SpringMVC 域对象共享数据

在Spring MVC中，可以通过以下几种方式在控制器之间共享域对象数据：

1. 使用Model对象：

@Controller
public class SomeController {
    @GetMapping("/some")
    public String someMethod(Model model) {
        model.addAttribute("attributeName", "attributeValue");
        return "someView";
    }
}
 
@Controller
public class AnotherController {
    @ModelAttribute("attributeName")
    public String getSharedData() {
        return "sharedData";
    }
 
    @GetMapping("/another")
    public String anotherMethod(@ModelAttribute("attributeName") String sharedData) {
        // 使用sharedData
        return "anotherView";
    }
}

2. 使用Session属性：

@Controller
public class SomeController {
    @GetMapping("/some")
    public String someMethod(HttpSession session) {
        session.setAttribute("attributeName", "attributeValue");
        return "someView";
    }
}
 
@Controller
public class AnotherController {
    @GetMapping("/another")
    public String anotherMethod(HttpSession session) {
        String sharedData = (String) session.getAttribute("attributeName");
        // 使用sharedData
        return "anotherView";
    }
}

3. 使用HttpServletRequest：

@Controller
public class SomeController {
    @GetMapping("/some")
    public String someMethod(HttpServletRequest request) {
        request.setAttribute("attributeName", "attributeValue");
        return "someView";
    }
}
 
@Controller
public class AnotherController {
    @GetMapping("/another")
    public String anotherMethod(HttpServletRequest request) {
        String sharedData = (String) request.getAttribute("attributeName");
        // 使用sharedData
        return "anotherView";
    }
}

4. 使用ServletContext：

@Controller
public class SomeController {
    @GetMapping("/some")
    public String someMethod(ServletContext context) {
        context.setAttribute("attributeName", "attributeValue");
        return "someView";
    }
}
 
@Controller
public class AnotherController {
    @GetMapping("/another")
    public String anotherMethod(ServletContext context) {
        String sharedData = (String) context.getAttribute("attributeName");
        // 使用sharedData
        return "anotherView";
    }
}

选择哪种方式取决于需要共享数据的范围和生命周期。通常，Model对象和Session属性用于在用户会话范围内共享数据，而HttpServletRequest和ServletContext用于在整个Web应用程序范围内共享数据。