结对编码
要求：1.实现页面跳转（至少两个页面）
2.使用多线程以及网络编程
功能：从网络获取新闻，并以列表的形式表现出来；当点击一条新闻时，此新闻可以在另一个页面打开，显示的是此新闻详情。
代码如下：
1.主界面的列表布局
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:orientation="vertical"> 6 7 <ListView 8 android:id="@+id/list" 9 android:layout_width="match_parent" 10 android:layout_height="match_parent" /> 11 </LinearLayout>
2.主布局列表中所绑定适配器的布局
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent"> 6 7 <ImageView 8 android:layout_width="150px" 9 android:layout_height="105px" 10 app:srcCompat="@mipmap/ic_launcher" 11 android:id="@+id/item_pic" /> 12 13 <LinearLayout 14 android:orientation="vertical" 15 android:layout_width="match_parent" 16 android:layout_height="wrap_content"> 17 18 <TextView 19 android:text="标题" 20 android:layout_width="match_parent" 21 android:layout_height="wrap_content" 22 android:id="@+id/item_title" 23 android:textColor="#000000" 24 android:textSize="14sp" /> 25 26 <LinearLayout 27 android:orientation="horizontal" 28 android:layout_width="match_parent" 29 android:layout_height="wrap_content"> 30 31 <TextView 32 android:text="来源" 33 android:layout_width="wrap_content" 34 android:layout_height="wrap_content" 35 android:id="@+id/item_description" 36 android:layout_weight="1" /> 37 38 <TextView 39 android:text="时间" 40 android:layout_width="wrap_content" 41 android:layout_height="wrap_content" 42 android:id="@+id/item_time" 43 android:textAlignment="textEnd" 44 android:layout_weight="1" /> 45 </LinearLayout> 46 </LinearLayout> 47 </LinearLayout>
3.显示新闻详情
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:tools="http://schemas.android.com/tools" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent" 6 tools:context="com.example.demo.Activityweb"> 7 8 <WebView 9 android:id="@+id/web" 10 android:layout_width="match_parent" 11 android:layout_height="match_parent" /> 12 13 </LinearLayout>
4.网络连接工具类
1 package com.example.demo; 2 3 import android.graphics.Bitmap; 4 import android.graphics.BitmapFactory; 5 import android.os.Handler; 6 import android.os.Message; 7 8 import java.io.BufferedReader; 9 import java.io.IOException; 10 import java.io.InputStream; 11 import java.io.InputStreamReader; 12 import java.net.HttpURLConnection; 13 import java.net.URL; 14 15 /** 16 * 网络连接工具类 17 */ 18 19 public class HttpUtil { 20 //API的key--可以在百度API中获取 21 public static final String APIKEY = "****************************"; 22 //获取新闻频道API 23 public static final String GUONEI = "https://api.tianapi.com/tiyu/"; 24 public static final String surl = HttpUtil.GUONEI + "?key=" + HttpUtil.APIKEY + "&num=20"; 25 public static final int what = 1; 26 27 /** 28 * 获取连接和返回json数据 29 * 30 * @param handler 31 */ 32 public void httpGetData_Get(final Handler handler) { 33 34 new Thread(new Runnable() { 35 @Override 36 public void run() { 37 HttpURLConnection httpURLConnection = null; 38 try { 39 //创建URL对象 40 URL url = new URL(surl); 41 //返回一个URLConnection对象，它表示到URL所引用的远程对象链接 42 httpURLConnection = (HttpURLConnection) url.openConnection(); 43 //设定请求方法，默认是GET方法 44 httpURLConnection.setRequestMethod("GET"); 45 //设置连接超时时间 46 httpURLConnection.setConnectTimeout(30000); 47 //设置读取数据超时时间 48 httpURLConnection.setReadTimeout(5000); 49 //获取响应状态码 50 int responseCode = httpURLConnection.getResponseCode(); 51 if (responseCode == 200) { 52 //定义一个输入流，获取服务器返回的数据 53 InputStream is = httpURLConnection.getInputStream(); 54 InputStreamReader isr = new InputStreamReader(is); 55 BufferedReader br = new BufferedReader(isr); 56 //逐行遍历 57 String request = ""; 58 String response = ""; 59 60 while ((request = br.readLine()) != null) { 61 response += request; 62 Message msg = new Message(); 63 msg.what = what; 64 msg.obj = response; 65 handler.sendMessage(msg); 66 } 67 br.close(); 68 isr.close(); 69 is.close(); 70 } 71 } catch (IOException e) { 72 73 e.printStackTrace(); 74 } finally { 75 if (httpURLConnection != null) { 76 httpURLConnection.disconnect(); 77 } 78 } 79 } 80 }).start(); 81 } 82 83 /** 84 * 图片的下载返回Bitmap数据 85 * 86 * @param pic_url 图片的URL 87 * @param handler 88 */ 89 public void getImgFromUrl(final String pic_url, final Handler handler) { 90 91 new Thread() { 92 @Override 93 public void run() { 94 super.run(); 95 HttpURLConnection httpURLConnection = null; 96 try { 97 URL url = new URL(pic_url); 98 httpURLConnection = (HttpURLConnection) url.openConnection(); 99 httpURLConnection.setRequestMethod("GET"); 100 httpURLConnection.setReadTimeout(5000); 101 httpURLConnection.setConnectTimeout(10000); 102 int responseCode = httpURLConnection.getResponseCode(); 103 if (responseCode == 200) { 104 //获取输入流 105 InputStream is = httpURLConnection.getInputStream(); 106 //转换为Bitmap数据 107 Bitmap bitmap = BitmapFactory.decodeStream(is); 108 109 Message msg = new Message(); 110 msg.what = 1; 111 msg.obj = bitmap; 112 handler.sendMessage(msg); 113 is.close(); 114 } 115 } catch (IOException e) { 116 e.printStackTrace(); 117 } finally { 118 if (httpURLConnection != null) { 119 httpURLConnection.disconnect(); 120 } 121 } 122 } 123 }.start(); 124 } 125 }
5.主页面的逻辑代码
1 package com.example.demo; 2 3 import android.content.Context; 4 import android.content.Intent; 5 import android.graphics.Bitmap; 6 import android.os.Bundle; 7 import android.os.Handler; 8 import android.os.Message; 9 import android.support.v7.app.AppCompatActivity; 10 import android.util.Log; 11 import android.view.LayoutInflater; 12 import android.view.View; 13 import android.view.ViewGroup; 14 import android.widget.AdapterView; 15 import android.widget.BaseAdapter; 16 import android.widget.ImageView; 17 import android.widget.ListView; 18 import android.widget.TextView; 19 20 import org.json.JSONArray; 21 import org.json.JSONException; 22 import org.json.JSONObject; 23 24 import java.util.ArrayList; 25 import java.util.HashMap; 26 import java.util.List; 27 import java.util.Map; 28 29 public class MainActivity extends AppCompatActivity { 30 List<Map<String, Object>> mapList; 31 Adapter adapter; 32 ListView lv; 33 34 Handler handler = new Handler() { 35 @Override 36 public void handleMessage(Message msg) { 37 super.handleMessage(msg); 38 switch (msg.what) { 39 case 1: 40 //json解析 41 String response = msg.obj.toString(); 42 try { 43 //解析json对象 44 JSONObject object = new JSONObject(response); 45 //解析json数组 46 JSONArray Array = object.getJSONArray("newslist"); 47 //遍历 48 for (int i = 0; i < Array.length(); i++) { 49 Map<String, Object> map = new HashMap<>(); 50 String ctime = Array.getJSONObject(i).getString("ctime"); 51 String title = Array.getJSONObject(i).getString("title"); 52 String description = Array.getJSONObject(i).getString("description"); 53 String url = Array.getJSONObject(i).getString("url"); 54 String picUrl = Array.getJSONObject(i).getString("picUrl"); 55 map.put("ctime", ctime); 56 map.put("title", title); 57 map.put("description", description); 58 map.put("url", url); 59 map.put("picUrl", picUrl); 60 //将解析出来的数据存入数组 61 mapList.add(map); 62 } 63 } catch (JSONException e) { 64 e.printStackTrace(); 65 } 66 //将listview适配器存入数据 67 adapter = new Adapter(MainActivity.this, mapList); 68 lv = (ListView) findViewById(R.id.list); 69 lv.setAdapter(adapter); 70 //listview的监听 71 lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { 72 @Override 73 public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) { 74 //获取mapList里新闻详情的URL地址,并将地址通过intent传到Activityweb中打开 75 Intent intent = new Intent(MainActivity.this, Activityweb.class); 76 intent.putExtra("URL", mapList.get(i).get("url").toString()); 77 intent.putExtra("description", mapList.get(i).get("description").toString()); 78 startActivityForResult(intent, 1001); 79 80 } 81 }); 82 break; 83 } 84 } 85 }; 86 87 88 @Override 89 protected void onCreate(Bundle savedInstanceState) { 90 super.onCreate(savedInstanceState); 91 setContentView(R.layout.activity_main); 92 mapList = new ArrayList<>(); 93 //打开网络连接 94 HttpUtil h = new HttpUtil(); 95 h.httpGetData_Get(handler); 96 97 } 98 99 /** 100 * listview适配器 101 */ 102 class Adapter extends BaseAdapter { 103 List<Map<String, Object>> list; 104 Context context; 105 LayoutInflater layout; 106 107 Adapter(Context context, List<Map<String, Object>> list) { 108 this.context = context; 109 layout = LayoutInflater.from(context); 110 this.list = list; 111 } 112 113 @Override 114 public int getCount() { 115 return list.size(); 116 } 117 118 @Override 119 public Object getItem(int i) { 120 return null; 121 } 122 123 @Override 124 public long getItemId(int i) { 125 return 0; 126 } 127 128 @Override 129 public View getView(int i, View v, ViewGroup viewGroup) { 130 final Items items = new Items(); 131 v = layout.inflate(R.layout.item, null); 132 items.title = (TextView) v.findViewById(R.id.item_title); 133 items.description = (TextView) v.findViewById(R.id.item_description); 134 items.time = (TextView) v.findViewById(R.id.item_time); 135 items.pic = (ImageView) v.findViewById(R.id.item_pic); 136 137 //给item里面的控件赋值 138 items.title.setText(mapList.get(i).get("title").toString()); 139 items.description.setText(mapList.get(i).get("description").toString()); 140 items.time.setText(mapList.get(i).get("ctime").toString()); 141 142 Handler pic = new Handler() { 143 @Override 144 public void handleMessage(Message msg) { 145 super.handleMessage(msg); 146 if (msg.what == 1) { 147 //将Bitmap的数据赋给imageview 148 Bitmap bitmap = (Bitmap) msg.obj; 149 items.pic.setImageBitmap(bitmap); 150 } 151 } 152 }; 153 //打开网络连接获取图片 154 HttpUtil h = new HttpUtil(); 155 h.getImgFromUrl(mapList.get(i).get("picUrl").toString(), pic); 156 return v; 157 } 158 159 class Items { 160 ImageView pic; 161 TextView title; 162 TextView description; 163 TextView time; 164 } 165 } 166 }
6.web页面的逻辑代码--用于显示新闻详情
1 package com.example.demo; 2 3 import android.content.Intent; 4 import android.os.Bundle; 5 import android.support.v7.app.AppCompatActivity; 6 import android.webkit.WebSettings; 7 import android.webkit.WebView; 8 import android.webkit.WebViewClient; 9 10 public class Activityweb extends AppCompatActivity { 11 12 private WebView webview; 13 14 @Override 15 protected void onCreate(Bundle savedInstanceState) { 16 super.onCreate(savedInstanceState); 17 setContentView(R.layout.activity_web); 18 19 //获取MainActivity传过来的网址 20 Intent i = getIntent(); 21 String URL = i.getStringExtra("URL"); 22 String description = i.getStringExtra("description"); 23 setTitle(description); 24 25 webview = (WebView) findViewById(R.id.web); 26 //设置WebView属性，能够执行Javascript脚本 27 webview.getSettings().setJavaScriptEnabled(true); 28 //加载需要显示的网页 29 webview.loadUrl(URL); 30 //禁用缓存 31 webview.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE); 32 //设置Web视图,而不是打开系统应用 33 webview.setWebViewClient(new WebViewClient() { 34 @Override 35 public boolean shouldOverrideUrlLoading(WebView view, String url) { 36 view.loadUrl(url); 37 return true; 38 } 39 }); 40 41 } 42 43 }
7.最后不要忘记在AndriodMainfest文件中添加网络权限声明：
<uses-permission android:name="android.permission.INTERNET" />
8.运行截图
