Jsoup抓取数据实现为一个网站做第三方Android客户端

一前言

学Android有很大一部分的乐趣其实就是做出一个网站客户端，比官方广告少，速度快，不臃肿，受到众多网友追捧。

由于学校图书馆网站没有APP，网站也没有移动版的，所以说体验相当差，用的实在是太烦就做了这个小应用，先下看下效果。

二Jsoup实现抓取书名

Jsoup是一个Java的一个工具包，百度一搜一大堆，不对Jsoup做过多介绍，先来看看对http://222.188.3.137:8080/opac/search.php的抓取。

这里抓取到数据只要往适配器里填充数据就好了。

 1 package com.wyf.newlibrary;
 2 
 3 import org.jsoup.Jsoup;
 4 import org.jsoup.nodes.Document;
 5 import org.jsoup.nodes.Element;
 6 import org.jsoup.select.Elements;
 7 
 8 import java.io.IOException;
 9 
10 public class BookNameJsoup {
11     String url;
12 
13     String[] bName;
14     String[] bLink;
15     String nextPage;
16 
17     public BookNameJsoup(String  link) {
18 
19         url = link;
20         bName = new String[20];
21         bLink = new String[20];
22 
23     }
24 
25     public void init() {
26         try {
27             Document doc = Jsoup.connect(url).get();
28             int j = 0;
29             Elements bookName = doc.getElementsByTag("h3").select("a");
30             for (Element i : bookName) {
31                 bName[j] = i.text().trim();
32                 bLink[j++] = i.attr("abs:href");
33             }
34 
35             Elements next=doc.getElementsByAttributeValue("class", "blue");
36         for(Element i:next)
37         {
38             if(i.text().contains("下一页"))
39             {
40                 nextPage=i.attr("abs:href");
41                 break;
42             }
43 
44         }
45             
46         } catch (IOException e) {
47             // TODO Auto-generated catch block
48             e.printStackTrace();
49         }
50     }
51 
52     /***************
53      * 得到LINK
54      ********************/
55     public String[] getBookName() {
56         return bName;
57     }
58 
59 
60 
61     /*******************
62      * 得到LINK
63      ******************************/
64 
65     public String[] getLink() {
66         return bLink;
67     }
68 
69 
70     public  String getNextPage()
71     {
72         return  nextPage;
73     }
74 
75 
76     /***
77      * 判断搜索结果是否为空
78      */
79 
80     
81     }

三 MainActivity(书名列表界面)

在MainActivity中有一个ListView，在用Jsoup抓取到的数据往里面填充，ListView只用极其简单的布局，一看就能明白。

package com.wyf.newlibrary;

import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import com.umeng.analytics.MobclickAgent;
import com.umeng.update.UmengUpdateAgent;

import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;


public class MainActivity extends AppCompatActivity  {


    EditText edit_search;
    String url="我去",key;
    ListView list_bookname;
    ArrayList<String> bookName;  //得到的书名
    ArrayList<String> bookLink;   //书名链接
    ArrayAdapter adapter;
    GetBookName get;
    View foot,complete,fail;
    ProgressBar progressBar;
    boolean firstLoad=false;
    ImageButton ibtn_clear;


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

        init();
        initEvent();
        list_bookname.setAdapter(adapter);



    }

    private void initEvent() {
        
        edit_search.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {

                if(actionId== EditorInfo.IME_ACTION_SEARCH)
                 {
                     url=edit_search.getText().toString().trim();
                     try {
                         url= URLEncoder.encode(url,"UTF-8");
                     } catch (UnsupportedEncodingException e) {
                         e.printStackTrace();
                     }
                     bookName.clear();
                     bookLink.clear();
                     boolean  loadNothing=true;
                     if(url!=null)
                     {
                         firstLoad=true;
                         new GetBookName(url).execute();
                     }
                     else{
                         Toast.makeText(MainActivity.this, "不能为空", Toast.LENGTH_SHORT).show();
                     }



                 }

                return false;
            }
        });

        list_bookname.setOnScrollListener(new AbsListView.OnScrollListener() {
            //AbsListView view 这个view对象就是listview
            int lastItem;
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
                if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
                    if (view.getLastVisiblePosition() == view.getCount() - 1) {
                        if(url!=null)
                        {
                            list_bookname.addFooterView(foot);
                            new GetBookName().execute();
                        }

                        else if(bookName.isEmpty()){
                            list_bookname.addFooterView(fail);

                        }
                        else {
                            list_bookname.addFooterView(complete);
                        }


                    }
                }
            }
            @Override
            public void onScroll(AbsListView view, int firstVisibleItem,
                                 int visibleItemCount, int totalItemCount) {
                lastItem = firstVisibleItem + visibleItemCount - 1 ;
            }
        });
/*************************************ListView每个Item设置监听，转到这本书具体信息的Activity*************************************************/
        list_bookname.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent=new Intent(MainActivity.this,BookInfoActivity.class);
                intent.putExtra("href",bookLink.get(position));
                startActivity(intent);

            }
        });
    }


    private void init() {

       // ibtn_clear= (ImageButton) findViewById(R.id.ibtn_clear);
        edit_search= (EditText) findViewById(R.id.edit_search);
        list_bookname= (ListView)findViewById(R.id.list_bookname);
        bookName=new ArrayList<String>();
        bookLink=new ArrayList<String>();
        adapter=new ArrayAdapter(MainActivity.this,android.R.layout.simple_list_item_1,bookName);
        foot= LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_foot,null);
        fail= LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_fail,null);
        complete= LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_complete,null);
        progressBar= (ProgressBar) findViewById(R.id.progressBar);

        UmengUpdateAgent.update(this);

    }


    /***
     * 获取图书馆书名数据
     */
    class GetBookName extends AsyncTask {

        BookNameJsoup jsoup;
        URL href;


        public GetBookName(String keyword)  {
            super();
            url="http://222.188.3.137:8080/opac/openlink.php?strSearchType=title&match_flag=forward&historyCount=1&strText="+keyword+
                    "&doctype=ALL&with_ebook=on&displaypg=20&showmode=list&sort=CATA_DATE&orderby=desc&dept=ALL&page=1";

            try {
              href=new URL(url);
                url=href.toString();

            } catch (MalformedURLException e) {
                e.printStackTrace();
            }


        }
        public GetBookName()
        {
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            Log.d("TAG", "onPreExecute: "+url);
            if(firstLoad)
            {
                progressBar.setVisibility(View.VISIBLE);
                firstLoad=false;
            }

        }

        @Override
        protected Object doInBackground(Object[] params) {

            jsoup=new BookNameJsoup(url);
            jsoup.init();
            return null;
        }



        @Override
        protected void onPostExecute(Object o) {
            super.onPostExecute(o);
            progressBar.setVisibility(View.GONE);

                String[] book = jsoup.getBookName();
                String[] link = jsoup.getLink();

                for (int i = 0; i < 20; i++) {
                    if (book[i] != null) {
                        bookName.add(book[i]);
                        Log.d("TAG", "onPostExecute: " + book[i]);
                    } else {
                        break;
                    }
                    if (link != null) {
                        bookLink.add(link[i]);
                    }
                }
                if(bookName.isEmpty())
                {
                    list_bookname.addFooterView(fail);
                }else {
                    list_bookname.removeFooterView(fail);
                }

                url = jsoup.getNextPage();
                list_bookname.removeFooterView(foot);
                adapter.notifyDataSetChanged();
        }
    }

   

}

四  书的详细信息

这里展现的是书的信息。如图

package com.wyf.newlibrary;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.ScrollView;
import android.widget.TextView;

import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.umeng.analytics.MobclickAgent;

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

import java.io.UnsupportedEncodingException;

public class BookInfoActivity extends AppCompatActivity {

    TextView text_bookName,text_douban,text_position;
    ImageView image_logo;
    String url,logoUrl;
    ScrollView scrollView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_book_info);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        setTitle("图书信息");
        url=getIntent().getStringExtra("href");

        init();

        RequestQueue queue= Volley.newRequestQueue(BookInfoActivity.this);
        StringRequest stringRequest=new StringRequest(url, new Response.Listener<String>() {
            @Override
            public void onResponse(String s) {
                try {
                    s=new String(s.getBytes("ISO-8859-1"),"utf-8");
                   // Toast.makeText(BookInfoActivity.this, s, Toast.LENGTH_SHORT).show();
                    new  GetDetail(s).execute();
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError volleyError) {
                Log.d("TAG", "onErrorResponse: "+"i fail");
            }
        });
        queue.add(stringRequest);

    }


    private void init() {
        text_bookName= (TextView) findViewById(R.id.text_bookname);
        text_douban= (TextView) findViewById(R.id.text_douban);
        text_position= (TextView) findViewById(R.id.text_position);
         scrollView= (ScrollView) findViewById(R.id.scroll_position);

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        if(item.getItemId()==android.R.id.home)
        {
            finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }


/*****************异步请求拿到数据**********************/
    class GetDetail extends AsyncTask{
        String response,name,douBan="110",position="图书位置：
";

        public GetDetail(String response) {
            super();
            this.response=response;
        }

        @Override
        protected Object doInBackground(Object[] params) {
            Document doc= Jsoup.parse(response);
             name=doc.getElementsByAttributeValue("class","booklist").first().text();
             name=name.substring(name.indexOf(":")+1);
          //  douBan=doc.getElementsByAttributeValue("id","douban_content").select("p").text();

            Elements a=doc.select("dl.booklist");
            String temp;
            for(Element i:a)
            {

                System.out.println(i.lastElementSibling().text());
                if(i.text().contains("提要文摘附注")&&i.text().length()>8)
                {
                    temp=i.text();

                   douBan=temp;

                }
            }

            //douBan=doc.select("intro").text();
             logoUrl=doc.select("img#book_img").attr("src");
             Elements posi=doc.getElementsByAttributeValue("align","left");
            posi=posi.select("tr.whitetext");


             for(Element i:posi)
             {
                 if(i.text()!=null)
                 {
                     //temp=i.text();
                    // temp=temp.substring(0,temp.indexOf(' '))+temp.substring(temp.indexOf("-"));
                     //Log.d("TAG", "doInBackground: "+temp);
                     position+=i.text()+"
";

                 }

             }
            return null;
        }

        @Override
        protected void onPostExecute(Object o) {
            super.onPostExecute(o);
            text_bookName.setText(name);
            text_douban.setText(douBan);
            text_position.setText(position);

            if(douBan.equals("110"))
            {
                text_douban.setVisibility(View.GONE);
            }

            scrollView.setVisibility(View.VISIBLE);

        }
    }

  

}

五  总结

这个Demo其实并不难，很容易理解，但要对Jsoup和异步请求有所了解。你也可以做出自己第三方客户端。

附上源码http://pan.baidu.com/s/1c1B1VIo

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原文地址：https://www.cnblogs.com/dadafeige/p/5419896.html