Java发送http请求

一 创建maven项目

二 导入依赖

<!--    httpclient 依赖-->
    <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>httpclient</artifactId>
      <version>4.3.5</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.7.7</version>
    </dependency>
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-io</artifactId>
      <version>1.3.2</version>
    </dependency>

    <!--引入json相关包-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.47</version>
    </dependency>

三 封装post方法

public class Test {

    public static byte[] encrypt(String content, String password) {
        try {
            byte[] enCodeFormat = password.getBytes();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            byte[] byteContent = content.getBytes("utf-8");
            cipher.init(1, key);
            return cipher.doFinal(byteContent);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String jsonFormat(String resString){

        StringBuffer jsonForMatStr = new StringBuffer();
        int level = 0;
        for(int index=0;index<resString.length();index++)//将字符串中的字符逐个按行输出
        {
            //获取s中的每个字符
            char c = resString.charAt(index);

            //level大于0并且jsonForMatStr中的最后一个字符为\n,jsonForMatStr加入\t
            if (level > 0  && '\n' == jsonForMatStr.charAt(jsonForMatStr.length() - 1)) {
                jsonForMatStr.append(getLevelStr(level));
            }
            //遇到"{"和"["要增加空格和换行，遇到"}"和"]"要减少空格，以对应，遇到","要换行
            switch (c) {
                case '{':
                case '[':
                    jsonForMatStr.append(c + "\n");
                    level++;
                    break;
                case ',':
                    jsonForMatStr.append(c + "\n");
                    break;
                case '}':
                case ']':
                    jsonForMatStr.append("\n");
                    level--;
                    jsonForMatStr.append(getLevelStr(level));
                    jsonForMatStr.append(c);
                    break;
                default:
                    jsonForMatStr.append(c);
                    break;
            }
        }
        return jsonForMatStr.toString();
    }

    private static String getLevelStr(int level) {
        StringBuffer levelStr = new StringBuffer();
        for (int levelI = 0; levelI < level; levelI++) {
            levelStr.append("\t");
        }
        return levelStr.toString();
    }

    public static String post(String url, String headers, String params){
        System.out.println("请求地址：" + url);

        System.out.println("请求参数：");
        System.out.println(jsonFormat(params));
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 设置请求内容
            httpPost.setEntity(new ByteArrayEntity(params.getBytes()));

            // 设置自定义请求头
            if (!headers.isEmpty()) {
                JSONObject jh = JSON.parseObject(headers);
                for (String h : jh.keySet()) {
                    if (h.equals("Content-Type")) {
                        httpPost.addHeader(h, jh.getString(h));
                    } else {
                        // 设置公共请求头
                        httpPost.addHeader("Content-Type", "application/json; charset=utf-8");
                    }
                    httpPost.addHeader(h, jh.getString(h));
                }
            } else {
                // 设置公共请求头
                httpPost.addHeader("Content-Type", "application/json; charset=utf-8");
            }
            // 执行http请求
            response = httpClient.execute(httpPost);

            //获取响应数据
            if (response.getStatusLine().getStatusCode() == 200) {
                resultString = EntityUtils.toString(response.getEntity());// 返回json字符串格式：
            }
            System.out.println("响应参数：");
            System.out.println(jsonFormat(resultString));

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return resultString;
    }

    public static void main(String[] args) {
        String data = "{\"amount\":64.39}";
        String decrypt_data =  new String(Base64.encodeBase64(encrypt(data, "xxxxx_PASSWORD")));
        System.out.println(decrypt_data);
        String params = String.format("{\"decrypt_data\":%s,\"data\":\"%s\"}",data, decrypt_data);
        String url = "http://xxxxx/a/b/";
        post(url, "", params);
    }
}