2021 6 3

顶会热词后端dao层：

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import bean.keyword;
import bean.paper;
public class dao {
    public Connection getConnection()
    {
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        String url = "jdbc:mysql://localhost:3306/paper?serverTimezone=GMT%2B8";
        String username = "root";
        String password="123456";
        Connection a=null;
        try {
            a = DriverManager.getConnection(url,username,password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return a;
    }
    public List<paper>getallpaper() throws NumberFormatException, SQLException//获取所有论文数据
    {
        List<paper> list=new ArrayList<paper>();
        Connection coon=getConnection();
        String sql="select* from pypaper";
        PreparedStatement pa=coon.prepareStatement(sql);
        ResultSet rs=pa.executeQuery(sql);
        while(rs.next())
        {
                paper p;
                try {
                    p = new paper(Integer.parseInt(rs.getString("id")),rs.getString("name"),rs.getString("herf"),rs.getString("writer"),rs.getString("Abstract"),rs.getString("time"),rs.getString("keywords"));
                    list.add(p);
                } catch (SQLException e) {
                    // TODO 自动生成的 catch 块
                    e.printStackTrace();
                }
        }
        rs.close();
        pa.cancel();
        coon.close();
        return list;
    }
    public List<paper>findpaper(String id,String name,String writer,String time,String keyword) throws SQLException//模糊查询论文
    {
        List<paper> list=new ArrayList<paper>();
        Connection coon=getConnection();
        String sql="select * from pypaper";
        //拼接模糊查询sql语句
        if(id.length()>0) sql=sql+" where id = '"+id+"'";
        if(name.length()>0&&sql.length()>21) sql=sql+" and name like '%"+name+"%'";
        if(name.length()>0&&sql.length()==21) sql=sql+" where name like '%"+name+"%'";
        if(writer.length()>0&&sql.length()>21) sql=sql+" and writer like '%"+writer+"%'";
        if(writer.length()>0&&sql.length()==21) sql=sql+" where writer like '%"+writer+"%'";
        if(time.length()>0&&sql.length()>21) sql=sql+" and time like '%"+time+"%'";
        if(time.length()>0&&sql.length()==21) sql=sql+" where time like '%"+time+"%'";
        if(keyword.length()>0&&sql.length()>21) sql=sql+" and keywords like '%"+keyword+"%'";
        if(keyword.length()>0&&sql.length()==21) sql=sql+" where keywords like '%"+keyword+"%'";
        //System.out.println(sql);
        PreparedStatement pa=coon.prepareStatement(sql);
        ResultSet rs=pa.executeQuery(sql);
        while(rs.next())
        {
                paper p;
                try {
                    p = new paper(Integer.parseInt(rs.getString("id")),rs.getString("name"),rs.getString("herf"),rs.getString("writer"),rs.getString("Abstract"),rs.getString("time"),rs.getString("keywords"));
                    list.add(p);
                } catch (SQLException e) {
                    // TODO 自动生成的 catch 块
                    e.printStackTrace();
                }
        }
        rs.close();
        pa.cancel();
        coon.close();
        return list;
    }
    public List<keyword>getkey(String id,String name,String writer,String time,String keyword) throws SQLException//获取关键词
    {
        List<keyword> list=new ArrayList<keyword>();
        Connection coon=getConnection();
        String sql="select* from pypaper";
        if(id.length()>0) sql=sql+" where id = '"+id+"'";
        if(name.length()>0&&sql.length()>21) sql=sql+" and name like '%"+name+"%'";
        if(name.length()>0&&sql.length()==21) sql=sql+" where name like '%"+name+"%'";
        if(writer.length()>0&&sql.length()>21) sql=sql+" and writer like '%"+writer+"%'";
        if(writer.length()>0&&sql.length()==21) sql=sql+" where writer like '%"+writer+"%'";
        if(time.length()>0&&sql.length()>21) sql=sql+" and time like '%"+time+"%'";
        if(time.length()>0&&sql.length()==21) sql=sql+" where time like '%"+time+"%'";
        if(keyword.length()>0&&sql.length()>21) sql=sql+" and keywords like '%"+keyword+"%'";
        if(keyword.length()>0&&sql.length()==21) sql=sql+" where keywords like '%"+keyword+"%'";
        PreparedStatement pa=coon.prepareStatement(sql);
        ResultSet rs=pa.executeQuery(sql);
        String TEMP="";
        while(rs.next())
        {
            TEMP+=rs.getString("keywords").replace('+', ' ');
        }
        int P=30;
        TEMP=TEMP.replace('+', ' ');//将关键词字符串的+替换为空格
        list=countToEng(TEMP);//对热词排序并生成keyword的list对象
        return list;
    }
    // 统计英文单词
            public List<keyword> countToEng(String str) {//生成keyword的list对象
                List<keyword> arraykey=new ArrayList<keyword>();
                // 定义返回数组
                String[] re_str = new String[30];
                // 定义ArrayList对象存储匹配到的单词
                ArrayList<String> array = new ArrayList<>();
                // 使用正则获取单词
                Pattern pattern = Pattern.compile("\b[\w+\-']+\b");
                Matcher matcher = pattern.matcher(str);
                while (matcher.find()) {
                    array.add(matcher.group());
                }
                // 定义Map集合存储单词，键为单词不重复，值为统计的数量
                TreeMap<String, Integer> map = new TreeMap<String, Integer>();
                // 遍历字符数组，获取到每一个字符
                for (String tstr : array) {
                    // 用每一个字符作为键，在TreeMap中查找
                    Integer val = map.get(tstr);
                    if (val == null) {
                        // 返回null，则不存在，存储1
                        map.put(tstr, 1);
                        //System.out.println("不存在："+tstr);
                    } else {
                        // 返回非null，则把值加1，重新存储
                        val++;
                        map.put(tstr, val);
                    }
                }
//                // 获取键值对的Set集合
                Set<Map.Entry<String, Integer>> sme = map.entrySet();
                // 遍历拼接
                for (Map.Entry<String, Integer> me : sme) {
                    keyword k=new keyword();
                    k.setName(me.getKey());
                    k.setValue(me.getValue());
                    arraykey.add(k);
                }
                arraykey=maopao(arraykey);//排序
                return arraykey;
            }
            public List<keyword> maopao(List<keyword> arr)//冒泡排序
            {
                for(int i=0;i<arr.size()-1;i++)
                {
                    int a=i;
                    keyword max=arr.get(i);
                    for(int j=i+1;j<arr.size();j++)
                    {
                        if(max.getValue()<arr.get(j).getValue())
                        {    
                            a=j;
                            max=arr.get(j);
                        }
                    }
                    arr.set(a, arr.get(i));
                    arr.set(i, max);
                    if(i==arr.size()-10)  break;
                }
                return arr;
            }
}