嵌入式 Java 网络服务器隐藏了应用程序界面
embedded Java web server hides app interface
我有一个用 JavaFX 编写的应用程序，用于控制剧院中的一些灯光，界面非常简单。基本上有两个按钮，一个在 3 秒内淡化亮起，另一个在 3 秒内淡化。该应用程序连接到以太网到串行服务器 (Sealevel Sealink 4104) 以控制灯。
我想添加一个浏览器界面，以便可以通过任何移动设备控制该应用程序。我已根据从该视频中获得的代码添加了一个 Java 网络服务器。
https://www.youtube.com/watch?v=G4Z2PQfOHdY
应用程序运行s，我可以在浏览器中获取我要查找的网页。但是，我的应用程序界面从未出现。这个想法是应用程序界面始终存在以表明它是 运行ning。网页界面将可用于将控制选项扩展到移动设备。
此时的主要问题是如何在不干扰应用程序界面功能的情况下让 Web 服务器在后台 运行？
网络服务器代码：
package lightcontrol2;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.StringTokenizer;
public final class JavaWebserver {
public final void StartServer() throws Exception {
// Set port number.
int port = 9000;
// Establish the listening socket.
ServerSocket serverSocket = new ServerSocket(port);
// Process HTTP sevice requests in an infinite loop.
while (true) {
// Listen for TCP connection request.
Socket connectionSocket = serverSocket.accept();
// Construct an object to process the HTTP request message.
HttpRequest request = new HttpRequest(connectionSocket);
// Create a new thread to process the request.
Thread thread = new Thread(request);
// Start the thread.
thread.start();
}
}
}
final class HttpRequest implements Runnable {
// Return carriage return (CR) and line feed (LF).
final static String CRLF = "\r\n";
Socket socket;
// Constructor.
public HttpRequest(Socket socket) throws Exception {
this.socket = socket;
}
// Implement the run() method of the Runnable interface.
// Within run(), explicitly catch and handle exceptions
// with try/ catch block.
@Override
public void run() {
try {
processRequest();
} catch (Exception e){
System.out.println(e);
}
}
private void processRequest() throws Exception {
// Get a reference to the socket's input and output streams.
InputStream instream = socket.getInputStream();
DataOutputStream os = new DataOutputStream(socket.getOutputStream());
// Set up input stream filters.
// Page 169, 10th line down or so . . .
// Reads the input data.
BufferedReader br = new BufferedReader(new InputStreamReader(instream));
// Get the request line of the HTTP request message.
// Get path/file.html version of http
String requestLine = br.readLine();
// Display the request line.
System.out.println();
System.out.println(requestLine);
// Deal with the request.
// Extract the filename from the request line.
// This is an input method with deliminators.
StringTokenizer tokens = new StringTokenizer(requestLine);
// Skip over the method, which should be 'GET'.
tokens.nextToken();
String fileName = tokens.nextToken();
// Root of the server.
String root = "/www/";
fileName = root + fileName;
// Open the requested file.
FileInputStream fis = null;
boolean fileExists = true;
try {
fis = new FileInputStream(fileName);
} catch (FileNotFoundException e) {
fileExists = false;
}
// Construct the response message.
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists) {
statusLine = "HTTP/1.0 200 OK" + CRLF;
contentTypeLine = "Content-type: " + contentType(fileName) + CRLF;
}
else {
statusLine = "HTTP/1.0 404 Not Found" + CRLF;
contentTypeLine = "Content-type: " + "text/html" + CRLF;
entityBody = "<HTML>" +
"<HEAD><TITLE>Not Found</TITLE></HEAD>" +
"<BODY>NOt Found</BODY></HTML>";
}
//Send the status line.
os.writeBytes(statusLine);
// Sent the content type line.
os.writeBytes(contentTypeLine);
// Send a blank line to indicate the end of the header lines.
os.writeBytes(CRLF);
// Send the entity body.
if (fileExists) {
sendBytes(fis, os);
os.writeBytes(statusLine);
fis.close();
} else {
os.writeBytes(statusLine);
os.writeBytes(entityBody);
os.writeBytes(contentTypeLine);
}
System.out.println("*****");
System.out.println(fileName);
System.out.println("*****");
// Get and display the header lines.
String headerLine = null;
while ((headerLine = br.readLine()).length() != 0) {
System.out.println(headerLine);
}
// Close streams and socket.
os.close();
br.close();
socket.close();
}
private static String contentType(String fileName) {
if (fileName.endsWith(".htm") || fileName.endsWith(".html")) {
return "text/html";
}
if (fileName.endsWith(".jpg") || fileName.endsWith(".jpeg")) {
return "image/jpeg";
}
if (fileName.endsWith(".gif")) {
return "image/gif";
}
return "application/octet-stream";
}
private static void sendBytes(FileInputStream fis, OutputStream os) throws Exception {
// Construct 1K buffer to hold bytes on way to the socket.
byte[] buffer = new byte[1024];
int bytes = 0;
// Copy requested file into the socket's output stream.
// read() returns -1, indicating end of file.
while ((bytes = fis.read(buffer)) != -1) {
os.write(buffer, 0, bytes);
}
}
}
接口代码如下：
package lightcontrol2;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
public class LightControl2 extends Application {
@Override
public void start(Stage primaryStage) throws Exception {
GridPane grid = createGrid();
SealinkConnect connect = new SealinkConnect();
JavaWebserver webserver = new JavaWebserver();
Button btnOn = new Button();
grid.add(btnOn, 0, 1);
btnOn.setText("3 Sec On");
btnOn.setOnAction((ActionEvent event) -> {
System.out.println("3N:100:A");
connect.sendCommand("3N:100:A");
});
Button btnOff = new Button();
grid.add(btnOff, 0, 2);
btnOff.setText("3 Sec Off");
btnOff.setOnAction((ActionEvent event) -> {
System.out.println("3F:A");
connect.sendCommand("3F:A");
});
BorderPane root = new BorderPane();
root.setPadding(new Insets(10));
root.setCenter(grid);
Scene scene = new Scene(root, 365, 300);
primaryStage.setTitle("Light Control Test");
primaryStage.setScene(scene);
scene.getStylesheets().add
(LightControl2.class.getResource("style.css").toExternalForm());
primaryStage.show();
connect.socketConnect();
webserver.StartServer();
}
private GridPane createGrid() {
GridPane grid = new GridPane();
grid.setAlignment(Pos.CENTER);
grid.setHgap(5);
grid.setVgap(10);
grid.setPadding(new Insets(10));
return grid;
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
我猜测 JavaFX 需要它的线程返回。它调用 start()，您在其中调用 webserver.StartServer()，后者又陷入无限 while(true) 循环。您也应该在单独的线程中执行套接字接受循环（并根据需要正确关闭它）并让 start 方法 return.
话虽这么说，我不建议您尝试自己实施 pseudo-HTTP-server - 这只是额外的代码、工作和维护，如果不是 RFC-compliant，可能会以各种方式出现问题。您可以使用大量可嵌入的轻量级 HTTP 服务器。作为 JLHTTP 的作者，我认为它可能很适合您的用例，但还有许多其他选择。
使用 JLHTTP 2.1，您需要这样的东西：
public void startWebServer() {
String dir = "."; // local folder to serve website files from
HTTPServer server = new HTTPServer(9000); // pick a port, any port
HTTPServer.VirtualHost host = server.getVirtualHost(null); // default virtual host
host.addContext("/", new FileContextHandler(new File(dir), "/")); // serve website files from disk directory
host.addContext("/api/lights", (request, response) -> {
Map<String, String> params = request.getParams();
String action = params.get("action");
if (action == null)
action = "";
switch (action) {
case "on":
connect.sendCommand("3N:100:A");
return 200; // ok
case "off":
connect.sendCommand("3F:A");
return 200; // ok
default:
return 400; // bad request
}
}, "GET", "POST"); // support both GET and POST requests
server.start();
}
备注：
- 网站文件（html/js/css/imags 等）是从磁盘提供的 - 该示例使用当前目录，但您应该将其更改为专用目录以防止意外访问敏感文件。
- 您的客户端代码可以通过表单、AJAX、url 和查询参数等使用 POST 或 GET 请求，只要它发送适当的动作参数和值。
- 您还应妥善关闭应用程序、连接、HTTPServer 等
- 此示例接受单个 on/off 操作参数。如果您在客户端需要更大的灵活性，您可以传递单独的 command/device/value 参数并在上下文处理程序中创建灯光控制器命令字符串。
- 一切正常后，您还应该考虑安全性，否则观众中的某些孩子会开始搞乱您的节目:-)
我有一个用 JavaFX 编写的应用程序，用于控制剧院中的一些灯光，界面非常简单。基本上有两个按钮，一个在 3 秒内淡化亮起，另一个在 3 秒内淡化。该应用程序连接到以太网到串行服务器 (Sealevel Sealink 4104) 以控制灯。
我想添加一个浏览器界面，以便可以通过任何移动设备控制该应用程序。我已根据从该视频中获得的代码添加了一个 Java 网络服务器。
https://www.youtube.com/watch?v=G4Z2PQfOHdY
应用程序运行s，我可以在浏览器中获取我要查找的网页。但是，我的应用程序界面从未出现。这个想法是应用程序界面始终存在以表明它是 运行ning。网页界面将可用于将控制选项扩展到移动设备。
此时的主要问题是如何在不干扰应用程序界面功能的情况下让 Web 服务器在后台 运行？
网络服务器代码：
package lightcontrol2;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.StringTokenizer;
public final class JavaWebserver {
public final void StartServer() throws Exception {
// Set port number.
int port = 9000;
// Establish the listening socket.
ServerSocket serverSocket = new ServerSocket(port);
// Process HTTP sevice requests in an infinite loop.
while (true) {
// Listen for TCP connection request.
Socket connectionSocket = serverSocket.accept();
// Construct an object to process the HTTP request message.
HttpRequest request = new HttpRequest(connectionSocket);
// Create a new thread to process the request.
Thread thread = new Thread(request);
// Start the thread.
thread.start();
}
}
}
final class HttpRequest implements Runnable {
// Return carriage return (CR) and line feed (LF).
final static String CRLF = "\r\n";
Socket socket;
// Constructor.
public HttpRequest(Socket socket) throws Exception {
this.socket = socket;
}
// Implement the run() method of the Runnable interface.
// Within run(), explicitly catch and handle exceptions
// with try/ catch block.
@Override
public void run() {
try {
processRequest();
} catch (Exception e){
System.out.println(e);
}
}
private void processRequest() throws Exception {
// Get a reference to the socket's input and output streams.
InputStream instream = socket.getInputStream();
DataOutputStream os = new DataOutputStream(socket.getOutputStream());
// Set up input stream filters.
// Page 169, 10th line down or so . . .
// Reads the input data.
BufferedReader br = new BufferedReader(new InputStreamReader(instream));
// Get the request line of the HTTP request message.
// Get path/file.html version of http
String requestLine = br.readLine();
// Display the request line.
System.out.println();
System.out.println(requestLine);
// Deal with the request.
// Extract the filename from the request line.
// This is an input method with deliminators.
StringTokenizer tokens = new StringTokenizer(requestLine);
// Skip over the method, which should be 'GET'.
tokens.nextToken();
String fileName = tokens.nextToken();
// Root of the server.
String root = "/www/";
fileName = root + fileName;
// Open the requested file.
FileInputStream fis = null;
boolean fileExists = true;
try {
fis = new FileInputStream(fileName);
} catch (FileNotFoundException e) {
fileExists = false;
}
// Construct the response message.
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists) {
statusLine = "HTTP/1.0 200 OK" + CRLF;
contentTypeLine = "Content-type: " + contentType(fileName) + CRLF;
}
else {
statusLine = "HTTP/1.0 404 Not Found" + CRLF;
contentTypeLine = "Content-type: " + "text/html" + CRLF;
entityBody = "<HTML>" +
"<HEAD><TITLE>Not Found</TITLE></HEAD>" +
"<BODY>NOt Found</BODY></HTML>";
}
//Send the status line.
os.writeBytes(statusLine);
// Sent the content type line.
os.writeBytes(contentTypeLine);
// Send a blank line to indicate the end of the header lines.
os.writeBytes(CRLF);
// Send the entity body.
if (fileExists) {
sendBytes(fis, os);
os.writeBytes(statusLine);
fis.close();
} else {
os.writeBytes(statusLine);
os.writeBytes(entityBody);
os.writeBytes(contentTypeLine);
}
System.out.println("*****");
System.out.println(fileName);
System.out.println("*****");
// Get and display the header lines.
String headerLine = null;
while ((headerLine = br.readLine()).length() != 0) {
System.out.println(headerLine);
}
// Close streams and socket.
os.close();
br.close();
socket.close();
}
private static String contentType(String fileName) {
if (fileName.endsWith(".htm") || fileName.endsWith(".html")) {
return "text/html";
}
if (fileName.endsWith(".jpg") || fileName.endsWith(".jpeg")) {
return "image/jpeg";
}
if (fileName.endsWith(".gif")) {
return "image/gif";
}
return "application/octet-stream";
}
private static void sendBytes(FileInputStream fis, OutputStream os) throws Exception {
// Construct 1K buffer to hold bytes on way to the socket.
byte[] buffer = new byte[1024];
int bytes = 0;
// Copy requested file into the socket's output stream.
// read() returns -1, indicating end of file.
while ((bytes = fis.read(buffer)) != -1) {
os.write(buffer, 0, bytes);
}
}
}
接口代码如下：
package lightcontrol2;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
public class LightControl2 extends Application {
@Override
public void start(Stage primaryStage) throws Exception {
GridPane grid = createGrid();
SealinkConnect connect = new SealinkConnect();
JavaWebserver webserver = new JavaWebserver();
Button btnOn = new Button();
grid.add(btnOn, 0, 1);
btnOn.setText("3 Sec On");
btnOn.setOnAction((ActionEvent event) -> {
System.out.println("3N:100:A");
connect.sendCommand("3N:100:A");
});
Button btnOff = new Button();
grid.add(btnOff, 0, 2);
btnOff.setText("3 Sec Off");
btnOff.setOnAction((ActionEvent event) -> {
System.out.println("3F:A");
connect.sendCommand("3F:A");
});
BorderPane root = new BorderPane();
root.setPadding(new Insets(10));
root.setCenter(grid);
Scene scene = new Scene(root, 365, 300);
primaryStage.setTitle("Light Control Test");
primaryStage.setScene(scene);
scene.getStylesheets().add
(LightControl2.class.getResource("style.css").toExternalForm());
primaryStage.show();
connect.socketConnect();
webserver.StartServer();
}
private GridPane createGrid() {
GridPane grid = new GridPane();
grid.setAlignment(Pos.CENTER);
grid.setHgap(5);
grid.setVgap(10);
grid.setPadding(new Insets(10));
return grid;
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
我猜测 JavaFX 需要它的线程返回。它调用 start()，您在其中调用 webserver.StartServer()，后者又陷入无限 while(true) 循环。您也应该在单独的线程中执行套接字接受循环（并根据需要正确关闭它）并让 start 方法 return.
话虽这么说，我不建议您尝试自己实施 pseudo-HTTP-server - 这只是额外的代码、工作和维护，如果不是 RFC-compliant，可能会以各种方式出现问题。您可以使用大量可嵌入的轻量级 HTTP 服务器。作为 JLHTTP 的作者，我认为它可能很适合您的用例，但还有许多其他选择。
使用 JLHTTP 2.1，您需要这样的东西：
public void startWebServer() {
String dir = "."; // local folder to serve website files from
HTTPServer server = new HTTPServer(9000); // pick a port, any port
HTTPServer.VirtualHost host = server.getVirtualHost(null); // default virtual host
host.addContext("/", new FileContextHandler(new File(dir), "/")); // serve website files from disk directory
host.addContext("/api/lights", (request, response) -> {
Map<String, String> params = request.getParams();
String action = params.get("action");
if (action == null)
action = "";
switch (action) {
case "on":
connect.sendCommand("3N:100:A");
return 200; // ok
case "off":
connect.sendCommand("3F:A");
return 200; // ok
default:
return 400; // bad request
}
}, "GET", "POST"); // support both GET and POST requests
server.start();
}
备注：
- 网站文件（html/js/css/imags 等）是从磁盘提供的 - 该示例使用当前目录，但您应该将其更改为专用目录以防止意外访问敏感文件。
- 您的客户端代码可以通过表单、AJAX、url 和查询参数等使用 POST 或 GET 请求，只要它发送适当的动作参数和值。
- 您还应妥善关闭应用程序、连接、HTTPServer 等
- 此示例接受单个 on/off 操作参数。如果您在客户端需要更大的灵活性，您可以传递单独的 command/device/value 参数并在上下文处理程序中创建灯光控制器命令字符串。
- 一切正常后，您还应该考虑安全性，否则观众中的某些孩子会开始搞乱您的节目:-)