springboot3时代创建springboot2程序项目

springboot3时代创建springboot2程序项目

目前，IDEA，springboot 官网，都不能创建基于JDK8(JDK1.8)的springboot程序了。

解决办法：

1. 先在官网（https://start.spring.io/）初始化一个 springboot3程序 （JDK17）。

2.解压压缩包，并修改pom.xml 文件 。

2.1 找到spring-boot-starter-parent，把 <version>3.1.9</version>修改为 <version>2.7.0</version>

2.2 找到 java.version，修改为 <java.version>1.8</java.version>。

3. 如果 String 报红字错码，鼠标移动上去，会提示你指定 JDK，选择JDK8 即可。

完整pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>apidemo1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>apidemo1</name>
    <description>api port test</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <image>
                        <builder>paketobuildpacks/builder-jammy-base:latest</builder>
                    </image>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Apidemo1Application：

package com.example.apidemo1;

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

@SpringBootApplication
public class Apidemo1Application {

    public static void main(String[] args) {
        SpringApplication.run(Apidemo1Application.class, args);
    }

}

HomeController：

package com.example.apidemo1;

import org.springframework.boot.system.ApplicationHome;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.File;

@RestController
public class HomeController {

    @RequestMapping("/test")
    String index() {

        String msg = "123";

        try {

            System.out.println( "msg:" + msg);

        } catch (Exception ex) {
            msg = ex.getMessage();
        }
        return "Hello Spring Boot  " + msg;
    }

    public String getJarRoot() {
        ApplicationHome home = new ApplicationHome(getClass());
        File jarFile = home.getSource();
        return jarFile.getParentFile().getPath();
    }

}

。。