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Java example source code file (InternalFlags.java)

This example Java source code file (InternalFlags.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bridge, complete, custom_class_loading, customclassloadingoption, enum, ignore, include_stack_traces, includestacktraceoption, log, logger, logging, nullable_provides, nullableprovidesoption, off, security, string, util

The InternalFlags.java Java example source code

/**
 * Copyright (C) 2013 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.inject.internal;


import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.logging.Logger;
/**
 * Contains flags for Guice.
 */
public class InternalFlags {
  private static final Logger logger = Logger.getLogger(InternalFlags.class.getName());

  private static final IncludeStackTraceOption INCLUDE_STACK_TRACES
      = parseIncludeStackTraceOption();

  private static final CustomClassLoadingOption CUSTOM_CLASS_LOADING
      = parseCustomClassLoadingOption();

  private static final NullableProvidesOption NULLABLE_PROVIDES
      = parseNullableProvidesOption(NullableProvidesOption.ERROR);


  /**
   * The options for Guice stack trace collection.
   */
  public enum IncludeStackTraceOption {
    /** No stack trace collection */
    OFF,
    /**  Minimum stack trace collection (Default) */
    ONLY_FOR_DECLARING_SOURCE,
    /** Full stack trace for everything */
    COMPLETE
  }

  /**
   * The options for Guice custom class loading.
   */
  public enum CustomClassLoadingOption {
    /** No custom class loading */
    OFF,
    /** Automatically bridge between class loaders (Default) */
    BRIDGE
  }

  public enum NullableProvidesOption {
    /** Ignore null parameters to @Provides methods. */
    IGNORE,
    /** Warn if null parameters are passed to non-@Nullable parameters of provides methods. */
    WARN,
    /** Error if null parameters are passed to non-@Nullable parameters of provides parameters */
    ERROR
  }

  public static IncludeStackTraceOption getIncludeStackTraceOption() {
    return INCLUDE_STACK_TRACES;
  }

  public static CustomClassLoadingOption getCustomClassLoadingOption() {
    return CUSTOM_CLASS_LOADING;
  }

  public static NullableProvidesOption getNullableProvidesOption() {
    return NULLABLE_PROVIDES;
  }

  private static IncludeStackTraceOption parseIncludeStackTraceOption() {
    return getSystemOption("guice_include_stack_traces",
        IncludeStackTraceOption.ONLY_FOR_DECLARING_SOURCE);
  }

  private static CustomClassLoadingOption parseCustomClassLoadingOption() {
    return getSystemOption("guice_custom_class_loading",
        CustomClassLoadingOption.BRIDGE, CustomClassLoadingOption.OFF);
  }

  private static NullableProvidesOption parseNullableProvidesOption(
      NullableProvidesOption defaultValue) {
    return getSystemOption("guice_check_nullable_provides_params", defaultValue);
  }

  /**
   * Gets the system option indicated by the specified key; runs as a privileged action.
   *
   * @param name of the system option
   * @param defaultValue if the option is not set
   *
   * @return value of the option, defaultValue if not set
   */
  private static <T extends Enum T getSystemOption(final String name, T defaultValue) {
    return getSystemOption(name, defaultValue, defaultValue);
  }

  /**
   * Gets the system option indicated by the specified key; runs as a privileged action.
   *
   * @param name of the system option
   * @param defaultValue if the option is not set
   * @param secureValue if the security manager disallows access to the option
   *
   * @return value of the option, defaultValue if not set, secureValue if no access
   */
  private static <T extends Enum T getSystemOption(final String name, T defaultValue,
      T secureValue) {
    Class<T> enumType = defaultValue.getDeclaringClass();
    String value = null;
    try {
      value = AccessController.doPrivileged(new PrivilegedAction<String>() {
        public String run() {
          return System.getProperty(name);
        }
      });
      return (value != null && value.length() > 0) ? Enum.valueOf(enumType, value) : defaultValue;
    } catch (SecurityException e) {
      return secureValue;
    } catch (IllegalArgumentException e) {
      logger.warning(value + " is not a valid flag value for " + name + ". "
          + " Values must be one of " + Arrays.asList(enumType.getEnumConstants()));
      return defaultValue;
    }
  }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java InternalFlags.java source code file:



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