Java tutorial
/* * 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 io.prestosql.plugin.hive; import io.prestosql.hadoop.HadoopFileSystemCache; import io.prestosql.hadoop.HadoopNative; import io.prestosql.plugin.hive.authentication.GenericExceptionAction; import io.prestosql.plugin.hive.authentication.HdfsAuthentication; import io.prestosql.spi.connector.ConnectorSession; import io.prestosql.spi.security.ConnectorIdentity; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import javax.inject.Inject; import java.io.IOException; import java.util.Optional; import static com.google.common.base.MoreObjects.toStringHelper; import static java.util.Objects.requireNonNull; public class HdfsEnvironment { static { HadoopNative.requireHadoopNative(); HadoopFileSystemCache.initialize(); } private final HdfsConfiguration hdfsConfiguration; private final HdfsAuthentication hdfsAuthentication; private final boolean verifyChecksum; @Inject public HdfsEnvironment(HdfsConfiguration hdfsConfiguration, HiveClientConfig config, HdfsAuthentication hdfsAuthentication) { this.hdfsConfiguration = requireNonNull(hdfsConfiguration, "hdfsConfiguration is null"); this.verifyChecksum = requireNonNull(config, "config is null").isVerifyChecksum(); this.hdfsAuthentication = requireNonNull(hdfsAuthentication, "hdfsAuthentication is null"); } public Configuration getConfiguration(HdfsContext context, Path path) { return hdfsConfiguration.getConfiguration(context, path.toUri()); } public FileSystem getFileSystem(HdfsContext context, Path path) throws IOException { return getFileSystem(context.getIdentity().getUser(), path, getConfiguration(context, path)); } public FileSystem getFileSystem(String user, Path path, Configuration configuration) throws IOException { return hdfsAuthentication.doAs(user, () -> { FileSystem fileSystem = path.getFileSystem(configuration); fileSystem.setVerifyChecksum(verifyChecksum); return fileSystem; }); } public <R, E extends Exception> R doAs(String user, GenericExceptionAction<R, E> action) throws E { return hdfsAuthentication.doAs(user, action); } public void doAs(String user, Runnable action) { hdfsAuthentication.doAs(user, action); } public static class HdfsContext { private final ConnectorIdentity identity; private final Optional<String> source; private final Optional<String> queryId; private final Optional<String> schemaName; private final Optional<String> tableName; public HdfsContext(ConnectorIdentity identity) { this.identity = requireNonNull(identity, "identity is null"); this.source = Optional.empty(); this.queryId = Optional.empty(); this.schemaName = Optional.empty(); this.tableName = Optional.empty(); } public HdfsContext(ConnectorSession session, String schemaName) { requireNonNull(session, "session is null"); requireNonNull(schemaName, "schemaName is null"); this.identity = requireNonNull(session.getIdentity(), "session.getIdentity() is null"); this.source = requireNonNull(session.getSource(), "session.getSource()"); this.queryId = Optional.of(session.getQueryId()); this.schemaName = Optional.of(schemaName); this.tableName = Optional.empty(); } public HdfsContext(ConnectorSession session, String schemaName, String tableName) { requireNonNull(session, "session is null"); requireNonNull(schemaName, "schemaName is null"); requireNonNull(tableName, "tableName is null"); this.identity = requireNonNull(session.getIdentity(), "session.getIdentity() is null"); this.source = requireNonNull(session.getSource(), "session.getSource()"); this.queryId = Optional.of(session.getQueryId()); this.schemaName = Optional.of(schemaName); this.tableName = Optional.of(tableName); } public ConnectorIdentity getIdentity() { return identity; } public Optional<String> getSource() { return source; } public Optional<String> getQueryId() { return queryId; } public Optional<String> getSchemaName() { return schemaName; } public Optional<String> getTableName() { return tableName; } @Override public String toString() { return toStringHelper(this).omitNullValues().add("user", identity).add("source", source.orElse(null)) .add("queryId", queryId.orElse(null)).add("schemaName", schemaName.orElse(null)) .add("tableName", tableName.orElse(null)).toString(); } } }