Spring Boot 嵌入式 HornetQ 集群不转发消息

http://docs.jboss.org/hornetq/2.2.5.Final/user-manual/en/html/architecture.html#d0e595

“HornetQ核心被设计为一组简单的POJO，因此，如果您有一个内部需要消息传递功能的应用程序，但您不想将其公开为HornetQ服务器，则可以直接实例化并在您自己的应用程序中嵌入HornetQ服务器。

如果要嵌入它，则不会将其公开为服务器。每个容器都有一个单独的实例。这相当于启动 2 个大黄蜂副本并给它们相同的队列名称。一个在第一个实例上写入该队列，另一个在第二个实例上侦听队列。

如果要以这种方式分离应用程序，则需要有一个充当服务器的位置。可能，您想要群集。这不是大黄蜂特的，顺便说一句。你经常会发现这种模式。

滤波器

package it.unitn.disi.webdev.claudiovigliarolo;

import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@WebFilter(filterName = "AuthenticationFilter", urlPatterns = { "/*" })
public class AuthenticationFilter implements Filter {
    private ServletContext context;

    public void init(FilterConfig fConfig) throws ServletException {
        this.context = fConfig.getServletContext();
        this.context.log("AuthenticationFilter initialized");
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)

            throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
        String uri = req.getRequestURI();
        HttpSession session = req.getSession(false);
        boolean isLoggedIn = session != null && session.getAttribute("username") != null;

        if (!isLoggedIn && !uri.endsWith("start.jsp")) {
            res.sendRedirect("start.jsp");

        } else {
            chain.doFilter(request, response);
        }
    }

    public void destroy() {
        // close any resources here
    }
}<filter-mapping><filter-name>AuthenticationFilter</filter-name><url-pattern>/*</url-pattern>
  </filter-mapping>

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@WebServlet(name = "GetItems", urlPatterns = { "/GetItems" })
public class GetItems extends HttpServlet {

    String dbURL = "jdbc:derby://localhost:1527/ExamDerbyDB";
    String user = "WEBENGINE";
    String password = "WEBENGINE";
    Connection conn = null;

    @Override
    public void init() {
        try {
            Class.forName("org.apache.derby.jdbc.ClientDriver");
            conn = DriverManager.getConnection(dbURL, user, password);
        } catch (ClassNotFoundException | SQLException ex) {
            ex.printStackTrace();

        }
    }

    @Override
    public void destroy() {
        try {
            if (conn != null) {
                conn.close();
            }
        } catch (SQLException ex) {
            System.err.println("Database connection problem: can't close connection");

        }
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=UTF-8");
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        StringBuilder ret = new StringBuilder();

        ArrayList<String> inserted = getAllItemsFromDB();

        String jsonResponse = getListJson(inserted);
        response.setContentType("application/json;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {

            out.println(jsonResponse);
        }
    }

    private ArrayList<String> getAllItemsFromDB() throws ServletException {
        ArrayList elements = new ArrayList();
        
        PreparedStatement stm = null;
        ResultSet result = null;
        
        try {
            String query = "SELECT USERNAME FROM USERS";
            stm = conn.prepareStatement(query);
            result = stm.executeQuery();
            while(result.next()) {
                String string = result.getString(1); 
                elements.add(string);
            }
            stm.close();
            result.close();

        } catch (SQLException ex) {
            System.err.println("Database connection problem");
        } finally {
            try {
                if(stm != null) stm.close();
                if(result != null) result.close();
            } catch (SQLException ex) {
               System.err.println("Database connection problem: can't close statement/result");
            }
        
        return elements;
    }

    public String getListJson(ArrayList<String> list) {
        if (list.size() == 0)
            return null;
        StringBuilder ret = new StringBuilder("[");
        String prefix = "";
        for (int i = 0; i < list.size(); i++) {
            StringBuilder sb = new StringBuilder();
            ret.append(prefix);
            prefix = ",";
            ret.append(sb.append("{\"message\":\"").append(list.get(i)).append("\"}").toString());
        }
        ret.append("]");
        return ret.toString();
    }
}

类.java

public class MessageList {
    protected final LinkedList<Message> list;

    public MessageList() {
        this.list = new LinkedList<>();
    }

    public void addMessage(Message m) {
        this.list.add(m);
    }

    public void deleteMessage(String message_id) {
        for (Message a : list) {
            if (a.message_id.equals(message_id)) {
                list.remove(a);
            }
        }
    }

    public Message getMessage(String message_id) {
        for (Message a : list) {
            if (a.message_id.equals(message_id)) {
                return a;
            }
        }
        return null;

    }

    public void addLike(String message_id) {
        for (Message a : list) {
            if (a.message_id.equals(message_id)) {
                a.isLiked++;
            }
        }
    }

    StringBuilder ret = new StringBuilder("[");
    String prefix = "";for(
    int i = 0;i<list.size();i++)
    {
        Message m = list.get(i);
        ret.append(prefix);
        prefix = ",";
        ret.append(m.toJson());
    }ret.append("]");

    return ret.toString();
    }

    public String getListJson()
    {
        if(list.size() == 0)
        {
            return null;
        }
        
        StringBuilder ret = new StringBuilder("[");
        String prefix = "";
        for(int i=0; i<list.size(); i++) {
            StringBuilder sb = new StringBuilder();
            ret.append(prefix);
            prefix = ",";
            ret.append(sb.append("{\"message\":\"").append(list.get(i)).append("\"}").toString());
        }
        ret.append("]");
        
        return ret.toString();
    }
}

形式

<!DOCTYPE html>
<html lang="en">
  <body>
    <script>
      function validateForm(form) {
        var username = document.getElementById("username").value;
        var password = document.getElementById("password").value;
        var error = document.getElementById("error");
        error.innerHTML = "";
        if (username === "" || password == "") {
          form.reset();
          error.innerHTML = "password / username empty";
          return false;
        }
        return true;
      }
    </script>

    <div class="container" style="width: 500px; float: left">
      <h2 class="text-center">Welcome to the App</h2>
      <form
        id="registerForm"
        method="POST"
        onsubmit="return validateForm(this)"
        action="Registration"
      >
        <div class="form-group">
          <label for="username">Username:</label>
          <input
            type="text"
            class="form-control"
            id="username"
            placeholder="Enter email"
            name="username"
          />
        </div>
        <div class="form-group">
          <label for="password">Password:</label>
          <input
            type="password"
            class="form-control"
            id="password"
            placeholder="Enter password"
            name="password"
          />
        </div>
        <div class="form-group form-check"></div>
        <button type="submit" class="btn btn-primary">Submit</button>
      </form>
      <div id="error" class="alert" role="alert"></div>
    </div>
  </body>
</html>

常规

//servelet context
ServletContext application=getServletContext();
application.setAttribute("messages", messages);



//SESSION
HttpSession session = request.getSession();
String name = (String) request.getParameter("username");
session.setAttribute("username", name);


//random id java
String uniqueID = UUID.randomUUID().toString();

//package
it.unitn.disi.webdev.claudiovigliarolo

//project name
VIGLIAROLO_C_202314

//get contextpath
    String contextPath = request.getContextPath();
        System.out.println("Context Path = " + contextPath);
        response.sendRedirect(contextPath + "/main.html");


//BOOTstrap
  <head>
    <title>Bootstrap Example</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
  </head>



//redirect to other page
window.location.replace("http://stackoverflow.com");



//CONTENT type
response.setContentType("application/json;charset=UTF-8");  
response.setContentType("text/html;charset=UTF-8");






//zuccherino
    protected final LinkedList<Message> list;
    
      public MessageList() {
        this.list = new LinkedList<>();
    }



<!DOCTYPE html>
<html lang="en">
<body>
<script>
function validateForm(form) {
    var username = document.getElementById("username").value;
     var password = document.getElementById("password").value;
      var error = document.getElementById("error");
      error.innerHTML = "";
    if(username === "" || password == "") {
         form.reset();
         error.innerHTML = "password / username empty";
         return false;
    }
   return true;
}
</script>

<div class="container " style="width:500px; float: left;">
   
  <h2 class="text-center">Welcome to the App</h2>
  <form id="registerForm" method="POST" onsubmit="return validateForm(this)" action="Registration">
    <div class="form-group">
      <label for="username">Username:</label>
      <input type="text" class="form-control" id="username" placeholder="Enter email" name="username">
    </div>
    <div class="form-group">
      <label for="password">Password:</label>
      <input type="password" class="form-control" id="password" placeholder="Enter password" name="password">
    </div>
    <div class="form-group form-check">
    </div>
    <button type="submit" class="btn btn-primary">Submit</button>
  </form>
 <div id="error" class="alert" role="alert">
  
</div>
</div>
</body>
</html>


//change styles
 const val =  keywords.some(k=>item.message.includes(k));
const color = val ? "#FFFF00;" : "transparent;";
document.getElementById("data").innerHTML +=
        "<div style=' margin-top:50px;flexdirection: row; display:flex; width:500px; background:" + color + "; justify-content: row; '>" +
        item.message +
        "</div>";


//setimeout
function refresh() {
// make Ajax call here, inside the callback call:
setTimeout(refresh, 5000);
// ...
}
// initial call, or just call refresh directly
setTimeout(refresh, 5000);


//template strings
`string text`

getclaudio postclaudio

<script>
  function onSendData() {
    var title = document.getElementById("username").value;
    var description = document.getElementById("password").value;
    console.log(title, description);
    var http = new XMLHttpRequest();
    var url = "Registration";
    var params = "password=" + description + "&username=" + title;
    http.open("POST", url, true);
    //Send the proper header information along with the request
    http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http.onreadystatechange = function () {
      //Call a function when the state changes.
      if (http.readyState == 4 && http.status == 200) {
        console.log("res", http.responseText);
      }
    };
    http.send(params);
  }
</script>
------GET---------------
  //loadData noparam
<script>

  loadData();

function loadData() {
    var xhttp = new XMLHttpRequest();
    xhttp.open("GET", "GetProducts", true);
    xhttp.responseType = "json";
    xhttp.onreadystatechange = function () {
        var done = 4,
                ok = 200;
        if (this.readyState === done && this.status === ok) {
            my_JSON_object = this.response;
            console.log("response", my_JSON_object);
            document.getElementById("data").innerHTML = "";
            my_JSON_object && my_JSON_object.forEach((item) => {
                console.log("item", item.message);
                document.getElementById("data").innerHTML +=
                        " <div class='card' style='width: 300px; margin-top:50px;'>" +
                        "<div class='card-body'>" +
                        " <h4 class='card-title'>" + item.name + "</h4>" +
                        "<p class='card-text'>" + item.description + "</p>" +
                        "  <p class='card-text'>Price: " + item.price + " $</p>" +
                        "    <a href='detail.html?name=" + item.name + "' class='card-link' >View details</a>" +
                        "   </div>    </div>";
            });
        }
    };
    xhttp.send();
}
</script>
<div id="data"></div>

 //loadData withparam
<script>
  function getData() {
  const urlParams = new URLSearchParams(window.location.search);
  const id = urlParams.get('id');
  const id2 = urlParams.get('id2');

  console.log(id)
  var url = "GetItems";
  let param1 = id;
  let param2 = id2;
  var params = "param1=" + param1 + "&param2=" + param2;
  var http = new XMLHttpRequest();
  http.open("GET", url + "?" + params, true);
  http.responseType = "json";
  http.onreadystatechange = function () {
      var done = 4,
              ok = 200;
      if (this.readyState === done && this.status === ok) {
          my_JSON_object = this.response;
          console.log("response", my_JSON_object);
          document.getElementById("data").innerHTML = "";
          my_JSON_object && my_JSON_object.forEach((item) => {
              console.log("item", item.message);
              document.getElementById("data").innerHTML +=
                      "<div style=' margin-top:50px;flexdirection: row; display:flex; width:500px; justify-content: row; '>" +
                      item.message +
                      "</div>";
          });
      }
  };
  http.send(null);
}
</script>
<div id="data"></div>







<div class="card" style="margin-top: 50px;">
  <div class="card-body">Content</div>
</div>


//render multiple parameters
onclick="showData('${item.name}', '${item.price}', '${item.punteggio}', '${item.extra}' )"

JSON servelet claudio

RETURN JSON
//create simple json response
response.setContentType("application/json;charset=UTF-8");  
StringBuilder ret = new StringBuilder();
ret.append("{\"ready\":\"").append("false").append("\"}");
try (PrintWriter out = response.getWriter()) {
    out.println(ret.toString());
}

JSON LIST CLASS
     public String toJSON() {
        StringBuilder ret = new StringBuilder("[");
        String prefix = "";
        for(int i=0; i<list.size(); i++) {
            Message m = list.get(i);
            ret.append(prefix);
            prefix = ",";
            ret.append(m.toJson());
        }
        ret.append("]");
                System.err.println("priting tojson"+ ret.toString());
        return ret.toString();
    }


JSON ITEM
    public String toJson() {
        StringBuilder ret = new StringBuilder();
        ret.append("{\"id\":\"").append(this.id).append("\",");
        ret.append("\"nome\":\"").append(this.nome).append("\",");
        ret.append("\"imgName\":\"").append(this.imgName).append("\"}");
        return ret.toString();
    }




STRING LIST
    public String wordsToJSON(ArrayList<String> list) {
        System.err.println("lunghezza" + list.size());
        if (list.size() == 0) {
            return null;
        }
        StringBuilder ret = new StringBuilder("[");
        String prefix = "";
        for (int i = 0; i < list.size(); i++) {
            StringBuilder sb = new StringBuilder();
            ret.append(prefix);
            prefix = ",";
            ret.append(sb.append("{\"message\":\"").append(list.get(i)).append("\"}").toString());
        }

        ret.append("]");
        System.err.println("jjj" + ret.toString());
        return ret.toString();
    }

    }
JSON RESPONSE OK
           ServletContext application=getServletContext();
            MappaDiCoppie mappaDiCoppie =  (MappaDiCoppie) application.getAttribute("mappaDiCoppie");
            HttpSession session= request.getSession();
            String username = (String) session.getAttribute("username");
            StringBuilder ret = new StringBuilder();
            if(mappaDiCoppie != null && username != null)
            {
                if(mappaDiCoppie.exists(username))
                    //ok 
                    ret.append("{\"ready\":\"").append("true").append("\"}");
                else  
                    //no wait
                    ret.append("{\"ready\":\"").append("false").append("\"}")
                    try (PrintWriter out = response.getWriter()) {
                    out.println(ret.toString());
                }
            }


            ```