12_Android中HttpClient的应用,doGet,doPost,doHttpClientGet,doHttpClient请求,另外借助第三方框架实现网络连接的应用,

简介: 准备条件,编写一个web项目。编写一个servlet,若用户名为lisi,密码为123,则返回“登录成功”,否则”登录失败”。项目名为ServerItheima28。代码如下: package com.itheima28.servlet;   import java.io.IOException; import java.io.PrintWriter;

  1. 准备条件,

  1. 编写一个web项目。编写一个servlet,若用户名为lisi,密码为123,则返回登录成功,否则登录失败。项目名为ServerItheima28。代码如下:

package com.itheima28.servlet;

 

import java.io.IOException;

import java.io.PrintWriter;

 

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

 

public class LoginServlet extends HttpServlet {

 

         /**

          * The doGet method of the servlet. <br>

          *

          * This method is called when a form has its tag value method equals to get.

          *

          * @param request the request send by the client to the server

          * @param response the response send by the server to the client

          * @throws ServletException if an error occurred

          * @throws IOException if an error occurred

          */

         public void doGet(HttpServletRequest request, HttpServletResponse response)

                            throws ServletException, IOException {

                   String username = request.getParameter("username");       // 采用的编码是: iso-8859-1

                   String password = request.getParameter("password");

                  

                   // 采用iso8859-1的编码对姓名进行逆转, 转换成字节数组, 再使用utf-8编码对数据进行转换, 字符串

                   username = new String(username.getBytes("iso8859-1"), "utf-8");

                   password = new String(password.getBytes("iso8859-1"), "utf-8");

                  

                   System.out.println("姓名: " + username);

                   System.out.println("密码: " + password);

                  

                   if("lisi".equals(username) && "123".equals(password)) {

                            /*

                             * getBytes 默认情况下, 使用的iso8859-1的编码, 但如果发现码表中没有当前字符,

                             * 会使用当前系统下的默认编码: GBK

                             */

                            response.getOutputStream().write("登录成功".getBytes("utf-8"));

                   } else {

                            response.getOutputStream().write("登录失败".getBytes("utf-8"));

                   }

         }

 

         /**

          * The doPost method of the servlet. <br>

          *

          * This method is called when a form has its tag value method equals to post.

          *

          * @param request the request send by the client to the server

          * @param response the response send by the server to the client

          * @throws ServletException if an error occurred

          * @throws IOException if an error occurred

          */

         public void doPost(HttpServletRequest request, HttpServletResponse response)

                            throws ServletException, IOException {

                   System.out.println("doPost");

                   doGet(request, response);

         }

 

}

 

  1. 使用github上的android-async-http-master框架:

2 编写Android应用,应用截图如下:

代码结构如下:

清单文件

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.itheim28.submitdata"

    android:versionCode="1"

    android:versionName="1.0" >

 

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="19" />

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

 

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name="com.itheim28.submitdata.MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

 

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

 

</manifest>

3  编写布局文件activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >

 

    <EditText

        android:id="@+id/et_username"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:hint="请输入姓名" />

 

    <EditText

        android:id="@+id/et_password"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:hint="请输入密码" />

 

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:onClick="doGet"

        android:text="Get方式提交" />

 

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:onClick="doPost"

        android:text="Post方式提交" />

   

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:onClick="doHttpClientOfGet"

        android:text="使用HttpClient方式提交Get请求" />

 

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:onClick="doHttpClientOfPost"

        android:text="使用HttpClient方式提交Post请求" />

</LinearLayout>

4 NetUtils的内容如下:

package com.itheim28.submitdata.utils;

 

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.net.URLEncoder;

 

import android.util.Log;

 

public class NetUtils {

 

         private static final String TAG = "NetUtils";

 

         /**

          * 使用post的方式登录

          *

          * @param userName

          * @param password

          * @return

          */

         public static String loginOfPost(String userName, String password) {

                   HttpURLConnection conn = null;

                   try {

                            URL url = new URL(

                                              "http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet");

 

                            conn = (HttpURLConnection) url.openConnection();

 

                            conn.setRequestMethod("POST");

                            conn.setConnectTimeout(10000); // 连接的超时时间

                            conn.setReadTimeout(5000); // 读数据的超时时间

                            conn.setDoOutput(true); // 必须设置此方法, 允许输出

                            // conn.setRequestProperty("Content-Length", 234); // 设置请求头消息,

                            // 可以设置多个

 

                            // post请求的参数

                            String data = "username=" + userName + "&password=" + password;

 

                            // 获得一个输出流, 用于向服务器写数据, 默认情况下, 系统不允许向服务器输出内容

                            OutputStream out = conn.getOutputStream();

                            out.write(data.getBytes());

                            out.flush();

                            out.close();

 

                            int responseCode = conn.getResponseCode();

                            if (responseCode == 200) {

                                     InputStream is = conn.getInputStream();

                                     String state = getStringFromInputStream(is);

                                     return state;

                            } else {

                                     Log.i(TAG, "访问失败: " + responseCode);

                            }

                   } catch (Exception e) {

                            e.printStackTrace();

                   } finally {

                            if (conn != null) {

                                     conn.disconnect();

                            }

                   }

                   return null;

         }

 

         /**

          * 使用get的方式登录

          *

          * @param userName

          * @param password

          * @return 登录的状态

          */

         public static String loginOfGet(String userName, String password) {

                   HttpURLConnection conn = null;

                   try {

                            String data = "username=" + URLEncoder.encode(userName)

                                               + "&password=" + URLEncoder.encode(password);

                            URL url = new URL(

                                               "http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet?"

                                                                 + data);

                            conn = (HttpURLConnection) url.openConnection();

 

                            conn.setRequestMethod("GET"); // get或者post必须得全大写

                            conn.setConnectTimeout(10000); // 连接的超时时间

                            conn.setReadTimeout(5000); // 读数据的超时时间

 

                            int responseCode = conn.getResponseCode();

                            if (responseCode == 200) {

                                     InputStream is = conn.getInputStream();

                                     String state = getStringFromInputStream(is);

                                     return state;

                            } else {

                                     Log.i(TAG, "访问失败: " + responseCode);

                            }

                   } catch (Exception e) {

                            e.printStackTrace();

                   } finally {

                            if (conn != null) {

                                     conn.disconnect(); // 关闭连接

                            }

                   }

                   return null;

         }

 

         /**

          * 根据流返回一个字符串信息

          *

          * @param is

          * @return

          * @throws IOException

          */

         private static String getStringFromInputStream(InputStream is)

                            throws IOException {

                   ByteArrayOutputStream baos = new ByteArrayOutputStream();

                   byte[] buffer = new byte[1024];

                   int len = -1;

 

                   while ((len = is.read(buffer)) != -1) {

                            baos.write(buffer, 0, len);

                   }

                   is.close();

 

                   String html = baos.toString(); // 把流中的数据转换成字符串, 采用的编码是: utf-8

 

                   // String html = new String(baos.toByteArray(), "GBK");

 

                   baos.close();

                   return html;

         }

}

5 NetUtils2代码如下:

package com.itheim28.submitdata.utils;

 

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.List;

 

import org.apache.http.HttpResponse;

import org.apache.http.NameValuePair;

import org.apache.http.client.HttpClient;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.message.BasicNameValuePair;

 

import android.util.Log;

 

public class NetUtils2 {

 

         private static final String TAG = "NetUtils";

 

         /**

          * 使用post的方式登录

          *

          * @param userName

          * @param password

          * @return

          */

         public static String loginOfPost(String userName, String password) {

                   HttpClient client = null;

                   try {

                            // 定义一个客户端

                            client = new DefaultHttpClient();

 

                            // 定义post方法

                            HttpPost post = new HttpPost(

                                              "http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet");

 

                            // 定义post请求的参数

                            List<NameValuePair> parameters = new ArrayList<NameValuePair>();

                            parameters.add(new BasicNameValuePair("username", userName));

                            parameters.add(new BasicNameValuePair("password", password));

 

                            // post请求的参数包装了一层.

 

                            // 不写编码名称服务器收数据时乱码. 需要指定字符集为utf-8

                            UrlEncodedFormEntity entity = new UrlEncodedFormEntity(parameters,

                                               "utf-8");

                            // 设置参数.

                            post.setEntity(entity);

 

                            // 设置请求头消息

                            // post.addHeader("Content-Length", "20");

 

                            // 使用客户端执行post方法

                            HttpResponse response = client.execute(post); // 开始执行post请求,

                                                                                                                                            // 会返回给我们一个HttpResponse对象

 

                            // 使用响应对象, 获得状态码, 处理内容

                            int statusCode = response.getStatusLine().getStatusCode(); // 获得状态码

                            if (statusCode == 200) {

                                     // 使用响应对象获得实体, 获得输入流

                                     InputStream is = response.getEntity().getContent();

                                     String text = getStringFromInputStream(is);

                                      return text;

                            } else {

                                     Log.i(TAG, "请求失败: " + statusCode);

                            }

                   } catch (Exception e) {

                            e.printStackTrace();

                   } finally {

                            if (client != null) {

                                     client.getConnectionManager().shutdown(); // 关闭连接和释放资源

                            }

                   }

                   return null;

         }

 

         /**

          * 使用get的方式登录

          *

          * @param userName

          * @param password

          * @return 登录的状态

          */

         public static String loginOfGet(String userName, String password) {

                   HttpClient client = null;

                   try {

                            // 定义一个客户端

                            client = new DefaultHttpClient();

 

                            // 定义一个get请求方法

                            String data = "username=" + userName + "&password=" + password;

                            HttpGet get = new HttpGet(

                                               "http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet?" + data);

 

                            // response 服务器相应对象, 其中包含了状态信息和服务器返回的数据

                            // 开始执行get方法, 请求网络

                            HttpResponse response = client.execute(get);

 

                            // 获得响应码

                            int statusCode = response.getStatusLine().getStatusCode();

 

                            if (statusCode == 200) {

                                     InputStream is = response.getEntity().getContent();

                                     String text = getStringFromInputStream(is);

                                     return text;

                            } else {

                                     Log.i(TAG, "请求失败: " + statusCode);

                            }

                   } catch (Exception e) {

                            e.printStackTrace();

                   } finally {

                            if (client != null) {

                                     client.getConnectionManager().shutdown(); // 关闭连接, 和释放资源

                            }

                   }

                   return null;

         }

 

         /**

          * 根据流返回一个字符串信息

          *

          * @param is

          * @return

          * @throws IOException

          */

         private static String getStringFromInputStream(InputStream is)

                            throws IOException {

                   ByteArrayOutputStream baos = new ByteArrayOutputStream();

                   byte[] buffer = new byte[1024];

                   int len = -1;

 

                   while ((len = is.read(buffer)) != -1) {

                            baos.write(buffer, 0, len);

                   }

                   is.close();

 

                   String html = baos.toString(); // 把流中的数据转换成字符串, 采用的编码是: utf-8

 

                   // String html = new String(baos.toByteArray(), "GBK");

 

                   baos.close();

                   return html;

         }

}

6 MainActivity代码如下:

package com.itheim28.submitdata;

 

import android.app.Activity;

import android.os.Bundle;

import android.text.TextUtils;

import android.util.Log;

import android.view.View;

import android.widget.EditText;

import android.widget.Toast;

 

import com.itheim28.submitdata.utils.NetUtils;

import com.itheim28.submitdata.utils.NetUtils2;

 

public class MainActivity extends Activity {

 

         private static final String TAG = "MainActivity";

         private EditText etUserName;

         private EditText etPassword;

 

         @Override

         protected void onCreate(Bundle savedInstanceState) {

                   super.onCreate(savedInstanceState);

                   setContentView(R.layout.activity_main);

 

                   etUserName = (EditText) findViewById(R.id.et_username);

                   etPassword = (EditText) findViewById(R.id.et_password);

         }

 

         /**

          * 使用httpClient方式提交get请求

          *

          * @param v

          */

         public void doHttpClientOfGet(View v) {

                   Log.i(TAG, "doHttpClientOfGet");

                   final String userName = etUserName.getText().toString();

                   final String password = etPassword.getText().toString();

 

                   new Thread(new Runnable() {

 

                            @Override

                            public void run() {

                                     // 请求网络

                                     final String state = NetUtils2.loginOfGet(userName, password);

                                     // 执行任务在主线程中

                                     runOnUiThread(new Runnable() {

                                               @Override

                                               public void run() {

                                                        // 就是在主线程中操作

                                                        Toast.makeText(MainActivity.this, state, 0).show();

                                               }

                                     });

                            }

                   }).start();

         }

 

         /**

          * 使用httpClient方式提交post请求

          *

          * @param v

          */

         public void doHttpClientOfPost(View v) {

                   Log.i(TAG, "doHttpClientOfPost");

                   final String userName = etUserName.getText().toString();

                   final String password = etPassword.getText().toString();

 

                   new Thread(new Runnable() {

                            @Override

                            public void run() {

                                     final String state = NetUtils2.loginOfPost(userName, password);

                                     // 执行任务在主线程中

                                     runOnUiThread(new Runnable() {

                                               @Override

                                               public void run() {

                                                        // 就是在主线程中操作

                                                        Toast.makeText(MainActivity.this, state, 0).show();

                                               }

                                     });

                            }

                   }).start();

         }

 

         public void doGet(View v) {

                   final String userName = etUserName.getText().toString();

                   final String password = etPassword.getText().toString();

 

                   new Thread(new Runnable() {

 

                            @Override

                            public void run() {

                                     // 使用get方式抓去数据

                                     final String state = NetUtils.loginOfGet(userName, password);

 

                                     // 执行任务在主线程中

                                     runOnUiThread(new Runnable() {

                                               @Override

                                               public void run() {

                                                        // 就是在主线程中操作

                                                        Toast.makeText(MainActivity.this, state, 0).show();

                                               }

                                     });

                            }

                   }).start();

         }

 

         public void doPost(View v) {

                   final String userName = etUserName.getText().toString();

                   final String password = etPassword.getText().toString();

 

                   new Thread(new Runnable() {

                            @Override

                            public void run() {

                                     final String state = NetUtils.loginOfPost(userName, password);

                                     // 执行任务在主线程中

                                     runOnUiThread(new Runnable() {

                                               @Override

                                               public void run() {

                                                        // 就是在主线程中操作

                                                        Toast.makeText(MainActivity.this, state, 0).show();

                                               }

                                     });

                            }

                   }).start();

         }

}

7 MainActivity2 的代码如下:

package com.itheim28.submitdata;

 

import java.net.URLEncoder;

 

import org.apache.http.Header;

 

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.EditText;

import android.widget.Toast;

 

import com.loopj.android.http.AsyncHttpClient;

import com.loopj.android.http.AsyncHttpResponseHandler;

import com.loopj.android.http.RequestParams;

 

public class MainActivity2 extends Activity {

 

    protected static final String TAG = "MainActivity2";

    private EditText etUserName;

    private EditText etPassword;

 

    @Override

    protected void onCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.activity_main);

 

       etUserName = (EditText) findViewById(R.id.et_username);

       etPassword = (EditText) findViewById(R.id.et_password);

    }

 

    public void doGet(View v) {

       final String userName = etUserName.getText().toString();

       final String password = etPassword.getText().toString();

 

       AsyncHttpClient client = new AsyncHttpClient();

 

       String data = "username=" + URLEncoder.encode(userName) + "&password="

              + URLEncoder.encode(password);

 

        client.get("http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet?"

              + data, new MyResponseHandler());

    }

 

    public void doPost(View v) {

       final String userName = etUserName.getText().toString();

       final String password = etPassword.getText().toString();

 

       AsyncHttpClient client = new AsyncHttpClient();

 

       RequestParams params = new RequestParams();

       params.put("username", userName);

       params.put("password", password);

 

       client.post(

               "http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet",

              params, new MyResponseHandler());

    }

 

    class MyResponseHandler extends AsyncHttpResponseHandler {

 

       @Override

       public void onSuccess(int statusCode, Header[] headers,

              byte[] responseBody) {

           // Log.i(TAG, "statusCode: " + statusCode);

 

           Toast.makeText(

                  MainActivity2.this,

                  "成功: statusCode: " + statusCode + ", body: "

                         + new String(responseBody), 0).show();

       }

 

       @Override

       public void onFailure(int statusCode, Header[] headers,

              byte[] responseBody, Throwable error) {

           Toast.makeText(MainActivity2.this, "失败: statusCode: " + statusCode,

                  0).show();

       }

    }

}

 

 

 

 

 

 

 

 

 

 

 

 

 

目录
相关文章
|
11天前
|
JSON 网络协议 数据格式
网络协议基础:HTTP请求与响应详解
【7月更文挑战第11天】HTTP协议作为Web通信的核心,其请求与响应机制是理解网络通信的关键。本文详细介绍了HTTP请求与响应的格式、过程以及常用的请求方法,帮助读者更好地理解HTTP协议的工作原理和应用场景。在实际应用中,HTTP协议的可定制性和灵活性使其能够适应多种
|
27天前
|
缓存 网络协议 安全
Android网络面试题之Http基础和Http1.0的特点
**HTTP基础:GET和POST关键差异在于参数传递方式(GET在URL,POST在请求体),安全性(POST更安全),数据大小限制(POST无限制,GET有限制),速度(GET较快)及用途(GET用于获取,POST用于提交)。面试中常强调POST的安全性、数据量、数据类型支持及速度。HTTP 1.0引入了POST和HEAD方法,支持多种数据格式和缓存,但每个请求需新建TCP连接。**
28 5
|
25天前
|
安全 网络协议 算法
Android网络基础面试题之HTTPS的工作流程和原理
HTTPS简述 HTTPS基于TCP 443端口,通过CA证书确保服务器身份,使用DH算法协商对称密钥进行加密通信。流程包括TCP握手、证书验证(公钥解密,哈希对比)和数据加密传输(随机数加密,预主密钥,对称加密)。特点是安全但慢,易受特定攻击,且依赖可信的CA。每次请求可能复用Session ID以减少握手。
25 2
|
1月前
|
缓存 JSON 网络协议
Android面试题:App性能优化之电量优化和网络优化
这篇文章讨论了Android应用的电量和网络优化。电量优化涉及Doze和Standby模式,其中应用可能需要通过用户白名单或电池广播来适应限制。Battery Historian和Android Studio的Energy Profile是电量分析工具。建议减少不必要的操作,延迟非关键任务,合并网络请求。网络优化包括HTTPDNS减少DNS解析延迟,Keep-Alive复用连接,HTTP/2实现多路复用,以及使用protobuf和gzip压缩数据。其他策略如使用WebP图像格式,按网络质量提供不同分辨率的图片,以及启用HTTP缓存也是有效手段。
45 9
|
26天前
|
缓存 网络协议 Android开发
Android网络面试题之Http1.1和Http2.0
HTTP/1.1 引入持久连接和管道机制提升效率,支持分块传输编码和更多请求方式如PUT、PATCH。Host字段指定服务器域名,RANGE用于断点续传。HTTP/2变为二进制协议,实现多工处理,头信息压缩和服务器推送,减少延迟并优化资源加载。HTTP不断发展,从早期的简单传输到后来的高效交互。
25 0
Android网络面试题之Http1.1和Http2.0
|
1月前
|
JSON Java API
【Android】使用 Retrofit2 发送异步网络请求的简单案例
**摘要:** Retrofit是Android和Java的HTTP客户端库,简化了RESTful API交互。它通过Java接口定义HTTP请求,并提供注解管理参数、HTTP方法等。要使用Retrofit,首先在AndroidManifest.xml中添加`INTERNET`权限,然后在`build.gradle`中引入Retrofit和Gson依赖。创建服务器响应数据类和描述接口的接口,如`Result`和`Api`。通过Retrofit.Builder配置基础URL并构建实例,之后调用接口方法创建Call对象并发送异步请求。
55 1
|
1月前
|
缓存 网络协议 Java
Android面试题之Java网络通信基础知识
Socket是应用与TCP/IP通信的接口,封装了底层细节。网络通信涉及连接、读写数据。BIO是同步阻塞,NIO支持多路复用(如Selector),AIO在某些平台提供异步非阻塞服务。BIO示例中,服务端用固定线程池处理客户端请求,客户端发起连接并读写数据。NIO的关键是Selector监控多个通道的事件,减少线程消耗。书中推荐《Java网络编程》和《UNIX网络编程》。关注公众号AntDream了解更多。
25 2
|
1月前
|
XML JSON Java
Android面试题 之 网络通信基础面试题
序列化对比:Serializable码流大、性能低;XML人机可读但复杂;JSON轻量、兼容性好但空间消耗大;ProtoBuff高效紧凑。支持大量长连接涉及系统限制调整、缓冲区优化。select/poll/epoll是IO多路复用,epoll在高连接数下性能更优且支持边缘触发。水平触发持续通知数据,边缘触发仅通知新数据。直接内存减少一次拷贝,零拷贝技术如sendfile和MMAP提升效率。关注公众号&quot;AntDream&quot;了解更多技术细节。
18 1
|
1月前
|
安全 Android开发 数据安全/隐私保护
同样的 APP 为何在 Android 8 以后网络感觉变卡?
【6月更文挑战第8天】Android 8 及以后系统中,APP 网络感觉变卡源于更严格的安全机制和后台限制,系统对网络优化的侧重改变,以及APP自身兼容性问题。开发者需优化APP,适应新系统,用户可更新APP或检查权限设置。通过共同努力,有望改善网络卡顿现象,提升用户体验。
|
1月前
网络编程中的互联网协议 , IP地址 , 域名 , 端口 , 架构 , 网页数据请求 , 响应码
网络编程中的互联网协议 , IP地址 , 域名 , 端口 , 架构 , 网页数据请求 , 响应码