Code Records

Lia
86 阅读2分钟

Spring MVC入门 Code 记录

community

src

main

java

com.nowcoderbylia.community

config
AlphaConfig
package com.nowcoderbylia.community.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.text.SimpleDateFormat;

@Configuration
public class AlphaConfig {
    @Bean
    public SimpleDateFormat  simpleDateFormat() {
        return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    }
}
controller
AlphaController
package com.nowcoderbylia.community.controller;

import com.nowcoderbylia.community.service.AlphaService;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;

@Controller
@RequestMapping("/alpha")
public class AlphaController {

    @Autowired
    private AlphaService alphaService;

    @RequestMapping("/hello")
    @ResponseBody
    public String sayHello() {
        return "Hello Spring Boot.";
    }
    @RequestMapping("/data")
    @ResponseBody
    public String getData() {
        return alphaService.find();
    }

    @RequestMapping("/http")
    public void http(HttpServletRequest request, HttpServletResponse response) {
        // get request
        System.out.println(request.getMethod());
        System.out.println(request.getServletPath());
        Enumeration<String> enumeration = request.getHeaderNames();

        while (enumeration.hasMoreElements()) {
            String name = enumeration.nextElement();
            String value = request.getHeader(name);
            System.out.println(name + ": " + value);
        }

        System.out.println(request.getParameter("code"));

        // return response
        response.setContentType("text/html; charset=utf-8" );

        try (PrintWriter writer = response.getWriter()) {
            writer.write("<h1>Nowcoder</h1>");

        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
    // GET request

    // /students?current=1&limit=20
    @RequestMapping(path = "/students", method = RequestMethod.GET)
    @ResponseBody
    public String getStudents(
            @RequestParam(name = "current", required = false, defaultValue = "1") int current,
            @RequestParam(name = "limit", required = false, defaultValue = "10")int limit) {
        System.out.println(current);
        System.out.println(limit);
        return "some students";
    }

    // /student/123
    @RequestMapping(path = "/student/{id}", method = RequestMethod.GET)
    @ResponseBody
    public String getStudent(@PathVariable("id") int id) {
        System.out.println(id);
        return "a student";
    }

    // POST request
    @RequestMapping(path = "/student", method = RequestMethod.POST)
    @ResponseBody
    public String saveStudent(String name, int age) {
        System.out.println(name);
        System.out.println(age);
        return "success";
    }

    // respond HTML

    @RequestMapping(path = "/teacher", method = RequestMethod.GET)
    public ModelAndView getTeacher() {
        ModelAndView mav = new ModelAndView();
        mav.addObject("name", "zhangsan");
        mav.addObject("age","30");
        mav.setViewName("/demo/view");
        return mav;
    }

    @RequestMapping(path = "/school", method = RequestMethod.GET)
    public String getSchool(Model model) {
        model.addAttribute("name", "Peking University");
        model.addAttribute("age", "100");
        return "/demo/view";
    }

    // respond JSON(Async异步请求: 当前网页不刷新，但它悄悄访问了服务器返回了响应)
    // Java对象 -> JSON字符串 -> JS对象

    @RequestMapping(path = "/emp", method = RequestMethod.GET)
    @ResponseBody
    public Map<String, Object> getEmp() {
        Map<String, Object> emp = new HashMap<>();
        emp.put("name", "zhangsan");
        emp.put("age", 23);
        emp.put("salary", 8000);
        return emp;
    }
    @RequestMapping(path = "/emps", method = RequestMethod.GET)
    @ResponseBody
    public List<Map<String, Object>> getEmps() {
        List<Map<String, Object>> emps = new ArrayList<>();
        Map<String, Object> emp = new HashMap<>();
        emp.put("name", "zhangsan");
        emp.put("age", 23);
        emp.put("salary", 8000);
        emps.add(emp);

        emp = new HashMap<>();
        emp.put("name", "lisi");
        emp.put("age", 32);
        emp.put("salary", 5000);
        emps.add(emp);

        emp = new HashMap<>();
        emp.put("name", "wangwu");
        emp.put("age", 44);
        emp.put("salary", 6000);
        emps.add(emp);

        return emps;

    }

}
dao
AlphaDao.interface
package com.nowcoderbylia.community.dao;

public interface AlphaDao {

    String select();
}
AlphaDaoHibernateImpl
package com.nowcoderbylia.community.dao;

import org.springframework.stereotype.Repository;

@Repository("alphaHibernate")
public class AlphaDaoHibernateImpl implements AlphaDao{
    @Override
    public String select() {
        return "Hibernate";
    }
}
AlphaDaoMyBatisImpl
package com.nowcoderbylia.community.dao;

import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Repository;

@Repository
@Primary
public class AlphaDaoMyBatisImpl implements AlphaDao{
    @Override
    public String select() {
        return "MyBatis";
    }
}
service
AlphaService
package com.nowcoderbylia.community.service;

import com.nowcoderbylia.community.dao.AlphaDao;
import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class AlphaService {

    @Autowired
    private AlphaDao alphaDao;

    public AlphaService(){
        System.out.println("Instantiate AlphaService");
    }
    @PostConstruct
    public void init() {
        System.out.println("Initialize AlphaService");
    }

    @PreDestroy
    public void destroy() {
        System.out.println("Destroy AlphaService");
    }

    public String find() {
        return alphaDao.select();
    }
}
CommunityApplication
package com.nowcoderbylia.community;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class CommunityApplication {

   public static void main(String[] args) {
      SpringApplication.run(CommunityApplication.class, args);
   }

}

resources

test

java

com.nowcoderbylia.community

CommunityApplicationTests
package com.nowcoderbylia.community;

import com.nowcoderbylia.community.dao.AlphaDao;
import com.nowcoderbylia.community.service.AlphaService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.test.context.ContextConfiguration;

import java.security.PrivateKey;
import java.text.SimpleDateFormat;
import java.util.Date;

@SpringBootTest
@ContextConfiguration(classes = CommunityApplication.class)
class CommunityApplicationTests implements ApplicationContextAware {

   private ApplicationContext applicationContext;
   @Override
   public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
      this.applicationContext = applicationContext;
   }

   @Test
   public void testApplicationContext() {
      System.out.println(applicationContext);

      AlphaDao alphaDao = applicationContext.getBean(AlphaDao.class);
      System.out.println(alphaDao.select());

      alphaDao = applicationContext.getBean("alphaHibernate", AlphaDao.class);
      System.out.println(alphaDao.select());
   }

   @Test
   public void testBeanManagement() {
      AlphaService alphaService = applicationContext.getBean(AlphaService.class);
      System.out.println(alphaService);
   }

   @Test
   public void testBeanConfig() {
      SimpleDateFormat simpleDateFormat = applicationContext.getBean(SimpleDateFormat.class);
      System.out.println(simpleDateFormat.format(new Date()));
   }
   @Autowired
   @Qualifier("alphaHibernate")
   private AlphaDao alphaDao;

   @Autowired
   private AlphaService alphaService;

   @Autowired
   private SimpleDateFormat simpleDateFormat;
   @Test
   public void  testDI() {
      System.out.println(alphaDao);
      System.out.println(alphaService);
      System.out.println(simpleDateFormat);
   }
}

target

classes

generated-sources

generated-test-sources

test-classes

com

nowcodebylia

Community
CommunityApplicationTests (class)
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package com.nowcoderbylia.community;

import com.nowcoderbylia.community.dao.AlphaDao;
import com.nowcoderbylia.community.service.AlphaService;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.junit.jupiter.api.Test;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.test.context.ContextConfiguration;

@SpringBootTest
@ContextConfiguration(
    classes = {CommunityApplication.class}
)
class CommunityApplicationTests implements ApplicationContextAware {
    private ApplicationContext applicationContext;
    @Autowired
    @Qualifier("alphaHibernate")
    private AlphaDao alphaDao;
    @Autowired
    private AlphaService alphaService;
    @Autowired
    private SimpleDateFormat simpleDateFormat;

    CommunityApplicationTests() {
    }

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    @Test
    public void testApplicationContext() {
        System.out.println(this.applicationContext);
        AlphaDao alphaDao = (AlphaDao)this.applicationContext.getBean(AlphaDao.class);
        System.out.println(alphaDao.select());
        alphaDao = (AlphaDao)this.applicationContext.getBean("alphaHibernate", AlphaDao.class);
        System.out.println(alphaDao.select());
    }

    @Test
    public void testBeanManagement() {
        AlphaService alphaService = (AlphaService)this.applicationContext.getBean(AlphaService.class);
        System.out.println(alphaService);
    }

    @Test
    public void testBeanConfig() {
        SimpleDateFormat simpleDateFormat = (SimpleDateFormat)this.applicationContext.getBean(SimpleDateFormat.class);
        System.out.println(simpleDateFormat.format(new Date()));
    }

    @Test
    public void testDI() {
        System.out.println(this.alphaDao);
        System.out.println(this.alphaService);
        System.out.println(this.simpleDateFormat);
    }
}

pom.xml

avatar
文章
阅读
粉丝