Java基础知识三

public static boolean isValidUrl(String urlString){
    URI uri = null;
    try {
        uri = new URI(urlString);
    } catch (URISyntaxException e) {
        e.printStackTrace();
        return false;
    }
 
    if(uri.getHost() == null){
        return false;
    }
    if(uri.getScheme().equalsIgnoreCase("http") || uri.getScheme().equalsIgnoreCase("https")){
        return true;
    }
    return false;
}

// 使用stream的distinct方法实现去重，但是需要对象实现hashcode equals 方法
list.stream().distinct()

public class StreamOperateUtil {
    public static void main(String[] args) throws FileNotFoundException {
         
        InputStream input =  new FileInputStream("c:\\test.txt"); 
        //InputStream input =  httpconn.getInputStream(); //这里可以写你获取到的流
        
        ByteArrayOutputStream baos = cloneInputStream(input);
        
        // 打开两个新的输入流  
        InputStream stream1 = new ByteArrayInputStream(baos.toByteArray());  
        InputStream stream2 = new ByteArrayInputStream(baos.toByteArray());
        
    }
 
    private static ByteArrayOutputStream cloneInputStream(InputStream input) {
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int len;
            while ((len = input.read(buffer)) > -1) {
                baos.write(buffer, 0, len);
            }
            baos.flush();
            return baos;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
 
}

 /**
 * 将定位点 base64 图片转存到 minio 上
 */
InputStream in = null;
String base64=pin.getDwtp();
try {
    //截取base64头部，获取文件类型
    String fileType = Base64FileTypeEnum.getFileType(base64.substring(0, base64.indexOf(",")));
    //去掉头部，防止转换文件后打开显示文件损坏
    String s = base64.substring(base64.indexOf(",")+1);
    byte[] bytes = Base64.decode(s);
    // 上传
    in =new ByteArrayInputStream(bytes);
    // 执行上传
    String temp=MinioUtil.upload(in,"pin/"+uuid+"/定位图片"+fileType);
    pin.setDwtp(temp);

    // 写到文件中
    byte[] b =Base64.decode(imgStr);
    for (int i = 0; i < b.length; ++i) {
        if (b[i] < 0) {// 调整异常数据
            b[i] += 256;
        }
    }
    // 生成jpeg图片
    String imgFilePath = "D:\\tanbing2.jpg";// 新生成的图片
    OutputStream out = new FileOutputStream(imgFilePath);
    out.write(b);
    out.flush();
    out.close();
    
} catch (Exception e) {
    log.error("定位点图片转换失败", e);
} finally {
    if (in != null) {
        try {
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}