一、简介

二、WebView

public class MainActivity extends AppCompatActivity {

    private EditText et_url;
    private Button btn_join;
    private WebView wv_web;

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

        et_url = (EditText) findViewById(R.id.et_url);
        btn_join = (Button) findViewById(R.id.btn_join);
        wv_web = (WebView) findViewById(R.id.wv_web);

        //支持js
        wv_web.getSettings().setJavaScriptEnabled(true);
        // 当跳转到新的网页时，仍然在这个WebView中显示
        wv_web.setWebViewClient(new WebViewClient());
        wv_web.loadUrl("http://www.baidu.com");
        
        btn_join.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String urlStr = et_url.getText().toString();
                wv_web.loadUrl(urlStr);
            }
        });
    }
}

PS：感觉比ios的WebView好使

三、使用HTTP协议访问网络

3.1 HttpURLConnection

package com.example.jony.httpdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class URLConActivity extends AppCompatActivity {

    private static final String TAG = "URLConActivity";

    private EditText et_url_url;
    private Button btn_url_request;
    private TextView response_url_text;


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

        et_url_url = (EditText) findViewById(R.id.et_url_url);
        response_url_text = (TextView) findViewById(R.id.response_url_text);
        btn_url_request = (Button) findViewById(R.id.btn_url_request);

        btn_url_request.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                sendRequestWithHttpURLConnection();
            }
        });
    }

    private void sendRequestWithHttpURLConnection(){
        //子线程中进行网络数据请求
        new Thread(new Runnable() {
            @Override
            public void run() {

                //创建连接对象
                HttpURLConnection connection = null;
                BufferedReader reader = null;

                try {
                    URL url = new URL(et_url_url.getText().toString());
                    connection = (HttpURLConnection) url.openConnection();

                    //get方法
                    connection.setRequestMethod("GET");

                    //post方法
//                    connection.setRequestMethod("POST");
//                    DataOutputStream out = new DataOutputStream(connection.getOutputStream());
//                    out.writeBytes("userName=admin&password=123456");

                    //连接超时和读取超时单位毫秒
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);

                    InputStream in = connection.getInputStream();
                    reader = new BufferedReader(new InputStreamReader(in));
                    StringBuilder response = new StringBuilder();
                    String line;
                    while ((line = reader.readLine()) != null){
                        response.append(line);
                    }
                    showResponse(response.toString());
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {

                    if (reader != null){
                        try {
                            reader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }

                    if (connection != null){
                        connection.disconnect();
                    }
                }

            }
        }).start();
    }

    private void showResponse(final String response){
        //将线程切换到主线程更新UI
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
//                Log.d(TAG, "run:"+response);
                response_url_text.setText(response);
            }
        });
    }
}

3.2 OKHttp

package com.example.jony.httpdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.IOException;

import okhttp3.FormBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public class OKHttpActivity extends AppCompatActivity {

    private EditText et_ok_url;
    private Button btn_ok_request;
    private TextView response_ok_text;

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

        et_ok_url = (EditText) findViewById(R.id.et_ok_url);
        btn_ok_request = (Button) findViewById(R.id.btn_ok_request);
        response_ok_text = (TextView) findViewById(R.id.response_ok_text);

        btn_ok_request.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                sendRequestWithOKHttp();
            }
        });
    }

    private void sendRequestWithOKHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                OkHttpClient client = new OkHttpClient();
                

//                //Post请求
//                RequestBody requestBody = new FormBody.Builder()
//                        .add("username","admin")
//                        .add("password", "123456")
//                        .build();
//                Request request = new Request().Builder()
//                        .url("http://www.baidu.com")
//                        .post(requestBody)
//                        .build();
                
                Request request = new Request.Builder().url(et_ok_url.getText().toString()).build();

                try {
                    //创建call对象，并execute()方法发送请求获取返回数据
                    Response response = client.newCall(request).execute();

                    String responseData = response.body().string();
                    showResponse(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
        }).start();

    }

    private void showResponse(final String response){
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                response_ok_text.setText(response);


            }
        });
    }
}