Add integer validator.

Change-Id: If2dab9ae160c2152758ea4240175a0d928ae48c5
Reviewed-on: http://gerrit.dmdirc.com/3568
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>

src/com/dmdirc/util/validators/IntegerValidator.java

@@ -0,0 +1,68 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+package com.dmdirc.util.validators;
+
+/**
+ * Validates that a number is within certain bounds.
+ */
+public class IntegerValidator implements Validator<Integer> {
+
+    /**
+     * The minimum value for this number.
+     */
+    protected final int min;
+
+    /**
+     * The maximum value for this number.
+     */
+    protected final int max;
+
+    /**
+     * Creates a new numerical validator with the specified bounds.
+     *
+     * @param min The minimum value for the number, or -1 for unlimited.
+     * @param max The maximum value for the number, or -1 for unlimited.
+     */
+    public IntegerValidator(final int min, final int max) {
+        this.max = max == -1 ? Integer.MAX_VALUE : max;
+        this.min = min == -1 ? Integer.MIN_VALUE : min;
+        if (this.min > this.max) {
+            throw new IllegalArgumentException("min must be less than max.");
+        }
+    }
+
+    /**
+     * Retrieves the maximum value that this validator will allow.
+     *
+     * @return This validator's maximum value
+     */
+    public int getMax() {
+        return max;
+    }
+
+    /**
+     * Retrieves the minimum value that this validator will allow.
+     *
+     * @return This validator's minimum value
+     */
+    public int getMin() {
+        return min;
+    }
+
+    @Override
+    public ValidationResponse validate(final Integer object) {
+
+        if (object < min) {
+            return new ValidationResponse("Must be at least " + min);
+        } else if (object > max) {
+            return new ValidationResponse("Must be at most " + max);
+        } else {
+            return new ValidationResponse();
+        }
+    }
+
+}