实现基于UDP协议的的，两个进程(两个java程序)互相发送，并接受各自发送的数据的功能。

//客户端,根据配置文件的地址上传文件

public class Clinet {public static void main(String[] args) throws IOException {//调用方法获取picture的地址String picturePath = getPicturePath();System.out.println("picturePath:" + picturePath);//创建读取文件的流对象并进行包装FileInputStream fis = new FileInputStream(picturePath);BufferedInputStream bis = new BufferedInputStream(fis);//创建stocket对象Socket socket = new Socket("127.0.0.1", 10086);//把客户端输出字节流包装成一个缓冲字符输出流OutputStream out = socket.getOutputStream();BufferedOutputStream bos = new BufferedOutputStream(out);//开始读取,进行数据传输byte[] buffer = new byte[1024];int len;while ((len = bis.read(buffer)) != -1) {//获取相应的流,进行数据传输bos.write(buffer, 0, len);}//刷新缓冲流中的缓冲bos.flush();//单方面关闭socket中的输入或者输出流socket.shutdownOutput();//接收服务器端的反馈byte[] byteBuffer = new byte[1024];InputStream in = socket.getInputStream();/*因为socket的inputstream中的read方法是一个阻塞方法,当如果没有接收到数据就会阻塞*/len = in.read(byteBuffer);System.out.println(new String(byteBuffer, 0, len));//关闭流释放资源socket.close();bis.close();}public static String getPicturePath() throws IOException {//创建读取配置文件的流对象FileInputStream fis = new FileInputStream("d:\\config.properties");//读取配置文件//创建一个Properties对象Properties properties = new Properties();//利用Properties对象的load方法直接读取配置文件内容,并将其存储到Properties对象中properties.load(fis);//直接从Properties对象获取目标配置信息(即一条目标配置的属性值)String picturePath = properties.getProperty("picturePath");return picturePath;}
}

//服务器端,根据端口号接收数据,并输出.

public class Server {public static void main(String[] args) throws IOException {boolean flag = true;//创建服务器端的socket对象即ServerSocketServerSocket serverSocket = new ServerSocket(10086);//调用ServerSocketSocket socket = serverSocket.accept();//创建文件输出流FileOutputStream fos = new FileOutputStream("d:\\copy.jpg");//根据需要从Socket对象中获取流,并进行数据的读取/发送InputStream in = socket.getInputStream();//将服务器端输入字节流,包装成缓冲字符流BufferedInputStream br = new BufferedInputStream(in);//byte[] buffer = new byte[1024];int len;//Socket中的输入流的read方法是阻塞方法,// 所以服务器读取发送端数据这个循环不会自动终止while ((len = br.read(buffer)) != -1) {fos.write(buffer, 0, len);}//服务器端给客户端发送反馈消息OutputStream out = socket.getOutputStream();//发送端的Ip地址InetAddress sendIp = socket.getInetAddress();//发送端的端口号int port = socket.getPort();String response = "来自" + sendIp + "--" + port + "的文件,上传完毕";out.write(response.getBytes());//关闭socket,释放资源socket.close();serverSocket.close();fos.close();}
}

思路:利用Socket建立连接,进行数据的输入和输出.细节在注释中已经说明.