Mega Code Archive
Convert array to string
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/* ArraysX.java
{{IS_NOTE
Purpose:
Description:
History:
2001/11/13, Henri Chen: Created.
}}IS_NOTE
Copyright (C) 2001 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under GPL Version 3.0 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
import java.lang.reflect.Array;
/**
* Utilities for handling arrays.
*
* @author henrichen
*/
public class ArraysX {
/** Converts an array to a readable string (for debugging purpose).
*/
public final static String toString(Object[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
if (array[j] == array)
sb.append("(this array)");
else
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of int to a readable string (for debugging purpose).
*/
public final static String toString(int[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of long to a readable string (for debugging purpose).
*/
public final static String toString(long[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of short to a readable string (for debugging purpose).
*/
public final static String toString(short[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of byte to a readable string (for debugging purpose).
*/
public final static String toString(byte[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of char to a readable string (for debugging purpose).
*/
public final static String toString(char[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of boolean to a readable string (for debugging purpose).
*/
public final static String toString(boolean[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of float to a readable string (for debugging purpose).
*/
public final static String toString(float[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/** Converts an array of char to a readable string (for debugging purpose).
*/
public final static String toString(double[] array) {
if (array == null)
return "null";
StringBuffer sb = new StringBuffer(128).append('[');
for (int j = 0; j < array.length; ++j) {
sb.append(array[j]);
if (j != array.length - 1)
sb.append(", ");
}
return sb.append(']').toString();
}
/**
* Returns the hex String representation of a byte array without prefix 0x.
* The String is formed by making value[0] the leftmost two digits and
* value[value.length-1] the rightmost two digits.
*
* @param array the byte array
*/
public final static String toHexString(byte[] array) {
StringBuffer sb = new StringBuffer(array.length*2 + 8);
char ch;
for (int i=0; i< array.length; i++) {
// byte will be promote to integer first, mask with 0x0f is a must.
ch = Character.forDigit(array[i] >>> 4 & 0x0f, 16);
sb.append(ch);
ch = Character.forDigit(array[i] & 0x0f, 16);
sb.append(ch);
}
return sb.toString();
}
/**
* Returns the octal String representation of a byte array with optional
* prefix. The String is formed by making value[0] the leftmost three digits
* and value[value.length-1] the rightmost three digits.
*
* @param array the byte array
*/
public final static String toOctalString(byte[] array, String prefix) {
StringBuffer sb = new StringBuffer(array.length*(3+prefix.length()) + 8);
if (prefix == null) {
for (int i=0; i< array.length; i++) {
appendOctalDigits(sb, array[i]);
}
} else {
for (int i=0; i< array.length; i++) {
sb.append(prefix);
appendOctalDigits(sb, array[i]);
}
}
return sb.toString();
}
/**
* Returns the octal digit String buffer representation of a byte.
* @param byte the byte
*/
private final static StringBuffer appendOctalDigits(StringBuffer sb, byte b) {
// b will be promote to integer first, mask with 0x07 is a must.
return sb.append(Character.forDigit(b >>> 6 & 0x07, 8))
.append(Character.forDigit(b >>> 3 & 0x07, 8))
.append(Character.forDigit(b & 0x07, 8));
}
/**
* Duplicates the specified array.
*
* <p>The array could be an array of objects or primiitives.
*
* @param ary the array
* @param jb the beginning index (included)
* @param je the ending index (excluded)
* @return an array duplicated from ary
* @exception IllegalArgumentException if ary is not any array
* @exception IndexOutOfBoundsException if out of bounds
*/
public static final Object duplicate(Object ary, int jb, int je) {
int len = Array.getLength(ary);
if (jb<0 || je>len || jb>je)
throw new IndexOutOfBoundsException(jb + " or " + je + " exceeds " + len);
len = je - jb;
Object dst = Array.newInstance(ary.getClass().getComponentType(), len);
System.arraycopy(ary, jb, dst, 0, len);
return dst;
}
/**
* Duplicates the specified array.
* @param ary the array
* @return an array duplicated from ary
* @exception IllegalArgumentException if ary is not any array
* @exception IndexOutOfBoundsException if out of bounds
*/
public static final Object duplicate(Object ary) {
return duplicate(ary, 0, Array.getLength(ary));
}
/**
* Concat the two specified array.
*
* <p>The array could be an array of objects or primiitives.
*
* @param ary the array
* @param ary1 the array
* @return an array concat the ary and ary1
* @exception IllegalArgumentException if ary and ary1 component type are different
*/
public static final Object concat(Object ary, Object ary1) {
int len = Array.getLength(ary) + Array.getLength(ary1);
if (!ary.getClass().getComponentType().equals(ary1.getClass().getComponentType()))
throw new IllegalArgumentException("These concated array component type are different.");
Object dst = Array.newInstance(ary.getClass().getComponentType(), len);
System.arraycopy(ary, 0, dst, 0, Array.getLength(ary));
System.arraycopy(ary1, 0, dst, Array.getLength(ary), Array.getLength(ary1));
return dst;
}
/**
* Shrink the specified array. It is similar to duplicate, except
* it returns the previous instance if je==length && jb==0.
*
* @param ary the array
* @param jb the beginning index (included)
* @param je the ending index (excluded)
* @return ary or an array duplicated from ary
* @exception IllegalArgumentException if ary is not any array
* @exception IndexOutOfBoundsException if out of bounds
*/
public static final Object shrink(Object ary, int jb, int je) {
if (jb == 0 && je == Array.getLength(ary))
return ary; //nothing changed
return duplicate(ary, jb, je);
}
/**
* Resizes the specified array. Similar to {@link #shrink}, but
* it can enlarge and it keeps elements from the first.
*/
public static final Object resize(Object ary, int size) {
final int oldsz = Array.getLength(ary);
if (oldsz == size)
return ary;
final Object dst = Array.newInstance(ary.getClass().getComponentType(), size);
System.arraycopy(ary, 0, dst, 0, oldsz > size ? size: oldsz);
return dst;
}
/** Clones an array.
*/
public static final Object clone(Object ary) {
final int size = Array.getLength(ary);
final Object dst = Array.newInstance(ary.getClass().getComponentType(), size);
System.arraycopy(ary, 0, dst, 0, size);
return dst;
}
}
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