org.apache.maven.plugins:maven-compiler-plugin:3.10.1:compile cannot compile class LocalDate

[peter tong]

LocalDate should be available in java 17, but why maven-compiler-plugin:3.10.1 cannot recognize it?
the project is mainly from https://spring.io/guides/gs/accessing-data-mysql/
I just change the user class to add one more property with datatype LocalDate

private LocalDate test;

in my pom.xml, java is using version 17

<properties>
	<java.version>17</java.version>
</properties>

but the error seems it is not using java 17 to compile.


the error message is

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.10.1:compile (default-compile) on project accessing-data-mysql-complete: Compilation failure: Compilation failure:
[ERROR] /D:/IdeaProjects/gs-accessing-data-mysql/complete/src/main/java/com/example/accessingdatamysql/User.java:[18,17] cannot find symbol
[ERROR]   symbol:   class LocalDate
[ERROR]   location: class com.example.accessingdatamysql.User
[ERROR] /D:/IdeaProjects/gs-accessing-data-mysql/complete/src/main/java/com/example/accessingdatamysql/User.java:[44,16] cannot find symbol
[ERROR]   symbol:   class LocalDate
[ERROR]   location: class com.example.accessingdatamysql.User
[ERROR] /D:/IdeaProjects/gs-accessing-data-mysql/complete/src/main/java/com/example/accessingdatamysql/User.java:[48,29] cannot find symbol
[ERROR]   symbol:   class LocalDate
[ERROR]   location: class com.example.accessingdatamysql.User
[ERROR] -> [Help 1]

the pom is

<?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>3.0.0</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>accessing-data-mysql-complete</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>accessing-data-mysql-complete</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>17</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

the failed compile class is

package com.example.accessingdatamysql;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;

@Entity // This tells Hibernate to make a table out of this class
public class User {
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	private Integer id;

	private String name;

	private String email;

	private LocalDate test;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public LocalDate getTest() {
		return test;
	}

	public void setTest(LocalDate test) {
		this.test = test;
	}
}

I try to import java.time package but still fail.

[ERROR] /D:/IdeaProjects/gs-accessing-data-mysql/complete/src/main/java/com/example/accessingdatamysql/User.java:[7,12] cannot find symbol
[ERROR]   symbol:   class time
[ERROR]   location: package java

[Stephan van Hulst]

Did you write:

import java.time;

Then that's the problem.

It should be

import java.time.*;

Or use single class imports if that's your cup of tea.

[peter tong]

Stephan van Hulst wrote:Did you write:

import java.time;

Then that's the problem.

It should be

import java.time.*;

Or use single class imports if that's your cup of tea.

yes, after I change to

import java.time.*;

the class can be compiled.
But why Intellij cannot show me the error before?
I already check the checkbox build project automatically in Build, Execution, Deployment > Compiler.
IntelliJ should compile the class automatically when I save the class.

[Himai Minh]

Sometimes,  you may need to do File -> Invalidate Cache and restart your IntelliJ in order to make IntelliJ to work properly.

[peter tong]

peter tong wrote:
But why Intellij cannot show me the error before?
I already check the checkbox build project automatically in Build, Execution, Deployment > Compiler.
IntelliJ should compile the class automatically when I save the class.

Success finally, I  think the critical step is Right-click on pom.xml and then click on "Add as Maven Project" after new project from intellij  File > new > project from version control.