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Last Updated: June 30, 2016
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172
· drafa
063c9870873bc9dcc3a02b7a76fffab2

StringBuilderUtil

Facilitates the use of StringBuilder.

  • gist: https://gist.github.com/drafa/d97b2563147a55baadea
  • methods:
    • append(Object... obj) : StringBuilder -> Allows concatenation of objects to one another, adding at the end of the resulting string
    • insert(Object... obj) : StringBuilder -> Allows concatenation of objects to one another, adding at the beginning of the resulting string
/**
 * Allows concatenation of objects to one another, adding at the end of the 
 * resulting string
 * see {@link StringBuilder#append(Object) StringBuilder.append(Object obj)}
 * @param obj
 * @return a <code>StringBuilder</code> with all objects
 * @author https://github.com/drafa
 */
public static StringBuilder append(Object... obj) {
    if(obj==null) { return new StringBuilder("null"); }
    StringBuilder sb = new StringBuilder();
    int i=0, l=obj.length;
    while(i<l) { sb.append(obj[i++]); }
    return sb;
}
/**
 * Allows concatenation of objects to one another, adding at the beginning
 * of the resulting string
 * @see {@link StringBuilder#insert(Object) StringBuilder.insert(Object obj)}
 * @param obj
 * @return a <code>StringBuilder</code> with all objects
 * @author https://github.com/drafa
 */
public static StringBuilder insert(Object... obj) {
    if(obj==null) { return new StringBuilder("null"); }
    StringBuilder sb = new StringBuilder();
    int zero=0, i=zero, l=obj.length;
    while(i<l) { sb.insert(zero, obj[i++]); }
    return sb;
}
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Java 8 also has a static join() method which is much more powerful than your append method (you can e.g. define a delimiter for joining).

But if you're stuck with Java < 8 your implementation is quite nice.

To avoid code duplication, I would suggest that insert calls append with the array reversed, something like:

public static StringBuilder insert(Object... obj) {
    List<Object> l = new ArrayList<>(Arrays.asList(obj));
    Collections.reverse(l);

    return append(l.toArray());
}
over 1 year ago ·