将PDF下载到android设备下载文件夹Android

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.ResponseBody;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class PdfDownloader {
    private static final String PDF_URL = "https://example.com/example.pdf"; // 替换为实际的PDF文件URL
    private static final String DOWNLOAD_FOLDER = "/storage/emulated/0/Downloads/"; // 替换为实际的下载文件夹路径

    public void downloadPdf() {
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url(PDF_URL)
                .build();

        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                // 处理下载失败的情况
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (response.isSuccessful()) {
                    ResponseBody responseBody = response.body();
                    if (responseBody != null) {
                        InputStream inputStream = responseBody.byteStream();
                        File file = new File(DOWNLOAD_FOLDER, "example.pdf"); // 替换为实际的PDF文件名
                        FileOutputStream outputStream = new FileOutputStream(file);

                        byte[] buffer = new byte[4096];
                        int bytesRead;
                        while ((bytesRead = inputStream.read(buffer)) != -1) {
                            outputStream.write(buffer, 0, bytesRead);
                        }

                        outputStream.flush();
                        outputStream.close();
                        inputStream.close();

                        // 下载完成后的处理逻辑，例如显示一个通知或打开PDF文件
                    }
                }
            }
        });
    }
}