Android http请求代码

前言，Android的网络通信的方式有两种：使用Socket或者HTTP，今天这一篇我们详细讲解使用HTTP实现的网络通信，HTTP又包括两种方式编程方式：

（1）HttpUrlConnection；

（2）HttpClient；

好了，我们直接进行讲解，当然之前也会有一部分有关Android网络通信的其他知识，我们也应该了解。

一.获取网络状态的方法

（1）MainActivity.java中的关键代码

//网络管理类，可以判断是否能上网，以及网络类型

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ConnectivityManager cm=(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo info=cm.getActiveNetworkInfo();
if(info!=null){
Toast.makeText(MainActivity.this, “连网正常”+info.getTypeName(), Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(MainActivity.this, “未连网”, Toast.LENGTH_SHORT).show();
}



（2）注意：一定要在主配置文件中增加这个权限

它是application的兄弟标签：

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<uses-permission android:name=“android.permission.ACCESS_NETWORK_STATE”/>



（3）OK，我们看一下我们的设备的上网状态和类型吧：



二.使用URL访问网页源码

（1）MainActivity.java：

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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;
/**
* 访问网页源码
* @author asus
*
*/
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
//访问百度的html文件的源码
InputStream is=new URL(“http://www.baidu.com”).openStream();
//读取数据的包装流
BufferedReader br=new BufferedReader(new InputStreamReader(is));
//str用于读取一行数据
String str=null;
//StringBuffer用于存储所欲数据
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：有关网络的操作都需要在主配置文件里添加下面这个权限：

[java]
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<uses-permission android:name=“android.permission.INTERNET”/>&nb
1e4c5
sp;



三.WebView 控件的简单使用

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package com.example.l0903_webview;
import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
/**
* 就是一个浏览器控件
* 其实没什么用
* @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用于加载指定的网络地址
wv.loadUrl(”http://www.baidu.com”);
}
}



运行效果：



四.使用HttpUrlConnection的编写方式实现Android的网络通信

1.首先，自己先搭建一个服务器：





2.下面是客户端的事了：

(1)通过get方式：

MainActivity.java：

[java]
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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;
/**
* 通过Get方法获取服务器的数据
* 直接在地址中用”?+键值+value”的方式来使用
* 所以传递的参数直接显示出来，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();
//定义访问的服务器地址，10.0.2.2是Android的访问的本地服务器地址
String urlDate=”http://10.0.2.2:8080/My_Service/webdate.jsp?name=”+name;
try {
//封装访问服务器的地址
url=new URL(urlDate);
try {
//打开对服务器的连接
conn=(HttpURLConnection) url.openConnection();
//连接服务器
conn.connect();
/**读入服务器数据的过程**/
//得到输入流
is=conn.getInputStream();
//创建包装流
BufferedReader br=new BufferedReader(new InputStreamReader(is));
//定义String类型用于储存单行数据
String line=null;
//创建StringBuffer对象用于存储所有数据
StringBuffer sb=new StringBuffer();
while((line=br.readLine())!=null){
sb.append(line);
}
//用TextView显示接收的服务器数据
tv.setText(sb.toString());
System.out.println(sb.toString());
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
}
});
}
}



权限（同上面第二个，所有与网络有关的操作都需要添加，下面的就不再赘述了）

运行效果：



（2）通过post方式（安全）

MainActivity.java

[java]
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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;
/**
* 通过Post方法传递参数
* 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 {
//打开服务器
conn=(HttpURLConnection) url.openConnection();
//设置输入输出流
conn.setDoOutput(true);
conn.setDoInput(true);
//设置请求的方法为Post
conn.setRequestMethod(”POST”);
//Post方式不能缓存数据，则需要手动设置使用缓存的值为false
conn.setUseCaches(false);
//连接数据库
conn.connect();
/**写入参数**/
os=conn.getOutputStream();
//封装写给服务器的数据（这里是要传递的参数）
DataOutputStream dos=new DataOutputStream(os);
//写方法：name是key值不能变，编码方式使用UTF-8可以用中文
dos.writeBytes(”name=”+URLEncoder.encode(et.getText().toString(), “UTF-8”));
//关闭外包装流
dos.close();
/**读服务器数据**/
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();
}
}
});

}
}



五.使用HttpClient的编写方式实现Android的网络通信

1.服务器同上；

2.使用get的方式：

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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();
}

}
}



3.使用post的方式：

[java]
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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 {
//创建请求对象
private HttpPost post;
//创建客户端对象
private HttpClient cliet;
//创建发送请求的对象
private HttpResponse response;
//
private UrlEncodedFormEntity urlEntity;
//创建接收返回数据的对象
private HttpEntity entity;
//创建流对象
private InputStream is;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//包装请求的地址
post=new HttpPost(“http://10.0.2.2:8080/My_Service/webdate.jsp”);
//创建默认的客户端对象
cliet=new DefaultHttpClient();
//用list封装要向服务器端发送的参数
List<BasicNameValuePair> pairs=new ArrayList<BasicNameValuePair>();
pairs.add(new BasicNameValuePair(“name”, “llllllllll”));
try {
//用UrlEncodedFormEntity来封装List对象
urlEntity=new UrlEncodedFormEntity(pairs);
//设置使用的Entity
post.setEntity(urlEntity);
try {
//客户端开始向指定的网址发送请求
response=cliet.execute(post);
//获得请求的Entity
entity=response.getEntity();
is=entity.getContent();
//下面是读取数据的过程
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();
}

}
}



4.实现HttpClient通信与AsyncTask异步机制的结合：

[java]
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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;// 创建请求对象
private HttpGet httpGet;
// 创建客户端对象
private HttpClient httpClient;
// 发送请求的对象
private HttpResponse httpResponse;
// 接收返回数据
private HttpEntity httpEntity;
// 创建流
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 {
// 向服务器端发送请求
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, “请稍后。。。”, “正在请求数据”);
asyncTask.execute(”http://10.0.2.2:8080/My_Service/webdate.jsp?name=haha&age=hh”);
}
}



运行效果：










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