使用 Apache HttpClient

来源：互联网发布：国外实时数据库有哪些编辑：程序博客网时间：2024/06/06 18:35

为了更好的处理向web站点的请求,包括处理Session ,Cookie等细节问题,Apache 开源组织提供了一个 HttpClient项目.它是一个简单的HTTP客户端(并不是浏览器),可以用于发送HTTP请求,接受HTTP响应,.但不会缓存服务器的响应,不能执行HTML页面中嵌入的JavaScript代码,也不会对页面内容进行任何解析,处理.

使用 HttpClient 发送请求,接受响应. 需要如下几步:

创建 HttpClient 对象.
如需要发送GET 请求,则创建 HttpGet对象.如发动POST请求,则创建HttpPost对象.
如果需要发送请求参数,可调用 HttpGet,HttpPost共同的 setParams(HttpParams params) 方法来添加请求参数; 对于 HttpPost 对象而言, 也可调用setEntity(HttpEntity entity)方法来设置请求参数.
调用 HttpClient 对象的execute(HttpUriRequest request) 发送请求执行该方法返回一个HttpResponse.
调用 HttpResponse 的getAllHeaders(), getHeaders(String name),等方法获取服务器的响应头; 调用 HttpResponse 的getEntity()方法可获取 HttpEntity 对象,该对象包装了服务器的响应内容.程序可通过该对象获取服务器的响应内容.

package com.net.httpclient;import android.app.AlertDialog;import android.content.DialogInterface;import android.os.Bundle;import android.os.Handler;import android.os.Looper;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import org.apache.http.HttpEntity;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 org.apache.http.protocol.HTTP;import org.apache.http.util.EntityUtils;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.List;/** * 使用 Apache HttpClient * org.apache.http.client.HttpClient */public class HttpClientActivity extends AppCompatActivity {    TextView respone;    Button assess, login;    HttpClient httpClient;    Handler mHandler = new Handler() {        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            if(msg.what == 0x1234)            {                // 使用response文本框显示服务器响应                respone.append(msg.obj.toString() + "\n");            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_http_client);        //创建 DefaultHttpClient 对象        httpClient = new DefaultHttpClient();        respone = (TextView) findViewById(R.id.response);        assess = (Button) findViewById(R.id.accessSecret);        login = (Button) findViewById(R.id.showLogin);        initListener();    }    private void initListener() {        assess.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                new Thread() {                    @Override                    public void run() {                        super.run();                        //创建一个 HttpGet 对象                        HttpGet get = new HttpGet("http://169.254.214.117:8080/foo/secret.jsp");                        try {                            //发送 get 请求                            HttpResponse httpResponse = httpClient.execute(get);                            HttpEntity entity = httpResponse.getEntity();                            if (entity == null) {                                //读取服务器响应                                BufferedReader br = new BufferedReader(new InputStreamReader(entity.getContent()));                                String line = null;                                while ((line = br.readLine()) != null) {                                    Message msg = Message.obtain();                                    msg.what = 0x1234;                                    msg.obj = line;                                    mHandler.sendMessage(msg);                                }                            }                        } catch (IOException e) {                            e.printStackTrace();                        }                    }                }.start();            }        });        login.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                //加载登录界面                final View loginDialog = getLayoutInflater().inflate(R.layout.login, null);                //使用对话框供用户登录                new AlertDialog.Builder(HttpClientActivity.this)                        .setTitle("登录系统")                        .setView(loginDialog)                        .setPositiveButton("登录", new DialogInterface.OnClickListener() {                            @Override                            public void onClick(DialogInterface dialog, int which) {                                //获取用户输入的用户名, 密码                                final String name = ((EditText) loginDialog.findViewById(R.id.name)).getText().toString();                                final String pass = ((EditText) loginDialog.findViewById(R.id.pass)).getText().toString();                                //开启子线程                                new Thread() {                                    @Override                                    public void run() {                                        try {                                            HttpPost post = new HttpPost("http://169.254.214.117:8080/foo/login.jsp");                                            //如果传递参数个数比较多,可以对传递的多个参数进行封装                                            List<NameValuePair> params = new ArrayList<NameValuePair>();                                            params.add(new BasicNameValuePair("name", name));                                            params.add(new BasicNameValuePair("pass", pass));                                            //设置请求参数                                            post.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));                                            //发送 post请求                                            HttpResponse response =httpClient.execute(post);                                            //如果服务器成功的 返回响应                                            if (response.getStatusLine().getStatusCode()==200){                                                String msg = EntityUtils.toString(response.getEntity());                                                Looper.prepare();                                                //提示登录成功                                                Toast.makeText(HttpClientActivity.this, msg, Toast.LENGTH_SHORT).show();                                                Looper.loop();                                            }                                        } catch (Exception e) {                                            e.printStackTrace();                                        }                                    }                                }.start();                            }                        }).setNegativeButton("取消",null).show();            }        });    }}

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