > 0)
{
printf("Buffersize value is :%d\n", buffersize);
gets(a);
pBuf = malloc(buffersize);
if (!pBuf)
{
printf(errno, "Memory Error Cannot Allocate!\n");
gets(a);
exit(-1);
}
read_size = recv(socket, pBuf, buffersize, 0);
printf("Read size value is :%d \n", read_size);
gets(a);
printf("Buffersize value is:%d \n", pBuf);
gets(a);
if (read_size < 0)
{
printf("%d\n", strerror(errno));
printf("Data not written to the file:\n");
gets(a);
goto free;
}
//Write the currently read data into our text file
write_size = fwrite(pBuf, 1, read_size, text);
free(pBuf);
printf("Write size value is :%d \n", write_size);
gets(a);
printf("Buffer size value is :%d \n", buffersize);
gets(a);
//Increment the total number of bytes read
recv_size += read_size;
printf("Received size value is:%d \n", recv_size);
gets(a);
printf("Read size value is :%d \n", read_size);
gets(a);
}
}
free: fclose(text);
close(socket);
printf("Text Successfully Received:\n");
gets(a);
return 0;
}
添加java代码以供进一步引用
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class Server1 {
static ServerSocket serverSocket =null;
private static Socket socket;
public final static String FILE_TO_RECEIVED = "/home/sosdt010/Desktop/Testfile/text2.txt";
public final static int FILE_SIZE = 32092796 ;//4939993 ;//
static int current=0;
public static void main(String[] args) throws IOException, InterruptedException {
int port = 6777;
serverSocket = new ServerSocket(port);
System.out.println("Server Started and listening to the port 6777");
socket = serverSocket.accept();
InputStream is = socket.getInputStream();
//ois=new ObjectInputStream(socket.getInputStream());
//byte[] content = (byte[]) ois.readObject();
FileOutputStream fos=new FileOutputStream(FILE_TO_RECEIVED );
System.out.println(FILE_TO_RECEIVED);
byte [] mybytearray = new byte [FILE_SIZE];
// int bytesRead = is.read(mybytearray,0,mybytearray.length);
// System.out.println(mybytearray.length);
//current = bytesRead;
//System.out.println(current+"/n"+bytesRead);
int bytesRead;
do {
bytesRead =
is.read(mybytearray, 0,mybytearray.length-current);
if(bytesRead >= 0) current += bytesRead;
System.out.println(bytesRead );
} while(bytesRead > -1);
for(int a=0;a<current;a++){
fos.write(mybytearray[a]);
}
System.out.println(current +"new bytesread"+mybytearray.length);
//fos.write(mybytearray, 0,current);
System.out.println("Message received from server is "+current);
OutputStream os=socket.getOutputStream();
File myFile=new File(FILE_TO_RECEIVED);
System.out.println(FILE_TO_RECEIVED);
FileInputStream fis=new FileInputStream(myFile);
byte[] mybytearray1=new byte[(int)myFile.length()];
System.out.println(myFile.length());
fis.read(mybytearray1, 0, mybytearray1.length);
System.out.println("Bytes Read"+ mybytearray1.length);
os.write(mybytearray1, 0, mybytearray1.length);
System.out.println("Bytes write"+mybytearray1.length);
System.out.println(mybytearray1.length);
// byte[] content1 = Files.readAllBytes(new File(FILE_TO_SEND).toPath());
//oos.writeObject(content1);
os.flush();
fos.close();
is.close();
//fis.close();
//os.close();
socket.close();
}
}
我给出了我当前在程序中使用的接收代码
int receive_text(int socket)
{
int buffersize[8192],recv_size = 0,read_size = 1, write_size, size;
char *pBuf,a[50];
int errno;
FILE *text;
text = fopen("/home/sosdt009/Desktop/receivednew.txt", "w");
if (text == NULL)
{
printf("Error has occurred, text file could not be opened \n");
return -1;
}
//Loop while we have not received the entire file yet
while (read_size > 0)
{
ioctl(socket, FIONREAD, &buffersize);
printf("The Buffersize is :%d\n",buffersize);
gets(a);
printf("The size of socket is:%d\n",socket);
gets(a);
//We check to see if there is data to be read from the socket
if (buffersize > 0)
{
printf("Buffersize value is :%d\n", buffersize);
gets(a);
pBuf = malloc(buffersize);
/*if (!pBuf)
{
printf(errno, "Memory Error Cannot Allocate!\n");
gets(a);
exit(-1);
}*/
while ((read_size = recv(socket, buffersize, sizeof(buffersize), 0)) > 0)
{
fwrite(pBuf, 1, read_size, text); // plus error handling ...
}
//read_size = recv(socket, pBuf, buffersize, 0);
//printf("Read size value is :%d \n",read_size);
//gets(a);
//printf("Buffersize value is:%d \n",pBuf);
//gets(a);
if (read_size < 0)
{
printf("%d\n",strerror(errno));
printf("Data not written to the file:\n");
gets(a);
goto free;
}
//Write the currently read data into our text file
write_size = fwrite(pBuf,read_size,1,text);
free(pBuf);
printf("Write size value is :%d \n",write_size);
gets(a);
printf("Buffer size value is :%d \n",buffersize);
gets(a);
//Increment the total number of bytes read
recv_size += read_size;
printf("Received size value is:%d \n",recv_size);
gets(a);
printf("Read size value is :%d \n",read_size);
gets(a);
}
}
free:
fclose(text);
close(socket);
printf("Text Successfully Received:\n");
gets(a);
return 0;
}
我按照你的修改贴上代码
int receive_text(int socket)
{
int buffersize[8192],recv_size = 0,read_size=1, write_size, size;
char *pBuf,a[50];
int errno;
FILE *text;
text = fopen("/home/sosdt009/Desktop/receivednew.txt", "a");
if (text == NULL)
{
printf("Error has occurred, text file could not be opened \n");
return -1;
}
//Loop while we have not received the entire file yet
while (read_size > 0)
{
while ((read_size = recv(socket, buffersize, sizeof(buffersize), 0)) > 0)
{
fwrite(pBuf, read_size, 1, text); // plus error handling ...
printf("Write size value is :%d \n",write_size);
gets(a);
printf("Buffer size value is :%d \n",buffersize);
gets(a);
}
//while (!buffersize && ioctl (socket,FIONREAD,&buffersize) >= 0)
//ioctl(socket, FIONREAD, &buffersize);
//printf("The Buffersize is :%d\n",socket);
//gets(a);
//We check to see if there is data to be read from the socket
//if (buffersize > 0)
//{
//printf("Buffersize value is :%d\n", buffersize);
//gets(a);
//pBuf = malloc(buffersize);
if (!pBuf)
{
printf(errno, "Memory Error Cannot Allocate!\n");
gets(a);
exit(-1);
}
//read_size = recv(socket, pBuf, buffersize, 0);
//printf("Read size value is :%d \n",read_size);
//gets(a);
//printf("Buffersize value is:%d \n",pBuf);
//gets(a);
if (read_size < 0)
{
printf("%d\n",strerror(errno));
printf("Data not written to the file:\n");
gets(a);
goto free;
}
//Write the currently read data into our text file
write_size = fwrite(pBuf,read_size,1,text);
free(pBuf);
//
//Increment the total number of bytes read
recv_size += read_size;
printf("Received size value is:%d \n",recv_size);
gets(a);
printf("Read size value is :%d \n",read_size);
gets(a);
//}
}
free:
fclose(text);
close(socket);
printf("Text Successfully Received:\n");
gets(a);
return 0;
}
最佳答案
这是质量非常差的代码。
发送循环:
do
{
stat = send(socket, send_buffer, read_size, 0);
printf("The send size value is: %d \n", size);
gets(a);
printf("The read size value is: %d \n", read_size);
gets(a);
} while (stat < 0);
- “发送大小值”不是
size，而是stat - 在出现错误时重复此循环是没有意义的。
在所有数据尚未发送时不重复它也是毫无意义的，除非套接字正在阻塞并且没有中断，而您没有对此进行测试。更正确的版本是:
do { stat = send(socket, send_buffer, read_size, 0); printf("The send size value is: %d \n", stat); if (stat > 0) { send_buffer += stat; read_size -= stat; } } while (stat < 0 && errno == EINTR);
接收循环:
while(read_size > 0)
{
ioctl(socket, FIONREAD, &buffersize);
printf("The Buffersize is :%d\n",buffersize);
此时缓冲区大小为sizeof buffer。 *可在不阻塞的情况下读取的字节数由buffersize给出，*当且仅当*ioctl()`返回零。
printf("The size of socket is:%d\n",socket);
不存在“套接字的大小”这样的东西。删除。
// We check to see if there is data to be read from the socket
ioctl()，然后在下面的 recv() 中阻塞。
if (buffersize > 0)
{
printf("Buffersize value is :%d\n", buffersize);
您已经打印了此内容。删除。
pBuf = malloc(buffersize);
这是浪费时间和空间。使用固定大小的缓冲区并在循环开始之前分配它。删除这个。
read_size = recv(socket, pBuf, buffersize, 0);
printf("Read size value is :%d \n",read_size);
printf("Buffersize value is:%d \n",pBuf);
pBuf 不是“缓冲区大小值”，它是缓冲区的地址，打印它是没有意义的。删除这个。
if (read_size < 0)
{
printf("%d\n",strerror(errno));
printf("Data not written to the file:\n");
gets(a);
goto free;
}
这里您缺少对 read_size == 0 的测试，它指示流结束，因此您应该关闭套接字并退出循环。
printf("Buffer size value is :%d \n",buffersize);
第三次打印此值，该值没有更改，第四次打印此消息，一次使用了虚假值。删除这个。
整个循环，包括虚假的ioctl()和测试，以及malloc()和free()，都可以减少至:
int read_size;
char buffer[8192];
while ((read_size = recv(socket, buffer, sizeof buffer, 0)) > 0)
{
fwrite(pBuf, 1, read_size, text); // plus error handling ...
}
if (read_size < 0)
// print the error as you are doing.
您的 Java 代码同样不稳定。我不会详细评论，但可以简化为:
int bytesRead;
while ((bytesRead = is.read(mybytearray)) > 0)
{
fos.write(mybytearray, 0, bytesRead);
}
在两端的所有问题都得到解决之前，这永远不会起作用。
关于java - 如何通过tcp/ip从java接收文件到C？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31739033/