Android网络编程：通过Http与服务器交互

Http通信中的POST和GET请求方式的不同。GET可以获得静态页面，也可以把参数放在URL字符串后面，传递给服务器。而POST方法的参数是放在Http请求中。因此，在编程之前，应当首先明确使用的请求方法，然后再根据所使用的方式选择相应的编程方式。

如果服务器中使用Apache则Android可使用HttpClient接口

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<EditText
android:id="@+id/editText2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:editable="false"
android:cursorVisible="false"/>

<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="点击通过POST获取HTTP连接" />
<ScrollView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>

<EditText
android:id="@+id/editText1"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:editable="false"
android:cursorVisible="false"/>

</ScrollView>

<Button
android:id="@+id/button2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="点击通过GET获取HTTP连接" />

</LinearLayout>

package com.example.httptext;

import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
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.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {
String urlPost = "http://115.28.143.212:8899/MyHttpSample/response.jsp";
String urlGet = "http://www.baidu.com";

Button btnPost = null;
Button btnGET = null;
EditText etPost = null;
EditText etGet = null;
String postResult = null;
String getResult = null;

@Override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnPost = (Button) findViewById(R.id.button1);
btnGET = (Button) findViewById(R.id.button2);
etPost = (EditText) findViewById(R.id.editText2);
etGet = (EditText) findViewById(R.id.editText1);
btnPost.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
new Thread(){

@Override
public void run() {
httpPost();
httpGet();
handler.sendEmptyMessage(0);
}

}.start();

}
});
}
private Handler handler = new Handler(){

@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
etPost.setText(postResult);
etGet.setText(getResult);
}

};
public void httpPost(){
HttpPost httpPostRequest = new HttpPost(urlPost);//创建HttpPost对象
List<NameValuePair> httpParams = new ArrayList<NameValuePair>();//创建存放参数的ArrayList
httpParams.add(new BasicNameValuePair("name","Java"));//设置post参数
try{
httpPostRequest.setEntity(new UrlEncodedFormEntity(httpParams,HTTP.UTF_8));
//创建一个DefaultHttpClient对象，并令其执行设置好的HttpPost请求。
HttpResponse httpResponse = new DefaultHttpClient().execute(httpPostRequest);
if(httpResponse.getStatusLine().getStatusCode()==HttpStatus.SC_OK){
postResult = EntityUtils.toString(httpResponse.getEntity());
postResult = postResult.replace("\r\n|\n\r|\r|\n", "");//去掉信息中的回车和换行

}
}catch(Exception e){
e.printStackTrace();
}
}
public void httpGet(){
HttpGet htttpGetRequest =new HttpGet(urlGet);
try{
HttpResponse httpResponse = new DefaultHttpClient().execute(htttpGetRequest);
if(httpResponse.getStatusLine().getStatusCode()==HttpStatus.SC_OK){
getResult = EntityUtils.toString(httpResponse.getEntity());
getResult = getResult.replace("\r\n|\n\r|\r|\n", "");
}
}catch(Exception e){
e.printStackTrace();
}
}

}