springMVC拦截器中如何获得被拦截方法的返回值

Posted 2023-04-04

参考技术A 去阿帕奇下载apache.org/poi
项目的源码：
import org.apache.poi.ss.usermodel.Row
import org.apache.poi.xssf.usermodel.XSSFCell
import org.apache.poi.xssf.usermodel.XSSFRow
import org.apache.poi.xssf.usermodel.XSSFSheet
import org.apache.poi.xssf.usermodel.XSSFWorkbook
/**
* Created by WangQing on 15/11/20.
*/
class TestGroovy

void updateResourceDate()
def filePath = "./assets/people.xlsx"

File file = new File(filePath)

FileInputStream is = new FileInputStream(file);

XSSFWorkbook workbook = new XSSFWorkbook(is);
workbook.setMissingCellPolicy(Row.CREATE_NULL_AS_BLANK);

//循环sheet
(0..<workbook.sheetIterator().collect return it.@size).each s->
XSSFSheet sheet = workbook.getSheetAt(s);
int rows = sheet.physicalNumberOfRows;

//忽略第一行,标题行
(1..<rows).eachr->
XSSFRow row = sheet.getRow(r);
def cells = row.physicalNumberOfCells;

(0..<cells).eachc->
XSSFCell cell = row.getCell(c);

def name = "";

switch (c)
case 0:
name = "A:"
break;
case 1:
name = "B:"
break
case 2:
name = "C:"
break
case 3:
name = "D:"
break

print name + " "+cell+ ", ";


println "";




static main(args)
TestGroovy a = new TestGroovy();
a.updateResourceDate();

SpringMVC的拦截器

自定义拦截器很简单，只有如下三步：
1. 创建拦截器类实现HandlerInterceptor接口
2. 配置拦截器
3. 测试拦截器的拦截效果

当拦截器的preHandle方法返回true则会执行目标资源，如果返回false则不执行目标资源
多个拦截器情况下，配置在前的先执行，配置在后的后执行
拦截器中的方法执行顺序是：preHandler-------目标资源----postHandle---- afterCompletion

拦截器

public class MyInterceptor1 implements HandlerInterceptor {
    //在目标方法执行之前 执行
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws ServletException, IOException {
        System.out.println("preHandle.....");
}
    //在目标方法执行之后 视图对象返回之前执行
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
System.out.println("postHandle...");
    }
    //在流程都执行完毕后 执行
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        System.out.println("afterCompletion....");
    }
}

在SpringMVC的配置文件中配置

<!--配置拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--对哪些资源执行拦截操作-->
            <mvc:mapping path="/**"/>
            <bean class="com.code_g.interceptor.MyInterceptor1"/>
        </mvc:interceptor>
            <!--这里可以配置多个拦截器，形成拦截器链，拦截顺序为配置顺序-->
    </mvc:interceptors>

测试类

@Controller
public class TargetController {

    @RequestMapping("/target")
    public ModelAndView show(){
        System.out.println("目标资源执行......");
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        return modelAndView;
    }
}