Java发送Http请求

原文地址：Java发送Http请求

1、方法一，通过apache的httpclient

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import org.junit.Test;

import com.fasterxml.jackson.databind.ObjectMapper;

public class HttpTest {
    String uri = "http://127.0.0.1:8080/simpleweb";

    /**
     * Get方法
     */
    @Test
    public void test1() {
        try {
            CloseableHttpClient client = null;
            CloseableHttpResponse response = null;
            try {
                HttpGet httpGet = new HttpGet(uri + "/test1?code=001&name=测试");

                client = HttpClients.createDefault();
                response = client.execute(httpGet);
                HttpEntity entity = response.getEntity();
                String result = EntityUtils.toString(entity);
                System.out.println(result);
            } finally {
                if (response != null) {
                    response.close();
                }
                if (client != null) {
                    client.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Post发送form表单数据
     */
    @Test
    public void test2() {
        try {
            CloseableHttpClient client = null;
            CloseableHttpResponse response = null;
            try {
                // 创建一个提交数据的容器
                List<BasicNameValuePair> parames = new ArrayList<>();
                parames.add(new BasicNameValuePair("code", "001"));
                parames.add(new BasicNameValuePair("name", "测试"));

                HttpPost httpPost = new HttpPost(uri + "/test1");
                httpPost.setEntity(new UrlEncodedFormEntity(parames, "UTF-8"));

                client = HttpClients.createDefault();
                response = client.execute(httpPost);
                HttpEntity entity = response.getEntity();
                String result = EntityUtils.toString(entity);
                System.out.println(result);
            } finally {
                if (response != null) {
                    response.close();
                }
                if (client != null) {
                    client.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Post发送json数据
     */
    @Test
    public void test3() {
        try {
            CloseableHttpClient client = null;
            CloseableHttpResponse response = null;
            try {
                ObjectMapper objectMapper = new ObjectMapper();
                Map<String, Object> data = new HashMap<String, Object>();
                data.put("code", "001");
                data.put("name", "测试");

                HttpPost httpPost = new HttpPost(uri + "/test2");
                httpPost.setHeader(HTTP.CONTENT_TYPE, "application/json");
                httpPost.setEntity(new StringEntity(objectMapper.writeValueAsString(data),
                        ContentType.create("text/json", "UTF-8")));

                client = HttpClients.createDefault();
                response = client.execute(httpPost);
                HttpEntity entity = response.getEntity();
                String result = EntityUtils.toString(entity);
                System.out.println(result);
            } finally {
                if (response != null) {
                    response.close();
                }
                if (client != null) {
                    client.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

 2、方法二，通过JDK自带的HttpURLConnection

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import org.junit.Test;

import com.fasterxml.jackson.databind.ObjectMapper;

public class HttpApi {
    String uri = "http://127.0.0.1:7080/simpleweb";

    /**
     * Get方法
     */
    @Test
    public void test1() {
        try {
            URL url = new URL(uri + "/test1?code=001&name=测试");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            connection.setDoOutput(true); // 设置该连接是可以输出的
            connection.setRequestMethod("GET"); // 设置请求方式
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");

            BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
            String line = null;
            StringBuilder result = new StringBuilder();
            while ((line = br.readLine()) != null) { // 读取数据
                result.append(line + "
");
            }
            connection.disconnect();

            System.out.println(result.toString());//请求返回的数据，不会取的可以看我上一篇，java取json数据
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Post方法发送form表单
     */
    @Test
    public void test2() {
        try {
            URL url = new URL(uri + "/test1");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            connection.setDoInput(true); // 设置可输入
            connection.setDoOutput(true); // 设置该连接是可以输出的
            connection.setRequestMethod("POST"); // 设置请求方式
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");

            PrintWriter pw = new PrintWriter(new BufferedOutputStream(connection.getOutputStream()));
            pw.write("code=001&name=测试");
            pw.flush();
            pw.close();

            BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
            String line = null;
            StringBuilder result = new StringBuilder();
            while ((line = br.readLine()) != null) { // 读取数据
                result.append(line + "
");
            }
            connection.disconnect();

            System.out.println(result.toString());//请求返回的数据，不会取的可以看我上一篇，java取json数据
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Post方法发送json数据
     */
    @Test
    public void test3() {
        try {
            URL url = new URL(uri + "/test2");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            connection.setDoInput(true); // 设置可输入
            connection.setDoOutput(true); // 设置该连接是可以输出的
            connection.setRequestMethod("POST"); // 设置请求方式
            connection.setRequestProperty("Content-Type", "application/json;charset=UTF-8");

            ObjectMapper objectMapper = new ObjectMapper();
            Map<String, Object> data = new HashMap<String, Object>();
            data.put("code", "001");
            data.put("name", "测试");
            PrintWriter pw = new PrintWriter(new BufferedOutputStream(connection.getOutputStream()));
            pw.write(objectMapper.writeValueAsString(data));
            pw.flush();
            pw.close();

            BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
            String line = null;
            StringBuilder result = new StringBuilder();
            while ((line = br.readLine()) != null) { // 读取数据
                result.append(line + "
");
            }
            connection.disconnect();

            System.out.println(result.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3.   2020.08.19

 url是带着参数拼接好的。例如：sendHttpGet(StaticCode.CautionUrl+"?deviceId="+deviceId)

token:选填的Header参数。

/**
     * Http Get请求
     * @param url
     * @param token
     * @return
     * @throws Exception
     */
    public static String sendHttpGet(String url, String token) throws Exception {
           HttpClient httpClient;
           HttpGet postMethod;
           HttpResponse response;
           String reponseContent;
           httpClient = HttpClients.createDefault();
           postMethod = new HttpGet(url);
           postMethod.addHeader("Content-type", "application/json;charset=UTF-8");
           postMethod.addHeader("t-access-token", token);
           response = httpClient.execute(postMethod);
           HttpEntity httpEntity = response.getEntity();
           reponseContent = EntityUtils.toString(httpEntity);
           EntityUtils.consume(httpEntity);
           return reponseContent;

    }

JSONBody：拼接的json参数，比如String JSONBody = "{"appKey":""+StaticCode.appKey+"","appSecret":""+StaticCode.appSecret+""}";

/**
     * 发送http post请求
     *
     * @Create: 2020/8/19 13:58
     */
    public static String sendHttpPost(String url, String JSONBody) throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        httpPost.addHeader("Content-Type", "application/json; charset=UTF-8");
        httpPost.setEntity(new StringEntity(JSONBody));
        CloseableHttpResponse response = httpClient.execute(httpPost);
        //System.out.println(response.getStatusLine().getStatusCode() + "
");
        HttpEntity entity = response.getEntity();
        String responseContent = EntityUtils.toString(entity, "UTF-8");
        response.close();
        httpClient.close();
        return responseContent;
    }