java HTTP 请求工具

import lombok.extern.slf4j.Slf4j;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import .HttpURLConnection;
import .MalformedURLException;
import .URL;

/**
 * @description: HTTP请求工具
 * @author: Stephen
 * @create: 2019/11/12
 **/
@Slf4j
public class HttpRequest {

    /**
     * @param u     url地址
     * @param param 跟在?后面的参数
     *              格式如：String content = "access_token=" + URLEncoder.encode(access_token, "gbk") + "&image=" + URLEncoder.encode(image, "gbk");
     * @return
     */
    public static String sendPost2(String u, String param) {
        StringBuffer sbf = new StringBuffer();
        try {
            URL url = new URL(u);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");
            connection.setUseCaches(false);
            connection.setInstanceFollowRedirects(true);
            connection.addRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            connection.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
            connection.connect();
            DataOutputStream out = new DataOutputStream(connection.getOutputStream());
            if (!"".equals(param)) {
                out.writeBytes(param);
            }
            out.flush();
            out.close();
            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String lines;
            while ((lines = reader.readLine()) != null) {
                lines = new String(lines.getBytes(), "utf-8");
                sbf.append(lines);
            }
            reader.close();
            connection.disconnect();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sbf.toString();
    }

    /**
     * 发送 http POST 请求
     *
     * @param
     * @return
     */
    public static String sendPost(String u, String json) {
        StringBuffer sbf = new StringBuffer();
        try {
            URL url = new URL(u);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");
            connection.setUseCaches(false);
            connection.setInstanceFollowRedirects(true);
            connection.addRequestProperty("role", "Admin");
            connection.addRequestProperty("Content-Type", "application/json");
            connection.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
            connection.connect();
            DataOutputStream out = new DataOutputStream(connection.getOutputStream());
            if (!"".equals(json)) {
                out.writeBytes(json);
            }
            out.flush();
            out.close();
            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String lines;
            while ((lines = reader.readLine()) != null) {
                lines = new String(lines.getBytes(), "utf-8");
                sbf.append(lines);
            }
            reader.close();
            connection.disconnect();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sbf.toString();
    }

    /**
     * 发送 http Get 请求
     *
     * @param
     * @return
     */
    public static String sendGet(String u, String json) {
        StringBuffer sbf = new StringBuffer();
        try {
            URL url = new URL(u);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.addRequestProperty("role", "Admin");
            connection.addRequestProperty("Content-Type", "application/json");
            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String lines;
            while ((lines = reader.readLine()) != null) {
                lines = new String(lines.getBytes(), "utf-8");
                sbf.append(lines);
            }
            reader.close();
            connection.disconnect();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sbf.toString();
    }
}

其他方式参考

Java调用第三方http接口的方式

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;

/**
 * 基于 HttpClient 
 */
public final class HttpUtil {
    public static CloseableHttpClient httpClient = HttpClientBuilder.create().build();

    /**
     * get请求获取String类型数据
     * @param url 请求链接
     * @return
     */
    public static String get(String url){
        StringBuffer sb = new StringBuffer();
        HttpGet httpGet = new HttpGet(url);
        try {
            HttpResponse response = httpClient.execute(httpGet);

            HttpEntity entity = response.getEntity();
            InputStreamReader reader = new InputStreamReader(entity.getContent(),"utf-8");
            char [] charbufer;
            while (0<reader.read(charbufer=new char[10])){
                sb.append(charbufer);
            }
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            httpGet.releaseConnection();
        }
        return sb.toString();
    }

    /**
     * post方式请求数据
     * @param url 请求链接
     * @param data post数据体
     * @return
     */
    @SuppressWarnings("unchecked")
    public static String post(String url, Map<String,String> data){
        StringBuffer sb = new StringBuffer();
        HttpPost httpPost = new HttpPost(url);
        List<NameValuePair> valuePairs = new ArrayList<NameValuePair>();
        if(null != data) {
            for (String key : data.keySet()) {
                valuePairs.addAll((Collection<? extends NameValuePair>) new BasicNameValuePair(key, data.get(key)));
            }
        }
        try {
            // httpPost.setEntity(new UrlEncodedFormEntity((List<? extends org.apache.http.NameValuePair>) valuePairs));
            HttpResponse response = httpClient.execute(httpPost);
            HttpEntity httpEntity = response.getEntity();
            BufferedInputStream bis = new BufferedInputStream(httpEntity.getContent());
            byte [] buffer;
            while (0<bis.read(buffer=new byte[128])){
                sb.append(new String(buffer,"utf-8"));
            }
        }catch (UnsupportedEncodingException e){
            e.printStackTrace();
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            httpPost.releaseConnection();
        }
        return sb.toString();
    }


}