【自虐1.0】Spring MVC增删改查

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heruyi

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自虐

这是项目的包图

我只是想颠三倒四，然后把该记住的知识记住

环境：win7 MyEclipse10 jdk1.6 tomcat7 SpringMVC2.5

目标：CRUD

本文是根据这个小例子修改而来，感谢这位前辈

http://download.csdn.net/download/wxwzy738/5224307

总结的肯定有不对，不完整的地方，权当笔记。

首先是web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app 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">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
  	<servlet-name>hello</servlet-name>
  	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  	<init-param>
  		<param-name>contextConfigLocation</param-name>
  		<param-value>WEB-INF/web-main.xml</param-value>
  	</init-param>
  </servlet>
  <servlet-mapping>
  	<servlet-name>hello</servlet-name>
  	<url-pattern>*.htm</url-pattern>
  </servlet-mapping>
</web-app>

org.springframework.web.servlet.DispatcherServlet

这是springmvc的前端控制器，也就是说所有请求都将在这里找到url

servlet-mapping中定义的是路径，熟悉servlet的都知道，这里表示以url结尾的请求将进入控制器

init-param大概是服务器初始化时会加载到内存的配置，contextConfigLocation这个应该是spring容器会去读的配置文件。

web-main.xml文件

<?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/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
	
	<mvc:annotation-driven/>
	<mvc:resources location="/resources/" mapping="/resources/**"/>
	<context:component-scan base-package="cn.zinue100.controller"/>

	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/jsp/"></property>
		<property name="suffix" value=".jsp"></property>
	</bean>
	
	<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
		<property name="maxUploadSize" value="5000000"></property>
	</bean>
	
</beans>

<mvc:annotation-driven/>

大概是把spring默认配置成注解，而不是用xml

<mvc:resources location="/resources/" mapping="/resources/**"/>
这样根目录下面的resource的文件(.css,.js等)就不会被spring的DispatchServlet进行过滤

<context:component-scan base-package="cn.zinue100.controller"/>

配置注解扫描的包路径，也就是说，这个文件夹下注解中的路径，将起作用

</bean>

配置action中返回的视图配置

这个配置是controller向jsp跳转的配置，在jsp中海油自定义标签，但我现在不太懂这个配置，姑且放在一边

来看实体类吧

package cn.zinue100.bean;

import javax.validation.constraints.Size;

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.NotEmpty;

public class User {
	private String username;
	private String password;
	private String email;
	public User(){
		
	}
	public User(String username, String password, String email) {
		this.username = username;
		this.password = password;
		this.email = email;
	}
	
	@NotEmpty(message = "用户名不能为空")
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	@NotEmpty(message = "密码不能为空")
	@Size(min = 4, max = 8, message = "密码在4~8位之间")
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	@NotEmpty(message = "email不能为空")
	@Email(message = "email格式不正确")
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	@Override
	public String toString(){
		return username+"#"+password+"#"+email;
	}
}

@RequestMapping(value = "/hello")

表示要访问这个action的时候都要加上这个/hello路径

HelloController

package cn.zinue100.controller;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
//@RequestMapping(value = "/hello")
public class HelloController {
	
	@RequestMapping(value = "/hello.htm")
	public String hello(int id){
		System.out.println("hello action:"+id);
		return "redirect:/index.jsp";
	}
	
	@RequestMapping(value = "/hello1.htm")
	public String hello(int id,Map<String,Object> map){
		System.out.println("hello1 action:"+id);
		map.put("name", "huangjie");
		return "hello";
	}
	
	@RequestMapping(value = "/hello2.htm")
	public String hello2(int id,Model model){
		System.out.println("hello2 action:"+id);
		model.addAttribute("name", "huangjie");
		model.addAttribute("ok");
		return "hello";
	}

	@RequestMapping(value = "/hello3.htm")
	public String hello3(HttpServletRequest request){
		String id = request.getParameter("id");
		System.out.println("hello3 action:"+id);
		return "hello";
	}
}

接收参数getParameter()的时候:

如果地址栏/springmvc/hello.htm上面没有传递参数,那么当id为int型的时候会报错,当id为Integer的时候值为null

当地址栏为/springmvc/hello.htm?id=10的时候,action中有三种接收方式

1、String hello(@RequestParam(value = "userid") int id),这样会把地址栏参数名为userid的值赋给参数id,如果用地址栏上的参数名为id,则接收不到

2、String hello(@RequestParam int id),这种情况下默认会把id作为参数名来进行接收赋值

3、String hello(int id),这种情况下也会默认把id作为参数名来进行接收赋值

注:如果参数前面加上@RequestParam注解,如果地址栏上面没有加上该注解的参数,例如:id,那么会报404错误,找不到该路径

其中

第一个方法不能重定向web-info里面的文件,而且需要写上绝对路径

第二个方法是返回页面参数的第一种方式,在形参中放入一个map

第三个方法是回页面参数的第二种方式,在形参中放入一个Model

到request,response,session等,只要在方法形参中声明参数即可

UserController.java

package cn.zinue100.controller;

import java.io.File;
import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.validation.Valid;

import org.apache.commons.io.FileUtils;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import cn.zinue100.bean.User;

@Controller
@RequestMapping(value = "/user")
@SessionAttributes(value = "loginUser")
public class UserController {

	Map<String, User> users = new LinkedHashMap<String, User>();

	public UserController() {
		System.out.println("初始化....");
		users.put("zinue101", new User("zinue101", "123", "zinue101@qq.com"));
		users.put("zinue102", new User("zinue102", "123", "zinue102@qq.com"));
		users.put("zinue103", new User("zinue103", "123", "zinue103@qq.com"));
		users.put("zinue104", new User("zinue104", "123", "zinue104@qq.com"));
	}

	public void init(Model model, User user) {
		if (user != null) {
			users.put(user.getUsername(), user);
		}
		model.addAttribute("users", users);
	}

	@RequestMapping(value = "/list.htm")
	public String list(Model model) {
		init(model, null);
		return "user/userlist";
	}

	@RequestMapping(value = "/add.htm", method = RequestMethod.GET)
	public String add(Model model) {
		model.addAttribute(new User());
		return "user/adduser";
	}

	@RequestMapping(value = "/add.htm", method = RequestMethod.POST)
	public String add(@Valid User user, BindingResult binding, Model model) {
		if (binding.hasErrors()) {
			return "user/adduser";
		}
		init(model, user);
		return "redirect:/user/list.htm";
	}

	@RequestMapping(value = "/{username}.htm", method = RequestMethod.GET)
	public String show(@PathVariable String username, Model model) {
		User user = users.get(username);
		model.addAttribute("user", user);
		return "user/show";
	}

	@RequestMapping(value = "/delete/{username}.htm", method = RequestMethod.GET)
	public String delete(@PathVariable String username) {
		users.remove(username);
		return "redirect:/user/list.htm";
	}

	@RequestMapping(value = "/update/{username}.htm", method = RequestMethod.GET)
	public String update(@PathVariable String username, Model model) {
		User user = users.get(username);
		model.addAttribute("user", user);
		return "user/adduser";
	}

	@RequestMapping(value = "/update/{username}.htm", method = RequestMethod.POST)
	public String update(@PathVariable String username, @Valid User user,
			BindingResult br) {
		if (br.hasErrors()) {
			return "/user/adduser";
		}
		users.put(user.getUsername(), user);
		return "redirect:/user/list.htm";
	}

	@ResponseBody
	@RequestMapping(value = "/{username}.htm", params = "json")
	public User showJson(@PathVariable String username, Model model) {
		System.out.println("username:" + username);
		return users.get(username);
	}

	@RequestMapping(value = "/login.htm", method = RequestMethod.GET)
	public String login() {
		return "/user/login";
	}

	@RequestMapping(value = "/login.htm", method = RequestMethod.POST)
	public String login(String username, String password, Model model) {
		if (!users.containsKey(username)) {
			throw new RuntimeException("用户名不存在!");
		}
		if (!password.equals(users.get(username).getPassword())) {
			throw new RuntimeException("密码不正确");
		}
		// 存放入session中,因为前面已经加了@SessionAttributes(value = "loginUser")注解
		model.addAttribute("loginUser", users.get(username));
		return "redirect:/user/list.htm";
	}

	@ExceptionHandler(value = { RuntimeException.class })
	public String handlerException(Exception ex, HttpServletRequest req) {
		req.setAttribute("ex", ex);// 把异常放入request请求中
		return "error";// 转到error页面
	}

	@RequestMapping(value = "/redir.htm")
	public String redir(Model model, RedirectAttributes ra) {
		// model.addAttribute("movie", "海贼王");//使用这种方式在重定向是传递不了的
		ra.addFlashAttribute("movie", "海贼王");// 使用这种可以
		return "redirect:/user/list.htm";
	}

	@RequestMapping(value = "upload.htm", method = RequestMethod.GET)
	public String uploadPhoto() {
		return "user/upload";
	}

	@RequestMapping(value = "upload.htm", method = RequestMethod.POST)
	public String uploadPhoto(MultipartFile photo, Model model,
			HttpServletRequest req) {
		System.out.println(photo.getContentType());
		System.out.println(photo.getName());
		System.out.println(photo.getOriginalFilename());
		String realpath = req.getSession().getServletContext()
				.getRealPath("/upload/");
		System.out.println(realpath);
		try {
			FileUtils.copyInputStreamToFile(photo.getInputStream(), new File(
					realpath + "/" + photo.getOriginalFilename()));
		} catch (IOException e) {
			e.printStackTrace();
		}
		model.addAttribute("message", "上传成功");
		return "user/upload";
	}

	@RequestMapping(value = "uploads.htm", method = RequestMethod.POST)
	public String uploadPhoto(
			@RequestParam(required = false) MultipartFile[] photos,
			Model model, HttpServletRequest req) {
		String realpath = req.getSession().getServletContext()
				.getRealPath("/upload/");
		try {
			for (MultipartFile photo : photos) {
				if (photo.isEmpty())
					continue;
				FileUtils.copyInputStreamToFile(photo.getInputStream(),
						new File(realpath + "/" + photo.getOriginalFilename()));
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		model.addAttribute("message", "上传成功");
		return "user/upload";
	}
}

SessionAttributes(value = "loginUser")

写上这个注解的话那么在Model中进行添加key为loginUser的时候会默认添加到session中

我的初步理解Model这个对象就对应页面的dom树。如果页面有对象那么必须传，不然空指针

返回的字符串中

如果redirect打头就是重定向，如果没有就是转发

别的不贴了，放附件中吧