Question

我想删除连接到Mysql数据库的dataTable行。但当我点击dataTable内部的删除按钮时，没有任何事情发生（没有错误，行没有被删除）我在互联网上尝试了几种方法但没有任何反应，同样的事情没有错误也没有结果。我想提一下我是JSF的新手。我在下面的代码中引用了以下代码http://www.devmanuals.com/tutorials/java/jsf/database/deleteData.html
这是我的代码，

dataEditing.xhtml

 <form>
       <div id="eTable">
           <p:dataTable   value="#{feeding.updateData()}" var="avv">
                <p:column headerText="No.">
                    <h:outputText value="#{avv.ID}" />
                </p:column>
                <p:column headerText="Utterance">
                    <h:outputText value="#{avv.editUtterance}" />
                </p:column>
                 <p:column headerText="Device response">
                    <h:outputText value="#{avv.editDeviceResponse}" />
                </p:column>
                <p:column headerText="Comments">
                    <h:outputText value="#{avv.editComments}" />
                </p:column>
                <p:column>
                    <center> <p:commandButton value="Delete" action="#{feeding.delete(avv.ID)}"/>  </center>
                 </p:column>
         </p:dataTable>
   </div>

这是我的托管bean代码，

feeding.java

List<feeding> editboard;

public List<feeding> getEditBoard() {
    return editboard;
}

public List<feeding> updateData() {
    editboard = new ArrayList<feeding>();
    try {

        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/combi", "root", "#doubleinfinity7");
        ResultSet rs = null;
        conn.setAutoCommit(false);
        String str = "select * from device_assessment";
        PreparedStatement pst = conn.prepareStatement(str);

        rs = pst.executeQuery(str);
        while (rs.next()) {
            feeding usrr = new feeding();
            usrr.setEditUtterance(rs.getString("utterance"));
            usrr.setEditDeviceResponse(rs.getString("response"));
            usrr.setEditComments(rs.getString("comments"));
            usrr.setID(rs.getLong("ID"));

            editboard.add(usrr);
            Map<Long, Boolean> checked = new HashMap<Long, Boolean>();
            List<feeding> checkedItems = new ArrayList<feeding>();
            for (feeding item : editboard) {
                if (checked.get(item.getID()) != null) {
                    checkedItems.add(item);

                    usrr.delete(usrr.getID());
                }
            }
        }

    } catch (ClassNotFoundException | SQLException e) {
        throw new FacesException(e);
    }

    return editboard;

}

public void delete(long ID) {
    if (ID != 0) {
        System.out.println(" current ID : " + ID);

        FacesContext context = FacesContext.getCurrentInstance();
        try {

            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/combi", "root", "#doubleinfinity7");
            conn.setAutoCommit(false);
            String sql = "delete from device_assessment where ID=" + ID;
            PreparedStatement pst = conn.prepareStatement(sql);

            int i = pst.executeUpdate();
            if (i > 0) {
                System.out.println("Row deleted successfully");
            }

            conn.commit();

            context.addMessage(null, new FacesMessage("Successfully", "Deleted"));

        } catch (ClassNotFoundException | SQLException e) {
            throw new FacesException(e);
        }
    }

}

提前致谢!!

当我点击p：dataTable

0 个答案: