java - Understanding conditions for precise rethrow -

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static class firstexception extends exception { } static class secondexception extends exception { }  public void rethrowexception(string exceptionname) throws firstexception, secondexception {   try {     if (exceptionname.equals("first")) {       throw new firstexception();     } else {       throw new secondexception();     }   } catch (exception e) {     throw e;   } }

in detail, in java se 7 , later, when declare 1 or more exception types in catch clause, , rethrow exception handled catch block, compiler verifies type of rethrown exception meets following conditions:

the try block able throw it.

there no other preceding catch blocks can handle it.

it subtype or supertype of 1 of catch clause's exception parameters.

can explain meaning of these conditions?(examples counter these conditions)

also in last condition, it refers , catch clause's exception parameters in above code?


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