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
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();
}
3、总结
本文介绍了如何在Java中创建一个集成JACOB的HTTP服务。我们详细讲解了动态加载JACOB DLL、创建和配置HTTP服务器、实现IP白名单以及处理HTTP请求的具体实现步骤。通过这些步骤，你可以在Java应用中调用Windows的COM组件，并通过HTTP接口与外部系统进行交互。
