Controller组件实现重定向
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| @RequestMapping("/register6.do")
public String register6(
@ModelAttribute("account") XdlBankAccount account) {
return "forward:toLogin.do";
}
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| @RequestMapping("/register7.do")
public ModelAndView register7(
@ModelAttribute("account") XdlBankAccount account,ModelAndView mav) {
RedirectView rv = new RedirectView("toLogin.do");
mav.setView(rv);
return mav;
}
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中文参数乱码问题
之前的解决方案依然可用,但必须完全遵守之前的方式
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| @RequestMapping("/register8.do")
public String register8(HttpServletRequest request) {
try {
request.setCharacterEncoding("utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String acc_no = request.getParameter("acc_no");
System.out.println("acc_no:"+acc_no);
return "login";
}
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在webxml配置编码过滤器,把Post请求*.do的编码方式设为utf-8
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| <!-- 配置一个编码过滤器 -->
<filter>
<filter-name>CharacterEncoding</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncoding</filter-name>
<url-pattern>*.do</url-pattern>
</filter-mapping>
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| @RequestMapping("/register9.do")
public String register9(String acc_no,String acc_password,HttpServletRequest request) {
acc_no = request.getParameter("acc_no");
System.out.println("acc_no:"+acc_no);
return "login";
}
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拦截器
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拦截器接口的三个方法,调用时间请参考MVC注解配置图,博客Java_Spring框架(5)
preHandle()
在HandlerMapping之后,Controller之前调用,这个方法返回false,则代表终止后续调用;如果返回true,则代表继续后续调用。
postHandle()
在控制器之后,视图处理器之前
afterCompletion()
在视图处理器之后,响应之前
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拦截器的使用步骤
a.搭建一个基于标注的spring MVC(让用户发起登录,如果账号不是abc,密码是123,则登录成功;登录成功就把账号放入session中,重定向到 main.jsp。如果登录失败则提示用户登录失败。)
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| @RequestMapping("/login.do")
public String login(String acc_no,String acc_password,
HttpServletRequest request) {
if(!"abc".equals(acc_no) && "123".equals(acc_password)) {
request.getSession().setAttribute("acc_no", acc_no);
return "redirect:toMain.do";
}else {
request.setAttribute("msg", "登录失败");
return "login";
}
}
@RequestMapping("/toMain.do")
public String toMain() {
return "main";
}
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b.写一个拦截器,实现HandlerInterceptor接口
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| package com.xdl.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
public class MyCheckLoginInterceptor implements HandlerInterceptor {
@Override
public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
throws Exception {
System.out.println("afterCompletion");
}
@Override
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
Object arg2, ModelAndView arg3)
throws Exception {
System.out.println("postHandle");
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
Object method) throws Exception {
Object acc_no = request.getSession().getAttribute("acc_no");
if(acc_no != null) {
return true;
}else {
response.sendRedirect("toLogin.do");
return false;
}
}
}
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c.在Spring配置文件中配置拦截器
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| <!-- 配置拦截器 -->
<mvc:interceptors>
<mvc:interceptor>
//拦截的路径 比如 /* 拦截所有的一级请求 /** 拦截所有请求
<mvc:mapping path="/**"/>
//不拦截的请求 可以有多个
<mvc:exclude-mapping path="/toRegister.do"/>
<mvc:exclude-mapping path="/regist.do" /
//拦截器对象
<bean class="com.xdl.interceptor.MyCheckLoginInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>
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异常处理
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| <!-- 配置系统提供的异常处理器 -->
<bean id="exceptionResolver"
class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.Exception">error2</prop>
<prop key="java.lang.RuntimeException">error</prop>
</props>
</property>
</bean>
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| @RequestMapping("/toLogin.do")
public String toLogin() throws Exception {
if(1==1) {
throw new Exception("出大事了---检查异常");
}
return "login";
}
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实现HandlerExceptionResolver,让对应的异常跳转到对应的页面
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| package com.xdl.resolver;
import org.springframework.stereotype.Controller;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Controller
public class MyHandlerExceptionResolver implements HandlerExceptionResolver {
@Override
public ModelAndView resolveException(HttpServletRequest arg0,
HttpServletResponse arg1, Object arg2,
Exception e) {
ModelAndView mav = new ModelAndView();
if(e instanceof RuntimeException) {
mav.setViewName("error");
}else if(e instanceof Exception) {
mav.setViewName("error2");
}
return mav;
}
}
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- 局部异常处理 — 只针对一个具体的控制器起作用(异常方法中Exception的参数必须有)
在Controller组件里加入一个方法
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| @RequestMapping("/toLogin.do")
public String toLogin() throws Exception {
if(1==1) {
//throw new RuntimeException("出大事了 --- 运行时异常");
throw new Exception("出大事了---检查异常");
}
return "login";
}
//此方法只针对本类中发生的Exception
@ExceptionHandler
public String foo(Exception e) {
System.out.println(e.getMessage());
//getMessage是上述抛出异常时()里的字符串
return "error3";
}
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