Example usage:
// Send this chunk. Print something out.
String chunk = "print('Hello World')";
// Connect to the MotionNode Console service.
Client client = new Client(null, 32075);
// Create a LuaConsole object with our existing connection.
LuaConsole console = new LuaConsole(client);
LuaConsole.Result result = console.SendChunk(chunk, 5);
if (LuaConsole.ResultCode.Success == result.code) {
// This should be "Hello World\n"
System.out.println(result.string);
} else if (LuaConsole.ResultCode.Continue == result.code) {
System.err.println("incomplete Lua chunk: " + result.string);
} else {
System.err.println("command failed: " + result.string);
}
@endcode
*/
public class LuaConsole
{
/**
Defines the possible result codes from the console service.
*/
public enum ResultCode
{
// The Lua chunk was successfully parsed and executed. The
// printed results are in the result string.
Success,
// The Lua chunk failed due to a compile time or execution
// time error. An error description is in the result string.
Failure,
// The Lua chunk was incomplete. The Console service is waiting
// for a complete chunk before it executes.
// For example, "if x > 1 then" is incomplete since it requires
// and "end" token to close the "if" control statement.
Continue
}
/**
Simple container class for the result code and printed results
from a Lua chunk.
*/
public class Result
{
public ResultCode code = ResultCode.Failure;
public String string = null;
}; // class Result
/**
Store the open Client as a class member.
*/
private Client client = null;
/**
Create a console object with an existing console Client.
@param console_client a {@link Client} with an existing
connection to the MotionNode console service.
*/
public LuaConsole(Client console_client)
{
client = console_client;
}
public Result SendChunk(String chunk, int time_out_second)
throws Exception, IOException
{
Result result = new Result();
ByteBuffer data = ByteBuffer.wrap(chunk.getBytes());
if (client.writeData(data, time_out_second))
{
data = client.readData(time_out_second);
if (null != data)
{
byte code = data.get();
if (0 == code)
{
result.code = ResultCode.Success;
}
else if (1 == code)
{
result.code = ResultCode.Continue;
}
else if (2 == code)
{
result.code = ResultCode.Failure;
}
else
{
throw new Exception("unknown return code from Console service");
}
if (data.hasRemaining())
{
result.string = new String(data.array(), data.position(), data.remaining());
}
}
}
return result;
}
/**
Example usage and test function for the Client class.
*/
public static void main(String[] args)
throws Exception, UnknownHostException, IOException, SecurityException
{
// Connect to port 32075 on localhost.
String host = "";
int port = 32075;
// Parse a single command line argument that defines
// the remote host and port.
// For example, "www.google.com:80" or "10.0.0.1:32075"
//
// The port argument is optional and defaults to 32075.
//
if (args.length > 0)
{
String[] token_list = args[0].split(":");
if (token_list.length > 0)
{
host = token_list[0];
}
if (token_list.length > 1)
{
port = Integer.parseInt(token_list[1]);
}
}
Client client = new Client(host, port);
System.out.println("Connected to " + host + ":" + port);
// Make a Lua chunk, which is just a number of Lua commands
// that are compiled as one unit. We can only receive the
// printed results as feedback.
String chunk =
"if not node.is_reading() then" +
" node.close()" +
" node.scan()" +
" node.start()" +
" end" +
" if node.is_reading() then" +
" print('Reading from ' .. node.num_reading() .. ' device(s)')" +
" else" +
" print('Failed to start reading')" +
" end";
LuaConsole console = new LuaConsole(client);
LuaConsole.Result result = console.SendChunk(chunk, 5);
if (LuaConsole.ResultCode.Success == result.code)
{
System.out.println(result.string);
}
else if (LuaConsole.ResultCode.Continue == result.code)
{
System.err.println("incomplete Lua chunk: " + result.string);
}
else
{
System.err.println("command failed: " + result.string);
}
}
} // class LuaConsole