import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Enumeration;

import org.codelibs.core.exception.SQLRuntimeException;
import org.codelibs.core.lang.ClassUtil;

/**
 * Utility class for {@link java.sql.DriverManager}.
 *
 * @author koichik
 */
public abstract class DriverManagerUtil {

    /**
     * Do not instantiate.
     */
    protected DriverManagerUtil() {
    }

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.util;

import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Utility class for JVM-related operations.
 * This class provides methods for handling JVM options and version detection.
 */
public final class JvmUtil {

En los capítulos sobre seguridad, hay funciones utilitarias que se implementan de esta misma manera.

Si entendiste todo esto, ya sabes cómo funcionan por debajo esas herramientas de utilidad para seguridad.

import com.google.common.primitives.Booleans;
import com.google.errorprone.annotations.InlineMe;
import java.util.Comparator;
import org.jspecify.annotations.Nullable;

/**
 * A utility for performing a chained comparison statement. <b>Note:</b> Java 8+ users should
 * generally prefer the methods in {@link Comparator}; see <a href="#java8">below</a>.
 *
 * <p>Example usage of {@code ComparisonChain}:
 *

 */
package org.codelibs.core.convert;

import java.text.SimpleDateFormat;

import org.codelibs.core.lang.StringUtil;
import org.codelibs.core.text.DecimalFormatUtil;

/**
 * Utility class for conversions related to {@link Integer}.
 *
 * @author higa
 */
public abstract class IntegerConversionUtil {

    /**
     * Do not instantiate.
     */
    protected IntegerConversionUtil() {

import org.codelibs.core.exception.SAXRuntimeException;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Utility class for {@link SAXParser}.
 *
 * @author higa
 */
public abstract class SAXParserUtil {

    /**
     * Do not instantiate.
     */
    protected SAXParserUtil() {
    }

    /**

 */

package com.google.common.hash;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/** Static utility method for unchecked throwing of any {@link Throwable}. */
@GwtCompatible
final class SneakyThrows<T extends Throwable> {
  /**
   * Throws {@code t} as if it were an unchecked {@link Throwable}.
   *

 */

package com.google.common.base;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/** Static utility method for unchecked throwing of any {@link Throwable}. */
@GwtCompatible
final class SneakyThrows<T extends Throwable> {
  /**
   * Throws {@code t} as if it were an unchecked {@link Throwable}.
   *

import org.codelibs.core.exception.IllegalAccessRuntimeException;
import org.codelibs.core.exception.InstantiationRuntimeException;
import org.codelibs.core.exception.InvocationTargetRuntimeException;

/**
 * Utility class for {@link Constructor} operations.
 *
 * @author higa
 */
public abstract class ConstructorUtil {

    /**
     * Do not instantiate.
     */
    protected ConstructorUtil() {
    }

    /**

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.util;

import org.codelibs.fess.Constants;

/**
 * This class provides system-related utility methods.
 * It extends {@link org.codelibs.core.lang.SystemUtil} and adds
 * methods specific to the Fess application.
 */
public class SystemUtil extends org.codelibs.core.lang.SystemUtil {
    /**