How do I compile with -Xlint:unchecked?

Question

I'm getting a message when I compile my code:

Note: H:\Project2\MyGui2.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

How do I recompile with -Xlint:unchecked ?

Answer 1

Specify it on the command line for javac:

javac -Xlint:unchecked

Or if you are using Ant modify your javac target

  <javac ...>
    <compilerarg value="-Xlint"/>
  </javac> 

If you are using Maven, configure this in the maven-compiler-plugin

<compilerArgument>-Xlint:unchecked</compilerArgument>

Answer 2

对于IntelliJ 13.1 ，转到File -> Settings -> Project Settings -> Compiler -> Java Compiler ，并在右侧，对于Additional command line parameters输入"-Xlint:unchecked" 。

Answer 3

In gradle project, You can added this compile parameter in the following way:

gradle.projectsEvaluated {
    tasks.withType(JavaCompile) {
        options.compilerArgs << "-Xlint:unchecked"
    }
}

Answer 4

I know it sounds weird, but I'm pretty sure this is your problem:

Somewhere in MyGui.java you're using a generic collection without specifying the type. For example if you're using an ArrayList somewhere, you are doing this:

List list = new ArrayList();

When you should be doing this:

List<String> list = new ArrayList<String>();

Answer 5

There is another way for gradle:

compileJava {
    options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
}

Answer 6

For Android Studio add the following to your top-level build.gradle file within the allprojects block

tasks.withType(JavaCompile) {
    options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation" 
}

Answer 7

In CMD, write:

javac -Xlint:unchecked MyGui2.java

it will display the list of unchecked or unsafe operations.

Answer 8

If you work with an IDE like NetBeans, you can specify the Xlint:unchecked compiler option in the propertys of your project.

Just go to projects window, right click in the project and then click in Properties .

In the window that appears search the Compiling category, and in the textbox labeled Additional Compiler Options set the Xlint:unchecked option.

Thus, the setting will remain set for every time you compile the project.

Answer 9

other way to compile using -Xlint:unchecked through command line

javac abc.java -Xlint:unchecked

it will show the unchecked and unsafe warnings.

Answer 10

指定 Gradle 编译器参数的更简洁方法如下：

compileJava.options.compilerArgs = ['-Xlint:unchecked','-Xlint:deprecation']

Answer 11

FYI getting to these settings has changed for IntelliJ 15, new and improved for even deeper burial!

Now it's: File > Other Settings > Default Settings > 'Build, Execution, Deployment' > Compiler > Java Compiler

And in Additional command line parameters, same as before, write "-Xlint:unchecked".