android：HTTP通信 .
一、HttpURLConnection 方式
android提供了HttpURLConnection和HttpConnection 接口来开发HTTP程序。HttpURLConnection是java的标准类，继承自HttpConnection，两个类都是抽象类，不能实例化对象。
HttpURLConnection对象主要是通过URL的openConnection方法获得，创建HttpURLConnection连接的代码为
URL url = new URL("http://www.google.cn/");
HttpURLConnection conn = (HttpURLConnection) url.openConnection(); openConnection只创建HttpURLConnection或HttpConnection实例，但是不是真正的连接操作。并且每次openConnection都将创建一个新的实例。因此，在连接之前可以对其一些属性进行设置，比如:
conn.setDoInput(true); //设置输入输出流
conn.setDoOutput(true);
conn.setConnectTimeout(10000); //超时时间
conn.setRequestMethod("GET"); //"POST" HttpURLConnection默认使用get方式，要用post必须要用setRequestMethod设置
conn.setUseCaches(false); //Post请求不能使用缓存
连接完成之后关闭连接： conn.disconnect();
URL url = new URL("http://www.google.cn/");
//使用HttpURLConnection打开连接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//得到读取的内容(流)
InputStreamReader in = new InputStreamReader(urlConn.getInputStream());
// 为输出创建BufferedReader
BufferedReader buffer = new BufferedReader(in);
String inputLine = null;
//使用循环来读取获得的数据
while (((inputLine = buffer.readLine()) != null))
{
//我们在每一行后面加上一个"\n"来换行
resultData += inputLine + "\n";
}
//关闭InputStreamReader
in.close();
//关闭http连接
urlConn.disconnect();
--2--HttpURLConnection使用GET方式传递参数
修改网页地址，修改要传递的参数.“?par=abcdrfg”即时传递的参数par
String httpUrl = "http://192.168.1.110:8080/httpget.jsp?par=abcdrfg";
URL url = new URL(httpUrl );
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
--3--HttpURLConnection使用POST方式，则需要setRequestMethod设置。
String httpUrl = "http://192.168.1.110:8080/httpget.jsp";
//获得的数据
String resultData = "";
URL url = null;
try
{
//构造一个URL对象
url = new URL(httpUrl);
}
catch (MalformedURLException e)
{
Log.e(DEBUG_TAG, "MalformedURLException");
}
if (url != null)
{
try
{
// 使用HttpURLConnection打开连接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//因为这个是post请求,设立需要设置为true
urlConn.setDoOutput(true);
urlConn.setDoInput(true);
// 设置以POST方式
urlConn.setRequestMethod("POST");
// Post 请求不能使用缓存
urlConn.setUseCaches(false);
urlConn.setInstanceFollowRedirects(true);
// 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded"); 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，
// 要注意的是connection.getOutputStream会隐含的进行connect。
urlConn.connect();
//DataOutputStream流
DataOutputStream out = new DataOutputStream(urlConn.getOutputStream());
//要上传的参数
String content = "par=" + URLEncoder.encode("ABCDEFG", "gb2312");
//将要上传的内容写入流中
out.writeBytes(content);
//刷新、关闭
out.flush();
out.close();
配置一个权限，AndroidManifest.xml 中应该加入如下节点：
< uses-permission android:name="android.permission.INTERNET">
< /uses-permission>
二、HttpClient 接口
Apache提供了HttpClient，他对java.net 的类做了封装和抽象。更适合在android上开发应用。
HttpGet request = new HttpGet();
request.setURI(http://w26.javaeye.com);
==
HttpGet request = new HttpGet(httpUrl);
--1-- HttpClient Get 示例:
// http地址
String httpUrl = "http://192.168.1.110:8080/httpget.jsp?par=HttpClient_android_Get";
//HttpGet连接对象
HttpGet httpRequest = new HttpGet(httpUrl);
//取得HttpClient对象
HttpClient httpclient = new DefaultHttpClient();
//请求HttpClient，取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);
//请求成功
if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
{
//取得返回的字符串
String strResult = EntityUtils.toString(httpResponse.getEntity());
mTextView.setText(strResult);
}
else
{
mTextView.setText("请求错误!");
}
}
--2-- HttpClient POST 示例:
使用POST方法进行参数传递时，需要使用NameValuePair来保存要传递的参数。，另外，还需要设置所使用的字符集。
//HttpPost连接对象
HttpPost httpRequest = new HttpPost(httpUrl);
//使用NameValuePair来保存要传递的Post参数
List<NameValuePair> params = new ArrayList<NameValuePair>();
//添加要传递的参数
params.add(new BasicNameValuePair("par", "HttpClient_android_Post"));
//设置字符集
HttpEntity httpentity = new UrlEncodedFormEntity(params, "gb2312");
//请求httpRequest
httpRequest.setEntity(httpentity);
//取得默认的HttpClient
HttpClient httpclient = new DefaultHttpClient();
//取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);
//HttpStatus.SC_OK表示连接成功
if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
{
//取得返回的字符串
String strResult = EntityUtils.toString(httpResponse.getEntity());
mTextView.setText(strResult);
}
else
{
mTextView.setText("请求错误!");
}
}
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
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 android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class mian extends Activity {
/** Called when the activity is first created. */
private Button btnTest;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btnTest = (Button) findViewById(R.id.Button01);
btnTest.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
getWeather();
}
});
}
private void getWeather(){
try {
final String SERVER_URL = "http://webservice.webxml.com.cn/WebServices/WeatherWS.asmx/getWeather"; // 定义需要获取的内容来源地址
HttpPost request = new HttpPost(SERVER_URL); // 根据内容来源地址创建一个Http请求
List params = new ArrayList();
params.add(new BasicNameValuePair("theCityCode", "长沙")); // 添加必须的参数
params.add(new BasicNameValuePair("theUserID", "")); // 添加必须的参数
request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8)); // 设置参数的编码
HttpResponse httpResponse = new DefaultHttpClient().execute(request); // 发送请求并获取反馈
// 解析返回的内容
if (httpResponse.getStatusLine().getStatusCode() != 404)
{
String result = EntityUtils.toString(httpResponse.getEntity());
System.out.println(result);
}
} catch (Exception e) {
}
}
}
