-
Notifications
You must be signed in to change notification settings - Fork 1
Expand file tree
/
Copy pathFSDemo.java
More file actions
70 lines (61 loc) · 1.73 KB
/
Copy pathFSDemo.java
File metadata and controls
70 lines (61 loc) · 1.73 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
/*
This class implements a "fail-soft" array which prevents runtime errors.
*/
class FailSoftArray {
private int a[]; // reference to array
private int errval; // value to return if get() fails
public int length; // length is public
/*
Construct array give its size and the value to return if get() fails.
*/
public FailSoftArray(int size, int errv) {
a = new int[size];
errval = errv;
length = size;
}
// Return value at given index.
public int get(int index) {
if(ok(index)) return a[index];
return errval;
}
// Put a value at an index. Return false on failure.
public boolean put(int index, int val) {
if(ok(index)) {
a[index] = val;
return true;
}
return false;
}
// Return true if index is within bounds.
private boolean ok(int index) {
if(index >= 0 & index < length) return true;
return false;
}
}
// Demonstrate the fail-soft array.
class FSDemo {
public static void main(String args[]) {
FailSoftArray fs = new FailSoftArray(5, -1);
int x;
// show quite failures
System.out.println("Fail quietly.");
for(int i=0; i < (fs.length * 2); i++)
fs.put(i, i*10);
for(int i=0; i < (fs.length * 2); i++) {
x = fs.get(i);
if(x != -1) System.out.print(x + " ");
}
System.out.println("");
// now, handle failures
System.out.println("\nFail with error reports.");
for(int i=0; i < (fs.length * 2); i++)
if(!fs.put(i, i*10))
System.out.println("Index " + i + " out-of-bounds");
for(int i=0; i < (fs.length * 2); i++) {
x = fs.get(i);
if(x != -1) System.out.print(x + " ");
else
System.out.println("Index " + i + " out-of-bounds");
}
}
}