org.h2.util.StatementBuilder Maven / Gradle / Ivy
/*
* Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.util;
/**
* A utility class to build a statement. In addition to the methods supported by
* StringBuilder, it allows to add a text only in the second iteration. This
* simplified constructs such as:
*
* StringBuilder buff = new StringBuilder();
* for (int i = 0; i < args.length; i++) {
* if (i > 0) {
* buff.append(", ");
* }
* buff.append(args[i]);
* }
*
* to
*
* StatementBuilder buff = new StatementBuilder();
* for (String s : args) {
* buff.appendExceptFirst(", ");
* buff.append(a);
* }
*
*/
public class StatementBuilder {
private final StringBuilder builder = new StringBuilder();
private int index;
/**
* Create a new builder.
*/
public StatementBuilder() {
// nothing to do
}
/**
* Create a new builder.
*
* @param string the initial string
*/
public StatementBuilder(String string) {
builder.append(string);
}
/**
* Append a text.
*
* @param s the text to append
* @return itself
*/
public StatementBuilder append(String s) {
builder.append(s);
return this;
}
/**
* Append a character.
*
* @param c the character to append
* @return itself
*/
public StatementBuilder append(char c) {
builder.append(c);
return this;
}
/**
* Append a number.
*
* @param x the number to append
* @return itself
*/
public StatementBuilder append(long x) {
builder.append(x);
return this;
}
/**
* Reset the loop counter.
*
* @return itself
*/
public StatementBuilder resetCount() {
index = 0;
return this;
}
/**
* Append a text, but only if appendExceptFirst was never called.
*
* @param s the text to append
*/
public void appendOnlyFirst(String s) {
if (index == 0) {
builder.append(s);
}
}
/**
* Append a text, except when this method is called the first time.
*
* @param s the text to append
*/
public void appendExceptFirst(String s) {
if (index++ > 0) {
builder.append(s);
}
}
public String toString() {
return builder.toString();
}
/**
* Get the length.
*
* @return the length
*/
public int length() {
return builder.length();
}
}