Android中客户端请求服务器端的方式讲解(一)附源码

/**
     * Post的请求方式
     * 
     * @param model
     *            请求序号
     * @param paramList
     *            客户端请求的数据参数列表
     * @return
     */
    public JSONObject doPost(int model, List<NameValuePair> paramList) {

        try {
            // 客户端向服务器发送请求的数据
            List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>();
            params.add(new BasicNameValuePair("param1", "中国"));
            params.add(new BasicNameValuePair("param2", "美国"));

            // 1.定义请求的方式对象：
            HttpPost post = new HttpPost(Base_URL);
            // 2.定义请求的客户端对象
            HttpClient client = new DefaultHttpClient();

            // 将请求的数据封装在实体类中
            HttpEntity entity = new UrlEncodedFormEntity(paramList, HTTP.UTF_8);
            // 将实体类放置在URL中
            post.setEntity(entity);
            // 3.执行请求,返回响应的对象
            HttpResponse response = client.execute(post);
            if (response != null
                    && response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                // 获得从服务器中返回的结果:从服务器中返回的结果是字符串的形式
                String result = EntityUtils.toString(response.getEntity(),
                        HTTP.UTF_8);
                if (result.startsWith("{")) {
                    try {
                        return new JSONObject(result);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }

/**
     * 
     * @param model
     *            请求序号
     * @param paramList
     *            客户端请求的数据参数列表
     * @return
     */
    public JSONObject doGet(int model, List<NameValuePair> paramList) {

        // 客户端向服务器发送请求的数据
        // List<BasicNameValuePair> params = new
        // ArrayList<BasicNameValuePair>();
        // params.add(new BasicNameValuePair("param1", "中国"));
        // params.add(new BasicNameValuePair("param2", "美国"));
        // 对参数编码
        String param = URLEncodedUtils.format(paramList, HTTP.UTF_8);

        // 将URL与参数拼接
        // HttpGet get = new HttpGet(Base_URL + "?" + param);
        HttpGet get = new HttpGet(Base_URL + "?" + param);
        HttpClient httpClient = new DefaultHttpClient();

        try {
            // 发起GET请求
            HttpResponse response = httpClient.execute(get);
            if (response != null
                    && response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                // 从服务器中获得响应的数据
                String result = EntityUtils.toString(response.getEntity(),
                        HTTP.UTF_8);
                try {
                    return new JSONObject(result);
                } catch (JSONException e) {
                    e.printStackTrace();
                }

            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }

package com.chengdong.su.downloaddemo.service;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
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.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;

/**
 * 客户端向服务器端请求的工具
 * 
 * @author scd
 * 
 */
public class HttpUtil {
    /** 请求的URL */
    private String Base_URL = "http://www.baidu.com";
    /** TAG */
    private String TAG = getClass().getSimpleName();

    /**
     * Post的请求方式
     * 
     * @param model
     *            请求序号
     * @param paramList
     *            客户端请求的数据参数列表
     * @return
     */
    public JSONObject doPost(int model, List<NameValuePair> paramList) {

        try {
            // 客户端向服务器发送请求的数据
            List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>();
            params.add(new BasicNameValuePair("param1", "中国"));
            params.add(new BasicNameValuePair("param2", "美国"));

            // 1.定义请求的方式对象：
            HttpPost post = new HttpPost(Base_URL);
            // 2.定义请求的客户端对象
            HttpClient client = new DefaultHttpClient();

            // 将请求的数据封装在实体类中
            HttpEntity entity = new UrlEncodedFormEntity(paramList, HTTP.UTF_8);
            // 将实体类放置在URL中
            post.setEntity(entity);
            // 3.执行请求,返回响应的对象
            HttpResponse response = client.execute(post);
            if (response != null
                    && response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                // 获得从服务器中返回的结果:从服务器中返回的结果是字符串的形式
                String result = EntityUtils.toString(response.getEntity(),
                        HTTP.UTF_8);
                if (result.startsWith("{")) {
                    try {
                        return new JSONObject(result);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }

   /**
     * 
     * @param model
     *            请求序号
     * @param paramList
     *            客户端请求的数据参数列表
     * @return
     */
    public JSONObject doGet(int model, List<NameValuePair> paramList) {

        // 客户端向服务器发送请求的数据
        // List<BasicNameValuePair> params = new
        // ArrayList<BasicNameValuePair>();
        // params.add(new BasicNameValuePair("param1", "中国"));
        // params.add(new BasicNameValuePair("param2", "美国"));
        // 对参数编码
        String param = URLEncodedUtils.format(paramList, HTTP.UTF_8);

        // 将URL与参数拼接
        // HttpGet get = new HttpGet(Base_URL + "?" + param);
        HttpGet get = new HttpGet(Base_URL + "?" + param);
        HttpClient httpClient = new DefaultHttpClient();

        try {
            // 发起GET请求
            HttpResponse response = httpClient.execute(get);
            if (response != null
                    && response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                // 从服务器中获得响应的数据
                String result = EntityUtils.toString(response.getEntity(),
                        HTTP.UTF_8);
                try {
                    return new JSONObject(result);
                } catch (JSONException e) {
                    e.printStackTrace();
                }

            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }

}