HttpUtil

//包再百度云盘　　httpcomponents-client-4.5.5

package com.baidu.httpuntil;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
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.DefaultHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
//import org.apache.log4j.Logger;

/**
* HttpClient工具类
*/
public class HttpUtil {

//private static Logger logger = Logger.getLogger(HttpUtil.class);

/**
* get请求
* @return
*/
public static String doGet(String url) {
try {
HttpClient client = new DefaultHttpClient();
//发送get请求
HttpGet request = new HttpGet(url);
HttpResponse response = client.execute(request);

/**请求发送成功，并得到响应**/
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
/**读取服务器返回过来的json字符串数据**/
String strResult = EntityUtils.toString(response.getEntity());

return strResult;
}
}
catch (IOException e) {
e.printStackTrace();
}

return null;
}

/**
* post请求(用于key-value格式的参数)
* @param url
* @param params
* @return
*/
public static String doPost(String url, Map params){

BufferedReader in = null;
try {
// 定义HttpClient
HttpClient client = new DefaultHttpClient();
// 实例化HTTP方法
HttpPost request = new HttpPost();
request.setURI(new URI(url));

//设置参数
List<NameValuePair> nvps = new ArrayList<NameValuePair>();
for (Iterator iter = params.keySet().iterator(); iter.hasNext();) {
String name = (String) iter.next();
String value = String.valueOf(params.get(name));
nvps.add(new BasicNameValuePair(name, value));

//System.out.println(name +"-"+value);
}
request.setEntity(new UrlEncodedFormEntity(nvps,HTTP.UTF_8));

HttpResponse response = client.execute(request);
int code = response.getStatusLine().getStatusCode();
if(code == 200){ //请求成功
in = new BufferedReader(new InputStreamReader(response.getEntity()
.getContent(),"utf-8"));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}

in.close();

return sb.toString();
}
else{ //
System.out.println("状态码：" + code);
return null;
}
}
catch(Exception e){
e.printStackTrace();

return null;
}
}

/**
* post请求（用于请求json格式的参数）
* @param url
* @param params
* @return
*/
public static String doPost(String url, String params) throws Exception {

CloseableHttpClient httpclient = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(url);// 创建httpPost
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-Type", "application/json");
String charSet = "UTF-8";
StringEntity entity = new StringEntity(params, charSet);
httpPost.setEntity(entity);
CloseableHttpResponse response = null;

try {

response = httpclient.execute(httpPost);
StatusLine status = response.getStatusLine();
int state = status.getStatusCode();
if (state == HttpStatus.SC_OK) {
HttpEntity responseEntity = response.getEntity();
String jsonString = EntityUtils.toString(responseEntity);
return jsonString;
}
else{
//logger.error("请求返回:"+state+"("+url+")");
System.out.println("请求返回:"+state+"("+url+")");
}
}
finally {
if (response != null) {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
httpclient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}

}