Android开发之HttpClient异步请求数据的方法详解【附demo源码下载】

public class HttpClientUtil {
  private static HttpClient httpClient;
  static{
    //1.创建HttpClient对象
    httpClient=new DefaultHttpClient();
  }
  //2.执行该方法返回一个HttpResponse
  public static HttpResponse sendRequest(String url,List<NameValuePair>list){
    HttpResponse response=null;
    try {
    if(list==null){
      //Get方式
      HttpGet get=new HttpGet(url);
      response=httpClient.execute(get);
    }else{
      //Post方式
      HttpPost post=new HttpPost(url);
      //3.对于HttpPost对象而言，可调用setEntity(HttpEntity)方法设置请求参数。
      //4.使用HttpEntity下的UrlEncodedFormEntitiy对象传入一个放入BasicNameValuePair的集合中提交的数据。
      post.setEntity(new UrlEncodedFormEntity(list));
      response=httpClient.execute(post);
    }
    }catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    return response;
  }
}

public interface ResponseListener {
  public void onResult(String msg);
  public void onError(String msg);
}

//get方式
public void get(View view){
  String nameTe=name.getText().toString();
  String pwdTe=pwd.getText().toString();
  HttpClientTask task=new HttpClientTask(this);
  //要传进去的参数
  task.execute(BASIC+"?name="+nameTe+"&pwd="+pwdTe);
}
//post方式
public void post(View view){
  String nameTe=name.getText().toString();
  String pwdTe=pwd.getText().toString();
  List<NameValuePair>list=new ArrayList<NameValuePair>();
  list.add(new BasicNameValuePair("name", nameTe));
  list.add(new BasicNameValuePair("pwd", pwdTe));
  HttpClientTask task=new HttpClientTask(list, this);
  task.execute(BASIC);
}

public static final String BASIC="http://192.168.207.1:8090/ConnectionServlet/LoginServlet";

/*
 * Params:输入参数,如果不需要传递参数,则直接设为Void即可 --String
 * Progress:子线程执行的百分比 --Void
 * Result:返回的参数 --HttpResonse
 */
public class HttpClientTask extends AsyncTask<String, Void, HttpResponse>{
  private List<NameValuePair>list;
  private ResponseListener listener;
  //Get请求
  public HttpClientTask(ResponseListener listener) {
    super();
    // TODO Auto-generated constructor stub
    this.listener=listener;
  }
  //Post请求
  public HttpClientTask(List<NameValuePair>list,ResponseListener listener) {
    super();
    // TODO Auto-generated constructor stub
    this.list=list;
    this.listener=listener;
  }
  //doInBackground有返回值,并且返回值是由result决定的,
  //参数列表首先是一个可变长参数,是由Params决定的
  //执行时机:在onPreExecute方法执行后马上执行,该方法运行在后线程中
  //作用:主要负责执行那些很耗时的后台处理工作,可以调用publishProgress方法来更新实时的任务进度
  @Override
  protected HttpResponse doInBackground(String... params) {
    // TODO Auto-generated method stub
    HttpResponse response;
    //这里会返回一个response
    response=HttpClientUtil.sendRequest(params[0], list);
    return response;
  }
  //参数是由result决定的
  //作用:后台的计算结果将显示出来
  //可以进行一些结束处理
  @Override
  protected void onPostExecute(HttpResponse result) {
    // TODO Auto-generated method stub
    String msg;
    try {
      //result是响应内容
      //用EntityUtils.toString(HttpEntity,"编码方式")
      //将其转成为字符串
      msg=EntityUtils.toString(result.getEntity(), "UTF-8");
      if(listener!=null){
        listener.onResult(msg);
      }
    }catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      listener.onResult("出错了");
    }
    super.onPostExecute(result);
  }
}

@Override
  public void onResult(String msg) {
    // TODO Auto-generated method stub
    System.out.println(msg);
  }
  @Override
  public void onError(String msg) {
    // TODO Auto-generated method stub
    System.out.println("出错了");
  }

public class MainActivity extends Activity implements ResponseListener{
  private EditText name,pwd;
  public static final String BASIC="http://192.168.207.1:8090/ConnectionServlet/LoginServlet";
  //get方式
  public void get(View view){
    String nameTe=name.getText().toString();
    String pwdTe=pwd.getText().toString();
    HttpClientTask task=new HttpClientTask(this);
    //要传进去的参数
    task.execute(BASIC+"?name="+nameTe+"&pwd="+pwdTe);
  }
  //post方式
  public void post(View view){
    String nameTe=name.getText().toString();
    String pwdTe=pwd.getText().toString();
    List<NameValuePair>list=new ArrayList<NameValuePair>();
    list.add(new BasicNameValuePair("name", nameTe));
    list.add(new BasicNameValuePair("pwd", pwdTe));
    HttpClientTask task=new HttpClientTask(list, this);
    task.execute(BASIC);
  }
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    name=(EditText) findViewById(R.id.name);
    pwd=(EditText) findViewById(R.id.pwd);
  }
  @Override
  public void onResult(String msg) {
    // TODO Auto-generated method stub
    System.out.println(msg);
  }
  @Override
  public void onError(String msg) {
    // TODO Auto-generated method stub
    System.out.println("出错了");
  }
}