csv 导出Excel

Posted 2022-12-07 TT_DUL

import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;

import javax.servlet.http.HttpServletResponse;

public class A
public void exportToCSV(HttpServletResponse response)

    response.setContentType("application/csv;charset=gb18030");
    response.setHeader("Content-Disposition","attachment; filename=\\"" + "数据导出" + ".csv" + "\\"");
    PrintWriter print = null;
    print = response.getWriter();

    StringBuilder buffer = new StringBuilder(500);
    Connection conn = getConnection();
    PreparedStatement st =null;
    ResultSet rs=null;

    buffer.setLength(0);
    buffer.append("select id,name,password from users");

    try 
        st = conn.prepareStatement(buffer.toString());
        rs=st.executeQuery();
        ResultSetMetaData rsMetaData = rs.getMetaData();
        int colCou = rsMetaData.getColumnCount(); //计算查询出来结果的列数，本次查询查出3列
        StringBuffer linedata = new StringBuffer();
        int rscount = 0;

        linedata.append("ID");
        linedata.append(",");
        linedata.append("用户名称");
        linedata.append(",");
        linedata.append("用户密码");
        linedata.append("\\n");

        while (rs.next()) 
            rscount++;
            for (int i = 1; i <= colCou; i++) 
                linedata.append(rs.getString(i));

                if (i != colCou) 
                    linedata.append(",");
                

            
            linedata.append("\\n");
            if (rscount % 5000 == 0)  //每5000条写一次
                print.write(linedata.toString());
                linedata.setLength(0);
            
        
        if (linedata.length() > 0) 
            print.write(linedata.toString());
        

        rs.close();
        st.close();
    
    catch (Exception ex) 
        ex.printStackTrace();
    
    finally 
            try 
                if (rs != null)
                    rs.close();
                if (st != null)
                    st.close();
                if (conn != null)
                    conn.close();
                if (print != null)
                    print.close();
            
            catch (SQLException e) 
                e.printStackTrace();
            
    
    return;