Java 如何使用套接字通道发送文件名和文件内容

我想使用socketchannel将文件名和文件内容一起发送。 我尝试将文件名转换为字节，将这些字节包装在bytebuffer中，然后将这些缓冲区内容发送到客户端（这是在服务器端）

在客户端，我尝试循环浏览缓冲区中的内容，将字节转换为字符，并检查是否存在特殊字符以记录文件名的结尾。当识别出该字符时，我调用buffer方法

compact（）

，这样我现在就可以开始读取内容了。但这不管用！我的客户端第一个while循环

while（bb.haslaining（））

没有中断，并且没有从该循环打印字符

---

服务器端

FileChannel sbc;
    ServerSocketChannel ssc=null;
    SocketChannel clientchannel=null;

try { 

 ssc=ServerSocketChannel.open();
 ssc.bind(new InetSocketAddress(5002));

 clientchannel=ssc.accept();

String filename=f.getName()+"?";
  byte[] nameinbytes=filename.getBytes("UTF-8");
System.out.println("name of file to send: "+filename);
ByteBuffer namebuffer=ByteBuffer.wrap(nameinbytes);
clientchannel.write(namebuffer);

                sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);

                 int bytesread=sbc.read(buff);
                 double read=(double)bytesread;
                 while(bytesread != -1){
                read+=(double) bytesread;
                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data written");

SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),5002);
     clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);
     String filename="";
     while(bb.hasRemaining()){
         byte bm=bb.get();
         char c=(char)(bm & 0xFF);
         System.out.println(c);
         if(c != '?'){
             filename+=Character.toString(c);
         }else{
             bb.compact();
             break;
         }
     }

      File file=new File("C:\\Users\\C-I-C\\Desktop\\fromclient\\"+filename);

     bout =new FileOutputStream(file);
      sbc=bout.getChannel();

     while(bytesRead != -1){
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

客户端

FileChannel sbc;
    ServerSocketChannel ssc=null;
    SocketChannel clientchannel=null;

try { 

 ssc=ServerSocketChannel.open();
 ssc.bind(new InetSocketAddress(5002));

 clientchannel=ssc.accept();

String filename=f.getName()+"?";
  byte[] nameinbytes=filename.getBytes("UTF-8");
System.out.println("name of file to send: "+filename);
ByteBuffer namebuffer=ByteBuffer.wrap(nameinbytes);
clientchannel.write(namebuffer);

                sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);

                 int bytesread=sbc.read(buff);
                 double read=(double)bytesread;
                 while(bytesread != -1){
                read+=(double) bytesread;
                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data written");

SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),5002);
     clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);
     String filename="";
     while(bb.hasRemaining()){
         byte bm=bb.get();
         char c=(char)(bm & 0xFF);
         System.out.println(c);
         if(c != '?'){
             filename+=Character.toString(c);
         }else{
             bb.compact();
             break;
         }
     }

      File file=new File("C:\\Users\\C-I-C\\Desktop\\fromclient\\"+filename);

     bout =new FileOutputStream(file);
      sbc=bout.getChannel();

     while(bytesRead != -1){
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

Q

---

如何使用同一频道发送文件名和文件内容？

服务器端

FileChannel sbc;
    ServerSocketChannel ssc=null;
    SocketChannel clientchannel=null;

try { 

 ssc=ServerSocketChannel.open();
 ssc.bind(new InetSocketAddress(5002));

 clientchannel=ssc.accept();

String filename=f.getName()+"?";
  byte[] nameinbytes=filename.getBytes("UTF-8");
System.out.println("name of file to send: "+filename);
ByteBuffer namebuffer=ByteBuffer.wrap(nameinbytes);
clientchannel.write(namebuffer);

                sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);

                 int bytesread=sbc.read(buff);
                 double read=(double)bytesread;
                 while(bytesread != -1){
                read+=(double) bytesread;
                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data written");

SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),5002);
     clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);
     String filename="";
     while(bb.hasRemaining()){
         byte bm=bb.get();
         char c=(char)(bm & 0xFF);
         System.out.println(c);
         if(c != '?'){
             filename+=Character.toString(c);
         }else{
             bb.compact();
             break;
         }
     }

      File file=new File("C:\\Users\\C-I-C\\Desktop\\fromclient\\"+filename);

     bout =new FileOutputStream(file);
      sbc=bout.getChannel();

     while(bytesRead != -1){
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

将文件名转换为字节数组

将字节数组包装在ByteBuffer对象中

将ByteBuffer对象内容发送到套接字通道

发送包含文件名（当然是字节）的缓冲区后：

现在创建另一个ByteBuffer对象并为其指定大小

开始将文件内容从FileChannel对象读取到缓冲区

在while循环中，开始将内容发送到套接字通道，直到到达文件通道的文件结尾

ServerSocket server=ServerSocket.open();
server.bind(new InetSocketAddress(1000));
SocketChannel clientChannel= server.accept();
File fileToSend=new File("stalkunderflow.txt").
String filename=fileToSend.getName();
byte[] nameBytes=filename.getBytes("UTF-8");
ByteBuffer nameBuffer=ByteBuffer.wrap(nameBytes);
clientChannel.write(nameBuffer);

//now  prepare and send file contents

FileChannel sbc=FileChannel.open(fileToSend.toPath());
             ByteBuffer buff=ByteBuffer.allocate(10000000);

             int bytesread=sbc.read(buff);

             while(bytesread != -1){
            buff.flip();
           clientChannel.write(buff);
            buff.compact();
            bytesread=sbc.read(buff);
             }

客户端

FileChannel sbc;
    ServerSocketChannel ssc=null;
    SocketChannel clientchannel=null;

try { 

 ssc=ServerSocketChannel.open();
 ssc.bind(new InetSocketAddress(5002));

 clientchannel=ssc.accept();

String filename=f.getName()+"?";
  byte[] nameinbytes=filename.getBytes("UTF-8");
System.out.println("name of file to send: "+filename);
ByteBuffer namebuffer=ByteBuffer.wrap(nameinbytes);
clientchannel.write(namebuffer);

                sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);

                 int bytesread=sbc.read(buff);
                 double read=(double)bytesread;
                 while(bytesread != -1){
                read+=(double) bytesread;
                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data written");

SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),5002);
     clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);
     String filename="";
     while(bb.hasRemaining()){
         byte bm=bb.get();
         char c=(char)(bm & 0xFF);
         System.out.println(c);
         if(c != '?'){
             filename+=Character.toString(c);
         }else{
             bb.compact();
             break;
         }
     }

      File file=new File("C:\\Users\\C-I-C\\Desktop\\fromclient\\"+filename);

     bout =new FileOutputStream(file);
      sbc=bout.getChannel();

     while(bytesRead != -1){
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

创建一个ByteBuffer对象（可以称之为nameBuffer）并给它一个大小（不是大的）

将内容从套接字通道写入缓冲区

翻转缓冲区并开始将缓冲区内容写入字节数组。（在while循环中执行）

将字节数组转换为字符串，就有了文件名

之后，创建另一个ByteBuffer对象（称之为nameBuffer）来存储文件内容，现在您将从该nameBuffer读取到一个文件通道，该通道使用从nameBuffer获得的名称写入文件

 //this is a test enviroment,therefore my server is running on the same machine as the client. 
SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),1000);
 SocketChannel clientChannel=SocketChannel.open(address);

 ByteBuffer namebuff=ByteBuffer.allocate(500);
 clientChannel.read(namebuff);

byte[] namebyte=new byte[500];
String filename="";

int position=namebuff.position();

 while(namebuff.hasRemaining()){
    namebyte[position]=namebuff.get();
    position=namebuff.position();
 }
 filename=new String(namebyte,0,position);

 File file=new File(filename);

 ByteBuffer bb=ByteBuffer.allocate(10000000);
 int bytesRead=clientChannel.read(bb);
 FileOutputStream bout =new FileOutputStream(file);
  FileChannel sbc=bout.getChannel();

 while(bytesRead != -1){
   bb.flip();
   sbc.write(bb);
   bb.compact();
  bytesRead=clientChannel.read(bb);
 }

---

服务器端

FileChannel sbc;
    ServerSocketChannel ssc=null;
    SocketChannel clientchannel=null;

try { 

 ssc=ServerSocketChannel.open();
 ssc.bind(new InetSocketAddress(5002));

 clientchannel=ssc.accept();

String filename=f.getName()+"?";
  byte[] nameinbytes=filename.getBytes("UTF-8");
System.out.println("name of file to send: "+filename);
ByteBuffer namebuffer=ByteBuffer.wrap(nameinbytes);
clientchannel.write(namebuffer);

                sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);

                 int bytesread=sbc.read(buff);
                 double read=(double)bytesread;
                 while(bytesread != -1){
                read+=(double) bytesread;
                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data written");

SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),5002);
     clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);
     String filename="";
     while(bb.hasRemaining()){
         byte bm=bb.get();
         char c=(char)(bm & 0xFF);
         System.out.println(c);
         if(c != '?'){
             filename+=Character.toString(c);
         }else{
             bb.compact();
             break;
         }
     }

      File file=new File("C:\\Users\\C-I-C\\Desktop\\fromclient\\"+filename);

     bout =new FileOutputStream(file);
      sbc=bout.getChannel();

     while(bytesRead != -1){
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

将文件名转换为字节数组

将字节数组包装在ByteBuffer对象中

将ByteBuffer对象内容发送到套接字通道

发送包含文件名（当然是字节）的缓冲区后：

现在创建另一个ByteBuffer对象并为其指定大小

开始将文件内容从FileChannel对象读取到缓冲区

在while循环中，开始将内容发送到套接字通道，直到到达文件通道的文件结尾

ServerSocket server=ServerSocket.open();
server.bind(new InetSocketAddress(1000));
SocketChannel clientChannel= server.accept();
File fileToSend=new File("stalkunderflow.txt").
String filename=fileToSend.getName();
byte[] nameBytes=filename.getBytes("UTF-8");
ByteBuffer nameBuffer=ByteBuffer.wrap(nameBytes);
clientChannel.write(nameBuffer);

//now  prepare and send file contents

FileChannel sbc=FileChannel.open(fileToSend.toPath());
             ByteBuffer buff=ByteBuffer.allocate(10000000);

             int bytesread=sbc.read(buff);

             while(bytesread != -1){
            buff.flip();
           clientChannel.write(buff);
            buff.compact();
            bytesread=sbc.read(buff);
             }

客户端

FileChannel sbc;
    ServerSocketChannel ssc=null;
    SocketChannel clientchannel=null;

try { 

 ssc=ServerSocketChannel.open();
 ssc.bind(new InetSocketAddress(5002));

 clientchannel=ssc.accept();

String filename=f.getName()+"?";
  byte[] nameinbytes=filename.getBytes("UTF-8");
System.out.println("name of file to send: "+filename);
ByteBuffer namebuffer=ByteBuffer.wrap(nameinbytes);
clientchannel.write(namebuffer);

                sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);

                 int bytesread=sbc.read(buff);
                 double read=(double)bytesread;
                 while(bytesread != -1){
                read+=(double) bytesread;
                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data written");

SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),5002);
     clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);
     String filename="";
     while(bb.hasRemaining()){
         byte bm=bb.get();
         char c=(char)(bm & 0xFF);
         System.out.println(c);
         if(c != '?'){
             filename+=Character.toString(c);
         }else{
             bb.compact();
             break;
         }
     }

      File file=new File("C:\\Users\\C-I-C\\Desktop\\fromclient\\"+filename);

     bout =new FileOutputStream(file);
      sbc=bout.getChannel();

     while(bytesRead != -1){
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

创建一个ByteBuffer对象（可以称之为nameBuffer）并给它一个大小（不是大的）

将内容从套接字通道写入缓冲区

翻转缓冲区并开始将缓冲区内容写入字节数组。（在while循环中执行）

将字节数组转换为字符串，就有了文件名

之后，创建另一个ByteBuffer对象（称之为nameBuffer）来存储文件内容，现在您将从该nameBuffer读取到一个文件通道，该通道使用从nameBuffer获得的名称写入文件

 //this is a test enviroment,therefore my server is running on the same machine as the client. 
SocketAddress address=new InetSocketAddress(InetAddress.getLocalHost(),1000);
 SocketChannel clientChannel=SocketChannel.open(address);

 ByteBuffer namebuff=ByteBuffer.allocate(500);
 clientChannel.read(namebuff);

byte[] namebyte=new byte[500];
String filename="";

int position=namebuff.position();

 while(namebuff.hasRemaining()){
    namebyte[position]=namebuff.get();
    position=namebuff.position();
 }
 filename=new String(namebyte,0,position);

 File file=new File(filename);

 ByteBuffer bb=ByteBuffer.allocate(10000000);
 int bytesRead=clientChannel.read(bb);
 FileOutputStream bout =new FileOutputStream(file);
  FileChannel sbc=bout.getChannel();

 while(bytesRead != -1){
   bb.flip();
   sbc.write(bb);
   bb.compact();
  bytesRead=clientChannel.read(bb);
 }

---

最好的方法是在服务器和客户端之间定义某种协议。你可以去看看。@CristiFati我以前也这么做过。在我的例子中，我创建了一个

DataOutputStream来发送文件名和文件大小，然后创建了一个socketchanel

来发送内容。此方法需要两个端口。我在想有一种方法可以在整个过程中只使用一个端口。为什么发送两个内容需要两个端口？使用相同的连接（和通道），需要交替执行读/写操作。@CristiFati我们只编写一个通道。这就是客户端通道。如何编写文件名（字符串）并在客户端读取它。我很困惑。即使我在服务器端注册客户端通道，我也只能对其进行写入。你能给我举个例子吗？我必须承认我没有使用通道，但无论如何，不能读写同一个通道似乎很奇怪，特别是因为上面说：>通道表示与硬件设备、文件、网络套接字等实体的开放连接，或能够执行一个或多个不同I/O操作（例如读或写）的程序组件。最好的方法是在服务器和客户端之间定义某种协议。你可以去看看。@CristiFati我以前也这么做过。在我的例子中，我创建了一个

DataOutputStream来发送文件名和文件大小，然后创建了一个socketchanel

来发送内容。此方法需要两个端口。我在想有一种方法可以在整个过程中只使用一个端口。为什么发送两个内容需要两个端口？使用相同的连接（和通道），需要交替执行读/写操作。@CristiFati我们只编写一个通道。这就是客户端通道。如何编写文件名（字符串）并在客户端读取它。我很困惑。即使我在服务器端注册客户端通道，我也只能对其进行写入。你能给我举个例子吗？我必须承认我没有使用通道，但无论如何，不能读写同一个通道似乎很奇怪，特别是因为上面说：>通道表示与硬件设备、文件、网络套接字等实体的开放连接，或者一个能够执行一个或多个不同I/O操作的程序组件，例如读或写。@SaitejaPrasadam您记得在文件中附加文件类型吗？e、 g

fileName.txt

@SaitejaPrasadam还确认包含文件名的字节没有与文件内容混淆。i