URLconnection, HttpURLconnection, HttpClient를 사용하여 네트워크 자원에 간단하게 접근

URL의 OpenConnection 방법은 응용 프로그램과 URL 간의 통신 연결을 나타내는 URLconnection을 되돌려줍니다.프로그램은 그 실례를 통해 이 URL에 요청을 보내서 URL이 인용한 자원을 읽을 수 있습니다.
다음은 간단한 예시를 통해 보여 준다.
Activity:

package com.home.urlconnection;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
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.util.EntityUtils;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener {
	private Button urlConnectionBtn;
	private Button httpUrlConnectionBtn;
	private Button httpClientBtn;
	private TextView showTextView;
	private WebView webView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		init();
	}

	private void init() {
		urlConnectionBtn = (Button) findViewById(R.id.test_url_main_btn_urlconnection);
		httpUrlConnectionBtn = (Button) findViewById(R.id.test_url_main_btn_httpurlconnection);
		httpClientBtn = (Button) findViewById(R.id.test_url_main_btn_httpclient);
		showTextView = (TextView) findViewById(R.id.test_url_main_tv_show);
		webView = (WebView) findViewById(R.id.test_url_main_wv);
		urlConnectionBtn.setOnClickListener(this);
		httpUrlConnectionBtn.setOnClickListener(this);
		httpClientBtn.setOnClickListener(this);
	}

	@Override
	public void onClick(View v) {
		if (v == urlConnectionBtn) {
			try {
				//     URLConnection      
				URL url = new URL("http://192.168.1.100:8080/myweb/hello.jsp");
				//   URLConnection  
				URLConnection connection = url.openConnection();
				InputStream is = connection.getInputStream();
				byte[] bs = new byte[1024];
				int len = 0;
				StringBuffer sb = new StringBuffer();
				while ((len = is.read(bs)) != -1) {
					String str = new String(bs, 0, len);
					sb.append(str);
				}
				showTextView.setText(sb.toString());
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		if (v == httpUrlConnectionBtn) {
			//     HttpURLConnection      
			try {
				URL url = new URL(
						"http://192.168.1.100:8080/myweb/hello.jsp?username=abc");
				//   HttpURLConnection  
				HttpURLConnection connection = (HttpURLConnection) url
						.openConnection();
				//    GET  
				connection.setRequestMethod("GET");
				if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
					//       
					String message = connection.getResponseMessage();
					showTextView.setText(message);
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		if (v == httpClientBtn) {
			try {
				//   ApacheHttp       (    )
				HttpClient client = new DefaultHttpClient();

				//    Get     HttpGet  ，    HttpPost  
				// POST     
				HttpPost httpPost = new HttpPost(
						"http://192.168.1.100:8080/myweb/hello.jsp");
				//    Post               
				List dataList = new ArrayList();
				dataList.add(new BasicNameValuePair("username", "abc"));
				dataList.add(new BasicNameValuePair("pwd", "123"));
				// UrlEncodedFormEntity        Entity  
				httpPost.setEntity(new UrlEncodedFormEntity(dataList));

				// GET     
				// HttpGet httpGet = new
				// HttpGet("http://192.168.1.100:8080/myweb/hello.jsp?username=abc&pwd=321");

				//       
				HttpResponse httpResponse = client.execute(httpPost);
				//       
				HttpEntity entity = httpResponse.getEntity();
				//              
				String content = EntityUtils.toString(entity);
				//    TextView 
				// showTextView.setText(content);

				//   webview     
				webView.loadDataWithBaseURL(null, content, "text/html",
						"utf-8", null);
				//     url     
				// webView.loadUrl(url);
			} catch (ClientProtocolException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

}

위에서 사용한 URL은 필자의 본 컴퓨터에 배치된 웹 응용 프로그램입니다. 여기서 더 이상 제시하지 않고 여러분은 자신의 웹 응용 프로그램으로 바꾸면 됩니다.레이아웃 XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/test_url_main_btn_urlconnection"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="  URLConnection  " />

    <Button
        android:id="@+id/test_url_main_btn_httpurlconnection"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="  HttpURLConnection  " />

    <Button
        android:id="@+id/test_url_main_btn_httpclient"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="  Apache     " />

    <TextView
        android:id="@+id/test_url_main_tv_show"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <WebView
        android:id="@+id/test_url_main_wv"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

사용 권한:

 <uses-permission android:name="android.permission.INTERNET" />