import java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
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.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * 发送HTTP请求工具类
 * @author Rong.zhu
 *
 */
public class HttpUtils {
    private final static int CONNECT_TIMEOUT_VALUE = 20000;//请求(连接)超时:20秒
    private final static int SOCKET_TIMEOUT_VALUE = 60000;//响应超时:60秒,一定要设置，否则可能导致当前线程一直处于等待状态
    
    private static RequestConfig requestConfig;
    private static ResponseHandler<String> responseHandler;
    
    static{
        requestConfig = RequestConfig.custom()
                .setConnectTimeout(CONNECT_TIMEOUT_VALUE)//请求超时:connect timed out. connect refused
                .setSocketTimeout(SOCKET_TIMEOUT_VALUE) //响应超时:response timed out 
                .build();
        
        responseHandler = new ResponseHandler<String>() {
            public String handleResponse(final HttpResponse response) throws ClientProtocolException, IOException {
                int status = response.getStatusLine().getStatusCode();
                if (status >= 200 && status < 300) {
                    HttpEntity entity = response.getEntity();
                    return entity != null ? EntityUtils.toString(entity, "UTF-8") : null;
                } else {
                    throw new ClientProtocolException("request failed,unexpected response status: " + status);
                }
            }
        };
    }
    
    
    public static String postJSON(String url, Object sendData )throws Exception {
        HttpPost httppost = new HttpPost(url);
        httppost.setConfig(requestConfig);
        StringEntity entity = new StringEntity(JSONUtils.convertObject2Json(sendData),ContentType.create("application/json","UTF-8"));
        
        httppost.setEntity(entity);
        CloseableHttpClient httpClient = null;
        String responseBody = null;
        try{
            httpClient = HttpClients.createDefault();
            responseBody = httpClient.execute(httppost, responseHandler);
        }finally{
            if(httpClient != null) {
                httpClient.close();
            }
        }
        return responseBody;
    }
    
    /**
     * 发送POST请求,该方法将会对参数进行UTF-8编码
     * @param url
     * @param params
     * @return
     * @throws Exception
     */
    public static String post(String url, Map<String, String> params) throws Exception {
        //封装请求参数
        List<NameValuePair> nvps = new ArrayList<NameValuePair>();
        if(params != null) {
            Set<Entry<String, String>> entrySet = params.entrySet();
            for(Entry<String, String> entry : entrySet) {
                nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
            }
        }
        //对参数进行转码（特殊字符）
        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(nvps, "UTF-8"); 
        HttpPost httppost = new HttpPost(url);
        httppost.setConfig(requestConfig);
        httppost.setEntity(entity);
        CloseableHttpClient httpClient = null;
        String responseBody = null;
        try{
            httpClient = HttpClients.createDefault();
            responseBody = httpClient.execute(httppost, responseHandler);
        }finally{
            if(httpClient != null) {
                httpClient.close();
            }
        }
        return responseBody;
    }
    
    
    /**
     * 发送GET请求,该方法将会对参数进行UTF-8编码
     * @param url
     * @return
     * @throws Exception
     */
    public static String get(String url) throws Exception {
        StringBuffer encodedUrl = new StringBuffer();
        if(url.contains("?")) {
            encodedUrl.append(url.substring(0,url.lastIndexOf("?"))).append("?");
            String paramstr = url.substring(url.lastIndexOf("?")+1);
            String[] params = paramstr.split("&");
            for(String param: params) {
                String pkey = param.substring(0,param.lastIndexOf("="));
                String pvalue = param.substring(param.lastIndexOf("=")+1);
                encodedUrl.append(pkey).append("=").append(URLEncoder.encode(pvalue,"UTF-8")).append("&");//UTF-8转码
            }
            String temp = encodedUrl.toString();
            temp.substring(0, temp.lastIndexOf("&"));
            encodedUrl = new StringBuffer(temp);
        }else {
            encodedUrl.append(url);
        }
        HttpGet httpGet = new HttpGet(encodedUrl.toString());
        CloseableHttpClient httpClient = null;
        String responseBody = null;
        try{
            httpClient = HttpClients.createDefault();
            responseBody = httpClient.execute(httpGet, responseHandler);
        }finally{
            if(httpClient != null) {
                httpClient.close();
            }
        }
        return responseBody;
    }

}