指令打印程序（通过Socket）

1、对应的IP

2、将打印的文本文件

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;

public class PrintBySocket
{

    private static String ip = "172.16.12.251";// 更改成网络打印机的IP

    private static int port = 9100;// 更改成网络打印机的端口

    private static int timeout = 1000;// 设置超时时间

    public static void main(String[] args)
        throws Exception
    {
        String filepath = "C:\RFID2.txt";// 指令文件存放的位置
        File file = new File(filepath);
        byte[] command = new byte[10];
        String label = null;
        if (file.exists())
        {// 检查指令文件存在不存在
            InputStream is = new FileInputStream(file);
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int len = 0;
            while ((len = is.read(command)) > 0)
            {
                out.write(
                    command, 0, len);
            }
            // label = new String(out.toByteArray(),"utf-8");
            label = new String(out.toByteArray(), "gbk");
            System.out.println(label);
        }
        else
        {// 指令文件不存在则直接返回
            System.out.println("指令文件不存在");
            return;
        }

        Socket s = null;
        OutputStream writer = null;
        try
        {
            s = new Socket();
            s.connect(new InetSocketAddress(ip, port));
            s.setSoTimeout(timeout);
            writer = s.getOutputStream();
            byte[] bytes;
            // bytes = label.getBytes("utf-8");
            bytes = label.getBytes("gbk");
            writer.write(
                bytes, 0, bytes.length);
            writer.flush();
        }
        catch (IOException e)
        {
            throw new RuntimeException("试图连接到打印机的时候发生错误，请检查你的网络连接，并确认打印机已经开机!", e);
        }
        finally
        {
            if (writer != null)
            {
                try
                {
                    writer.close();
                }
                catch (Exception e)
                {
                }
            }
            if (s != null)
            {
                try
                {
                    s.close();
                }
                catch (Exception e)
                {
                }
            }
        }
    }
}