intellij 想法 - 错误：java：源代码版本 1.9 无效

Question

I'm trying to run my JSQL parser class, but I'm getting Error: java: invalid source release 1.9 .

I tried to following this answer . I changed File> Build,Execution,Deployment> Java Compiler> Project bytecode version: 1.8. However, I can't change the Module language level and Project language level to 1.8 because there's not option for that. I still get the same error below.

Error

Code

package cs4321.project2;

import java.io.FileReader;
import net.sf.jsqlparser.parser.CCJSqlParser;
import net.sf.jsqlparser.statement.Statement;
import net.sf.jsqlparser.statement.select.Select;

public class Parser {
    private static final String queriesFile = "resources/input/queries.sql";

    public static void main(String[] args) {
        try {
            CCJSqlParser parser = new CCJSqlParser(new FileReader(queriesFile));
            Statement statement;
            while ((statement = parser.Statement()) != null) {
                System.out.println("Read statement: " + statement);
                Select select = (Select) statement;
                System.out.println("Select body is " + select.getSelectBody());
            }
        } catch (Exception e) {
            System.err.println("Exception occurred during parsing");
            e.printStackTrace();
        }
    }
}

Answer 1

Select the project, then File > ProjectStructure > ProjectSettings > Modules -> sources You probably have the Language Level set at 9:

Just change it to 8 (or whatever you need) and you're set to go.

Also, check the same Language Level settings mentioned above, under Project Settings > Project

Answer 2

Sometimes the problem occurs because of the incorrect version of the project bytecode.

So verify it : File -> Settings -> Build, Execution, Deployment -> Compiler -> Java Compiler -> Project bytecode version and set its value to 8

Answer 3

I have had the same problem. There is an answer:

• 1. CTRL + ALT + SHIFT + S ;
  2. Then go to " Modules" ;
  3. " Dependencies ;
  4. Change " Module SDK ".

Got it! Now u have Java 9!

Answer 4

You should to set the JAVA SDK and appropriate language level in the project settings. Click to enlarge.

Answer 5

GRADLE projects

Since we started working with GRADLE,

Build.gradle: - even below line didn't help

sourceCompatibility = '16'

I am getting this ERROR most of the time and Solution is Change Gradle JVM to XX

Preferences | Build, Execution, Deployment | Build Tools | Gradle -> JVM

Answer 6

I was having this issue while running a SpringBoot project (Maven)

In my POM file I changed the java version from 11 to 8 and it worked:

<properties>
    <java.version>8</java.version> //The default was 11
</properties>

Make sure to Load maven changes else the change won't reflect.

Answer 7

When using maven project.

check pom.xml file

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>9</java.version>
</properties>

if you have jdk 8 installed in your machine, change java.version property from 9 to 8

Answer 8

I've just had a similar issue. The project had opened using Java 9 but even after all the modules and project were set back to 1.8, I was still getting the error.

I needed to force Gradle to refresh the project and then everything ran as expected.

Answer 9

Gradle I had the same issue and changing all the settings given in the earlier solutions made no difference. Than I went to the build.gradle and found this line and deleted it.

sourceCompatibility = '11'

and it worked! :)

Answer 10

Alternatively via Project Settings:

• Project Settings
• Project
• Project language Level (set to fit your needs)

Depending on how your build is set up, this may be the way to go.

Answer 11

For anyone struggling with this issue who tried DeanM's solution but to no avail, there's something else worth checking, which is the version of the JDK you have configured for your project. What I'm trying to say is that if you have configured JDK 8u191 (for example) for your project, but have the language level set to anything higher than 8, you're gonna get this error.

In this case, it's probably better to ask whoever's in charge of the project, which version of the JDK would be preferable to compile the sources.

Answer 12

在项目SDK 的项目结构中：将 SDK 修改为 11 或更高版本，在项目语言级别：修改为 11 - lambda 参数的局部变量语法

Answer 13

I also had the same problem in IntellijIdea, after selecting the project, then File > ProjectStructure > ProjectSettings > Modules -> sources the option was showing - the Language Level set at 9:

So, I Just change it to 8. Still my issue didn't got resolve.

The main issue was with pom.xml. I reimported the pom.xml file and my issue got resolved.

So, whenever you changed the pom.xml file, IDEA needs to update the project structure. For example if you've added there some more dependencies, IDEA needs to add them as project libraries.

In "Settings > Build, Execution, Deployment > Build Tools > Maven > Importing" you can choose "Import Maven projects automatically". This will automatically invoke "Reimport" action when the pom.xml is changed.

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Answer 14

Just additional note:

when you creating a new project from start.spring.io make sure you select your JDK version theirs by default is set to JDK 11, later it will cause the above issue.

Answer 15

File > Project Structure > Project > Project SDK > Choose Version File > Project Structure > Project > Project Language Level > Choose Version File > Project Structure > Modules > Sources Tab > Language Level > Choose Level File > Project Structure > Modules > Dependencies Tab > Module SDK > Choose Version

In Pom.xml under properties change to your version

<properties>
    <java.version>16</java.version>
</properties>

Right Click Pom then Mavem then Reload Project

Answer 16

I was able to overcome this issue only clearing/removing the VM configuration. But you should do all the following checks:

1. Menu File/Project Structure/Project (select the SDK and the correct language level -- in may case 1.8.0_201 and "8 - Lambdas...")

2. Menu File/Project Structure/Modules/Sources (on the right) - Select the same Language Level

3. Menu File/Project Structure/Dependencies (also on the right) - Select the same Module SDK

4. (If still does not work...) Menu Run/Edit configurations

I removed the lines from the configuration and all start running.

--module-path
${PATH_TO_FX}
--add-modules
javafx.controls,javafx.fxml