android访问web程序,Android网络编程使用HttpClient访问web站点(示例代码)

HttpClientDemo.java界面就是两个按钮和一个文本框

/*

* 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 params=new ArrayList();

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();

}