使用Java创建集成JACOB的HTTP服务

程序浅谈后端 2024-09-09

背景介绍

在Windows环境中，Java应用有时需要与Windows的COM组件进行交互。JACOB（Java COM Bridge）提供了一个桥梁，使得Java可以调用Windows的COM对象。本文将介绍如何创建一个Java HTTP服务，并集成JACOB来与Windows系统交互。

1、环境配置

首先，确保你已经安装了JDK和Maven。接着，在你的Maven项目的pom.xml文件中添加JACOB依赖：pom.xml

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<dependency>
    <groupId>com.hynnet</groupId>
    <artifactId>jacob</artifactId>
    <version>1.18</version>
</dependency>

这将自动下载JACOB库，并将其添加到你的项目中。

2、创建集成JACOB的HTTP服务

2.1 动态加载JACOB DLL

使用Java创建集成JACOB的HTTP服务

JACOB库需要用到DLL文件。我们将从资源中提取DLL文件，并动态加载它。以下代码展示了如何提取DLL并设置系统属性：java

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private static String extractDll(String dllFileName) throws IOException {
    InputStream dllStream = WindowsClient.class.getResourceAsStream("/lib/" + dllFileName);
    if (dllStream == null) {
        log.error("DLL 文件不存在: " + dllFileName);
        throw new IOException("DLL 文件不存在: " + dllFileName);
    }

    File tempDll = Files.createTempFile("jacob", ".dll").toFile();
    tempDll.deleteOnExit();

    try (FileOutputStream fos = new FileOutputStream(tempDll)) {
        byte[] buffer = new byte[1024];
        int bytesRead;
        while ((bytesRead = dllStream.read(buffer)) != -1) {
            fos.write(buffer, 0, bytesRead);
        }
    }

    return tempDll.getAbsolutePath();
}

在main方法中，调用extractDll方法提取DLL，并通过LibraryLoader类动态加载DLL：java

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public static void main(String[] args) throws IOException {
    String dllPath = extractDll("jacob-1.18-x64.dll");
    System.setProperty(LibraryLoader.JACOB_DLL_PATH, dllPath);
    LibraryLoader.loadJacobLibrary();
    // 继续后续步骤
}

2.2 创建并配置HTTP服务器

使用Java的HttpServer类创建一个简单的HTTP服务。服务器将监听指定的端口，并定义请求处理器：java

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int clientPort = 10005;
InetAddress localHost = InetAddress.getLocalHost();
String hostAddress = localHost.getHostAddress();

log.info("客户端启动，监听端口 " + clientPort);
log.info("访问地址: http://" + hostAddress + ":" + clientPort + "/receive");

HttpServer server = HttpServer.create(new InetSocketAddress(clientPort), 0);
server.createContext("/receive", new ReceiveHandler());
server.setExecutor(Executors.newCachedThreadPool());
server.start();

2.3 实现IP白名单java

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private static final Set<String> WHITELIST = new HashSet<>();
static {
    WHITELIST.add("127.0.0.1");
    WHITELIST.add("20.47.122.28");
}

static class ReceiveHandler implements HttpHandler {
    @Override
    public void handle(HttpExchange exchange) throws IOException {
        String remoteAddress = exchange.getRemoteAddress().getAddress().getHostAddress();
        log.info("收到来自 " + remoteAddress + " 的请求");

        if (!WHITELIST.contains(remoteAddress)) {
            String response = "403 Forbidden - 您的IP地址不在白名单中";
            exchange.sendResponseHeaders(403, response.getBytes().length);
            exchange.getResponseBody().write(response.getBytes());
            exchange.getResponseBody().close();
            log.info("拒绝访问: " + remoteAddress);
            return;
        }

        // 继续处理请求
    }
}

2.4 处理HTTP请求

在ReceiveHandler中处理HTTP请求，包括记录日志和响应请求。以下是如何读取请求体并处理消息的代码示例：ini

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@Override
public void handle(HttpExchange exchange) throws IOException {
    String remoteAddress = exchange.getRemoteAddress().getAddress().getHostAddress();
    log.info("收到来自 " + remoteAddress + " 的请求");

    if (!WHITELIST.contains(remoteAddress)) {
        String response = "403 Forbidden - 您的IP地址不在白名单中";
        exchange.sendResponseHeaders(403, response.getBytes().length);
        exchange.getResponseBody().write(response.getBytes());
        exchange.getResponseBody().close();
        log.info("拒绝访问: " + remoteAddress);
        return;
    }

    InputStream is = exchange.getRequestBody();
    byte[] bytes = readAllBytes(is);
    String message = new String(bytes, StandardCharsets.UTF_8);
    log.info("接收到的消息: " + message);

    String response = "消息已接收并处理";
    exchange.sendResponseHeaders(200, response.getBytes().length);
    exchange.getResponseBody().write(response.getBytes());
    exchange.getResponseBody().close();
}

private byte[] readAllBytes(InputStream is) throws IOException {
    ByteArrayOutputStream buffer = new ByteArrayOutputStream();
    byte[] data = new byte[1024];
    int bytesRead;
    while ((bytesRead = is.read(data, 0, data.length)) != -1) {
        buffer.write(data, 0, bytesRead);
    }
    return buffer.toByteArray();
}