Java模拟Http请求封装工具类

封装一个简单的Http请求工具类，主要方便设置代理请求，无需额外框架

1、需要引入的jar包

       <!-- 简化代码getter setter -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!-- 阿里的json工具包 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.68</version>
        </dependency>
        <!-- http请求工具 -->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.12</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore</artifactId>
            <version>4.4.13</version>
        </dependency>

2、测试需要的实体类

package com.ourlang.httphelper.util;

import lombok.Data;

/**
 * 测试post\get请求传递json数据实体类
 *
 * @author ourlang
 */
@Data
public class User {
    private Integer ID;
    private String Name;
}

3、 代码实现

package com.ourlang.httphelper.util;

import com.alibaba.fastjson.JSON;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.*;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.springframework.util.StringUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * http请求工具封装
 *
 * @author ourlang
 */
public class HttpHelper {

    /**
     * 发起GET同步请求
     *
     * @param uri        请求的url地址
     * @param headers    请求头参数map
     * @param parameters 请求参数map
     * @return 请求的结果字符串
     */
    public static String get(String uri, Map<String, String> headers, Map<String, String> parameters) {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        //封装get请求的参数
        StringBuilder urlParameters = addGetParameters(parameters);
        HttpGet httpGet = new HttpGet(uri + urlParameters);
        return getResultStr(headers, httpClient, httpGet);

    }

    /**
     * 发起PUT同步请求
     *
     * @param uri        请求的url地址
     * @param headers    请求头参数map
     * @param parameters 请求参数map
     * @return 请求的结果字符串
     */
    public static String put(String uri, Map<String, String> headers, Map<String, String> parameters, String jsonStr) throws UnsupportedEncodingException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        HttpPut httpPut = new HttpPut(uri);
        addParameters(httpPut, parameters, jsonStr);
        return getResultStr(headers, httpClient, httpPut);
    }

    /**
     * 发起POST同步请求
     *
     * @param uri        请求的url地址
     * @param headers    请求头参数map
     * @param parameters 请求参数map
     * @return 请求的结果字符串
     */
    public static String post(String uri, Map<String, String> headers, Map<String, String> parameters, String jsonStr) throws UnsupportedEncodingException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        HttpPost httpPost = new HttpPost(uri);
        addParameters(httpPost, parameters, jsonStr);
        return getResultStr(headers, httpClient, httpPost);
    }

    /**
     * 发起DELETE请求
     *
     * @param uri        请求的url地址
     * @param headers    请求头参数map
     * @param parameters 请求参数map
     * @return 请求的结果字符串
     */
    public static String delete(String uri, Map<String, String> headers, Map<String, String> parameters) {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        //封装get请求的参数
        StringBuilder urlParameters = addGetParameters(parameters);
        HttpDelete httpDelete = new HttpDelete(uri + urlParameters);
        return getResultStr(headers, httpClient, httpDelete);
    }

    /**
     * 添加get请求的参数
     *
     * @param parameters 请求参数的map
     * @return StringBuilder
     */
    private static StringBuilder addGetParameters(Map<String, String> parameters) {
        StringBuilder urlParameters = new StringBuilder();
        urlParameters.append("?");
        for (String key : parameters.keySet()) {
            String value = parameters.get(key);
            urlParameters.append(key).append("=").append(value).append("&");
        }
        return urlParameters;
    }

    /**
     * 设置请求头参数
     *
     * @param headers     请求头map集合
     * @param httpRequest http请求对象
     */
    private static void setHeaders(Map<String, String> headers, HttpRequestBase httpRequest) {
        if (headers != null && !headers.isEmpty()) {
            for (String key : headers.keySet()) {
                String value = headers.get(key);
                httpRequest.setHeader(key, value);
            }
        }
    }

    /**
     * POST、GET请求的参数添加方式
     *
     * @param parameters     需要添加到请求参数的map集合
     * @param postPutRequest post或者get请求对象
     * @param jsonStr        请求json参数
     * @throws UnsupportedEncodingException 传递参数引发的异常
     */
    private static void addParameters(HttpEntityEnclosingRequestBase postPutRequest, Map<String, String> parameters, String jsonStr) throws UnsupportedEncodingException {
        if (!StringUtils.isEmpty(jsonStr)) {
            postPutRequest.setHeader("Content-Type", "application/json;charset=UTF-8");
            postPutRequest.setEntity(new StringEntity(jsonStr, Charset.forName("UTF-8")));
        } else {
            // 1、构造list集合，往里面存请求的数据
            List<NameValuePair> list = new ArrayList<>();
            for (String key : parameters.keySet()) {
                String value = parameters.get(key);
                BasicNameValuePair basicNameValuePair = new BasicNameValuePair(key, value);
                list.add(basicNameValuePair);
            }
            //2 我们发现Entity是一个接口，所以只能找实现类，发现实现类又需要一个集合，集合的泛型是NameValuePair类型
            UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(list);
            //3 通过setEntity 将我们的entity对象传递过去
            postPutRequest.setEntity(formEntity);
        }

    }

    /**
     * 获取请求的返回结果字符串
     *
     * @param headers     请求头map集合
     * @param httpClient  htt请求对象
     * @param httpRequest 请求的http方式对象
     * @return 请求结果字符串
     */
    private static String getResultStr(Map<String, String> headers, CloseableHttpClient httpClient, HttpRequestBase httpRequest) {
        String body = null;
        CloseableHttpResponse response;
        //设置请求头的参数
        setHeaders(headers, httpRequest);
        try {
            //执行请求
            response = httpClient.execute(httpRequest);
            //请求成功执行
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                //获取返回的数据
                HttpEntity entity = response.getEntity();
                //转换成字符串
                body = EntityUtils.toString(entity);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
        return body;
    }



    public static void main(String[] args) throws Exception {
        Map<String, String> parameters = new HashMap<>(16);
        User data = new User();
        data.setID(9);
        data.setName("我的姓名");
        String ps = JSON.toJSONString(data);
        String s = put("http://192.168.0.101:7777/pathway/dictionary/patient/attribute/definition", null, parameters, ps);
        System.out.println(s);
    }
}

4、源码下载

https://github.com/ourlang/httphelper