HttpUtils

青旅半醒 2023-10-14 13:31 32阅读 0赞

import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.UnsupportedEncodingException;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Map;
    import java.util.Map.Entry;
    import java.util.Objects;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.client.entity.UrlEncodedFormEntity;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.client.methods.HttpUriRequest;
    import org.apache.http.entity.ContentType;
    import org.apache.http.entity.StringEntity;
    import org.apache.http.entity.mime.MultipartEntityBuilder;
    import org.apache.http.entity.mime.content.FileBody;
    import org.apache.http.entity.mime.content.StringBody;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.message.BasicNameValuePair;
    
    
    public class HttpUtils {
    
        /**
         * 字符编码
         */
        private final static String UTF8 = "utf-8";
        /**
         * 字节流数组大小（1MB）
         */
        private final static int BYTE_ARRAY_LENGTH = 1024 * 1024;
    
        /**
         * 执行get请求获取响应
         *
         * @param url 请求地址
         * @return 响应内容
         */
        public static String get(String url) {
            return get(url, null);
        }
    
        /**
         * 执行get请求获取响应
         *
         * @param url     请求地址
         * @param headers 请求头参数
         * @return 响应内容
         */
        public static String get(String url, Map<String, String> headers) {
            HttpGet get = new HttpGet(url);
            return getRespString(get, headers);
        }
    
        /**
         * 执行post请求获取响应
         *
         * @param url 请求地址
         * @return 响应内容
         */
        public static String post(String url) {
            return post(url, null, null);
        }
    
        /**
         * 执行post请求获取响应
         *
         * @param url    请求地址
         * @param params 请求参数
         * @return 响应内容
         */
        public static String post(String url, Map<String, String> params) {
            return post(url, null, params);
        }
    
        /**
         * 执行post请求获取响应
         *
         * @param url     请求地址
         * @param headers 请求头参数
         * @param params  请求参数
         * @return 响应内容
         */
        public static String post(String url, Map<String, String> headers, Map<String, String> params) {
            HttpPost post = new HttpPost(url);
            post.setEntity(getHttpEntity(params));
            return getRespString(post, headers);
        }
    
        /**
         * 执行post请求获取响应（请求体为JOSN数据）
         *
         * @param url  请求地址
         * @param json 请求的JSON数据
         * @return 响应内容
         */
        public static String postJson(String url, String json) {
            return postJson(url, null, json);
        }
    
        /**
         * 执行post请求获取响应（请求体为JOSN数据）
         *
         * @param url     请求地址
         * @param headers 请求头参数
         * @param json    请求的JSON数据
         * @return 响应内容
         */
        public static String postJson(String url, Map<String, String> headers, String json) {
            HttpPost post = new HttpPost(url);
            post.setHeader("Content-type", "application/json");
            post.setEntity(new StringEntity(json, UTF8));
            return getRespString(post, headers);
        }
    
        /**
         * 执行post请求获取响应（请求体包含文件）
         *
         * @param url    请求地址
         * @param params 请求参数（文件对应的value传File对象）
         * @return 响应内容
         */
        public static String postFile(String url, Map<String, Object> params) {
            return postFile(url, null, params);
        }
    
        /**
         * 执行post请求获取响应（请求体包含文件）
         *
         * @param url     请求地址
         * @param headers 请求头参数
         * @param params  请求参数（文件对应的value传File对象）
         * @return 响应内容
         */
        public static String postFile(String url, Map<String, String> headers, Map<String, Object> params) {
            HttpPost post = new HttpPost(url);
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            if (Objects.nonNull(params) && !params.isEmpty()) {
                for (Entry<String, Object> entry : params.entrySet()) {
                    String key = entry.getKey();
                    Object value = entry.getValue();
                    if (Objects.isNull(value)) {
                        builder.addPart(key, new StringBody("", ContentType.TEXT_PLAIN));
                    } else {
                        if (value instanceof File) {
                            builder.addPart(key, new FileBody((File) value));
                        } else {
                            builder.addPart(key, new StringBody(value.toString(), ContentType.TEXT_PLAIN));
                        }
                    }
                }
            }
            HttpEntity entity = builder.build();
            post.setEntity(entity);
            return getRespString(post, headers);
        }
    
        /**
         * 下载文件
         *
         * @param url      下载地址
         * @param path     保存路径（如：D:/images，不传默认当前工程根目录）
         * @param fileName 文件名称（如：hello.jpg）
         */
        public static void download(String url, String path, String fileName) {
            HttpGet get = new HttpGet(url);
            File dir = new File(path);
            if (!dir.exists()) {
                dir.mkdirs();
            }
            String filePath = null;
            if (Objects.isNull(path) || path.isEmpty()) {
                filePath = fileName;
            } else {
                if (path.endsWith("/")) {
                    filePath = path + fileName;
                } else {
                    filePath += path + "/" + fileName;
                }
            }
            File file = new File(filePath);
            if (!file.exists()) {
                try {
                    file.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            try (FileOutputStream fos = new FileOutputStream(file); InputStream in = getRespInputStream(get, null)) {
                if (Objects.isNull(in)) {
                    return;
                }
                byte[] bytes = new byte[BYTE_ARRAY_LENGTH];
                int len = 0;
                while ((len = in.read(bytes)) != -1) {
                    fos.write(bytes, 0, len);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        /**
         * 获取请求体HttpEntity
         *
         * @param params 请求参数
         * @return HttpEntity
         */
        private static HttpEntity getHttpEntity(Map<String, String> params) {
            List<BasicNameValuePair> pairs = new ArrayList<BasicNameValuePair>();
            for (Entry<String, String> entry : params.entrySet()) {
                pairs.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
            }
            HttpEntity entity = null;
            try {
                entity = new UrlEncodedFormEntity(pairs, UTF8);
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            return entity;
        }
    
        /**
         * 设置请求头
         *
         * @param request 请求对象
         * @param headers 请求头参数
         */
        private static void setHeaders(HttpUriRequest request, Map<String, String> headers) {
            if (Objects.nonNull(headers) && !headers.isEmpty()) {
                // 请求头不为空，则设置对应请求头
                for (Entry<String, String> entry : headers.entrySet()) {
                    request.setHeader(entry.getKey(), entry.getValue());
                }
            } else {
                // 请求为空时，设置默认请求头
                request.setHeader("Connection", "keep-alive");
                request.setHeader("Accept-Encoding", "gzip, deflate, br");
                request.setHeader("Accept", "*/*");
                request.setHeader("User-Agent",
                        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36");
            }
        }
    
        /**
         * 执行请求，获取响应流
         *
         * @param request 请求对象
         * @return 响应内容
         */
        private static InputStream getRespInputStream(HttpUriRequest request, Map<String, String> headers) {
            // 设置请求头
            setHeaders(request, headers);
            // 获取响应对象
            HttpResponse response = null;
            try {
                response = HttpClients.createDefault().execute(request);
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
            // 获取Entity对象
            HttpEntity entity = response.getEntity();
            // 获取响应信息流
            InputStream in = null;
            if (Objects.nonNull(entity)) {
                try {
                    in = entity.getContent();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return in;
        }
    
        /**
         * 执行请求，获取响应内容
         *
         * @param request 请求对象
         * @return 响应内容
         */
        private static String getRespString(HttpUriRequest request, Map<String, String> headers) {
            byte[] bytes = new byte[BYTE_ARRAY_LENGTH];
            int len = 0;
            try (InputStream in = getRespInputStream(request, headers);
                 ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
                if (Objects.isNull(in)) {
                    return "";
                }
                while ((len = in.read(bytes)) != -1) {
                    bos.write(bytes, 0, len);
                }
                return bos.toString(UTF8);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "";
        }
    
    }