java http的get、post、post json参数的方法

对于http的post json参数方法使用的是Apache的HttpClient-4.x.Jar，先引入jar

在maven添加如下：

      <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
   <dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.12</version>
  </dependency>

使用Apache的HttpClient-4.x.Jar包。

Jar包Maven下载地址：https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient。

1、先创建HttpUtil 工具类：

package com.game.www.utils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.methods.HttpPost;
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.BasicHeader;
import org.apache.http.protocol.HTTP;

import com.alibaba.fastjson.JSONObject;

public class HttpUtil {

    
    public static String doGet(String httpurl) {
        
        HttpURLConnection connection = null;
        InputStream is = null;
        BufferedReader br = null;
        String result = null;// 返回结果字符串
        try {
            // 创建远程url连接对象
            URL url = new URL(httpurl);
            // 通过远程url连接对象打开一个连接，强转成httpURLConnection类
            connection = (HttpURLConnection) url.openConnection();
            // 设置连接方式：get
            connection.setRequestMethod("GET");
            // 设置连接主机服务器的超时时间：15000毫秒
            connection.setConnectTimeout(15000);
            // 设置读取远程返回的数据时间：60000毫秒
            connection.setReadTimeout(60000);
            // 发送请求
            connection.connect();
            // 通过connection连接，获取输入流
            if (connection.getResponseCode() == 200) {
                is = connection.getInputStream();
                // 封装输入流is，并指定字符集
                br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                // 存放数据
                StringBuffer sbf = new StringBuffer();
                String temp = null;
                while ((temp = br.readLine()) != null) {
                    sbf.append(temp);
                    sbf.append("
");
                }
                result = sbf.toString();
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            if (null != br) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
 
            if (null != is) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
 
            connection.disconnect();// 关闭远程连接
        }
 
        return result;
    }
    

    public static String doPost(String httpUrl, String param) {
 
        HttpURLConnection connection = null;
        InputStream is = null;
        OutputStream os = null;
        BufferedReader br = null;
        String result = null;
        try {
            URL url = new URL(httpUrl);
            // 通过远程url连接对象打开连接
            connection = (HttpURLConnection) url.openConnection();
            // 设置连接请求方式
            connection.setRequestMethod("POST");
            // 设置连接主机服务器超时时间：15000毫秒
            connection.setConnectTimeout(150000);
            // 设置读取主机服务器返回数据超时时间：60000毫秒
            connection.setReadTimeout(600000);
 
            // 默认值为：false，当向远程服务器传送数据/写数据时，需要设置为true
            connection.setDoOutput(true);
            // 默认值为：true，当前向远程服务读取数据时，设置为true，该参数可有可无
            connection.setDoInput(true);
            // 设置传入参数的格式:请求参数应该是 name1=value1&name2=value2 的形式。
            connection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");
            // 设置鉴权信息：Authorization: Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0
            connection.setRequestProperty("Authorization",
                    "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");
            // 通过连接对象获取一个输出流
            os = connection.getOutputStream();
            // 通过输出流对象将参数写出去/传输出去,它是通过字节数组写出的
            os.write(param.getBytes());
            // 通过连接对象获取一个输入流，向远程读取
            if (connection.getResponseCode() == 200) {
                is = connection.getInputStream();
                // 对输入流对象进行包装:charset根据工作项目组的要求来设置
                br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
 
                StringBuffer sbf = new StringBuffer();
                String temp = null;
                // 循环遍历一行一行读取数据
                while ((temp = br.readLine()) != null) {
                    sbf.append(temp);
                    sbf.append("
");
                }
                result = sbf.toString();
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            if (null != br) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != os) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != is) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            // 断开与远程地址url的连接
            connection.disconnect();
        }
        return result;
    }
    
    /**
     * 发送post请求
     * @param URL
     * @param json
     *
     * @return
     */
    public static String sendPost(String URL,JSONObject json) {
        CloseableHttpClient client = HttpClients.createDefault();
        HttpPost post = new HttpPost(URL);
        post.setHeader("Content-Type", "application/json");
        post.addHeader("Authorization", "Basic YWRtaW46");
        String result;
        try {
            StringEntity s = new StringEntity(json.toString(), "utf-8");
            s.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,
                    "application/json"));
            post.setEntity(s);
            // 发送请求
            HttpResponse httpResponse = client.execute(post);
            // 获取响应输入流
            InputStream inStream = httpResponse.getEntity().getContent();
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    inStream, "utf-8"));
            StringBuilder strber = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null)
                strber.append(line + "
");
            inStream.close();
            result = strber.toString();
            if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                System.out.println("请求服务器成功，做相应处理");
            } else {
                System.out.println("请求服务端失败");
            }
        } catch (Exception e) {
//            logger.error("请求异常："+e.getMessage());
            throw new RuntimeException(e);
        }
        return result;
    }
    
    
}

2、spring mvc 的controller 测试案例：

    @RequestMapping(value = "/get", method = RequestMethod.GET, produces = "text/html;charset=UTF-8")
    @ResponseBody
    @ApiOperation(value = "get", notes = "get")
    @ApiResponse(response= String.class, code = 200, message = "接口返回对象参数")
    public String get(HttpServletRequest request, HttpServletResponse response) {
        
        try {
            String url = "http://11.29.11.19:8080/Inv/baseData/action/getList";
            String result = HttpUtil.doGet(url);
            
            return result;
        
        } catch (Exception e) {
            e.printStackTrace();
            return "fail";
        }
    }
    
    @RequestMapping(value = "/post", method = RequestMethod.GET, produces = "text/html;charset=UTF-8")
    @ResponseBody
    @ApiOperation(value = "post", notes = "post")
    @ApiResponse(response= String.class, code = 200, message = "接口返回对象参数")
    public String post(HttpServletRequest request, HttpServletResponse response) {
        
        try {
            String url = "http://11.29.11.19:8080/Inv/baseData/action/query";
            String p = "limit=10&offset=2";
            String result = HttpUtil.doPost(url, p);
        
            return result;
        
        } catch (Exception e) {
            e.printStackTrace();
            return "fail";
        }
    }
    
    
    @RequestMapping(value = "/postJson", method = RequestMethod.GET, produces = "text/html;charset=UTF-8")
    @ResponseBody
    @ApiOperation(value = "postJson", notes = "postJson")
    @ApiResponse(response= String.class, code = 200, message = "接口返回对象参数")
    public String postJson(HttpServletRequest request, HttpServletResponse response) {
        
        try {
            String url = "http://11.29.11.19:8080/my/api/user/login";
            
            JSONObject jsonObject = new JSONObject();
            
            jsonObject.put("loginname", "123456");
            jsonObject.put("pwd", "123456");
            String result = HttpUtil.sendPost(url,jsonObject);
        
            return result;
        
        } catch (Exception e) {
            e.printStackTrace();
            return "fail";
        }
    }