java实现将图片转Base64字符，Base64转图片

图片转base64

java">import java.io.*;
import java.util.Base64;public class ImageToBase64Converter {public static void main(String[] args) {String imagePath = "path/to/your/image.png"; // 替换为你的图片路径String outputFilePath = "out.txt";try {File imageFile = new File(imagePath);FileInputStream fis = new FileInputStream(imageFile);ByteArrayOutputStream bos = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int bytesRead;while ((bytesRead = fis.read(buffer)) != -1) {bos.write(buffer, 0, bytesRead);}byte[] imageBytes = bos.toByteArray();String base64Image = Base64.getEncoder().encodeToString(imageBytes);BufferedWriter writer = new BufferedWriter(new FileWriter(outputFilePath));writer.write(base64Image);writer.close();System.out.println("Base64 representation of the image has been written to out.txt.");fis.close();bos.close();} catch (IOException e) {e.printStackTrace();}}
}

base64转图片

java">import java.io.*;
import java.util.Base64;public class Base64ToImageConverter {public static void main(String[] args) {String inputFilePath = "out.txt";String outputImagePath = "output.png";try {BufferedReader reader = new BufferedReader(new FileReader(inputFilePath));StringBuilder base64Image = new StringBuilder();String line;while ((line = reader.readLine()) != null) {base64Image.append(line);}byte[] imageBytes = Base64.getDecoder().decode(base64Image.toString());FileOutputStream fos = new FileOutputStream(outputImagePath);fos.write(imageBytes);fos.close();System.out.println("Image has been successfully written to output.png.");} catch (IOException e) {e.printStackTrace();}}
}

扩展需求：批量操作

批量操作。将 E:\资料\gw-资料路径下的所有png格式图片，转成base64 ，输出到E:\资料\gw-资料\out.txt 。保留原文件名称的情况下，再将out.txt里面的base64 还原成多个png图片

java">import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Base64;public class BatchImageToBase64Converter {public static void main(String[] args) {String inputFolderPath = "E:\\资料\\gw-资料";String outputFilePath = "E:\\资料\\gw-资料\\out.txt";try {BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outputFilePath), "UTF-8"));Files.walk(Paths.get(inputFolderPath)).filter(Files::isRegularFile).filter(path -> path.toString().toLowerCase().endsWith(".png")).forEach(path -> {try {byte[] imageBytes = Files.readAllBytes(path);String base64Image = Base64.getEncoder().encodeToString(imageBytes);writer.write("File: " + path.getFileName() + "\n");writer.write(base64Image + "\n");writer.write("----------\n");} catch (IOException e) {e.printStackTrace();}});writer.close();System.out.println("Base64 representations of images have been written to out.txt.");} catch (IOException e) {e.printStackTrace();}}
}

还原：

java">import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Base64;public class BatchBase64ToImageConverter {public static void main(String[] args) {String inputFilePath = "E:\\资料\\gw-资料\\out.txt";String outputFolderPath = "E:\\资料\\gw-资料\\restored_images";try {BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(inputFilePath), "UTF-8"));String line;while ((line = reader.readLine()) != null) {if (line.startsWith("File: ")) {String fileName = line.substring("File: ".length());String base64Data = reader.readLine().trim();byte[] imageBytes = Base64.getDecoder().decode(base64Data);Path outputPath = Paths.get(outputFolderPath, fileName);Files.createDirectories(outputPath.getParent());Files.write(outputPath, imageBytes);System.out.println("Image \"" + fileName + "\" restored.");}}reader.close();System.out.println("All images have been restored.");} catch (IOException e) {e.printStackTrace();}}
}