链接 【 https://github.com/Davis-Samuel/SpringMVC-order 】
1.父项目SpringMVC
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依赖：
<dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.2.3.RELEASE</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <!--jackson工具依赖--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.10.1</version> </dependency> </dependencies>
2.HelloMVC
模块springmvc-02-hellomvc
- 步骤：【https://blog.kuangstudy.com/index.php/archives/318/】
- 注意错误：如果jar包存在，显示无法输出，就在IDEA的项目发布中，添加lib依赖！
3.使用注解开发
模块springmvc-annotation
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建立普通maven项目，再右键添加模块，右键添加web框架，再在pom.xml中添加资源预留代码，再设置里添加lib目录添加依赖，操作如上图。再模块的pom.xml中添加资源预留代码
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配置web.xml：
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <!--1.注册servlet--> <servlet> <servlet-name>SpringMVC</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!--通过初始化参数指定SpringMVC配置文件的位置，进行关联--> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <!-- 启动顺序，数字越小，启动越早 --> <load-on-startup>1</load-on-startup> </servlet> <!--所有请求都会被springmvc拦截 --> <servlet-mapping> <servlet-name>SpringMVC</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- spring的编码过滤器--> <filter> <filter-name>encoding</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>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app> -
在resource中创建springmvc.xml文件对应web.xml中的classpath关联路径：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 自动扫描包，让指定包下的注解生效,由IOC容器统一管理 --> <context:component-scan base-package="com.it.controller"/> <!-- json乱码解决--> <mvc:annotation-driven> <mvc:message-converters register-defaults="true"> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <constructor-arg value="UTF-8"/> </bean> <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> <property name="objectMapper"> <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean"> <property name="failOnEmptyBeans" value="false"/> </bean> </property> </bean> </mvc:message-converters> </mvc:annotation-driven> <!-- 让Spring MVC不处理静态资源 --> <mvc:default-servlet-handler /> <!-- 支持mvc注解驱动 在spring中一般采用@RequestMapping注解来完成映射关系 要想使@RequestMapping注解生效 必须向上下文中注册DefaultAnnotationHandlerMapping 和一个AnnotationMethodHandlerAdapter实例 这两个实例分别在类级别和方法级别处理。 而annotation-driven配置帮助我们自动完成上述两个实例的注入。 --> <mvc:annotation-driven /> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/WEB-INF/jsp/" /> <!-- 后缀 --> <property name="suffix" value=".jsp" /> </bean> </beans> -
根据springmvc.xml中的前后缀和自动扫描包，依次创建创建。
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在WEB-INF下创建jsp文件夹，创建hello.jsp：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> ${msg} </body> </html> -
创建com.it.controller，创建HelloController.java：
package com.it.controller; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class HelloController { @RequestMapping("/Hello") //url请求路径，(tomcat地址)后填入 public String hello(Model model){ model.addAttribute("mag","hhhhhhkkksdsdadadasdasdas"); return "hello"; //被视图解析器处理，对应要跳转的jsp的名字 } //可以写多个@RequestMapping("")以及方法，代表多个servlet。 }
RestFul风格
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地址栏中编写：
http://localhost:8080/test/1/"2" -
HelloController.java：
package com.it.controller; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class HelloController2 { //使用 @PathVariable 注解，让方法参数的值对应绑定到一个URI模板变量上。 @RequestMapping("/test/{a}/{b}") public String test(@PathVariable("a") int a, @PathVariable("b") String b, Model model){ String re = a + b; model.addAttribute("msg",re); return "hello"; } }//通过下方不同的请求方式，达到不同的结果和效果 //@GetMapping("/test/{a}/{b}") //@PostMapping("/test/{a}/{b}") //@PutMapping("/test/{a}/{b}") //@DeleteMapping("/test/{a}/{b}") //@PatchMapping("/test/{a}/{b}")
4.转发重定向
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右侧的路径代表web文件夹下的.jsp。web文件夹相当于没有，web文件下的东西与Java文件等都是同级的。唯独WEB-INF不能直接访问，需要写全路径。
关于转发?(有视图解析器)
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默认是转发。要根据视图解析器的开始和结尾路径进行拼接转发，加/和不加/，都看与视图解析器的前后路径的拼接，如下图，如果转发超出了WEB-INF那就转发不到，需要重定向。
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return "forward:a" //默认在/WEB-INF/jsp/ 下; return "forward:/a" //默认在/WEB-INF/jsp 下; return "forward:/a.jsp" //不在/WEB-INF/jsp 下
关于重定向(有视图解析器)
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return "redirect:/a.jsp"; //写重定向的全路径(/.jsp)，在WEB-INF下就写上/WEB-INF......
无视图解析器
- 写重定向的全路径(/.jsp)
5.向前端传递参数
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UserController.java：
package com.it.controller; import com.it.pojo.User; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; @Controller @RequestMapping("/user") public class UserController { //@RequestParam("name"),必须用name去接受参数， 必写 ！！！ @GetMapping("/t4") public String test4(@RequestParam("name") String name, Model model){ // 接受前端参数 System.out.println(name); // 将结果返回给前端 model.addAttribute("msg",name); // 视图转发 return "hello"; } // 向前端传递对象(字段名一致)：localhost:8080/user/t5？name= & id= & age= @GetMapping("/t5") public String test5(User user,Model model){ return "hello"; } }
6.解决乱码
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tomcat配置文件添加编码serve.xml:
<Connector URIEncoding="utf-8" port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> -
先试一下spring的filter过滤器，web.xml：
<!-- spring的编码过滤器--> <filter> <filter-name>encoding</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>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> -
spring的过滤器都不行，tomcat的编码修改也不行的极端情况使用自定义过滤：
com.it.filter.EcodingFilter.java：
package com.it.filter; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.Map; public class EncodingFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { //处理response的字符编码 HttpServletResponse myResponse=(HttpServletResponse) response; myResponse.setContentType("text/html;charset=UTF-8"); // 转型为与协议相关对象 HttpServletRequest httpServletRequest = (HttpServletRequest) request; // 对request包装增强 HttpServletRequest myrequest = new MyRequest(httpServletRequest); chain.doFilter(myrequest, response); } public void init(FilterConfig filterConfig) throws ServletException { } } //自定义request对象，HttpServletRequest的包装类 class MyRequest extends HttpServletRequestWrapper { private HttpServletRequest request; //是否编码的标记 private boolean hasEncode; //定义一个可以传入HttpServletRequest对象的构造函数，以便对其进行装饰 public MyRequest(HttpServletRequest request) { super(request);// super必须写 this.request = request; } // 对需要增强方法 进行覆盖 @Override public Map getParameterMap() { // 先获得请求方式 String method = request.getMethod(); if (method.equalsIgnoreCase("post")) { // post请求 try { // 处理post乱码 request.setCharacterEncoding("utf-8"); return request.getParameterMap(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } else if (method.equalsIgnoreCase("get")) { // get请求 Map<String, String[]> parameterMap = request.getParameterMap(); if (!hasEncode) { // 确保get手动编码逻辑只运行一次 for (String parameterName : parameterMap.keySet()) { String[] values = parameterMap.get(parameterName); if (values != null) { for (int i = 0; i < values.length; i++) { try { // 处理get乱码 values[i] = new String(values[i] .getBytes("ISO-8859-1"), "utf-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } } } hasEncode = true; } return parameterMap; } return super.getParameterMap(); } //取一个值 @Override public String getParameter(String name) { Map<String, String[]> parameterMap = getParameterMap(); String[] values = parameterMap.get(name); if (values == null) { return null; } return values[0]; // 取回参数的第一个值 } //取所有值 @Override public String[] getParameterValues(String name) { Map<String, String[]> parameterMap = getParameterMap(); String[] values = parameterMap.get(name); return values; } }web.xml：
<filter> <filter-name>filter</filter-name> <filter-class>com.it.filter.EncodingFilter</filter-class> </filter> <filter-mapping> <filter-name>filter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
7.JSON
模块springmvc-json
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配置lib目录，tomcat
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引入依赖：
<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.10.1</version> </dependency> -
pojo.User.java：
package com.it.pojo; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @AllArgsConstructor @NoArgsConstructor public class User { private int id; private String name; private int age; } -
springmvc.xml：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 自动扫描指定的包，下面所有注解类交给IOC容器管理 --> <context:component-scan base-package="com.it.controller"/> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/WEB-INF/jsp/" /> <!-- 后缀 --> <property name="suffix" value=".jsp" /> </bean> </beans> -
web.xml：
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <servlet> <servlet-name>SpringMVC</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>SpringMVC</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <filter> <filter-name>encoding</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>encoding</filter-name> <url-pattern>/</url-pattern> </filter-mapping> </web-app> -
JSON工具类含有时间，JSONUtils.java：
package com.it.jsonutils; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializationFeature; import java.text.SimpleDateFormat; public class JSONUtils { public static String getJSON(Object obj) throws JsonProcessingException { return getJSON(obj,"yyyy-MM-dd HH:mm:ss"); } public static String getJSON(Object obj,String dateFormat){ ObjectMapper mapper = new ObjectMapper(); //不使用时间差的方式 mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false); //自定义日期格式对象 SimpleDateFormat sdf = new SimpleDateFormat(dateFormat); //指定日期格式 mapper.setDateFormat(sdf); try { return mapper.writeValueAsString(obj); } catch (JsonProcessingException e) { e.printStackTrace(); } return null; } } -
UserConterller.java：
package com.it.controller; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.it.jsonutils.JSONUtils; import com.it.pojo.User; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.RestController; import java.util.ArrayList; import java.util.Date; import java.util.List; @Controller //也可以使用 @RestController里面所有的方法都只会返回 json 字符串了 public class UserController { @RequestMapping("/j") @ResponseBody //有了它就不走视图解析器了 public String test() throws JsonProcessingException { User user = new User(123, "lisi",456); ObjectMapper mapper = new ObjectMapper(); //将对象转化为JSON字符串 String s = mapper.writeValueAsString(user); return s; } @RequestMapping("/jj") @ResponseBody //有了它就不走视图解析器了 public String test2() throws JsonProcessingException { User user3 = new User(12, "lii",46); User user1 = new User(13, "isi",56); User user2 = new User(23, "si",45); List<User> user = new ArrayList<User>(); user.add(user1); user.add(user2); user.add(user2); return JSONUtils.getJSON(user); } @RequestMapping("/jjj") @ResponseBody public String test3() throws JsonProcessingException { Date date = new Date(); return JSONUtils.getJSON(date); } } -
json乱码解决，springmvc.xml：
<!-- json乱码解决--> <mvc:annotation-driven> <mvc:message-converters register-defaults="true"> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <constructor-arg value="UTF-8"/> </bean> <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> <property name="objectMapper"> <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean"> <property name="failOnEmptyBeans" value="false"/> </bean> </property> </bean> </mvc:message-converters> </mvc:annotation-driven>
8.ajax
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@RestController public class AjaxController { @RequestMapping("/a3") public String a3(String name,String pwd){ String msg = ""; if (name !=null){ if ("admin".equals(name)){ msg = "ok"; }else { msg = "error"; } } if (pwd !=null){ if ("admin".equals(name)){ msg = "ok"; }else { msg = "fail"; } } return msg; } } -
<script src="${pageContext.request.contextPath}/lib/jquery-3.4.1.js"></script> <script> function t1() { $.post({ url : "${pageContext.request.contextPath}/a3", //$('#name').val()是取的输入框的值，赋值给name //隐式调用 public String a3(String name,String pwd) 这个方法，将name传给后端，然后调用之后返回mas，也就是data=mag的值 data: {"name":$('#name').val()}, success:function (data) { if (data.toString() === "ok"){ $('#info').html(data) } } }) } </script> </head> <body>
用户名：
- 写一个User.java,然后AjaxConller.java：
```java
package com.it.controller;
import com.it.pojo.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
@RestController
public class AjaxController {
@RequestMapping("/t1")
public String text1(){
return "hello ajax";
}
@RequestMapping("/a1")
public void a(String name, HttpServletResponse response) throws IOException {
if ("haha".equals(name)){
response.getWriter().print("true");
}else {
response.getWriter().print("false");
}
}
@RequestMapping("/a2")
public List<User> a2(){
List<User> users = new ArrayList<User>();
users.add(new User("li","nan",1));
users.add(new User("aai","aafan",10));
users.add(new User("bbbi","ndan",10));
return users;
}
@RequestMapping("/a3")
public String a3(String name,String pwd){
String msg = "";
if (name !=null){
if ("admin".equals(name)){
msg = "ok";
}else {
msg = "error";
}
}
if (pwd !=null){
if ("admin".equals(name)){
msg = "ok";
}else {
msg = "fail";
}
}
return msg;
}
}
-
test2：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> <script src="${pageContext.request.contextPath}/lib/jquery-3.4.1.js"></script> <script> $(function () { $('#btn').click(function () { $.post('${pageContext.request.contextPath}/a2',function (data) { var html = ""; for (let i=0; i<data.length;i++){ html+= '<tr>'+ '<td>'+data[i].name+'</td>'+ '<td>'+data[i].sex+'</td>'+ '<td>'+data[i].age+'</td>'+ '</tr>'; } $('#content').html(html); }) }) }); </script> </head> <body> <input type="button" value="加载数据" id="btn"> <table> <tr> <td>姓名</td> <td>性别</td> <td>年龄</td> </tr> <tbody id="content"> </tbody> </table> </body> </html> -
index.jsp：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> <script src="${pageContext.request.contextPath}/lib/jquery-3.4.1.js"></script> <script> function a() { $.post({ url:"${pageContext.request.contextPath}/a1", data:{"name":$('#username').val()}, success:function (data) { alert(data); } }) } </script> </head> <body> <%-- 失去焦点的时候，发送一个请求到后台--%> <input type="text" id="username" onblur="a()"> </body> </html>
注册提示效果
-
我们写一个Controller：
@RequestMapping("/a3") public String ajax3(String name,String pwd){ String msg = ""; //模拟数据库中存在数据 if (name!=null){ if ("admin".equals(name)){ msg = "OK"; }else { msg = "用户名输入错误"; } } if (pwd!=null){ if ("123456".equals(pwd)){ msg = "OK"; }else { msg = "密码输入有误"; } } return msg; //由于@RestController注解，将msg转成json格式返回 } -
前端页面 login.jsp：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>ajax</title> <script src="${pageContext.request.contextPath}/jquery-3.1.1.min.js"></script> <script> function a1(){ $.post({ url:"${pageContext.request.contextPath}/a3", data:{'name':$("#name").val()}, success:function (data) { if (data.toString()=='OK'){ $("#userInfo").css("color","green"); }else { $("#userInfo").css("color","red"); } $("#userInfo").html(data); } }); } function a2(){ $.post({ url:"${pageContext.request.contextPath}/a3", data:{'pwd':$("#pwd").val()}, success:function (data) { if (data.toString()=='OK'){ $("#pwdInfo").css("color","green"); }else { $("#pwdInfo").css("color","red"); } $("#pwdInfo").html(data); } }); } </script> </head> <body> <p> 用户名:<input type="text" id="name" onblur="a1()"/> <span id="userInfo"></span> </p> <p> 密码:<input type="text" id="pwd" onblur="a2()"/> <span id="pwdInfo"></span> </p> </body> </html>