Android网络编程使用HttpClient访问web站点

/*
* 用HttpClientlai 来访问提交请求，接收响应
* A,发送GET请求
* 1,创建HttpClient对象；HttpClient httpclient=new DefaultHttpClient();
* 2,发送GET请求,创建HttpGet对象：HttpGet httpget=new HttpGet("http://www.baidu.com");
* 3，用HttpClient对象实行HttpGet对象会得到服务器响应对象HttpResponse的对象，响应就封装在HttpResponse中：
*  HttpResponse httpresponse=httpclient.execute(httpget);
* 4,从httpresponse响应中获得Http实例
HttpEntity entity=httpresponse.getEntity();
* */
public class HttpClientDemo extends Activity {
TextView response;
//声明HttpClient对象
HttpClient httpclient;
Handler handler=new Handler(){
public void handleMessage(Message msg){
if(msg.what==0x123){
//  使用response显示服务器的响应
response.append(msg.obj.toString()+"\n");
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_http_client);
//1,创建DefaultHttpClient对象，接口回调HttpClient是个接口
httpclient=new DefaultHttpClient();
response=(TextView) findViewById(R.id.response);
}
/*
* 向服务发送GET请求流程
*
* */
public void accessSecret(View v){
response.setText("");
//点击按钮，开启线程，在线程中发送Get请求
new Thread(){
public void run(){
//2,创建一个HttpGet对象
HttpGet httpget=new HttpGet("http://localhost:8080/foo/secret.jsp");//jsp部署在To吗cat服务器上
try {
//3，用HttpClient对象实行HttpGet对象会得到服务器响应对象HttpResponse的对象，响应就封装在HttpResponse中
HttpResponse httpresponse=httpclient.execute(httpget);
//4,从httpresponse响应中获得Http实例
HttpEntity entity=httpresponse.getEntity();
if(entity!=null){
//5,entity实例中获得内容，建立输入流，读取服务器内容
BufferedReader br=new BufferedReader(new InputStreamReader(entity.getContent()));
String line=null;
while((line=br.readLine())!=null){//循环从输入流中读取内容
Message msg=new Message();
msg.what=0x123;
msg.obj=line;
handler.sendMessage(msg);//发给UI线程更新UI组件
}
}

} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
}.start();
}
/*
* 发送Post请求流程
*
*
* */
public void showLogin(View v){
final View loginDialog=getLayoutInflater().inflate(R.layout.login, null);
new AlertDialog.Builder(HttpClientDemo.this)
.setTitle("登录系统")
.setView(loginDialog)
.setPositiveButton("确定", new DialogInterface.OnClickListener(){

@Override
public void onClick(DialogInterface dialog, int which) {
// 获取对话框的用户名和密码

final String name=((EditText)loginDialog.findViewById(R.id.name)).getText().toString();
final String pass=((EditText)loginDialog.findViewById(R.id.pass)).getText().toString();
//点击确定，开启线程，在线程中发送Post请求
new Thread(){
public void run(){
try {
//2,创建HttpPost对象
HttpPost httppost=new HttpPost("http://localhost:8080/foo/login.jsp");//jsp部署在To吗cat服务器上
//3,对传递的参数进行封装，NameValuePair是简单名称值对节点类型
List<NameValuePair> params=new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("name",name));//添加参数
params.add(new BasicNameValuePair("pass",pass));
//3,设置编码
httppost.setEntity(new UrlEncodedFormEntity(params,HTTP.UTF_8));
//4,HttpClient对象执行HttpPost请求，获得相应
HttpResponse httpresponse=httpclient.execute(httppost);
//5,如果状态码是200就表示服务器成功相应
if(httpresponse.getStatusLine().getStatusCode()==200){
//200：响应成功，301/302：重定向，404：not found未找到资源 ，501服务器遇到错误，使其无法对请求提供服务
String msg = EntityUtils.toString(httpresponse.getEntity());
Looper.prepare();
//提示登录成功
Toast.makeText(HttpClientDemo.this, msg, Toast.LENGTH_LONG).show();
Looper.loop();
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}.start();

}
}).setNegativeButton("取消", null).show();

}