安卓Andriod使用入门(二十五)【爬新闻】

读书多了，容颜自然改变。许多时候，自己可能以为许多看过的书籍都成过眼烟云，不复记忆，其实他们仍是潜在的。在气质里，在谈吐上，在胸襟的无涯。当然，也能显露在生活和文字中。

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MyAdapter.java代码:

package siso.jsoupnews.adapter;


import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;
import siso.jsoupnews.MessageActivity;
import siso.jsoupnews.R;
import siso.jsoupnews.domain.Message;

/*
 * 我的新闻ListView的adapter。
 * */

public class MyAdapter extends BaseAdapter {

private List<Message> messages;//ListView显示的数据

private int resource;//显示列表项的Layout

private LayoutInflater inflater;//界面生成器

private Context context;//


public MyAdapter(List<Message> messages, int resource, Context context) {

this.messages = messages;

this.resource = resource;

this.context = context;

        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }


@Override
public int getCount() {

return messages.size();

    }


@Override
public Object getItem(int arg0) {

return messages.get(arg0);

    }


@Override
public long getItemId(int arg0) {

return arg0;

    }


@Override 
public View getView(int arg0, View arg1, ViewGroup arg2) {

if (arg1 == null) {

            arg1 = inflater.inflate(resource, null);

        }

final Message message = messages.get(arg0);

        ImageView img = (ImageView) arg1.findViewById(R.id.img);

//设置ListView中的Item中的TextView

        img.setImageResource(message.getImg());

//为TextView设置监听器

        img.setOnClickListener(new OnClickListener() {


@Override

public void onClick(View arg0) {

                Toast.makeText(context, message.getImg(), Toast.LENGTH_LONG).show();

            }

        });

        TextView title = (TextView) arg1.findViewById(R.id.title);

        title.setText(message.getTitle());

        title.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// Uri uri = Uri.parse("http://www.baidu.com");
// Intent it = new Intent(Intent.ACTION_VIEW,uri);
// context.startActivity(it);//打开新闻页面
                context.startActivity(new Intent(context, MessageActivity.class).putExtra("url", message.getUrl()));//putExtra("url", message.getUrl()) 将MessageActivity中url 对应替换成message中的url
// Toast.makeText(context, message.getTitle(), Toast.LENGTH_LONG).show();

            }

        });

        TextView points = (TextView) arg1.findViewById(R.id.points);

        points.setText(message.getPoints());

        points.setOnClickListener(new OnClickListener() {


@Override

public void onClick(View arg0) {

                Toast.makeText(context, message.getPoints(), Toast.LENGTH_LONG).show();

            }

        });

        TextView time = (TextView) arg1.findViewById(R.id.time);

        time.setText(message.getTime());

        time.setOnClickListener(new OnClickListener() {


@Override

public void onClick(View arg0) {

                Toast.makeText(context, message.getTime(), Toast.LENGTH_LONG).show();

            }

        });

        TextView comments = (TextView) arg1.findViewById(R.id.comments);

        comments.setText(message.getComments());

        comments.setOnClickListener(new OnClickListener() {


@Override

public void onClick(View arg0) {

                Toast.makeText(context, message.getComments(), Toast.LENGTH_LONG).show();

            }

        });

return arg1;

    }


}

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Message.java代码:

package siso.jsoupnews.domain;

public class Message {

private int img;//goodBarcode
private String title;//goodName 新闻标题
private String points;//goodProvider 新闻点击数
private String time;//新闻发布时间
private String comments;//新闻评论数



private String url;//新闻地址

public int getImg() {
return img;
    }

public void setImg(int img) {
this.img = img;
    }

public String getTitle() {
return title;
    }

public void setTitle(String title) {
this.title = title;
    }


public String getPoints() {
return points;
    }

public void setPoints(String points) {
this.points = points;
    }

public String getComments() {
return comments;
    }

public void setComments(String comments) {
this.comments = comments;
    }

public String getTime() {
return time;
    }

public void setTime(String time) {
this.time = time;
    }
public String getUrl() {
return url;
    }

public void setUrl(String url) {
this.url = url;
    }
public Message(int img, String title, String points, String time, String comments,String url) {

this.img = img;

this.title = title;

this.points = points;

this.time = time;

this.comments = comments;

this.url = url;

    }

}

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MainActivity.java代码:

package siso.jsoupnews;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;


import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import siso.jsoupnews.adapter.MyAdapter;
import siso.jsoupnews.domain.Message;

//jsoup


public class MainActivity extends Activity {
private static final String[] strs2 = new String[30];
private static final String[] link = new String[30];
//定义一个String数组用来显示ListView的内容private ListView lv;/** Called when the activity is first created. */
private ListView listView = null;
private static final int DIALOG_KEY = 0;
private ProgressAsyncTask myTask;
private List<Map<String, String>> messageList = new ArrayList<>();

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//进入页面 加载新闻信息
        myTask = new ProgressAsyncTask();
        myTask.execute();
//点击“更新”按钮时 重新加载新闻信息
        Button sync = (Button) findViewById(R.id.id_btn_sync);
        sync.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
                myTask = new ProgressAsyncTask();
                myTask.execute();
            }
        });
    }

// 弹出"查看"对话框
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DIALOG_KEY: {
                ProgressDialog dialog = new ProgressDialog(this);
                dialog.setMessage("获取数据中 请稍候...");
                dialog.setIndeterminate(true);
                dialog.setCancelable(true);
return dialog;
            }
        }
return null;
    }


    class ProgressAsyncTask extends AsyncTask<Integer, Integer, String> {

        ProgressDialog bar;

public ProgressAsyncTask() {
super();

        }

/**
 * 这里的Integer参数对应AsyncTask中的第一个参数 这里的String返回值对应AsyncTask的第三个参数
 * 该方法并不运行在UI线程当中，主要用于异步操作，所有在该方法中不能对UI当中的空间进行设置和修改
 * 但是可以调用publish Progress方法触发onProgressUpdate对UI进行操作
 */
@Override
protected String doInBackground(Integer... params) {
try {
                Document doc = Jsoup.connect("https://news.ycombinator.com/newest").get();
                Elements athings = doc.select("tr.athing");
                Elements subtexts = doc.select("td.subtext");
int index = 0;
for (Element athing : athings) {
                    Map<String, String> messageMap = new HashMap<>();
                    messageMap.put("rank", athing.getElementsByClass("rank").text());//序号
                    Element title = athing.select("td.title a").first();
                    messageMap.put("title", title.text());//新闻标题
                    messageMap.put("title_href", title.attr("abs:href"));//新闻链接
if (athing.select("td.title a").size()>=2) {
                        Element sitestr = athing.select("td.title a").get(1);
                        messageMap.put("sitestr", sitestr.text());//发表网站
                        messageMap.put("sitestr_href", sitestr.attr("abs:href")); //发表网站链接
                    }

                    Element subtext = subtexts.get(index);
if (null != subtext) {
                        Element score = subtext.select("span.score").first();
                        messageMap.put("points", score.text());//point数
                        Element user = subtext.select("a").first();
                        messageMap.put("user", user.text());//用户
                        messageMap.put("user_href", user.attr("abs:href"));//用户链接
                        Element times = subtext.select("a").get(1);
                        messageMap.put("times", times.text());//发表时间
                        Element comments = subtext.select("a").last();
                        messageMap.put("comments", comments.text());//评论数
                    }
                    index++;
                    messageList.add(messageMap);
                }

            } catch (IOException e) {
                Toast.makeText(MainActivity.this, "" + "检查网络", Toast.LENGTH_SHORT).show();
// TODO Auto-generated catch block
                e.printStackTrace();
            }
return null;
        }

/**
 * 这里的String参数对应AsyncTask中的第三个参数（也就是接收doInBackground的返回值）
 * 在doInBackground方法执行结束之后在运行，并且运行在UI线程当中 可以对UI空间进行设置
 */
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
            bar.dismiss();
// 获得ListView句柄
            listView = (ListView) findViewById(R.id.listView);
final MyAdapter mgs = new MyAdapter(getListData(), R.layout.item, MainActivity.this);

            listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
//int position =Integer.parseInt(arg1.getTag().toString());
                    mgs.getView(arg2, arg1, listView);
                }

            });

            listView.setAdapter(mgs);
        }

/*ListView数据*/
private List<Message> getListData() {
            List<Message> list = new ArrayList<Message>();
for (Map<String, String> messageMap : messageList) {
                Message message = new Message(R.drawable.icon, messageMap.get("rank")+messageMap.get("title"),messageMap.get("points") +" by "+messageMap.get("user"),messageMap.get("times"), messageMap.get("comments"), messageMap.get("title_href"));
                list.add(message);
            }

return list;
        }

// 该方法运行在UI线程当中,并且运行在UI线程当中 可以对UI空间进行设置
@Override
protected void onPreExecute() {
            bar = new ProgressDialog(MainActivity.this);
            bar.setMessage("正在加载数据····");
            bar.setIndeterminate(false);
            bar.setCancelable(false);
            bar.show();
        }

/**
 * 这里的Intege参数对应AsyncTask中的第二个参数
 * 在doInBackground方法当中，，每次调用publishProgress方法都会触发onProgressUpdate执行
 * onProgressUpdate是在UI线程中执行，所有可以对UI空间进行操作
 */
@Override
protected void onProgressUpdate(Integer... values) {
            Log.d("onProgressUpdate", "abc");
        }
    }


@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
    }

//menu操作控制
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
switch (item.getItemId()) {
case R.id.action_about:
                Toast.makeText(MainActivity.this, "" + "关于", Toast.LENGTH_SHORT).show();
break;
case R.id.action_settings:

                Toast.makeText(MainActivity.this, "" + "设置", Toast.LENGTH_SHORT).show();
break;
case R.id.action_quit:

                Toast.makeText(MainActivity.this, "" + "退出", Toast.LENGTH_SHORT).show();
break;
default:
break;
        }
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
        }

return super.onOptionsItemSelected(item);
    }

//格式化输出 当标题长度超过width时 截取前width个字
private static String trim(String s, int width) {
if (s.length() > width)
return s.substring(0, width - 1) + "..";
else
return s;
    }
}

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MessageActivity.java代码:

package siso.jsoupnews;

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MessageActivity extends Activity {
private WebView webView;
private  String url;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_message);
        webView = (WebView) findViewById(R.id.webview);
        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);//设置可读取JavaScript网页
        webSettings.setAllowFileAccess(true);//可读取文件
        webSettings.setBuiltInZoomControls(true);
// webView.loadUrl("http://blog.csdn.net/qq_29407877");//要跳转的网页地址
        url=getIntent().getStringExtra("url");
        webView.loadUrl(url);//要跳转的网页地址
        webView.setWebViewClient(new WebViewClient());
    }

private class webViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
return true;
        }
    }
}

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activity_main.xml内容:

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/listView"
        android:layout_centerHorizontal="true"
        android:textColor="@drawable/itemcolor"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="更新"
        android:id="@+id/id_btn_sync"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_above="@id/listView"/>
</RelativeLayout>

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activity_message.xml内容:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:orientation="vertical">
<WebView
 android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/webview">

</WebView>
</LinearLayout>

---

item.xml内容:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="50dp"
android:paddingLeft="2dp" android:paddingRight="2dp">
<ImageView
 android:id="@+id/img"
android:layout_height="fill_parent"
android:layout_width="20dp"
android:layout_alignParentLeft="true" />
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_height="fill_parent"
android:layout_width="fill_parent" android:layout_toRightOf="@id/img"
android:paddingLeft="2dp">
<TextView
 android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#000000"
android:textSize="18dp" />
<RelativeLayout
 android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
 android:id="@+id/points"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#cbcaca"
android:paddingRight="5dp"
android:textSize="14dp"
android:clickable="true"
 />
<TextView
 android:id="@+id/time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#cbcaca"
android:textSize="12dp"
android:clickable="true"
android:layout_toRightOf="@id/points"/>
<TextView
 android:id="@+id/padding"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#cbcaca"
android:textSize="12dp"
android:text=" | "
android:layout_toRightOf="@id/time"/>
<TextView
 android:id="@+id/comments"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#cbcaca"
android:textSize="12dp"
android:paddingLeft="5dp"
android:clickable="true"
android:layout_toRightOf="@id/padding"/>

</RelativeLayout>

</LinearLayout>
<!--<CheckBox-->
<!--android:id="@+id/checked"-->
<!--android:layout_height="fill_parent"-->
<!--android:layout_width="wrap_content"-->
<!--android:layout_alignParentRight="true"-->
<!--android:checked="false"-->
<!--android:focusable="false" />-->
</RelativeLayout>

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AndroidManifest.xml内容:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="siso.jsoupnews">

<uses-permission android:name="android.permission.INTERNET"/><!--获取网络权限-->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/><!--获 取网络状态权限-->
<application
 android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MessageActivity"></activity>
<activity
 android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN"
android:exported="true"/>

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- <meta-data android:name="com.google.android.backup.api_key"
 android:value="" />-->
</application>

</manifest>

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运行结果如图:

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