Java學習之Spring MVC路由映射
0x00 前言
補充缺失的Javaweb部分內容。
0x01 Spring MVC路由映射
web.xml中配置解析路徑
<display-name>login</display-name>
<servlet>
<servlet-name>loginservlet</servlet-name>
<jsp-file>/WEB-INF/view/login.jsp</jsp-file>
</servlet>
<servlet-mapping>
<servlet-name>loginservlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>
訪問http://xxx/login/login 即可訪問到/WEB-INF/view/login.jsp文件
Config類中配置
WebMvcConfigurerAdapter類
WebMvcConfigurerAdapter配置類是spring提供的一種配置方式，采用javabean的方式替代傳統的基於xml的配置來對spring框架進行自定義的配置
public void configurePathMatch(PathMatchConfigurer configurer) {}
/*配置Web Service或REST API設計中內容協商,即根據客戶端的支持內容格式情況來封裝響應消息體，如xml,json*/
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {}
/*配置路徑匹配參數*/
public void configureAsyncSupport(AsyncSupportConfigurer configurer) {}
/* 使得springmvc在接口層支持異步*/
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {}
/* 注冊參數轉換和格式化器*/
public void addFormatters(FormatterRegistry registry) {}
/* 注冊配置的攔截器*/
public void addInterceptors(InterceptorRegistry registry) {}
/* 自定義靜態資源映射*/
public void addResourceHandlers(ResourceHandlerRegistry registry) {}
/* cors跨域訪問*/
public void addCorsMappings(CorsRegistry registry) {}
/* 配置頁面直接訪問，不走接口*/
public void addViewControllers(ViewControllerRegistry registry) {}
/* 注冊自定義的視圖解析器*/
public void configureViewResolvers(ViewResolverRegistry registry) {}
/* 注冊自定義控制器(controller)方法參數類型*/
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {}
/* 注冊自定義控制器(controller)方法返回類型*/
public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {}
/* 重載會覆蓋掉spring mvc默認注冊的多個HttpMessageConverter*/
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {}
/* 僅添加一個自定義的HttpMessageConverter,不覆蓋默認注冊的HttpMessageConverter*/
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {}
/* 注冊異常處理*/
public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {}
/* 多個異常處理，可以重寫次方法指定處理順序等*/
public void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {}
}
package com.zeluli.springmvc;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;
@Configuration
@EnableWebMvc
@ComponentScan("com.zeluli.springmvc")
public class SpringMVCConfig extends WebMvcConfigurerAdapter {
//路由映射的快捷設置
//視圖控制器配置
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/indextest").setViewName("/index");
}
@Bean
public InternalResourceViewResolver viewResolver(){
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/classes/views/");
viewResolver.setSuffix(".jsp");
viewResolver.setViewClass(JstlView.class);
return viewResolver;
}
//創建自定義攔截器的對象
@Bean
public CustomInterceptor customInterceptor(){
return new CustomInterceptor();
}
//添加自定義攔截器
@Override
public void addInterceptors(InterceptorRegistry registry) {
super.addInterceptors(registry);
registry.addInterceptor(customInterceptor());
}
}
package com.zeluli.springmvc;
import javax.servlet.ServletRegistration.Dynamic;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class WebInitializer implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
context.register(SpringMVCConfig.class);
context.setServletContext(servletContext);
Dynamic servlet = (Dynamic) servletContext.addServlet("dispatcher", new DispatcherServlet(context));
servlet.addMapping("/");
servlet.setLoadOnStartup(1);
}
}
相當於web.xml里面的
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
看到viewResolver方法中添加了/WEB-INF/classes/views/*.jsp的映射。
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class FirstController {
@RequestMapping("/")
public String success() {
return "index";
}
}
訪問即可訪問到/WEB-INF/classes/views/index.jsp
http://localhost:8080/SpringMVCWithMaven_war/
error 頁面配置
package com.zeluli.springmvc.advice;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.ModelAndView;
@ControllerAdvice
public class ExceptionHandlerAdvice {
@ExceptionHandler(value=Exception.class) //攔截所有的Exception
public ModelAndView exception(Exception exception, WebRequest request) {
ModelAndView modelAndView = new ModelAndView("error");//error頁面
modelAndView.addObject("errorMessage", exception.getMessage()); //錯誤信息
System.out.println(exception.getMessage());
return modelAndView;
}
}
package com.zeluli.springmvc.web;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class AdviceController {
@RequestMapping("/advice")
public String getMsg() {
throw new IllegalArgumentException("非常抱歉，參數有誤");
}
}
多個路由映射同一方法
可以將多個路由映射到同一個Controller的方法上。當我們給@RequestMapping的value屬性賦值一個數組時，數組中的路徑都會映射到該注解所修飾的方法中。
@RequestMapping(value = {"/name1", "/name2"}, produces = "text/plain;charset=UTF-8")
public @ResponseBody String remove(HttpServletRequest request) {
return "請求地址:" + request.getRequestURI() + " 已經被訪問了！";
}
配置路由參數
在路由配置中，我們可以為路由添加參數，然后使用@PathVariable注解來獲取該路徑變量的值。下方創建的sub2()方法的路由配置中就帶有路徑變量的，使用{路徑變量}來聲明路徑變量，使用@PathVariable來獲取路徑變量。
@RequestMapping(value="/sub2/{value1}/{value2}/resource")
@ResponseBody
public String sub2(HttpServletRequest request, @PathVariable String value1, @PathVariable String value2) {
return "請求地址：" + request.getRequestURI() + " 移動端：" + value1 + " 平台："+ value2;
}
Get單請求
@RequestMapping(value = "/sub3")
@ResponseBody
public String sub3(HttpServletRequest request, String param) {
return "請求地址" + request.getRequestURI() + " get參數 = " + param;
}
Get多請求
如果一個Get請求有多個參數怎么辦呢？肯定不能再用上述方法類獲取參數的值了。在Spring框架中，支持將獲取的參數直接映射成Model。前提是參數的名稱必須和特定Model中的屬性名稱相同，接下來我們就來做這件事情。將用戶傳入的參數直接映射成Model。
首先我們得創建一個Model，下方這段代碼就是我們創建的Model，該Model比較簡單，只有兩個屬性，一個是studentNumber，另一個則是name。Model類中還對應着各個屬性的getter和setter方法
package com.zeluli.model;
public class StudentModel {
private String studentNumber;
private String name;
public StudentModel() {
super();
}
public String getStudentNumber() {
return studentNumber;
}
public void setStudentNumber(String studentNumber) {
this.studentNumber = studentNumber;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
在路由對應的方法中直接使用相應的Model對象進行接收即可，在接收的過程中會將參數中相應的值賦給該Model對象中相應的屬性。
//將請求直接映射為Model
//http://localhost:8080/SpringMVCWithMaven/route/sub4?studentNumber=12&name=zeluli
@RequestMapping(value = "/sub4")
@ResponseBody
public String sub4(HttpServletRequest request, StudentModel student) {
return "請求地址:" + request.getRequestURI() + " 參數studentNumber = " + student.getStudentNumber() + " studentName:" + student.getName();
}
JSON數據輸出
//返回json數據
//http://localhost:8080/SpringMVCWithMaven/route/getjson?studentNumber=12&name=zeluli
@RequestMapping(value="/getjson", produces="application/json;charset=UTF-8")
@ResponseBody
public StudentModel getJson(StudentModel student) {
return student;
}
返回XML數據
@RequestMapping(value="/getxml", produces="application/xml;charset=UTF-8")
@ResponseBody
public StudentModel getXML(StudentModel student) {
return student;
}
接受JSON數據
public void getList(@RequestBody JSONObject json) {
//去除字符串
String uid = json.getString("uid");
System.out.println("uid:" + uid);
路由快捷設置
我們也可以在SpringMVC的配置文件中來快速的設置路由與JSP頁面的映射關系，當然實現起來也是比較簡單的。只需要我們的Spring的配置類繼承於WebMvcConfigurerAdapter然后重寫addViewControllers()方法即可。在addViewController()的方法中來進行路由到JSP頁面的映射關系。
//路由映射的快捷設置
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/indextest").setViewName("/index");
}
參考文章
https://www.cnblogs.com/ludashi/p/6432080.html
0x02 結尾
記錄知識點