安卓开发地址选择器获取外部储存u盘地址并创建pdf文件并写入数据到pdf文件里

import android.app.Activity;

import android.content.Intent;

import android.net.Uri;

import android.os.Bundle;

import android.os.Environment;

import android.os.storage.StorageManager;

import android.os.storage.StorageVolume;

import android.provider.DocumentsContract;

import android.widget.Toast;

import androidx.annotation.Nullable;

import androidx.appcompat.app.AppCompatActivity;

import androidx.documentfile.provider.DocumentFile;

import com.itextpdf.kernel.pdf.PdfDocument;

import com.itextpdf.kernel.pdf.PdfWriter;

import com.itextpdf.layout.Document;

import com.itextpdf.layout.element.Paragraph;

import java.io.IOException;

import java.io.OutputStream;

public class PdfWriteToUsbActivity extends AppCompatActivity {

private static final int REQUEST_CODE_OPEN_DIRECTORY = 1;

private String selectedDirectory;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_pdf_write_to_usb);

// 打开文档树选择器

openDirectoryPicker();

}

private void openDirectoryPicker() {

Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);

startActivityForResult(intent, REQUEST_CODE_OPEN_DIRECTORY);

}

@Override

protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {

super.onActivityResult(requestCode, resultCode, data);

if (requestCode == REQUEST_CODE_OPEN_DIRECTORY && resultCode == Activity.RESULT_OK && data != null) {

// 获取用户选择的目录的 URI

selectedDirectory = data.getData().toString();

// 创建 PDF 文件并写入数据

createAndWriteToPdf();

}

}

private void createAndWriteToPdf() {

if (selectedDirectory != null) {

DocumentFile pickedDir = DocumentFile.fromTreeUri(this, Uri.parse(selectedDirectory));

if (pickedDir != null && pickedDir.exists() && pickedDir.isDirectory()) {

// 在选择的目录下创建一个 PDF 文件

DocumentFile newFile = pickedDir.createFile("application/pdf", "new_file.pdf");

if (newFile != null && newFile.exists()) {

// 写入数据到 PDF 文件

writeDataToPdf(newFile);

} else {

// 文件创建失败

Toast.makeText(this, "PDF file creation failed", Toast.LENGTH_SHORT).show();

}

}

} else {

Toast.makeText(this, "Please select a directory first", Toast.LENGTH_SHORT).show();

}

}

private void writeDataToPdf(DocumentFile pdfFile) {

try {

// 创建 PdfWriter 和 PdfDocument

OutputStream outputStream = getContentResolver().openOutputStream(pdfFile.getUri());

PdfWriter pdfWriter = new PdfWriter(outputStream);

PdfDocument pdfDocument = new PdfDocument(pdfWriter);

// 创建 Document

Document document = new Document(pdfDocument);

// 写入数据到 PDF

document.add(new Paragraph("Hello, this is a sample PDF document."));

// 关闭 Document

document.close();

// 显示成功消息

Toast.makeText(this, "PDF file created and data written successfully", Toast.LENGTH_SHORT).show();

} catch (IOException e) {

e.printStackTrace();

// 处理异常

}

}

}