How to use

delete

method

in

java.lang.StringBuilder

  private void clear(StringBuilder sb) {
    sb.delete(0, sb.length());
  }
}

private void removeFirstEmptyLine() {
  int len = NL.length();
  if (buf.substring(0, len).equals(NL)) {
    buf.delete(0, len);
  }
}

private void flushBuilder() {
  if (mBuilder.length() > 0) {
    Log.v("GLSurfaceView", mBuilder.toString());
    mBuilder.delete(0, mBuilder.length());
  }
}

private void flushBuilder() {
  if (mBuilder.length() > 0) {
    Log.v("GLSurfaceView", mBuilder.toString());
    mBuilder.delete(0, mBuilder.length());
  }
}

private static StringBuilder clearLastComma(StringBuilder buff) {
  int lastComma = buff.lastIndexOf(", ");
  // No comma found, take everything
  if (-1 != lastComma)
    buff.delete(lastComma, buff.length());
  return buff;
}

private static StringBuilder clearLastComma(StringBuilder buff) {
  int lastComma = buff.lastIndexOf(", ");
  // No comma found, take everything
  if (-1 != lastComma)
    buff.delete(lastComma, buff.length());
  return buff;
}

private String headerValue() {
 StringBuilder result = new StringBuilder();
 if (noCache) result.append("no-cache, ");
 if (noStore) result.append("no-store, ");
 if (maxAgeSeconds != -1) result.append("max-age=").append(maxAgeSeconds).append(", ");
 if (sMaxAgeSeconds != -1) result.append("s-maxage=").append(sMaxAgeSeconds).append(", ");
 if (isPrivate) result.append("private, ");
 if (isPublic) result.append("public, ");
 if (mustRevalidate) result.append("must-revalidate, ");
 if (maxStaleSeconds != -1) result.append("max-stale=").append(maxStaleSeconds).append(", ");
 if (minFreshSeconds != -1) result.append("min-fresh=").append(minFreshSeconds).append(", ");
 if (onlyIfCached) result.append("only-if-cached, ");
 if (noTransform) result.append("no-transform, ");
 if (immutable) result.append("immutable, ");
 if (result.length() == 0) return "";
 result.delete(result.length() - 2, result.length());
 return result.toString();
}

private static String takeUntilDotOrEnd(StringBuilder buff) {
  final int firstPointIdx = buff.indexOf(".");
  String    result;
  if (-1 == firstPointIdx) {
    result = buff.toString();
    buff.setLength(0);
  } else {
    result = buff.substring(0, firstPointIdx);
    buff.delete(0, firstPointIdx + 1);
  }
  return result;
}

private static String takeUntilDotOrEnd(StringBuilder buff) {
  final int firstPointIdx = buff.indexOf(".");
  String    result;
  if (-1 == firstPointIdx) {
    result = buff.toString();
    buff.setLength(0);
  } else {
    result = buff.substring(0, firstPointIdx);
    buff.delete(0, firstPointIdx + 1);
  }
  return result;
}

@Override
public String toString() {
 StringBuilder sb = new StringBuilder("GroupedLinkedMap( ");
 LinkedEntry<K, V> current = head.next;
 boolean hadAtLeastOneItem = false;
 while (!current.equals(head)) {
  hadAtLeastOneItem = true;
  sb.append('{').append(current.key).append(':').append(current.size()).append("}, ");
  current = current.next;
 }
 if (hadAtLeastOneItem) {
  sb.delete(sb.length() - 2, sb.length());
 }
 return sb.append(" )").toString();
}

private static StringBuilder strip(final StringBuilder input,
                  final String prefix, final String suffix) {
  int start = input.indexOf(prefix);
  while (start != -1) {
    int end = input.indexOf(suffix, start + prefix.length());
    if (end == -1) {
      end = input.length();
    }
    input.delete(start, end + suffix.length());
    start = input.indexOf(prefix, start);
  }
  return input;
}

/**
 * Append the query string of the current request to the target redirect URL.
 * @param targetUrl the StringBuilder to append the properties to
 * @param request the current request
 * @since 4.1
 */
protected void appendCurrentQueryParams(StringBuilder targetUrl, HttpServletRequest request) {
  String query = request.getQueryString();
  if (StringUtils.hasText(query)) {
    // Extract anchor fragment, if any.
    String fragment = null;
    int anchorIndex = targetUrl.indexOf("#");
    if (anchorIndex > -1) {
      fragment = targetUrl.substring(anchorIndex);
      targetUrl.delete(anchorIndex, targetUrl.length());
    }
    if (targetUrl.toString().indexOf('?') < 0) {
      targetUrl.append('?').append(query);
    }
    else {
      targetUrl.append('&').append(query);
    }
    // Append anchor fragment, if any, to end of URL.
    if (fragment != null) {
      targetUrl.append(fragment);
    }
  }
}

String key = sb.substring(keyStart + PropertyAccessor.PROPERTY_KEY_PREFIX.length(), keyEnd);
if ((key.startsWith("'") && key.endsWith("'")) || (key.startsWith("\"") && key.endsWith("\""))) {
  sb.delete(keyStart + 1, keyStart + 2);
  sb.delete(keyEnd - 2, keyEnd - 1);
  keyEnd = keyEnd - 2;

private String joinReasons(List<Conflict> conflicts) {
  StringBuilder result = new StringBuilder();
  result.append("(");
  for (Conflict conflict : conflicts) {
    result.append(conflict.reason);
    result.append(", ");
  }
  result.delete(result.length() - 2, result.length());
  result.append(")");
  return result.toString();
}

  private void logDataPoints(Collection<DataPoint> dataPoints, StringBuilder sb, String header) {
    for (DataPoint p : dataPoints) {
      sb.delete(header.length(), sb.length());
      sb.append(p.getName())
       .append(padding).delete(header.length() + 23, sb.length()).append("\t")
       .append(p.getValue());
      LOG.info(sb.toString());
    }
  }
}

private String headerValue() {
 StringBuilder result = new StringBuilder();
 if (noCache) result.append("no-cache, ");
 if (noStore) result.append("no-store, ");
 if (maxAgeSeconds != -1) result.append("max-age=").append(maxAgeSeconds).append(", ");
 if (sMaxAgeSeconds != -1) result.append("s-maxage=").append(sMaxAgeSeconds).append(", ");
 if (isPrivate) result.append("private, ");
 if (isPublic) result.append("public, ");
 if (mustRevalidate) result.append("must-revalidate, ");
 if (maxStaleSeconds != -1) result.append("max-stale=").append(maxStaleSeconds).append(", ");
 if (minFreshSeconds != -1) result.append("min-fresh=").append(minFreshSeconds).append(", ");
 if (onlyIfCached) result.append("only-if-cached, ");
 if (noTransform) result.append("no-transform, ");
 if (immutable) result.append("immutable, ");
 if (result.length() == 0) return "";
 result.delete(result.length() - 2, result.length());
 return result.toString();
}

private static String subNodeToString(Node node) {
  StringBuilder stringBuilder = new StringBuilder();
  if (node != null) {
    NodeList nodeList = node.getChildNodes();
    stringBuilder.append(nodeToString(node, false));
    stringBuilder.append(StringUtil.CRLF_STRING);
    int nodeListLength = nodeList.getLength();
    for (int i = 0; i < nodeListLength; i++) {
      Node childNode = nodeList.item(i);
      if (childNode.getNodeType() != Node.ELEMENT_NODE) {
        continue;
      }
      stringBuilder.append(nodeToString(childNode, true));
      stringBuilder.append(StringUtil.CRLF_STRING);
    }
    if (stringBuilder.length() > StringUtil.CRLF_STRING.length()) {
      stringBuilder.delete(stringBuilder.length() - StringUtil.CRLF_STRING.length(), stringBuilder.length());
    }
  }
  return stringBuilder.toString();
}

  public String test() {
    // a chain we can't simplify
    return new StringBuilder("[init]").append("a1").delete(1, 2).toString();
  }
}

@Override
public void clear()
{
  builder.delete( 0, builder.length() );
  field = 0;
}

  @Override
  protected void render (ModelBatch batch, Array<ModelInstance> instances) {
    if(emitters.size > 0){
      //Update
      float delta = Gdx.graphics.getDeltaTime();
      builder.delete(0, builder.length());
      builder.append(Gdx.graphics.getFramesPerSecond());
      fpsLabel.setText(builder);
      ui.act(delta);

      billboardParticleBatch.begin();
      for (ParticleController controller : emitters){
        controller.update();
        controller.draw();
      }
      billboardParticleBatch.end();
      batch.render(billboardParticleBatch, environment);
    }
    batch.render(instances, environment);
    ui.draw();
  }
}