intellij idea - Error: java: invalid source releas

问题:

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();
        }
    }
}

回答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

回答2:

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!

回答3:

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.

回答4:

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.

回答5:

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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