进度九（10.27）

今天完成了多条件查询的后台代码。

package servlet;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import dao.SelectDao;
import bean.Table;

@WebServlet("/SelectServlet")
public class SelectServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    public SelectServlet() {
        super();
        // TODO Auto-generated constructor stub
    }
    
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        
        String[] yhf;
        yhf=request.getParameterValues("yhf");
        String[] name;
        name=request.getParameterValues("name");
        String[] value;
        value=request.getParameterValues("value");
        String[] jingmo;
        jingmo=request.getParameterValues("jingmo");
        
        List<Table> table = SelectDao.getTable(yhf, name, value, jingmo, yhf.length);
               
        request.setAttribute("table", table);
        request.getRequestDispatcher("admin/alltable.jsp").forward(request,response);
        
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

package dao;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import bean.Table;
import util.DBUtil;

public class SelectDao {
    
    public static List<Table> getTable(String yhf[],String name[],String value[],String jingmo[],int length) {
        
        System.out.println(Arrays.toString(yhf));
        System.out.println(Arrays.toString(name));
        System.out.println(Arrays.toString(value));
        System.out.println(Arrays.toString(jingmo));
        
        String sql = "select * from t_table where ";
        
        if(yhf[0].equals("binghan")) {
            
            if(jingmo[0].equals("jingque")) {                
                sql +=name[0]+" = '"+value[0]+"'";
            }
            
            else if(jingmo[0].equals("mohu")) {                
                sql = sql + name[0]+" like '%"+value[0]+"%'";
            }
            System.out.println("1:"+sql);
        }
        
        if(yhf[0].equals("buhan")) {
            
            if(jingmo[0].equals("jingque")) {
                sql = sql + "not " + name[0]+" = '"+value[0]+"'";
            }
            
            else if(jingmo[0].equals("mohu")) {
                sql = sql + "not " + name[0]+" like '%"+value[0]+"%'";
            }
            System.out.println("2:"+sql);
        }                                
        
        for(int i=1;i<length;i++) {
            
            if(yhf[i].equals("binghan")) {
                   
                if(jingmo[i].equals("jingque")) {
                    sql = sql + " and "+name[i]+" = '"+value[i]+"'";
                }
                
                else if(jingmo[i].equals("mohu")) {
                    sql = sql + " and "+name[i]+" like '%"+value[i]+"%'";
                }
                
                else if(jingmo[i].equals("null")) {
                    break;
                }
                
                System.out.println("3:"+sql);
            }
            
            else if(yhf[i].equals("huohan")) {
                
                if(jingmo[i].equals("jingque")) {
                    sql = sql + " or "+name[i]+" = '"+value[i]+"'";
                }
                
                else if(jingmo[i].equals("mohu")) {
                    sql = sql + " or "+name[i]+" like '%"+value[i]+"%'";
                }
                
                else if(jingmo[i].equals("null")) {
                    break;
                }
                
                System.out.println("4:"+sql);
                
            }
            
            else if(yhf[i].equals("buhan")) {
                
                if(jingmo[i].equals("jingque")) {
                    sql = sql + " not "+name[i]+" = '"+value[i]+"'";
                }
                
                else if(jingmo[i].equals("mohu")) {
                    sql = sql + " not "+name[i]+" like '%"+value[i]+"%'";
                }
                
                else if(jingmo[i].equals("null")) {
                    break;
                }
                
                System.out.println("5:"+sql);
                
            }
            
        }

        System.out.println("6:"+sql);
        
        
        List<Table> list = new ArrayList<>();
        Connection conn = DBUtil.getConnection();
        Statement state = null;
        ResultSet rs = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                Table table = new Table();
                
                int wjid = rs.getInt("wjid");
                String jsxqmc = rs.getString("jsxqmc");
                String jgqc = rs.getString("jgqc");
                String gkglbm = rs.getString("gkglbm");
                String szdy = rs.getString("szdy");
                String frdb = rs.getString("frdb");
                String lxr = rs.getString("lxr");
                String jgsx = rs.getString("jgsx");
                int ntrjeze = rs.getInt("ntrjeze");            
                String jsxqjjfs = rs.getString("jsxqjjfs");                
                String kjhdlx = rs.getString("kjhdlx");                                        
                String xkfl = rs.getString("xkfl");            
                String xqjsssly = rs.getString("xqjsssly");
                String xqjsyyhy = rs.getString("xqjsyyhy");
                String glcs = rs.getString("glcs");
                String xssh = rs.getString("xssh");
                String bmsh = rs.getString("bmsh");
                
                table.setWjid(wjid);
                table.setJsxqmc(jsxqmc);
                table.setJsxqjjfs(jsxqjjfs);
                table.setKjhdlx(kjhdlx);
                table.setGkglbm(gkglbm);
                table.setJgqc(jgqc);
                table.setLxr(lxr);
                table.setSzdy(szdy);
                table.setFrdb(frdb);
                table.setJgsx(jgsx);
                table.setNtrjeze(ntrjeze);
                table.setXkfl(xkfl);
                table.setXqjsssly(xqjsssly);
                table.setXqjsyyhy(xqjsyyhy);
                table.setGlcs(glcs);
                table.setXssh(xssh);
                table.setBmsh(bmsh);

                list.add(table);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }        
        return list;
    }

}

servlet层将前台收到的"yhf" "name" "value" "jingmo"的值传到dao层。

String sql = "select * from t_table where ";
        
        if(yhf[0].equals("binghan")) {
            
            if(jingmo[0].equals("jingque")) {                
                sql +=name[0]+" = '"+value[0]+"'";
            }
            
            else if(jingmo[0].equals("mohu")) {                
                sql = sql + name[0]+" like '%"+value[0]+"%'";
            }
            System.out.println("1:"+sql);
        }
        
        if(yhf[0].equals("buhan")) {
            
            if(jingmo[0].equals("jingque")) {
                sql = sql + "not " + name[0]+" = '"+value[0]+"'";
            }
            
            else if(jingmo[0].equals("mohu")) {
                sql = sql + "not " + name[0]+" like '%"+value[0]+"%'";
            }
            System.out.println("2:"+sql);
        }                                
        
        for(int i=1;i<length;i++) {
            
            if(yhf[i].equals("binghan")) {
                   
                if(jingmo[i].equals("jingque")) {
                    sql = sql + " and "+name[i]+" = '"+value[i]+"'";
                }
                
                else if(jingmo[i].equals("mohu")) {
                    sql = sql + " and "+name[i]+" like '%"+value[i]+"%'";
                }
                
                else if(jingmo[i].equals("null")) {
                    break;
                }
                
                System.out.println("3:"+sql);
            }
            
            else if(yhf[i].equals("huohan")) {
                
                if(jingmo[i].equals("jingque")) {
                    sql = sql + " or "+name[i]+" = '"+value[i]+"'";
                }
                
                else if(jingmo[i].equals("mohu")) {
                    sql = sql + " or "+name[i]+" like '%"+value[i]+"%'";
                }
                
                else if(jingmo[i].equals("null")) {
                    break;
                }
                
                System.out.println("4:"+sql);
                
            }
            
            else if(yhf[i].equals("buhan")) {
                
                if(jingmo[i].equals("jingque")) {
                    sql = sql + " not "+name[i]+" = '"+value[i]+"'";
                }
                
                else if(jingmo[i].equals("mohu")) {
                    sql = sql + " not "+name[i]+" like '%"+value[i]+"%'";
                }
                
                else if(jingmo[i].equals("null")) {
                    break;
                }
                
                System.out.println("5:"+sql);
                
            }
            
        }

dao层将接受到的数组的数据通过if语句拼装成一个完整的sql语句。

例如：

select * from t_table where jgqc = '石家庄铁道大学' or lxr like '%安振%'