Java的http post请求01之HttpURLConnection

package com.ricoh.rapp.ezcx.iwbservice.webservice;

import java.io.BufferedOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.net.URL;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.ricoh.rapp.ezcx.iwbservice.util.Constant;
import com.ricoh.rapp.ezcx.iwbservice.util.Utils;

public class HttpRequest {
    private final Logger logger = LoggerFactory.getLogger(HttpRequest.class);

    /**
     * http请求
     *
     * @param urlPath
     *            请求路径http://127.0.0.1:8080/index
     * @param requestStr
     *            请求参数
     *
     */
    public JSONObject execute(String urlPath, String requestStr) {
        HttpURLConnection httpConnection = null;
        try {
            URL url = new URL(urlPath);
            httpConnection = (HttpURLConnection) url.openConnection();

            httpConnection.setRequestMethod("POST");
            httpConnection.setDoOutput(true); // post请求为true;get请求为false并且不用out写入数据
            httpConnection.setDoInput(true); // 有相应数据
            httpConnection.setConnectTimeout("3 * 1000");
            httpConnection.setReadTimeout("Charset");

            // set http header
            httpConnection.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
            httpConnection.setRequestProperty("Charset", "UTF-8");
            httpConnection.connect();

            // send data
            OutputStream buf = httpConnection.getOutputStream();
            buf = new BufferedOutputStream(buf);

            OutputStreamWriter out = new OutputStreamWriter(buf);
            if (requestStr == null || requestStr.length() == 0) {
                requestStr = new JSONObject().toString();
            }
            out.write(requestStr);
            out.flush();
            out.close();

            // receive data
            InputStream inputStream = httpConnection.getInputStream();
            if (httpConnection.getResponseCode() != HttpURLConnection.HTTP_OK) {
                logger.error("connect ezcs service failed: " + httpConnection.getResponseCode());
                JSONObject responseJson = new JSONObject();
                responseJson.put(ResponseKey.KEY_RESULT,
                        com.ricoh.rapp.unifiedPlatform.dsdkService.constant.HttpConstant.ResultCode.ERROR_SERVER_HTTP_ERROR);
                return responseJson;
            }
            String response = Utils.convertStreamToString(inputStream, Constant.ENCODING_UTF_8);
            logger.debug("response from ezcs service: " + response);
            JSONObject responseJson = JSON.parseObject(response);
            return responseJson;
        } catch (Exception e) {
            e.printStackTrace();
            logger.debug("connect local ezcs service exception: " + e.getMessage());
            JSONObject responseJson = new JSONObject();
            if (e instanceof SocketTimeoutException || e instanceof SocketException) {
                responseJson.put(ResponseKey.KEY_RESULT,
                        com.ricoh.rapp.unifiedPlatform.dsdkService.constant.HttpConstant.ResultCode.ERROR_SERVER_HTTP_ERROR);
            } else {
                responseJson.put(ResponseKey.KEY_RESULT,
                        com.ricoh.rapp.unifiedPlatform.dsdkService.constant.HttpConstant.ResultCode.ERROR_INNER_ERROR);
            }
            return responseJson;
        } finally {
            if (httpConnection != null) {
                httpConnection.disconnect();
            }
        }
    }

    public static class ResponseKey {
        public static final String KEY_RESULT = "result";
        public static final String KEY_REASON = "reason";
        public static final String KEY_DATA = "data";
        public static final String KEY_EXTRA = "extra";
    }
}