Java Switch Statement

You can do this:

switch (variable){
  case A:  do statement_1; do statement_3; break;
  case B:  do statement_2; do statement_3; break;    
}

i would recommend to define exactly what staments should be executed:

switch (variable){
    case A: 
        statement_1();
        statement_3();
        break;
    case B: 
        statement_2();
        statement_3();
        break;
}

for Update-3:

create methods for those 10 lines:

public void statement_1() {
    //your 10 lines of code
}

if you're always executing statement_3, except for case C you can go with if/else-blocks as you wrote them.

but in my honest opinion: define EXACTLY what has to be done in which case if you have a small amount of cases. it is easier to read for others