Java通过ESC/POS指令打印条码

首先看一段简单代码，来实现打印文本的功能。

	Socket socket = socket = new Socket();
	// 设置发送地址
	SocketAddress addr = new InetSocketAddress("127.0.0.1", 9100);
	// 超时1秒，并连接服务器
	socket.connect(addr, 1000);

	OutputStream socketOut = socket.getOutputStream();
	socket.isClosed();
	OutputStreamWriter writer = new OutputStreamWriter(socketOut, "GBK");
		
	try{

		//初始化打印机
		writer.write(0x1B);
		writer.write(0x40);
		writer.flush();
		
		//打印文本
		writer.write("文本内容");
		writer.write("\n");
		writer.write("\n");
		writer.flush();

		//切纸
		writer.write(0x1D);
		writer.write(86);
		writer.write(65);
		writer.write(0);
		writer.flush();

    }finally {
            writer.close();
            socketOut.close();
            socket.close();
    }

 下面了解几条常见的指令

（1）设置字体居中（居左0、居右2）

		writer.write(0x1B);
		writer.write(97);
		writer.write(1);//字体居中

 （2）调整字体大小

		writer.write(0x1D);
		writer.write(33);
		//横向放大一倍 要将纵向放大与横向放大求和
		writer.write(17);

 （3）设置字体大小默认

		//设置字体大小默认
		writer.write(0x1D);
		writer.write(33);
		writer.write(0);

 下面是条码相关的指令：

（1）设置条码的位置

		writer.write(0x1B);
		writer.write(97);
		//设置条码居中
		writer.write(1);

 （2）设置条码的宽度

	writer.write(0x1D);
	writer.write('w');
	writer.write(2);//默认是2  2-6 之间
	writer.flush();
			

 （3）设置条码的高度

	//设置条形码的高度
	writer.write(0x1D);
	writer.write('h');
	writer.write(120);//默认是60
	writer.flush();

 （3）条码注释打印在条码下方

	writer.write(0x1D);
	writer.write(72);
	writer.write(2);

 （4）打印条码

writer.write(0x1D);
writer.write('k');
//选择code128
writer.write(73);
//设置字符个数
writer.write(14);
//使用CODEB来打印
writer.write(123);
writer.write(66);
//条形码内容
writer.write(value);
writer.flush();