HttpClient请求传json参数

http请求，参数为json字符串

public String setMessage(String requestData) {
		String result = "";
		try {
			result = HttpClientUtils.doPost(url, method, requestData);
		} catch (ClientProtocolException e) {
			e.printStackTrace();
			throw new ValidationException(SystemError.CONNECTION_FAIL);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return result;    }

HttpClientUtils工具类

package com.feeling.mc.agenda.util;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
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.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import net.logstash.logback.encoder.org.apache.commons.lang.StringUtils;
/**
 * 使用
 * @author liangwenbo
 *
 */
@SuppressWarnings({ "resource", "deprecation" })
public class HttpClientUtils {


	public static String doGet(String url,String params) throws ClientProtocolException, IOException {
		
		String response = null;
		HttpClient httpClient = new DefaultHttpClient();
		HttpGet httpGet = new HttpGet(url);
		HttpResponse httpResponse = httpClient.execute(httpGet);
		if (httpResponse.getStatusLine().getStatusCode() == 200) {
			// 请求和响应都成功了
			HttpEntity entity = httpResponse.getEntity();// 调用getEntity()方法获取到一个HttpEntity实例
			response = EntityUtils.toString(entity, "utf-8");// 用EntityUtils.toString()这个静态方法将HttpEntity转换成字符串,防止
																// //服务器返回的数据带有中文,所以在转换的时候将字符集指定成utf-8就可以了
		}
		return response;
	}
	/**
	 * localhost：8091/message
	 * @param url http:localhost：8080
	 * @param method 方法
	 * @return params 参数
	 * @throws ClientProtocolException
	 * @throws IOException
	 */
	public static String doPost(String url, String method, String params) throws ClientProtocolException, IOException {
		String response = null;
		
		String sendUrl = url+method;
		
		HttpClient httpClient = new DefaultHttpClient();
		HttpPost httpPost = new HttpPost(sendUrl);
		
		 if (StringUtils.isNotBlank(params)) {
			 httpPost.setEntity(new StringEntity(params, "utf-8"));
	     }
		HttpResponse httpResponse = httpClient.execute(httpPost); 
		if (httpResponse.getStatusLine().getStatusCode() == 200) {
			// 请求和响应都成功了
			HttpEntity entity = httpResponse.getEntity();// 调用getEntity()方法获取到一个HttpEntity实例
			response = EntityUtils.toString(entity, "utf-8");// 用EntityUtils.toString()这个静态方法将HttpEntity转换成字符串,防止
																// //服务器返回的数据带有中文,所以在转换的时候将字符集指定成utf-8就可以了
		}
		return response;
	}

}