【Java】【spring boot】springboot入门

quick start

进入
https://start.spring.io/
在依赖里 加一个springweb
版本不要选snapshot
Java选14 generate就会下载一个压缩包

解压 用idea打开
找到src/main/java/com/example/demo/DemoApplication.java
改成以下内容

              package com.example.demo;
              import org.springframework.boot.SpringApplication;
              import org.springframework.boot.autoconfigure.SpringBootApplication;
              import org.springframework.web.bind.annotation.GetMapping;
              import org.springframework.web.bind.annotation.RequestParam;
              import org.springframework.web.bind.annotation.RestController;
              
              @SpringBootApplication
              @RestController
              public class DemoApplication {
                
                  
                  public static void main(String[] args) {
                  SpringApplication.run(DemoApplication.class, args);
                  }
                  
                  @GetMapping("/hello")
                  public String hello(@RequestParam(value = "name", defaultValue = "World") String name) {
                  return String.format("Hello %s!", name);
                  }
                
              }
            

点build会报一个错 无效的发行版
感觉是我的java版本太新了 guide里面也说建议用Java8或者11
但是我是14

到这个里面把language level改成11好了

到项目路径运行指令

mvnw spring-boot:run

等了半天困得受不了 了
下来发现已经好了。

到浏览器试一下

还可以带参数

building an application

需要Gradle 4+ or Maven 3.2+
但是我都没有 不知道行不行

重新起一个springboot项目
https://start.spring.io/
加入web依赖

创建一个web application
src/main/java/com/example/springboot/HelloController.java

package com.example.springboot;

import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.RequestMapping;

@RestController
public class HelloController {

	@RequestMapping("/")
	public String index() {
		return "Greetings from Spring Boot!";
	}

}

create an application class
src/main/java/com/example/springboot/Application.java

package com.example.springboot;

import java.util.Arrays;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class Application {

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

	@Bean
	public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
		return args -> {

			System.out.println("Let's inspect the beans provided by Spring Boot:");

			String[] beanNames = ctx.getBeanDefinitionNames();
			Arrays.sort(beanNames);
			for (String beanName : beanNames) {
				System.out.println(beanName);
			}

		};
	}

}

运行

./mvnw spring-boot:run

让这个springboot项目保持运行，额外再起一个终端

添加单元测试
注意是在test文件夹
src/test/java/com/example/springboot/HelloControllerTest.java

package com.example.springboot;

import static org.hamcrest.Matchers.equalTo;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import org.junit.jupiter.api.Test;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;

@SpringBootTest
@AutoConfigureMockMvc
public class HelloControllerTest {

	@Autowired
	private MockMvc mvc;

	@Test
	public void getHello() throws Exception {
		mvc.perform(MockMvcRequestBuilders.get("/").accept(MediaType.APPLICATION_JSON))
				.andExpect(status().isOk())
				.andExpect(content().string(equalTo("Greetings from Spring Boot!")));
	}
}

也可以写一个简单的全栈继承测试
创建一个test
src/test/java/com/example/springboot/HelloControllerIT.java

package com.example.springboot;

import static org.assertj.core.api.Assertions.*;

import java.net.URL;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.server.LocalServerPort;
import org.springframework.http.ResponseEntity;

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class HelloControllerIT {

	@LocalServerPort
	private int port;

	private URL base;

	@Autowired
	private TestRestTemplate template;

    @BeforeEach
    public void setUp() throws Exception {
        this.base = new URL("http://localhost:" + port + "/");
    }

    @Test
    public void getHello() throws Exception {
        ResponseEntity<String> response = template.getForEntity(base.toString(),
                String.class);
        assertThat(response.getBody()).isEqualTo("Greetings from Spring Boot!");
    }
}

服务器会随机开一个port