java将图片转成base64

Java可以将图片转成base64字符串的方法主要有两种：

1.使用Java自带的Base64类

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Base64;

public class ImageToBase64 {
    public static void main(String[] args) {
        String base64Str = null;
        InputStream in = null;
        try {
            in = new FileInputStream("image.jpg");
            byte[] bytes = new byte[in.available()];
            in.read(bytes);
            base64Str = Base64.getEncoder().encodeToString(bytes);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println(base64Str);
    }
}

2.使用第三方库Apache Commons Codec

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import org.apache.commons.codec.binary.Base64;

public class ImageToBase64 {
    public static void main(String[] args) {
        String base64Str = null;
        FileInputStream fileInputStreamReader = null;
        try {
            File file = new File("image.jpg");
            byte[] bytes = new byte[(int) file.length()];
            fileInputStreamReader = new FileInputStream(file);
            fileInputStreamReader.read(bytes);
            base64Str = new String(Base64.encodeBase64(bytes), "UTF-8");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fileInputStreamReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println(base64Str);
    }
}