CODEWITHSUNDEEP
javaunit-testingjunitmockito
Vishal Roy
Vishal Roy

Reputation: 130

How to write unit test in java for loading file

I want to perform unit test to check file loading in java. I saw some posts on Mockitos doThrow but don't get the implementation of it exactly.

My method looks something like this.

    public void loadPropertiesFile(String filepath){
    logger.info("Loading properties file");
    try{
        prop.load(new FileInputStream(filepath));
        logger.info("Properties file read");
    }catch(IOException e){
        e.printStackTrace();
        logger.info("Properties file read error");
    }
}

I was trying to test it like this but getting error on improper usage of doThrow:

@Test
    public void loadPropertiesFileTestTrue(){
        Utility util=new Utility();

        doThrow(FileNotFoundException.class)
            .when(util)
            .loadPropertiesFile(null);

    }

Upvotes: 0

Views: 217

Answers (1)

Pavel Smirnov
Pavel Smirnov

Reputation: 4799

You can use doThrow() method on mocked objects only.
You should change your code like this:

@Test
public void loadPropertiesFileTestTrue(){
     Utility util=Mockito.mock(Utility.class);

     doThrow(FileNotFoundException.class)
            .when(util)
            .loadPropertiesFile(null);

}

Upvotes: 1

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