在android上下载pdf文件

<uses-permission android:name="android.permission.INTERNET" />

// 创建OkHttpClient实例
OkHttpClient client = new OkHttpClient();

// 创建请求对象
Request request = new Request.Builder()
        .url("http://example.com/file.pdf") // 替换为PDF文件的URL
        .build();

// 发送异步请求
client.newCall(request).enqueue(new Callback() {
    @Override
    public void onFailure(Call call, IOException e) {
        // 处理请求失败的情况
    }

    @Override
    public void onResponse(Call call, Response response) throws IOException {
        if (response.isSuccessful()) {
            // 获取响应数据
            ResponseBody body = response.body();

            // 将响应数据保存为PDF文件
            InputStream inputStream = body.byteStream();
            File pdfFile = new File(Environment.getExternalStorageDirectory(), "downloaded.pdf");
            FileOutputStream outputStream = new FileOutputStream(pdfFile);
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }
            outputStream.flush();
            outputStream.close();
            inputStream.close();

            // 下载完成后，可以通知用户或者进行其他处理
        }
    }
});