HttpURLConnection发送各种内容格式

通过java.net.HttpURLConnection类实现http post发送Content-Type为multipart/form-data的请求。

json处理使用com.fasterxml.jackson

图片压缩使用net.coobird.thumbnailator

log使用org.slf4j

一些静态变量

    private static final Charset charset = StandardCharsets.UTF_8;

    public enum Method {

        POST, GET
    }

    private static final Logger logger = LoggerFactory.getLogger(HttpHandler.class);

?自定义一些header

public static JsonNode getResponseWithHeaders(String urlString, Map<String, String> headerMap) throws HttpAccessException {
        try {
//            logger.debug("Requesting: {}", urlString);
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
//            connection.setRequestProperty("Content-Type", MediaType.APPLICATION_JSON);
            connection.setRequestProperty("Accept", MediaType.APPLICATION_JSON);
            connection.setRequestMethod("GET");
            if (headerMap != null) {
                headerMap.entrySet().forEach((header) -> {
                    connection.setRequestProperty(header.getKey(), header.getValue());
                });
            }

            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                return JsonUtil.getObjectMapper().readTree(new InputStreamReader(connection.getInputStream(), charset));
            } else {
                logger.error("Bad response code: {}", responseCode);
                throw new HttpAccessException("Bad response code: " + responseCode);
            }
        } catch (MalformedURLException e) {
            throw new HttpAccessException("Malformed url", e);
        } catch (JsonProcessingException parseException) {
            throw new HttpAccessException("Failed to parse response as JSON", parseException);
        } catch (IOException e) {
            throw new HttpAccessException("IOException", e);
        }
    }

get/post application/json?并接收application/json

public static JsonNode requestJsonResponse(String urlString, Method method, String body) throws HttpAccessException {
        try {
//            logger.debug("Requesting: {}", urlString);
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestProperty("Content-Type", MediaType.APPLICATION_JSON);
            connection.setRequestProperty("Accept", MediaType.APPLICATION_JSON);
            connection.setRequestMethod(method == Method.POST ? "POST" : "GET");

            if (body != null) {
                OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), charset);
                logger.debug("Sending payload: {}", body);
                writer.write(body);
                writer.close();
            }

            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                return JsonUtil.getObjectMapper().readTree(new InputStreamReader(connection.getInputStream(), charset));
            } else {
                logger.error("Bad response code: {}", responseCode);
                throw new HttpAccessException("Bad response code: " + responseCode);
            }
        } catch (MalformedURLException e) {
            throw new HttpAccessException("Malformed url", e);
        } catch (JsonProcessingException parseException) {
            throw new HttpAccessException("Failed to parse response as JSON", parseException);
        } catch (IOException e) {
            throw new HttpAccessException("IOException", e);
        }
    }

public <T> T postReadClassResponse(String urlString, Object body, Class<T> responseClass) throws HttpAccessException {
        try {
//            logger.debug("Requesting: {}", urlString);
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestProperty("Content-Type", MediaType.APPLICATION_JSON_VALUE);
            connection.setRequestProperty("Accept", MediaType.APPLICATION_JSON_VALUE);
            connection.setRequestMethod("POST");

            objectMapper.writeValue(connection.getOutputStream(), body);

            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                return objectMapper.readValue(connection.getInputStream(), responseClass);
//                return objectMapper.readTree(new InputStreamReader(connection.getInputStream(), charset));
            } else {
//                log.error("Bad response code: {}", responseCode);
                throw new HttpAccessException("Bad response code: " + responseCode);
            }
        } catch (MalformedURLException e) {
            throw new HttpAccessException("Malformed url", e);
        } catch (JsonProcessingException parseException) {
            throw new HttpAccessException("Failed to parse response as JSON", parseException);
        } catch (IOException e) {
            throw new HttpAccessException("IOException", e);
        }
    }

post application/x-www-form-urlencoded

public static String postApplicationFormUrlencoded(String urlString, Map<String, Object> body) throws HttpAccessException {
        StringBuilder sb = new StringBuilder();
        if (body != null && !body.isEmpty()) {
            body.entrySet().forEach(e -> {
                sb.append(e.getKey()).append('=');
                sb.append(e.getValue()).append('&');
            });
            sb.deleteCharAt(sb.length() - 1);
        }

        try {
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestProperty("Content-Type", MediaType.APPLICATION_FORM_URLENCODED);
            connection.setRequestProperty("Accept", MediaType.WILDCARD);
            connection.setRequestMethod("POST");

            OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), charset);
            writer.write(sb.toString());
            writer.close();

            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), charset));
                StringBuilder buffer = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    buffer.append(line);
                }
                return buffer.toString();
            } else {
                int code = connection.getResponseCode();
                logger.error("Bad response code: {}", code);
                throw new HttpAccessException("Bad response code: " + code);
            }
        } catch (MalformedURLException e) {
            throw new HttpAccessException("Malformed url", e);
        } catch (IOException e) {
            throw new HttpAccessException("IOException", e);
        }
    }

加载图片并压缩

public static byte[] requestImg(String urlString, int width, int height) throws HttpAccessException {
        try {
//            logger.debug("Requesting: {}", urlString);
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestMethod("GET");

            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                var inStream = connection.getInputStream();
                var outStream = new ByteArrayOutputStream();
                if (width > 0 & height > 0) {
                    try {
                        //压缩
                        Thumbnailator.createThumbnail(inStream, outStream, width, height);
                        inStream.close();
                        return outStream.toByteArray();
                    } catch (IOException ex) {
                        logger.warn("Thumbnailator error, url:", urlString, ex);
                    }
                }

                byte[] buffer = new byte[1024];
                int len = 0;
                while ((len = inStream.read(buffer)) != -1) {
                    outStream.write(buffer, 0, len);
                }
                inStream.close();
                return outStream.toByteArray();
            } else {
                int code = connection.getResponseCode();
                logger.error("Bad response code: {}", code);
                throw new HttpAccessException("Bad response code: " + code);
            }
        } catch (MalformedURLException e) {
            throw new HttpAccessException("Malformed url", e);
        } catch (IOException e) {
            throw new HttpAccessException("IOException", e);
        }
    }

post application/json 并接收byte array

public static byte[] postTryReadImg(String urlString, JsonNode body) throws HttpAccessException {
        try {
//            logger.debug("Requesting: {}", urlString);
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");

            if (body != null) {
                OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), charset);
                logger.debug("Sending payload: {}", body);
                writer.write(body.toString());
                writer.close();
            }

            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                var inStream = connection.getInputStream();
                var outStream = new ByteArrayOutputStream();

                byte[] buffer = new byte[1024];
                int len;
                while ((len = inStream.read(buffer)) != -1) {
                    outStream.write(buffer, 0, len);
                }
                inStream.close();
                return outStream.toByteArray();
            } else {
                int code = connection.getResponseCode();
                logger.error("Bad response code: {}", code);
                throw new HttpAccessException("Bad response code: " + code);
            }
        } catch (MalformedURLException e) {
            throw new HttpAccessException("Malformed url", e);
        } catch (IOException e) {
            throw new HttpAccessException("IOException", e);
        }
    }

post?multipart/form-data 并接收json

public static HttpPostMultipart buildMultiPartRequest(String requestURL, Map<String, String> headers, String boundary) throws Exception {
        return new HttpPostMultipart(requestURL, headers, boundary);
    }

    public static class HttpPostMultipart {
        private final String boundary;
        private static final String LINE_FEED = "\r\n";
        private HttpURLConnection httpConn;
        //        private String charset;
        private OutputStream outputStream;
        private PrintWriter writer;

        /**
         * 构造初始化 http 请求，content type设置为multipart/form-data
         */
        private HttpPostMultipart(String requestURL, Map<String, String> headers, String boundary) throws Exception {
//            this.charset = charset;
            if (StringUtil.isStringEmpty(boundary)) {
                boundary = UUID.randomUUID().toString();
            }
            this.boundary = boundary;
            URL url = new URL(requestURL);
            httpConn = (HttpURLConnection) url.openConnection();
            httpConn.setUseCaches(false);
            httpConn.setDoOutput(true);    // indicates POST method
            httpConn.setDoInput(true);
            httpConn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
            if (headers != null && headers.size() > 0) {
                Iterator<String> it = headers.keySet().iterator();
                while (it.hasNext()) {
                    String key = it.next();
                    String value = headers.get(key);
                    httpConn.setRequestProperty(key, value);
                }
            }
            outputStream = httpConn.getOutputStream();
//            writer = new DataOutputStream(outputStream);
            writer = new PrintWriter(new OutputStreamWriter(outputStream, charset), true);
        }

        /**
         * 添加form字段到请求
         */
        public void addFormField(String name, String value) throws Exception {
            writer.append("--" + boundary).append(LINE_FEED);
            writer.append("Content-Disposition: form-data; name=\"" + name + "\"").append(LINE_FEED);
            writer.append("Content-Type: text/plain; charset=" + charset).append(LINE_FEED);
            writer.append(LINE_FEED);
            writer.append(value).append(LINE_FEED);
//            writer.write(sb.toString().getBytes());
            writer.flush();
        }

        /**
         * 添加文件
         */
        public void addFilePart(String fieldName, String fileName, InputStream fileStream) throws Exception {
            writer.append("--").append(boundary).append(LINE_FEED);
            writer.append("Content-Disposition: form-data; name=\"").append(fieldName).append("\"; filename=\"").append(fileName).append("\"").append(LINE_FEED);
            writer.append("Content-Type: ").append(URLConnection.guessContentTypeFromName(fileName)).append(LINE_FEED);
//            sb.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
            writer.append(LINE_FEED);
//            writer.write(sb.toString().getBytes());
            writer.flush();

            byte[] bufferOut = new byte[1024];
            if (fileStream != null) {
                int bytesRead = -1;
                while ((bytesRead = fileStream.read(bufferOut)) != -1) {
                    outputStream.write(bufferOut, 0, bytesRead);
                }
//                while (fileStream.read(bufferOut) != -1) {
//                    writer.write(bufferOut);
//                }
                fileStream.close();
            }

//            outputStream.flush();
            writer.append(LINE_FEED);
            writer.flush();
        }

        /**
         * Completes the request and receives response from the server.
         */
        public JsonNode finish() throws Exception {
            writer.flush();
            writer.append("--").append(boundary).append("--").append(LINE_FEED);
//            writer.write(("--" + boundary + "--" + LINE_FEED).getBytes());
            writer.close();

            // checks server's status code first
            int responseCode = httpConn.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                return JsonUtil.getObjectMapper().readTree(new InputStreamReader(httpConn.getInputStream()));
            } else {
                logger.error("Bad response code: {}", responseCode);
                throw new HttpAccessException("Bad response code: " + responseCode);
            }
        }
    }