# 設定と環境変数 { #settings-and-environment-variables }

多くの場合、アプリケーションは外部の設定や構成を必要とします。たとえば、シークレットキー、データベース認証情報、メールサービスの認証情報などです。

これらの設定の多くは可変（変更されうる）で、データベースのURLのようなものがあります。また、多くはシークレットのように機微な情報です。

そのため、アプリケーションが読み取る環境変数で提供するのが一般的です。

/// tip | 豆知識

環境変数について理解するには、[環境変数](../environment-variables.md)を参照してください。

///

## 型とバリデーション { #types-and-validation }

 * 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.
 */

import common.JvmVendor
import common.JvmVersion
import common.Os
import common.VersionedSettingsBranch
import configurations.CompileAll

 * 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 gradlebuild.docs;

import com.vladsch.flexmark.ext.anchorlink.AnchorLinkExtension;
import com.vladsch.flexmark.ext.tables.TablesExtension;

 * 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.common.collect;

import static com.google.common.truth.Truth.assertThat;
import static java.lang.Math.max;
import static java.util.Arrays.asList;

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * 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 org.apache.maven.repository.legacy.resolver.transform;

import javax.inject.Named;
import javax.inject.Singleton;

import org.apache.maven.artifact.Artifact;

 * 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.common.io;

import static com.google.common.base.StandardSystemProperty.LINE_SEPARATOR;
import static com.google.common.io.TestOption.CLOSE_THROWS;

 * 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.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

 * 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 org.apache.maven.execution;

import javax.inject.Named;
import javax.inject.Singleton;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

 * 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 org.apache.maven.lifecycle;

import java.util.List;
import java.util.Set;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.model.Plugin;