How to make unique record query

Question

How to make unique record query

Asked 7 years, 3 months ago

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I have a JSP that on the same screen I register for consultation. When opening the screen I have basically the fields for the registration below a grid with the list of the bank, so far so good, working. As soon as I open the screen, the database data is brought.

My problem is when I need to check a log. I have DAO working, but soon after running the DAO that brings the record I want, due to the fact that I do not know @Requestmapping setup, the page loads all the data again.

Page jsp:

<!DOCTYPE html>
<html lang="br">
<head>
    <%@ include file="/WEB-INF/views/tags/head.jsp"%>
</head>
<body>
    <%@ include file="/WEB-INF/views/tags/header.jsp"%>

    <div id="body">
        <div id="content">
            <div class="container-fluid" id="dashboard">
                <div class="row-fluid">
                    <div class="span9">
                        <div class="page-header">
                            <h1>Cadastro de Fundos</h1>
                        </div>
                        <form class="form-horizontal form-container" method="post" action="${pageContext.request.contextPath}/FundoServlet">
                            <input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}" />
                            <fieldset>
                                <div class="control-group" style="vertical-align: middle;">
                                    <label for="fundoid" class="control-label">Código</label>
                                    <div class="controls">
                                        <input type="text" id="fundoid" name="fundoid" class="input-xlarge" value="${Fundos.id}" maxlength="3" size="3">
                                        <input type="hidden" id="action" name="action" />
                                    </div>
                                </div>
                                <div class="control-group" style="vertical-align: middle;">
                                    <label for="fundoDescr" class="control-label">Descrição</label>
                                    <div class="controls">
                                        <input name="fundoDescr" autofocus="autofocus" value="${Fundos.fundoDescr}" />
                                        <input type="hidden" id="action" name="action" />
                                    </div>
                                </div>
                                <div class="control-group" style="vertical-align: middle;">
                                    <label for="enviar" class="control-label">Ação</label>
                                    <div class="controls">
                                        <select name="acao" required>
                                            <option selected value="Incluir">Incluir</option>
                                            <option value="Alterar">Alterar</option>
                                            <option value="Excluir">Excluir</option>
                                            <option value="Consultar">Consultar</option>
                                        </select>

                                        <input type="submit" id="enviar" name="enviar" value="Enviar">
                                        <input type="reset" id="limpar" name="limpar" value="Limpar">
                                    </div>
                                </div>
                            </fieldset>
                        </form>

                        <table id="dataTable" class="table table-bordered table-striped">
                            <thead>
                                <tr>
                                    <th style="width: 90px">Código<i class="sort"></i></th> 
                                    <th style="width: 90px">Descrição<i class="sort"></i></th>
                                    <th></th>
                                </tr>
                            </thead>
                            <tbody>
                                <c:forEach var="fundos" items="${fundos}">
                                    <tr>
                                        <td><c:out value="${fundos.id}" /></td> 
                                        <td><c:out value="${fundos.fundoDescr}" /></td>
                                    </tr>
                                </c:forEach>
                            </tbody>
                        </table>

                    </div>
                </div>
            </div>
        </div>
    </div>

    <%@ include file="/WEB-INF/views/tags/footer.jsp"%>
</body>
</html>

Class Fundoscontroller:

import java.sql.SQLException;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class FundosController {

    @Autowired
    private FundosServices fundosServices;

    @RequestMapping(path = "/monitor/fundos")
    public String listar(HttpServletRequest request) {
        final List<Fundos> fundos = fundosServices.findAll();
        request.getSession().setAttribute("fundos", fundos);

        return "/monitor/fundos";
    }

    @RequestMapping(value="/monitor/fundos/{id}", method = RequestMethod.GET)
    public String findById(HttpServletRequest request, @PathVariable("id") long id) throws SQLException {
        final Fundos fundos = fundosServices.findById(id);
        request.getSession().setAttribute("fundos", fundos);

        return "/monitor/fundos/{id}";
    }
}

Class Fundosservices:

import java.sql.SQLException;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
@Transactional
public class FundosServices {

    @Autowired
    FundosDAO fundosDao;

    public List<Fundos> findAll() {
        return this.fundosDao.listar();
    }

    public Fundos findById(long id) {
        Fundos retorno = null;
        try {
            retorno = this.fundosDao.findById(id);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return retorno;
    }
}

Fundoservlet class:

import java.io.IOException;

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

@WebServlet("/FundoServlet")
public class FundoServlet extends HttpServlet {

    private static final long serialVersionUID = 7159377112218914143L;


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String acao = request.getParameter("acao");
        String destino = "/monitor/fundos";

        Fundos fundo = new Fundos();
        FundosDAO fundosDao = new FundosDAO();

        try {

            if (acao.equalsIgnoreCase("Excluir")) {
                fundo.setId(Integer.parseInt(request.getParameter("fundoid")));
                fundosDao.deleteFundo(fundo);
            } else if (acao.equalsIgnoreCase("Incluir")) {
                fundo.setFundoDescr(request.getParameter("fundoDescr"));
                fundosDao.inserir(fundo);
            } else if (acao.equalsIgnoreCase("Consultar")) {
                fundo = fundosDao.findById(Integer.parseInt(request.getParameter("fundoid")));
                destino = "/monitor/fundos/15";
            }

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

        RequestDispatcher rd = request.getRequestDispatcher(destino);
        rd.forward(request, response);
    }
}

Class Fundosdao:

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.stereotype.Repository;

@Repository
public class FundosDAO extends GenericDAO<Integer, Fundos> {

    @PersistenceContext
    private EntityManager manager;

    public List<Fundos> listar() {
        final List<Fundos> retorno = manager.createQuery("select fundos from Fundos fundos", Fundos.class).getResultList();

        return retorno;
    }

    public Fundos findById(long id) throws SQLException {
        Connection conn = ConnectionFactory.getConnection();
        PreparedStatement pstm = conn.prepareStatement("SELECT FUNDO_DESCR FROM TTCMT_FUNDOS WHERE FUNDO_ID = ?");
        pstm.setFloat(1, id);
        ResultSet rs = pstm.executeQuery();
        Fundos fundos = new Fundos();
        while (rs.next()) {
            fundos.setId(id);
            fundos.setFundoDescr(rs.getString("FUNDO_DESCR"));
        }
       rs.close();
       return fundos;
    }

    public void inserir(Fundos fundo) {
        try {
            Connection conexao = getConexao();
            PreparedStatement pstm = conexao.prepareStatement("INSERT INTO TTCMT_FUNDOS (FUNDO_DESCR) values (?)");
            pstm.setString(1, fundo.getFundoDescr());
            pstm.execute();
            pstm.close();
            conexao.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void deleteFundo(Fundos fundo) throws SQLException {
        Connection conexao = getConexao();
        String sql = "DELETE FROM TTCMT_FUNDOS WHERE FUNDO_ID = ?";
        PreparedStatement pstm = conexao.prepareStatement(sql);
        pstm.setLong(1, fundo.getId());
        pstm.execute();
        pstm.close();
    }
}

2 answers

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by Giuliana Bezerra • **3,707** points · Answer 1 · 2017-08-18T13:43:51+00:00

The problem is the scope of the bean you are using, which when undeclared is Singleton. This scope loses the information saved at each request. If you change the scope for Session, for example, the data will no longer be loaded at each request, which is the behavior you want. It would be something like:

@Controller
@Scope("session") // Aqui adiciona o escopo
public class FundosController {
   [...]
}

To learn more about the available scopes, I recommend this link.

by leopcx • 1 point · Answer 2 · 2018-01-19T15:20:44+00:00

-2

creates a Dao method with the sql string like this:

String sql = "select * from <nome da tabela> where <coluna a pesquisar> = ? ;

String sql = "select * from <table name>Where <id>= ? ;

– leopcx

2018/01/19 at 15:21
public List <Table> Buscarporum(Int id1){ String sql = "select * from <table name> Where id= ? //CONSTROE PREPAREDSTATEMENT COM SQL Preparedstatement preparer; List <Table> list = new Arraylist<Table>(); Try { preparer = con.prepareStatement(sql); setInt preparer(1,id1);

– leopcx

2018/01/19 at 15:28
Leo does not comment on your own response. Make an issue of your Original Reply with whatever you want to include.

– hugocsl

2018/01/19 at 15:58