exception中finally语句块的return问题

exception中finally语句块的return问题:如果try或catch语句中有return，

会先执行finally再执行return,但下面的一段程序我编译后提示缺少return语句，请教各位是怎么回事，

我开始以为只有try中有return确实有可能不执行，于是我又在catch中加了一个return，但提示还是一样。代码如下：
public String printAllCustomers() throws SQLException{
Connection con=null;
Statement stmt=null;
ResultSet rs=null;
String s=null;
StringBuffer sb=new StringBuffer();
try{
con=provider.getConnection();
stmt=con.createStatement();
//查询记录
rs= stmt.executeQuery("SELECT ID,NAME,AGE,ADDRESS from CUSTOMERS");
//输出查询结果
while (rs.next()){
long id = rs.getLong(1);
String name = rs.getString(2);
int age = rs.getInt(3);
String address = rs.getString(4);

//返回结果
sb.append("id="+id+",name="+name+",age="+age+",address="+address);
s=sb.toString();
return s;
}
}catch(SQLException e){
return s;
}
finally{
closeResultSet(rs);
closeStatement(stmt);
closeConnection(con);
}
}

------解决方法--------------------------------------------------------

Java code

 public String printAllCustomers() throws SQLException{  Connection con=null;  Statement stmt=null;  ResultSet rs=null;  String s=null;  StringBuffer sb=new StringBuffer();  try{  con=provider.getConnection();  stmt=con.createStatement();  //查询记录  rs= stmt.executeQuery("SELECT ID,NAME,AGE,ADDRESS from CUSTOMERS");  //输出查询结果  while (rs.next()){ //BEGIN----------------------------------------  long id = rs.getLong(1);   String name = rs.getString(2);   int age = rs.getInt(3);   String address = rs.getString(4);     //返回结果   sb.append("id="+id+",name="+name+",age="+age+",address="+address);   s=sb.toString();   return s;  } //END---------------------------------------- }catch(SQLException e){ return s;  }  finally{  closeResultSet(rs);  closeStatement(stmt);  closeConnection(con);  }  }