Java: on the difference between return and throw in catch statement blocks in try-catch-finally

in the following example

Student s = new Student("lily", 3);  //name, age
    try{
        int i = 3;
        int j = i/0;
        return s.toString();
    }catch (Exception e){
        Student t = s;
        return t.toString();               // 1
    }finally {
        s.setName("baga");
        System.out.println(s.toString());   // 2
    }

statement 2 executes before statement 1. The result is that Name is baga age is: 3
statement 1 returns the following:
Name is lily age is: 3
, which means that return is a deep copy of s, and s cannot be affected by finally blocks

Grammar Sugar try with resource

    try(FileInputStream fis = new FileInputStream(file)){
        fis.read();
    } catch (IOException e3){
        ...
    }
    


    try{
        FileInputStream fis = new FileInputStream(file);
        Throwable t = null;
        try{
            fis.read();
        }catch (Throwable t1){
            t = t1;
            throw t1;
        }finally {
            if(fis != null){
                if(t != null){
                    try {
                        fis.close();
                    }catch (Throwable t2){
                        t.addSuppressed(t2); 
                    }
                }
                else {
                    fis.close();
                }
            }
        }
    }catch (IOException e3){
        ...
    }

where we see

in the catch block

t=t1;
throw t1;

then the following:

t.addSuppressed(t2);

T2 can be carried by the T1 that can be thrown, indicating that throw T1 retains a shallow copy and can be affected by finally blocks

what is the difference?

Java

Mar.23,2021

import java.io.File; import java.io.FileInputStream; import java.io.IOException; import org.junit.Test; public class TestExample { public static class Student { private String name; private int age; public Student(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { // TODO Auto-generated method stub return "Name is " + name + " age is " + age; } public void setName(String string) { this.name = string; } } public String get() { Student s = new Student("lily", 3); // name, age try { int i = 3; int j = i / 0; return s.toString(); } catch (Exception e) { Student t = s; return t.toString(); // 1 } finally { s.setName("baga"); System.out.println(s.toString()); // 2 } } @Test public void test1() { try { File file = new File(""); FileInputStream fis = new FileInputStream(file); Throwable t = null; try { fis.read(); } catch (Throwable t1) { t = t1; throw t1; } finally { if (fis != null) { if (t != null) { try { fis.close(); } catch (Throwable t2) { t.addSuppressed(t2); } } else { fis.close(); } } } } catch (IOException e3) { } } @Test public void test() { String result = get(); System.out.print(result); } }