java.lang.IllegalArgumentException：無法解析屬性設置bean的屬性名hourtoreserve com.ti.project.vaadin.vaadinprojectti.Day

Question

我試圖在簡單的vaadin UI中從我的數據庫打印值。我是從這個教程做的一切：https://vaadin.com/blog/-/blogs/building-a-web-ui-for-mysql-databases-in-plain-java-

我改變了一點，我想不通爲什麼我不能用自己的一組列。如果我評論與setColumns和bindInstanceFields一切正常，但在相反的順序線......在另一種情況下，我得到的標題提到的錯誤。

下面的代碼：

日類別：

package com.ti.project.vaadin.vaadinprojectti; 

public class Day { 
    private String hourToReserve; 
    private String reservedOn; 

    public Day(String hourToReserve, String reservedOn) { 
     this.hourToReserve = hourToReserve; 
     this.reservedOn = reservedOn; 
    } 

    public String getHourToReserve() { 
     return hourToReserve; 
    } 

    public void setHourToReserve(String hourToReserve) { 
     this.hourToReserve = hourToReserve; 
    } 

    public String getReservedOn() { 
     return reservedOn; 
    } 

    public void setReservedOn(String reservedOn) { 
     this.reservedOn = reservedOn; 
    } 
} 

DayService類別：

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.jdbc.core.JdbcTemplate; 
import org.springframework.stereotype.Component; 

import java.util.List; 

@Component 
public class DayService { 

    @Autowired 
    private JdbcTemplate jdbcTemplate; 

    public List<Day> findAll(String dayName) { 
     return jdbcTemplate.query(
       "SELECT hourtoreserve, reservedon FROM " + dayName, 
       (rs, rowNum) -> new Day(
         rs.getString("hourtoreserve"), 
         rs.getString("reservedon"))); 
    } 

    public void update(Day day, String dayName){ 
     jdbcTemplate.update(
       "UPDATE " + dayName + " SET reservedon=?", 
       day.getReservedOn()); 
    } 
} 

和Vaadin UI代碼，其中發生了錯誤：

package com.ti.project.vaadin.vaadinprojectti; 

import com.vaadin.data.Binder; 
import com.vaadin.server.VaadinRequest; 
import com.vaadin.spring.annotation.SpringUI; 
import com.vaadin.ui.*; 
import org.springframework.beans.factory.annotation.Autowired; 


@SpringUI 
public class VaadinUI extends UI { 

@Autowired 
private DayService service; 

private Day day; 
private Binder<Day> binder = new Binder<>(Day.class); 

private Grid<Day> grid = new Grid(Day.class); 

@Override 
protected void init(VaadinRequest request) { 

    updateGrid(); 

    grid.setColumns("hourtoreserve", "reservedon"); // if this is commented 
    binder.bindInstanceFields(this);   // it works but columns are in wrong order 
    VerticalLayout layout = new VerticalLayout(grid); 
    setContent(layout); 
} 

private void updateGrid() { 
    List<Day> days = service.findAll("monday"); 
    grid.setItems(days); 
} 

Answer 1

我解決了我的問題。原來，你需要把grid.setColumns（）從類方法的具體變量名綁定！所以在我的情況下，它應該是：

代替：

grid.setColumns("hourtoreserve", "reservedon") 

它應該是：

grid.setColumns("hourToReserve", "reservedOn")