前言，Android的網絡通信的方式有兩種：使用Socket或者HTTP，今天這一篇我們詳細講解使用HTTP實現的網絡通信，HTTP又包括兩種方式編程方式：
（1）HttpUrlConnection；
（2）HttpClient；
? ?好了，我們直接進行講解，當然之前也會有一部分有關Android網絡通信的其他知識，我們也應該了解。
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一.獲取網絡狀態的方法
（1）MainActivity.java中的關鍵代碼
| 1 2 3 4 5 6 7 8 | //網絡管理類，可以判斷是否能上網，以及網絡類型????????????ConnectivityManager cm=(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);????????????NetworkInfo info=cm.getActiveNetworkInfo();????????????if(info!=null){????????????????Toast.makeText(MainActivity.this,?"連網正常"+info.getTypeName(), Toast.LENGTH_SHORT).show();????????????}else{????????????????Toast.makeText(MainActivity.this,?"未連網", Toast.LENGTH_SHORT).show();????????????} |
（2）注意：一定要在主配置文件中增加這個權限
? ?它是application的兄弟標簽：
| 1 | <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> |
（3）OK，我們看一下我們的設備的上網狀態和類型吧：
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二.使用URL訪問網頁源碼
（1）MainActivity.java：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | package?com.example.l0903_urldata;import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStream;import?java.io.InputStreamReader;import?java.net.MalformedURLException;import?java.net.URL;import?android.app.Activity;import?android.os.Bundle;/**?* 訪問網頁源碼?* @author asus?*?*/public?class?MainActivity?extends?Activity {????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????try?{????????????//訪問百度的html文件的源碼????????????InputStream is=new?URL("http://www.baidu.com").openStream();????????????//讀取數據的包裝流????????????BufferedReader br=new?BufferedReader(new?InputStreamReader(is));????????????//str用于讀取一行數據????????????String str=null;????????????//StringBuffer用于存儲所欲數據????????????StringBuffer sb=new?StringBuffer();????????????while((str=br.readLine())!=null){????????????????sb.append(str);????????????}????????????System.out.println(sb.toString());????????}?catch?(MalformedURLException e) {????????????e.printStackTrace();????????}?catch?(IOException e) {????????????e.printStackTrace();????????}????}} |
（2）注意：有關網絡的操作都需要在主配置文件里添加下面這個權限：
| 1 | <uses-permission android:name="android.permission.INTERNET"/> |
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三.WebView 控件的簡單使用
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | package?com.example.l0903_webview;import?android.app.Activity;import?android.os.Bundle;import?android.webkit.WebView;/**?* 就是一個瀏覽器控件?* 其實沒什么用?* @author asus?*?*/public?class?MainActivity?extends?Activity {????private?WebView wv;????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????wv=(WebView) findViewById(R.id.webView1);????????//WebView控件的方法，loadUrl用于加載指定的網絡地址????????wv.loadUrl("http://www.baidu.com");????}} |
? ?運行效果：
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四.使用HttpUrlConnection的編寫方式實現Android的網絡通信
1.首先，自己先搭建一個服務器：
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2.下面是客戶端的事了：
(1)通過get方式：
? ?MainActivity.java：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 | package?com.example.l0903_httpurlcnectionget;import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStream;import?java.io.InputStreamReader;import?java.net.HttpURLConnection;import?java.net.MalformedURLException;import?java.net.URL;import?android.app.Activity;import?android.os.Bundle;import?android.view.View;import?android.view.View.OnClickListener;import?android.widget.EditText;import?android.widget.TextView;/**?* 通過Get方法獲取服務器的數據?* 直接在地址中用"?+鍵值+value"的方式來使用?* 所以傳遞的參數直接顯示出來，不安全?* @author asus?*?*/public?class?MainActivity?extends?Activity {????private?HttpURLConnection conn;????private?URL url;????private?InputStream is;????private?TextView tv;????private?EditText et;????private?String name;????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????tv=(TextView) findViewById(R.id.textView1);????????et=(EditText) findViewById(R.id.editText1);????????findViewById(R.id.button1).setOnClickListener(new?OnClickListener() {??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????@Override????????????public?void?onClick(View v) {????????????????name=et.getText().toString();????????????????//定義訪問的服務器地址，10.0.2.2是Android的訪問的本地服務器地址????????????????String urlDate="http://10.0.2.2:8080/My_Service/webdate.jsp?name="+name;????????????????try?{????????????????????//封裝訪問服務器的地址????????????????????url=new?URL(urlDate);????????????????????try?{????????????????????????//打開對服務器的連接????????????????????????conn=(HttpURLConnection) url.openConnection();????????????????????????//連接服務器????????????????????????conn.connect();????????????????????????/**讀入服務器數據的過程**/????????????????????????//得到輸入流????????????????????????is=conn.getInputStream();????????????????????????//創建包裝流????????????????????????BufferedReader br=new?BufferedReader(new?InputStreamReader(is));????????????????????????//定義String類型用于儲存單行數據????????????????????????String line=null;????????????????????????//創建StringBuffer對象用于存儲所有數據????????????????????????StringBuffer sb=new?StringBuffer();????????????????????????while((line=br.readLine())!=null){????????????????????????????sb.append(line);????????????????????????}????????????????????????//用TextView顯示接收的服務器數據????????????????????????tv.setText(sb.toString());????????????????????????System.out.println(sb.toString());????????????????????}?catch?(IOException e) {????????????????????????e.printStackTrace();????????????????????}????????????????}?catch?(MalformedURLException e) {????????????????????e.printStackTrace();????????????????}????????????}????????});????}} |
? ?權限（同上面第二個，所有與網絡有關的操作都需要添加，下面的就不再贅述了）
? ?運行效果：
?
（2）通過post方式（安全）
MainActivity.java
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 | package?com.example.l0903_httpurlconectionpost;import?java.io.BufferedReader;import?java.io.DataOutputStream;import?java.io.IOException;import?java.io.InputStream;import?java.io.InputStreamReader;import?java.io.OutputStream;import?java.net.HttpURLConnection;import?java.net.MalformedURLException;import?java.net.URL;import?java.net.URLEncoder;import?android.app.Activity;import?android.os.Bundle;import?android.view.View;import?android.view.View.OnClickListener;import?android.widget.EditText;import?android.widget.TextView;/**?* 通過Post方法傳遞參數?* 安全?* @author asus?*?*/public?class?MainActivity?extends?Activity {????private?HttpURLConnection conn;????private?URL url;????private?InputStream is;????private?OutputStream os;????private?EditText et;????private?TextView tv;????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????et=(EditText) findViewById(R.id.editText1);????????tv=(TextView) findViewById(R.id.tv);????????findViewById(R.id.button1).setOnClickListener(new?OnClickListener() {???????????????????????????????????????????????????????????????????????????????????????????????@Override????????????public?void?onClick(View v) {????????????????// TODO Auto-generated method stub????????????????String urlDate="http://10.0.2.2:8080/My_Service/webdate.jsp";????????????????try?{????????????????????url=new?URL(urlDate);????????????????????try?{????????????????????????//打開服務器????????????????????????conn=(HttpURLConnection) url.openConnection();????????????????????????//設置輸入輸出流????????????????????????conn.setDoOutput(true);????????????????????????conn.setDoInput(true);????????????????????????//設置請求的方法為Post????????????????????????conn.setRequestMethod("POST");????????????????????????//Post方式不能緩存數據，則需要手動設置使用緩存的值為false????????????????????????conn.setUseCaches(false);????????????????????????//連接數據庫????????????????????????conn.connect();????????????????????????/**寫入參數**/????????????????????????os=conn.getOutputStream();????????????????????????//封裝寫給服務器的數據（這里是要傳遞的參數）????????????????????????DataOutputStream dos=new?DataOutputStream(os);????????????????????????//寫方法：name是key值不能變，編碼方式使用UTF-8可以用中文????????????????????????dos.writeBytes("name="+URLEncoder.encode(et.getText().toString(),?"UTF-8"));????????????????????????//關閉外包裝流????????????????????????dos.close();????????????????????????/**讀服務器數據**/????????????????????????is=conn.getInputStream();????????????????????????BufferedReader br=new?BufferedReader(new?InputStreamReader(is));????????????????????????String line=null;????????????????????????StringBuffer sb=new?StringBuffer();????????????????????????while((line=br.readLine())!=null){????????????????????????????sb.append(line);????????????????????????}????????????????????????tv.setText(sb.toString());????????????????????????System.out.println(sb.toString());????????????????????}?catch?(IOException e) {????????????????????????e.printStackTrace();????????????????????}????????????????}?catch?(MalformedURLException e) {????????????????????e.printStackTrace();????????????????}????????????}????????});???????????????????????????????????????????????????????????????????????????????}} |
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五.使用HttpClient的編寫方式實現Android的網絡通信
1.服務器同上；
2.使用get的方式：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | package?com.example.l0903_http_get;import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStream;import?java.io.InputStreamReader;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.methods.HttpGet;import?org.apache.http.impl.client.DefaultHttpClient;import?android.app.Activity;import?android.os.Bundle;public?class?MainActivity?extends?Activity {????private?HttpGet get;????private?HttpClient cliet;????private?HttpResponse response;????private?HttpEntity entity;????private?InputStream is;????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????get=new?HttpGet("http://10.0.2.2:8080/My_Service/webdate.jsp?name=ooooooo");????????cliet=new?DefaultHttpClient();????????try?{????????????response=cliet.execute(get);????????????entity=response.getEntity();????????????is=entity.getContent();????????????BufferedReader br=new?BufferedReader(new?InputStreamReader(is));????????????String line=null;????????????StringBuffer sb=new?StringBuffer();????????????while((line=br.readLine())!=null){????????????????sb.append(line);????????????}????????????System.out.println(sb.toString());????????}?catch?(ClientProtocolException e) {????????????e.printStackTrace();????????}?catch?(IOException e) {????????????e.printStackTrace();????????}????????????????????????????????????????????????????}} |
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3.使用post的方式：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 | package?com.example.l0903_http_post;import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStream;import?java.io.InputStreamReader;import?java.io.UnsupportedEncodingException;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?android.app.Activity;import?android.os.Bundle;public?class?MainActivity?extends?Activity {????//創建請求對象????private?HttpPost post;????//創建客戶端對象????private?HttpClient cliet;????//創建發送請求的對象????private?HttpResponse response;????//????private?UrlEncodedFormEntity urlEntity;????//創建接收返回數據的對象????private?HttpEntity entity;????//創建流對象????private?InputStream is;????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????//包裝請求的地址????????post=new?HttpPost("http://10.0.2.2:8080/My_Service/webdate.jsp");????????//創建默認的客戶端對象????????cliet=new?DefaultHttpClient();????????//用list封裝要向服務器端發送的參數????????List<BasicNameValuePair> pairs=new?ArrayList<BasicNameValuePair>();????????pairs.add(new?BasicNameValuePair("name",?"llllllllll"));????????try?{????????????//用UrlEncodedFormEntity來封裝List對象????????????urlEntity=new?UrlEncodedFormEntity(pairs);????????????//設置使用的Entity????????????post.setEntity(urlEntity);????????????try?{????????????????//客戶端開始向指定的網址發送請求????????????????response=cliet.execute(post);????????????????//獲得請求的Entity????????????????entity=response.getEntity();????????????????is=entity.getContent();????????????????//下面是讀取數據的過程????????????????BufferedReader br=new?BufferedReader(new?InputStreamReader(is));????????????????String line=null;????????????????StringBuffer sb=new?StringBuffer();????????????????while((line=br.readLine())!=null){????????????????????sb.append(line);????????????????}????????????????System.out.println(sb.toString());????????????}?catch?(ClientProtocolException e) {????????????????e.printStackTrace();????????????}?catch?(IOException e) {????????????????e.printStackTrace();????????????}????????}?catch?(UnsupportedEncodingException e) {????????????e.printStackTrace();????????}??????????????????????????????????????????????????????????????????????????????????????????????}} |
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4.實現HttpClient通信與AsyncTask異步機制的結合：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 | package?com.example.l0903_http_asynctask_get;import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStream;import?java.io.InputStreamReader;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.methods.HttpGet;import?org.apache.http.impl.client.DefaultHttpClient;import?android.app.Activity;import?android.app.ProgressDialog;import?android.os.AsyncTask;import?android.os.Bundle;import?android.widget.TextView;/**?*?* @author asus?*?*/public?class?MainActivity?extends?Activity {????private?TextView tv;// 創建請求對象????private?HttpGet httpGet;????// 創建客戶端對象????private?HttpClient httpClient;????// 發送請求的對象????private?HttpResponse httpResponse;????// 接收返回數據????private?HttpEntity httpEntity;????// 創建流????private?InputStream in;????private?ProgressDialog pd;????@Override????protected?void?onCreate(Bundle savedInstanceState) {????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main);????????tv = (TextView) findViewById(R.id.tv);????????AsyncTask<String, Void, String> asyncTask =?new?AsyncTask<String, Void, String>() {????????????@Override????????????protected?String doInString...? params) {????????????????String urlstr = params[0];????????????????httpGet =?new?HttpGet(urlstr);????????????????httpClient =?new?DefaultHttpClient();????????????????try?{????????????????????// 向服務器端發送請求????????????????????httpResponse = httpClient.execute(httpGet);????????????????????httpEntity = httpResponse.getEntity();????????????????????in = httpEntity.getContent();????????????????????BufferedReader br =?new?BufferedReader(????????????????????????????new?InputStreamReader(in));????????????????????String line =?null;????????????????????StringBuffer sb =?new?StringBuffer();????????????????????while?((line = br.readLine()) !=?null) {????????????????????????sb.append(line);????????????????????}????????????????????System.out.println(sb.toString());????????????????????return?sb.toString();????????????????}?catch?(ClientProtocolException e) {????????????????????e.printStackTrace();????????????????}?catch?(IOException e) {????????????????????e.printStackTrace();????????????????}????????????????return?null;????????????}????????????@Override????????????protected?void?onPostExecute(String result) {????????????????if?(result !=?null) {????????????????????tv.setText(result);????????????????????pd.dismiss();// 消除dialog????????????????}????????????????super.onPostExecute(result);????????????}????????};????????pd = ProgressDialog.show(this,?"請稍后。。。",?"正在請求數據");????????asyncTask.execute("http://10.0.2.2:8080/My_Service/webdate.jsp?name=haha&age=hh");????}} |
運行效果：
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解釋和配合fork的使用)
