java保存网络图片到本地

导入两个包
commons-codec
commons-io
导入okhttp

    <dependencies>
        <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>okhttp</artifactId>
            <version>3.6.0</version>
        </dependency>
    </dependencies>

import java.io.*;

public class ImageBase64Utils {


    public static String bytesToBase64(byte[] bytes) {
        return org.apache.commons.codec.binary.Base64.encodeBase64String(bytes);// 返回Base64编码过的字节数组字符串
    }

    /**
     * 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
     *
     * @param path 图片路径
     * @return base64字符串
     */
    public static String imageToBase64(String path) throws IOException {// 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
        byte[] data = null;
        // 读取图片字节数组
        InputStream in = null;
        try {
            in = new FileInputStream(path);
            data = new byte[in.available()];
            in.read(data);
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return org.apache.commons.codec.binary.Base64.encodeBase64String(data);// 返回Base64编码过的字节数组字符串
    }

    /**
     * 处理Base64解码并写图片到指定位置
     *
     * @param base64 图片Base64数据
     * @param path   图片保存路径
     * @return
     */
    public static boolean base64ToImageFile(String base64, String path) throws IOException {// 对字节数组字符串进行Base64解码并生成图片
        // 生成jpeg图片
        try {
            OutputStream out = new FileOutputStream(path);
            return base64ToImageOutput(base64, out);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return false;
    }

    /**
     * 处理Base64解码并输出流
     *
     * @param base64
     * @param out
     * @return
     */
    public static boolean base64ToImageOutput(String base64, OutputStream out) throws IOException {
        if (base64 == null) { // 图像数据为空
            return false;
        }
        try {
            // Base64解码
            byte[] bytes = org.apache.commons.codec.binary.Base64.decodeBase64(base64);
            for (int i = 0; i < bytes.length; ++i) {
                if (bytes[i] < 0) {// 调整异常数据
                    bytes[i] += 256;
                }
            }
            // 生成jpeg图片
            out.write(bytes);
            out.flush();
            return true;
        } finally {
            try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

    public static void main(String[] args) {
        String url = "http://adminweb.himytunai.com/api/auth/captcha?width=120&height=50&serialId=fjKDNFie";
        try {
            OkHttpClient client = new OkHttpClient();
            //获取请求对象
            Request request = new Request.Builder().url(url).build();
            //获取响应体
            ResponseBody body = client.newCall(request).execute().body();
            //获取流
            InputStream in = body.byteStream();

            byte[] bytes = IOUtils.toByteArray(in);
            System.out.println(new String(bytes));
            String s = ImageBase64Utils.bytesToBase64(bytes);
            ImageBase64Utils.base64ToImageFile(s, "F:\\javatest\\src\\main\\java\\dfdfd.png");

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}