Cannot cast from SOMETHING to SOMETHING (Error in 1.4) (Works in 1.6)

Question

Our company have developed an accounting program, and it is already near completion.
We developed it with JavaBean and Eclipse in Windows Environment with JRE 1.6.0_05
When we tried to compile and run the program in our linux environment (Server) that runs on 1.4 , the casting error occured..
we have written a program to generate all casting errors that occurred in our project.
import java.math.*;
import java.util.*;
public class testnow {
     public static void main(String[] args){
          //Declare ALL Primitive!
          int TestINT = 150;
          Boolean TestBOOL = true;
          String TestSTR = "Streng" + "th";
          BigDecimal TestDCM = BigDecimal.valueOf(20);
          Date TestDATE = new Date();
          //Declare ALL Object
          Object TestINTObj = 150;
          Object TestSTRObj = "Strength";
          Object TestDCMObj = BigDecimal.valueOf(20);
          Object TestBOOLObj = true;
          Object TestDATEObj = new Date();
          if(TestINT == (Integer)TestINTObj){
               System.out.println("TEST Integer PASSED");
          if(TestSTR.equals((String)TestSTRObj)){
               System.out.println("TEST String PASSED");
          if(TestDCM.equals(TestDCMObj)){
               System.out.println("TEST Decimal PASSED");
          if(TestBOOL == (Boolean)TestBOOLObj){
               System.out.println("TEST Boolean PASSED");
          if(TestDATE.equals((Date)TestDATEObj)){
               System.out.println("TEST Date PASSED");
}the following is what happened when i run javac testnow.java
1. ERROR in testnow.java
(at line 6)
Integer TestINT = 150;
^^^^^^^
Type mismatch: cannot convert from int to Integer
2. ERROR in testnow.java
(at line 7)
Boolean TestBOOL = (Boolean)true;
^^^^^^^^^^^^^
Cannot cast from boolean to Boolean
3. ERROR in testnow.java
(at line 11)
Object TestINTObj = (Object)150;
^^^^^^^^^^^
Cannot cast from int to Object
4. ERROR in testnow.java
(at line 14)
Object TestBOOLObj = true;
^^^^^^^^^^^
Type mismatch: cannot convert from boolean to Object
4 problems (4 errors)
in our windows development JRE 1.6 , it run well and gives the following output :
TEST Integer PASSED
TEST String PASSED
TEST Decimal PASSED
TEST Boolean PASSED
TEST Date PASSED
how do we solve this? i mean we have been using this "convenience" casting all over our code . :(
please help
thanks a lot.
Cheers and God Bless,
Chowi

Answer 1

You've got a lot of problems there, and not all of them are due to Java version incompatibilites. I'll take them in the order I see them. public static Object FindDataInTable(ArrayList TargetTable, String TypeColumn,
         String TargetColumn, Object TargetData, String ReturnedColumn){ The convention is to give methods and variables names that start with lowercase letters. That makes your code easier to read, which makes it easier for us to help you. Later on, I see you also use a mix of underscores and camelcase. Underscores should be used only in constant names; class, method and variable names should use only camelcase.
Also, if you don't have a good reason to make that first argument an ArrayList, you should declare it as a List instead. That leaves the calling code the option of using a different List implementation should they need to.
Next, you assign a primitive value to an Object reference: Object ReturnedObject = 0; That requires autoboxing, as others have pointed out, which didn't exist in JDK 1.4. Even if you could use autoboxing though, that assignment would be a bad idea; a variable of type Object should be assigned a default value of {color:000080}null{color}, not a number. However, you may not need to declare that variable at all, as I explain later.
Next you use a "foreach" loop, another feature that was added in JDK 1.5; you'll have to switch to the old-style loop if you want this code to work under JDK 1.4. While you're at it, you should declare your "SingleRow" variable inside the loop, since it's not used anywhere else: for (Iterator it = TargetTable.iterator(); it.hasNext(); ) {
    Model_DatabaseQuery SingleRow = (Model_DatabaseQuery)it.next(); Next I see you using matches() to compare String values: if(TypeColumn.matches("String")){
    if(((String)TargetData).matches((String)CheckData)){ You get away with that because the strings contain only letters, but you need to look up the docs for matches() so you'll understand why you shoudn't be using it here. But this is nothing compared to the next issue: if((Integer)TargetData == (Integer)CheckData){ // WRONG WRONG WRONG That can't possibly have worked right, no matter what version of Java you ran it under. You NEVER use == to compare the values objects! You should have been using equals() for all those comparisions, not matches(), and definitely not ==.
But I don't see why you're doing all those checks on the column type anyway. All you ever do after that is compare the same two values, so just do it: for (Iterator it = targetTable.iterator(); it.hasNext(); ) {
    Model_DatabaseQuery SingleRow = (Model_DatabaseQuery)it.next();
    Object CheckData = SingleRow.Get_object(TargetColumn);
    if (CheckData != null && CheckData.equals(TargetData)) {
        return SingleRow.Get_object(ReturnedColumn);
} If there are other columns that you're supposed to ignore, you may still need to check the column type, but you could do that in one {color:000080}if{color} statement; you don't have to check them all separately.