Joshua Bloch in &quot;*Effective Java*&quot; said that 

&gt; Use checked exceptions for
&gt; recoverable conditions and runtime
&gt; exceptions for programming errors
&gt; (Item 58 in 2nd edition)

Let&#39;s see if I understand this correctly.

Here is my understanding of a checked exception:

    try{
        String userInput = //read in user input
        Long id = Long.parseLong(userInput);
    }catch(NumberFormatException e){
        id = 0; //recover the situation by setting the id to 0
    }
**1. Is the above considered a checked exception?**

**2. Is RuntimeException an unchecked exception?**

Here is my understanding of an unchecked exception:

    try{
        File file = new File(&quot;my/file/path&quot;);
        FileInputStream fis = new FileInputStream(file);   
    }catch(FileNotFoundException e){
        
    //3. What should I do here?
        //Should I &quot;throw new FileNotFoundException(&quot;File not found&quot;);&quot;?
        //Should I log?
        //Or should I System.exit(0);?
    }

**4. Now, couldn&#39;t the above code also be a checked exception? I can try to recover the situation like this? Can I?** (Note: my 3rd question is inside the `catch` above)

    try{
        String filePath = //read in from user input file path
        File file = new File(filePath);
        FileInputStream fis = new FileInputStream(file);   
    }catch(FileNotFoundException e){
        //Kindly prompt the user an error message
        //Somehow ask the user to re-enter the file path.
    }
 
**5. Why do people do this?**

    public void someMethod throws Exception{

    }

Why do they let the exception bubble up? Isn&#39;t handling the error sooner better? Why bubble up? 

**6. Should I bubble up the exact exception or mask it using Exception?**

**Below are my readings**

https://stackoverflow.com/questions/499437/in-java-when-should-i-create-a-checked-exception-and-when-should-it-be-a-runtim

https://stackoverflow.com/questions/27578/when-to-choose-checked-and-unchecked-exceptions

All Unchecked Exception Solutions on Gang of Coders

Total of 1 Unchecked Exception Solutions

Understanding checked vs unchecked exceptions in Java