Http发送GET/POST请求

package com.webservice.test;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.databind.ObjectMapper;

public class HttpTest {
    public static final String POST_URL = "http://10.0.1.127:8080/jqscm/rest/diamond/queryAll/";

    public static final String GET_URL = "http://10.0.1.127:8080/jqscm/rest/diamond/queryByCerNum/";

    public static final ObjectMapper MAPPER = new ObjectMapper();

    public static void main(String[] args) {
        httpURLConnectionGET();
        httpURLConnectionPOST();
    }

    /**
     * 接口调用GET请求方式
     */
    private static void httpURLConnectionGET() {
        BufferedReader in = null;
        StringBuffer sb = new StringBuffer();

        try {
            String param = "cerNumber=10083890";
            String urlParamString = GET_URL + "?" + param;
            URL realUrl = new URL(urlParamString);
            // 打开和URL之间的连接
            HttpURLConnection conn = (HttpURLConnection) realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("Accept", "*/*");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible;MSIE 6.0;Windows NT 5.1;SV1)");
            // 建立实际连接
            conn.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = conn.getHeaderFields();
            // 遍历所有的响应头字段
            for (String key : map.keySet()) {
                System.out.println(key + "-->" + map.get(key));
            }
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream()));

            String line;
            while ((line = in.readLine()) != null) {
                sb.append(line);
            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常" + e);
            e.printStackTrace();
        } finally {// 使用finally块来关闭输入流
            try {
                if (in != null) {
                    in.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println(sb);
    }

    /**
     * 接口调用 POST请求方式
     */
    @SuppressWarnings({ "static-access" })
    private static void httpURLConnectionPOST() {

        try {
            URL url = new URL(POST_URL);
            // 调用URL的openConnection方法，返回URLConnection类型连接
            URLConnection urlConnection = url.openConnection();
            // 将URLConnection类型连接强转为HttpURLConnection类型连接
            HttpURLConnection conn = (HttpURLConnection) urlConnection;// 此时conn为一个待连接对象
            // 设置连接输出流为true,默认为FALSE，（POST请求是以流的形式隐式的传递参数）
            conn.setDoOutput(true);
            // 设置连接输入流为TRUE
            conn.setDoInput(true);
            // 设置请求方式为POST
            conn.setRequestMethod("POST");
            // 设置post请求缓存为FALSE
            conn.setUseCaches(false);
            // 设置该HttpURLConnection实例是否自动执行重定向
            conn.setFollowRedirects(true);

            // 设置请求头里面的各个属性
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            // 建立连接（请求未开始，直到conn.getInputStream()方法调用时才发起，以上各个参数设置需在此方法之前进行）
            conn.connect();

            // 创建输入输出流，用于向连接里面输出携带的参数
            DataOutputStream out = new DataOutputStream(conn.getOutputStream());
            Map<String, String> map = new HashMap<String, String>();
            map.put("cerNumber", "10083890");
            String params = MAPPER.writeValueAsString(map);

            // 将参数输出到连接
            out.writeBytes(params);

            // 输出完成后刷新并关闭流
            out.flush();
            out.close();// 切记

            System.out.println(conn.getResponseCode());

            // 连接发送请求，处理服务器响应（从连接获取到输入流并包装为bufferedReader）
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));

            String line;
            StringBuffer sb = new StringBuffer();// 用来存储响应数据

            // 循环读取流
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }

            // 关闭流
            br.close();
            // 销毁连接
            conn.disconnect();
            System.out.println(sb.toString());

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}