String content = "这是段.md文件的内容。其中[这是一个链接](./html/README.md)，还有其他内容，这里又有一个[another link](another.md)，这次链接到了another.md。";
 
//括号用于分组；需要匹配括号则用\c
//[^\]] 表示任意不是']'的字符，后面的*表示任意多个
Pattern p = Pattern.compile("\\[([^\\]]*)\\]\\(([^\\)]*)\\)", Pattern.CASE_INSENSITIVE);
 
Matcher matcher = p.matcher(content);
while(matcher != null && matcher.find()) {
    String link = matcher.group();
    for(int i=0; i<= matcher.groupCount(); i++){
        //得到的分组，第0个是整个字串，例如第一次发现时打印：[这是一个链接](./html/README.md)
        //第一个是正则表达式中第一个括号匹配到的内容，例如第一次发现时打印：这是一个链接
        System.out.println(matcher.group(i));
    }
    System.out.println();
}

import java.net.*;
import java.io.*;
 
public class WebsocketClient {
 
    public static void main(String[] args) throws Exception {
 
        String hostname = "localhost";
        int port = 8080;
 
        try (Socket socket = new Socket(hostname, port)) {
 
            OutputStream output = socket.getOutputStream();
            PrintWriter writer = new PrintWriter(output, true);
 
            writer.println("GET /chat HTTP/1.1");
            writer.println("Host: " + hostname + ":" + port);
            // 下面两行是告诉服务器端，此次连接的使用的http协议期望升级到websocket协议，如果服务端同意升级会返回
            // Connection: upgrade  upgrade: websocket表示已经升级了，而且状态吗是101 switching protocols
            writer.println("Connection: upgrade");
            writer.println("Upgrade: WebSocket");
            // 下面这2行是必须的，sec-websocket-key是base64格式的一个随机数，由客户端生成
            // sec-websocket-version是指明客户端的websocket版本
            writer.println("Sec-WebSocket-Key:  "AQIDBAUGBwgJCgsMDQ4PEC=" =");
            writer.println("Sec-WebSocket-Version: 13");
            writer.println("User-Agent: MSIE");
            writer.println("Origin: http://localhost:8080/");
            writer.println();
 
            InputStream input = socket.getInputStream();
 
            BufferedReader reader = new BufferedReader(new InputStreamReader(input));
 
            System.out.println("request sent...");
            int i=0;
            while (i < 10) {
                if (reader.ready()){
                    // 在读websocket发送过来的消息时，这里没有解码消息帧，都当字符串了，消息的数据报文格式前面有些事数据包控制的bit，所以打印时有乱码
                    char[] bin = new char[2048];
                    int len = reader.read(bin, 0, bin.length);
                    char[] buf = new char[len];
                    System.arraycopy(bin, 0, buf, 0, len);
                    System.out.println(new String(buf));
                    i++;
                }
            }
            // 连接好了后可以发送数据，发送的数据报格式是 Base Framing Protocol， ABNF RFC5234
            writer.close();
            output.close();
            socket.close();
        } catch (UnknownHostException ex) {
            System.out.println("Server not found: " + ex.getMessage());
        } catch (IOException ex) {
            System.out.println("I/O error: " + ex.getMessage());
        }
    }
}

package cn.devmgr.activemqlistener;

import org.apache.activemq.ActiveMQConnectionFactory;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Message;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;

public class JmsMessageSender {

    public static void main(String[] argvs) throws Exception {
        ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
        Connection connection = connectionFactory.createConnection();
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

        // 消息生产者；发送消息
        Queue queue = session.createQueue("print-queue");
        String payload = "需要打印了";
        Message msg = session.createTextMessage(payload);
        MessageProducer producer = session.createProducer(queue);
        System.out.println("Sending text '" + payload + "'");
        producer.send(msg);

        session.close();
        connection.close();
    }
}

package cn.devmgr.activemqlistener;

import org.apache.activemq.ActiveMQConnectionFactory;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;

public class JmsMessageReceiver {

    public static void main(String[] argvs) throws Exception {
        ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
        Connection connection = connectionFactory.createConnection();
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

        // 消息消费者： 接收消息
        Queue queue = session.createQueue("print-queue");
        MessageConsumer consumer = session.createConsumer(queue);
        consumer.setMessageListener(new ConsumerMessageListener("print-queue"));
        connection.start();

        //60秒后退出
        Thread.sleep(60000);
        session.close();

        connection.close();
    }


    public static class ConsumerMessageListener implements javax.jms.MessageListener {
        private String consumerName;

        public ConsumerMessageListener(String consumerName) {
            this.consumerName = consumerName;
        }

        public void onMessage(Message message) {
            TextMessage textMessage = (TextMessage) message;
            try {
                System.out.println(consumerName + " received " + textMessage.getText());
            } catch (JMSException e) {
                e.printStackTrace();
            }
        }

    }
}

@ResponseBody
@GetMapping("/export")
public ResponseEntity<byte[]> exportExcel() throws Exception{
    logger.trace("exportExcel");
    HttpHeaders responseHeaders = new HttpHeaders();
    responseHeaders.setContentDispositionFormData("attachment",new String("导出的文件名.xlsx".getBytes(), "ISO8859-1"));
    responseHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);

    //中文文件名需要用iso8859-1编码
    InputStream templateIs = this.getClass().getResourceAsStream("/excel-templates/templet.xlsx");
    XSSFWorkbook workbook = new XSSFWorkbook(templateIs);
    XSSFSheet sheet = workbook.getSheetAt(0);

    List<SampleItem> list = getDataList();

    CellStyle cellStyle = workbook.createCellStyle();
    CreationHelper createHelper = workbook.getCreationHelper();
    cellStyle.setDataFormat(createHelper.createDataFormat().getFormat("yyyy/mm/dd"));

    for (int i=0; i<list.size(); i++) {
        SampleItem si = list.get(i);

        XSSFRow row = sheet.createRow(i + 1);

        Cell cell1 = row.createCell(0);
        cell1.setCellValue(si.getDate());
        cell1.setCellStyle(cellStyle);

        Cell cell2 = row.createCell(1);
        cell2.setCellValue(si.getName());

        Cell cell3 = row.createCell(2);
        cell3.setCellValue(si.getScore());
    }

    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    workbook.write(bos);
    workbook.close();
    return new ResponseEntity<byte[]>(bos.toByteArray(), responseHeaders, HttpStatus.OK);
}

package cn.devmgr.tutorial;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

@SpringBootApplication
public class Application extends SpringBootServletInitializer{

	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);
	}
}

@Configuration
public class MvcConfig implements WebMvcConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        // URL访问所有的/css/开头的url，都映射到src/main/resources/statics/css目录下；
        // 注意需要classpath:开头
        registry.addResourceHandler("/css/**")
            .addResourceLocations("classpath:/static/css/");
    }
    
}