java 後端post請求

直接上乾貨
工具類

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class Post {
	/**
	 * 向指定的 URL發送遠程POST方法的請求
	 * 

	 *            ，
	 * @return 所代表遠程資源的響應結果
	 */
	public static String sendPost(String url, JSON json) {
		//PrintWriter out = null;
		OutputStreamWriter out = null;
		BufferedReader in = null;
		JSONObject jsonObject = null;
		String result = "";
		try {
			URL realUrl = new URL(url);
			// 打開和URL之間的連接
			HttpURLConnection conn = (HttpURLConnection) realUrl
					.openConnection();
			// 設置通用的請求屬性
			conn.setRequestMethod("POST");
			// 發送POST請求必須設置下面的屬性
			conn.setDoOutput(true);
			conn.setDoInput(true);
			conn.setUseCaches(false);
			// 設置請求屬性
			conn.setRequestProperty("Content-Type",
					"application/json; charset=utf-8");
			conn.connect();
			// 獲取URLConnection對象對應的輸出流
			//out = new PrintWriter(conn.getOutputStream());
			out = new OutputStreamWriter(conn.getOutputStream(), "utf-8");
			// 發送請求參數
			//out.print(JSON.toJSONString(json));
			out.write(JSON.toJSONString(json));
			// flush輸出流的緩衝
			out.flush();
			// 定義BufferedReader輸入流來讀取URL的響應
			in = new BufferedReader(
					new InputStreamReader(conn.getInputStream()));
			String line = "";
			while ((line = in.readLine()) != null) {
				result += line;
			}
			// 將返回結果轉換爲字符串
			//jsonObject = JSONObject.parseObject(result);
		} catch (Exception e) {
			/*throw new RuntimeException("遠程通路異常" + e.toString());*/
			e.printStackTrace();
		}
		// 使用finally塊來關閉輸出流、輸入流
		finally {
			try {
				if (out != null) {
					out.close();
				}
				if (in != null) {
					in.close();
				}
			} catch (IOException ex) {
				ex.printStackTrace();
			}
		}
		return result;
	}


	public static String sendPost(String url, String json) {
		PrintWriter out = null;
		BufferedReader in = null;
		String result = "";
		try {
			URL realUrl = new URL(url);
			// 打開和URL之間的連接
			HttpURLConnection conn = (HttpURLConnection) realUrl
					.openConnection();
			// 設置通用的請求屬性
			conn.setRequestMethod("POST");
			// 發送POST請求必須設置下面的屬性
			conn.setDoOutput(true);
			conn.setDoInput(true);
			conn.setUseCaches(false);
			// 設置請求屬性
			conn.setRequestProperty("Content-Type",
					"application/json; charset=utf-8");
			conn.connect();
			// 獲取URLConnection對象對應的輸出流
			out = new PrintWriter(conn.getOutputStream());
			// 發送請求參數
			out.print(json);
			// flush輸出流的緩衝
			out.flush();
			// 定義BufferedReader輸入流來讀取URL的響應
			in = new BufferedReader(
					new InputStreamReader(conn.getInputStream()));
			String line = "";
			while ((line = in.readLine()) != null) {
				result += line;
			}
			// 將返回結果轉換爲字符串
			//jsonObject = JSONObject.parseObject(result);
		} catch (Exception e) {
			throw new RuntimeException("遠程通路異常" + e.toString());
		}
		// 使用finally塊來關閉輸出流、輸入流
		finally {
			try {
				if (out != null) {
					out.close();
				}
				if (in != null) {
					in.close();
				}
			} catch (IOException ex) {
				ex.printStackTrace();
			}
		}
		return result;
	}
}

java發送請求

String url= eqptIp+"/sss/interfaces/getAllAdlMtt";
String startTime = getYesterday();
JSONObject object = new JSONObject();  //創建Json對象
object.put("startTime", startTime);         //設置Json對象的屬性
 String result = Post.sendPost(url,object);

處理的時候分爲兩種，如果直接是string之類的簡單返回值，這樣

JSONObject jsonObject = JSON.parseObject(result);
 String scanMsg = jsonObject.getString("scan_msg");

如果返回值是list格式json字符串之類的

List<AdlMttRepData> adlMttRepDatalList = JSONArray.parseArray(result, AdlMttRepData.class);

其中AdlMttRepData是自定義的實體類

對應的接收端

@RequestMapping(value = "getAllAdlMttRep")
    @ResponseBody
    public byte[] getAllAdlMttRep(HttpServletRequest request, HttpServletResponse response,@RequestBody String param) throws Exception{
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");

        List<topMttDataRep> list = null;
        String str="";
        if(param!=null&&!("").equals(param)){
            JSONObject jsStr = JSONObject.parseObject(param);
            String startTime = jsStr.getString("startTime");
            list= dataService.getAllAdlMttRep(startTime);
            if(list!=null&&list.size()>0){
                str = JSONObject.toJSONString(list,SerializerFeature.WriteMapNullValue);
            }else{
                str = "-10086";//當天沒有操作
            }

        }
        return (str+"").getBytes("UTF-8");
    }

或者是正常的返回（本人沒測試，理論上應該可以）