springmvc复习笔记

springmvc

1:j简单的入门案例

springmvc.xml

 
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">



<context:component-scan base-package="com.baidu">

context:component-scan>

<bean id="internalResourceViewResolver" class=" org.springframework.web.servlet.view.InternalResourceViewResolver"> 
<property name="prefix" value="WEB-INF/pages/">property>
<property name="suffix" value=".jsp">property>
bean>

beans>

pom,xml

  <properties>
    <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
    <maven.compiler.source>1.8maven.compiler.source>
    <maven.compiler.target>1.8maven.compiler.target>
    <spring.version>5.0.2.RELEASEspring.version>
  properties>

  
  <dependencies>
    <dependency>
      <groupId>org.springframeworkgroupId>
      <artifactId>spring-contextartifactId>
      <version>${spring.version}version>
    dependency>

    <dependency>
      <groupId>org.springframeworkgroupId>
      <artifactId>spring-webartifactId>
      <version>${spring.version}version>
    dependency>

    <dependency>
      <groupId>org.springframeworkgroupId>
      <artifactId>spring-webmvcartifactId>
      <version>${spring.version}version>
    dependency>

    <dependency>
      <groupId>javax.servletgroupId>
      <artifactId>servlet-apiartifactId>
      <version>2.5version>
      <scope>providedscope>
    dependency>

    <dependency>
      <groupId>javax.servlet.jspgroupId>
      <artifactId>jsp-apiartifactId>
      <version>2.0version>
      <scope>providedscope>
    dependency>

  dependencies>

web,.xml

<web-app id="WebApp_ID" version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<servlet >
  <servlet-name> dispartservletservlet-name>
  <servlet-class> org.springframework.web.servlet.DispatcherServletservlet-class>
  
  <init-param>
  
  <param-name>contextConfigLocationparam-name>
      <param-value>classpath:springmvc.xmlparam-value>
  init-param>
  <load-on-startup>1load-on-startup>
  servlet>
  <servlet-mapping>
  <servlet-name>dispartservletservlet-name>
  <url-pattern>/url-pattern>
  servlet-mapping>
web-app>

controller

package com.baidu;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.DispatcherServlet;

@Controller
public class AccountController {

	@RequestMapping("/hello")
	public String a(){
		
		return "success";
	}
}

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>








hello
dsd

success.jsp沈略

流程：

• 启动Tomcat容器会加载dispartservlet同时加了一个initparam,将springmvc.xml加载了
• springmvc配置了注解扫描
• 扫描controller,将其配置成一个bean

@Requestmapping注解介绍

• 参数：
• ​ String[] params() ：必须传一个属性,否则不能请求到
• RequestMethod[] method()枚举类型：值为GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS, TRACE

解决乱码过滤器

<filter-mapping>
  <filter-name>characterEncodingFilterfilter-name>
  <url-pattern>/*url-pattern>
  filter-mapping>

参数绑定集合

 <form action="/testspringmvc2/hello" method="post">
      绑定list集合
        密码：<input type="text" name="list[0].password" /><br/>
 <!--        金额：<input type="text" name="money" /><br/> -->
        用户姓名：<input type="text" name="list[0].username" /><br/>

   绑定map集合 </br>
  密码：<input type="text" name="map['one'].username" /><br/>
 <!--        金额：<input type="text" name="money" /><br/> -->
        用户姓名：<input type="text" name="map['one'].password" /><br/>

        <input type="submit" value="提交" />
    </form>

Account有list和map

package com.baidu.entity;

import java.util.List;
import java.util.Map;

public class Account {
	String username;
	
	String password;
	
	List<User>list;
	Map<String, User>map;
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public List<User> getList() {
		return list;
	}
	public void setList(List<User> list) {
		this.list = list;
	}
	public Map<String, User> getMap() {
		return map;
	}
	public void setMap(Map<String, User> map) {
		this.map = map;
	}
	@Override
	public String toString() {
		return "Account [username=" + username + ", password=" + password + ", list=" + list + ", map=" + map + "]";
	}
	
	
	
}

自定义转换器

spring提供了ConversionServiceFactoryBean进行类型转换，

只需要在xml中配置即可，

<bean id="converservice" class="org.springframework.context.support.ConversionServiceFactoryBean">
  
<property name="converters">
<set>
  
<bean class="com.baidu.entity.Myconvert">bean>
set>

property>

bean>


    <mvc:annotation-driven conversion-service="converservice"/>

package com.baidu.entity;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.springframework.core.convert.converter.Converter;

public class Myconvert implements Converter<String, Date>{

	public Date convert(String source) {
		// TODO Auto-generated method stub
		SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
		try {
			Date date = sdf.parse(source);
			return date;
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}

}

常用注解：

@requerstparam：用于controller和jsp中参数名称不一致的情况，requerstparam里面，加上参数的名称

@requerstbody：用于获取post请求方式的请求体，get没有请求体

@PathVariable 一般用于Restful风格，取参数

@modelattribute

浏览器一般只支持get和post请求，也可以装插件发put，delete请求，

如果没有装插件，怎么让浏览器发送put，delete请求呢，springmvc使用

HiddentHttpMethodFilter这个过滤器可以实现（了解就行）

响应结果重定向转发

@RequestMapping("/testforwardorredict")
	public String jj(HttpServletResponse res){
		//使用重定向或转发将不会经过视图解析器
		//使用重定向
	
		return "redirect:/index.jsp";
		
		//使用转发
		//return "forward:/WEB-INF/pages/success.jsp";
	}

复习下ajax

window.onload=function(){
	
	$.ajax(
			
	{
		url:"/testspringmvc2/hello",
    type:post,
		
		data:{username:"zhangsan",userage:"18" },
		success:function(data){
		}
	}
	);
}

文件上传

• 前提
  • 请求方式必须是post
  • form表单的enctype 必须是multipart/form-data

异常解析器

• 创建自定义异常

  • package com.baidu.utils;
    
    public class MyExeception extends Exception{
    	
    	
    private String message;
    
    public String getMessage() {
    	return message;
    }
    
    public void setMessage(String message) {
    	this.message = message;
    }
    
    public MyExeception(String message) {
    	// TODO Auto-generated constructor stub
    	this.message=message;
    }
    
    }
    
    

  • 创一个实现HandlerExceptionResolver的类

    • 	package com.baidu.utils;
      
      import javax.servlet.http.HttpServletRequest;
      import javax.servlet.http.HttpServletResponse;
      
      import org.springframework.web.servlet.HandlerExceptionResolver;
      import org.springframework.web.servlet.ModelAndView;
      
      public class HanderExeception implements HandlerExceptionResolver{
      
      	public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler,
      			Exception ex) {
      		// TODO Auto-generated method stub
      		Exception e=null;
      		
      		if(ex instanceof MyExeception){
      			e=new MyExeception("系统正在维护");
      			
      		}
      		ModelAndView mv=new ModelAndView();
      		
      		mv.setViewName("error");
      		mv.addObject("errormsg",e.getMessage());
      		return mv;
      	}
      
      }
      
      

  • springmvc.xml中添加

    • <bean class="com.baidu.utils.HanderExeception" id="handerExeception">bean>
      

  • 在controller制作一个异常

    • @Controller
      public class Acountcontroller {
      	@RequestMapping("/hello")
      	public String d() throws MyExeception{
      		try {
      			int i=1/0;
      			
      		} catch (Exception e) {
      			// TODO: handle exception
      			
      			throw new MyExeception("系统正在维护");
      		}
      		
      		return "success";
      	}
      	
      

原理:默认不处理，异常会一层层抛，最后抛到浏览器显示，如果在异常抛到dispartservlet时，用一个异常处理器，处理抛出来的异常，一旦出现了异常，前端控制器会指定异常处理器，如果我们定义了一个异常处理器实现了HandlerExceptionResolver并注册成了一个bean，异常处理器就会被调用然后跳转到指定页面。

拦截器

拦截器和过滤器的区别：

• 拦截器是springmvc才有的，filter是所有javaee项目都有的
• springmvc只能拦截controller的资源，filter加/*可以过滤所有资源

使用方法

• 创建一个拦截器类，实现HandlerInterceptor.

  • package com.baidu.utils;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.springframework.web.servlet.HandlerInterceptor;
    
    public class Myhanderinteceptor implements HandlerInterceptor{
    	
    	//访问controller前的操作
    	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    			throws Exception {
    		// TODO Auto-generated method stub
    		System.out.println("拦截器执行了...1");
    		return true;
    	}
    	
    
    }
    
    

• 配置springmvc.xml

  • <mvc:interceptors>
    
    <mvc:interceptor>
    <mvc:mapping path="/user/*"/>
    <bean class="com.baidu.utils.Myhanderinteceptor">bean>
    
    mvc:interceptor>
    mvc:interceptors>