在 Android 设备上搭建 Web 服务器

2024-05-24 服务器 0

public class Constants {

//服务端接口的端口号
public static final int PORT_SERVER = 1995;

public static final String GET_FILE = “/file”;

public static final String GET_IMAGE = “/image”;

public static final String POST_JSON = “/json”;

}

···
.registerHandler(Constants.GET_FILE, new DownloadFileHandler()) //注册一个文件下载接口
.registerHandler(Constants.GET_IMAGE, new DownloadImageHandler()) //注册一个图片下载接口
.registerHandler(Constants.POST_JSON, new JsonHandler()) //注册一个Post Json接口
···

例如，假设设备的 IP 地址是：192.168.0.101 ，那么在访问 http://192.168.0.101:1995/file 接口时，请求操作就会由 DownloadFileHandler 来处理

下载文件

DownloadFileHandler 实现了 RequestHandler 接口，在 handle 方法中可以获取到请求头，表单数据这些信息，，通过注解声明支持 Get 方式调用，在此直接返回一个文本文件用于下载

/**

作者：leavesC
时间：2018/4/5 16:30
描述：https://github.com/leavesC/AndroidServer
https://www.jianshu.com/u/9df45b87cfdf
*/
public class DownloadFileHandler implements RequestHandler {

@RequestMapping(method = {RequestMethod.GET})
@Override
public void handle(HttpRequest httpRequest, HttpResponse httpResponse, HttpContext httpContext) throws HttpException, IOException {
File file = createFile();
HttpEntity httpEntity = new FileEntity(file, ContentType.create(getMimeType(file.getAbsolutePath()), Charset.defaultCharset()));
httpResponse.setHeader(“Content-Disposition”, “attachment;filename=File.txt”);
httpResponse.setStatusCode(200);
httpResponse.setEntity(httpEntity);
}

private File createFile() {
File file = null;
OutputStream outputStream = null;
try {
file = File.createTempFile(“File”, “.txt”, MainApplication.get().getCacheDir());
outputStream = new FileOutputStream(file);
outputStream.write(“leavesC，这是一段测试文本”.getBytes());
} catch (IOException e) {
e.printStackTrace();
} finally {
if (outputStream != null) {
try {
outputStream.flush();
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return file;
}

}

这里直接在浏览器中访问接口（要和 Android Web服务器运行在同个局域网下），可以直接下载到文件

下载图片

类似的，下载图片的接口处理器 DownloadImageHandler 可以如下设计，在 handle 方法中返回应用的图标

/**

作者：leavesC
时间：2018/4/5 16:30
描述：https://github.com/leavesC/AndroidServer
https://www.jianshu.com/u/9df45b87cfdf
*/
public class DownloadImageHandler extends SimpleRequestHandler {

private File file = new File(Environment.getExternalStorageDirectory(), “leavesC.jpg”);

@RequestMapping(method = {RequestMethod.GET})
@Override
protected View handle(HttpRequest request) throws HttpException, IOException {
writeToSdCard();
HttpEntity httpEntity = new FileEntity(file, ContentType.create(getMimeType(file.getAbsolutePath()), Charset.defaultCharset()));
return new View(200, httpEntity);
}

private void writeToSdCard() throws IOException {
if (!file.exists()) {
synchronized (DownloadImageHandler.class) {
if (!file.exists()) {
boolean b = file.createNewFile();
if (!b) {
throw new IOException(“What broken cell phone.”);
}
Bitmap bitmap = BitmapFactory.decodeResource(MainApplication.get().getResources(), R.mipmap.ic_launcher_round);
OutputStream outputStream = null;
try {
outputStream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (outputStream != null) {
outputStream.flush();
outputStream.close();
}
}
}
}
}
}

}

Post表单

这里需要将注解值改为 RequestMethod.POST，通过 HttpRequestParser.getContentFromBody(httpRequest) 函数可以获取到表单数据，这里直接检测表单数据是否为 Json 字符串，是的话则为之多添加一个属性：“state” 作为返回值，否则返回只包含属性 “state” 的 Json 字符串

/**

作者：leavesC
时间：2018/4/5 16:30
描述：https://github.com/leavesC/AndroidServer
https://www.jianshu.com/u/9df45b87cfdf
*/
public class JsonHandler implements RequestHandler {

@RequestMapping(method = {RequestMethod.POST})
@Override
public void handle(HttpRequest httpRequest, HttpResponse httpResponse, HttpContext httpContext) throws HttpException, IOException {
String content = HttpRequestParser.getContentFromBody(httpRequest);
JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(content);
} catch (JSONException e) {
e.printStackTrace();
}
if (jsonObject == null) {
jsonObject = new JSONObject();
}
try {
jsonObject.put(“state”, “success”);
} catch (JSONException e) {
e.printStackTrace();
}
StringEntity stringEntity = new StringEntity(jsonObject.toString(), “utf-8”);
httpResponse.setStatusCode(200);
httpResponse.setEntity(stringEntity);
}
}
这里在 Postman 这个工具上进行 Post 操作
以上三个例子都是在电脑端调用的，这和在手机端调用是同个效果的