如何使用HttpURLConnection处理Error请求呢?

下文笔者讲述使用HttpURLConnection捕捉Error请求的方法分享，如下所示

实现思路:
    通过responseCode的返回状态码判断
	然后使用connection.getErrorStream()

例：
定义后台spring mvc返回错误状态码页面

   @GetMapping("/error")
    public ResponseEntity error() {
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("error");
    }

HttpURLConnnection捕捉Error请求页面

HttpURLConnection connection = (HttpURLConnection) new URL("http://localhost:8080/error").openConnection();
connection.setRequestMethod("GET");
//write header
connection.setRequestProperty("Content-Type", "application/json");

connection.connect();

BufferedReader reader;
try {
    int responseCode = connection.getResponseCode();
    if (responseCode == 200) {
        reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
    } else {
        log.error("发生异常，code={}", responseCode);
        reader = new BufferedReader(new InputStreamReader(connection.getErrorStream()));
    }

    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
    reader.close();

} finally {
    connection.disconnect();
}