这是我的控制器..
@RequestMapping(value = "/add",method = RequestMethod.GET)
public String add(Model model) {
return "add";
}
@RequestMapping(value = "/add",method = RequestMethod.POST)
public String added(@RequestParam("name") String name,Model model) {
City city = new City();
city.setCity(name);
service.addCity(city);
return "add";
}
这是我的JSP视图..这只是为了添加…这是add.jsp..so它回发给自己
<form method="post" action="/spring/krams/edit/add"> Linna nimi <input type="text" name="name"> <input type="submit" value="Test" name="submit" /> </form>
我希望JSP文件发生变化,以便当我将其发布到此文件时,它会说…“添加了城市”.那可能吗？
什么关于更新城市？
@RequestMapping(value = "/update",method = RequestMethod.POST)
public String updated(@RequestParam("city") int city_id,@RequestParam("text") String name,Model model) {
service.updateCity(name,city_id);
return "update";
}
这里没有对象？
解决方法
在post方法中,您可以使用addAttribute方法添加属性
@RequestMapping(value = "/add",Model model) {
City city = new City();
city.setCity(name);
service.addCity(city);
model.addAttribute("city",city);
return "add";
}
在JSP中,您可以检查属性city是否为null(标记为< c：if />).如果它不是null,那是因为它刚刚被添加到模型中,所以你可以显示你想要的任何东西. ${city.city}它只是一个JSTL表达式,它访问city属性,然后调用getter来访问该属性的city属性：
<%@ taglib uri="http://java.sun.com/jstl/core_rt" prefix="c" %>
<c:if test="${city != null}">
CITY <c:out value="${city.city}" /> ADDED
</c:if>
UPDATE
如果根据更新/创建操作需要不同的消息,则可以执行以下操作:(在示例中,当id param不为null时进行更新,因为id是要更新的城市的标识符)
@RequestMapping(value = "/add",method = RequestMethod.POST) public String added(@RequestParam(value="id",required=false) String id,@RequestParam("name") String name,Model model) { City city; String operation; if(id== null){ //create operation city = new City(); operation = "CREATE"; }else{ //update operation city = service.findCity(id); operation = "UPDATE"; } city.setCity(name); service.saveCity(city); //save or update model.addAttribute("city",city); model.addAttribute("operation",operation); //add operation param return "add"; }
在JSP中你可以做到：
<%@ taglib uri="http://java.sun.com/jstl/core_rt" prefix="c" %>
<c:if test="${operation == 'CREATE'}">
<c:if test="${city != null}">
CITY <c:out value="${city.city}" /> ADDED
</c:if>
<c:if test="${operation == 'UPDATE'}">
CITY <c:out value="${city.city}" /> UPDATED
</c:if>
</c:if>
