Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.accumulo.shell.commands; import java.util.Arrays; import java.util.Iterator; import java.util.Map.Entry; import org.apache.accumulo.core.client.AccumuloException; import org.apache.accumulo.core.client.AccumuloSecurityException; import org.apache.accumulo.core.client.TableNotFoundException; import org.apache.accumulo.core.conf.Property; import org.apache.accumulo.shell.Shell; import org.apache.accumulo.shell.Shell.Command; import org.apache.commons.cli.BasicParser; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.Option; import org.apache.commons.cli.OptionGroup; import org.apache.commons.cli.Options; import org.apache.commons.cli.ParseException; import org.slf4j.LoggerFactory; public abstract class ShellPluginConfigurationCommand extends Command { private Option removePluginOption, pluginClassOption, listPluginOption; private String pluginType; private Property tableProp; private String classOpt; ShellPluginConfigurationCommand(final String typeName, final Property tableProp, final String classOpt) { this.pluginType = typeName; this.tableProp = tableProp; this.classOpt = classOpt; } @Override public int execute(final String fullCommand, final CommandLine cl, final Shell shellState) throws Exception { final String tableName = OptUtil.getTableOpt(cl, shellState); if (cl.hasOption(removePluginOption.getOpt())) { // Remove the property removePlugin(cl, shellState, tableName); shellState.getReader().println("Removed " + pluginType + " on " + tableName); } else if (cl.hasOption(listPluginOption.getOpt())) { // Get the options for this table final Iterator<Entry<String, String>> iter = shellState.getConnector().tableOperations() .getProperties(tableName).iterator(); while (iter.hasNext()) { Entry<String, String> ent = iter.next(); // List all parameters with the property name if (ent.getKey().startsWith(tableProp.toString())) { shellState.getReader().println(ent.getKey() + ": " + ent.getValue()); } } } else { // Set the plugin with the provided options String className = cl.getOptionValue(pluginClassOption.getOpt()); // Set the plugin property on the table setPlugin(cl, shellState, tableName, className); } return 0; } protected void setPlugin(final CommandLine cl, final Shell shellState, final String tableName, final String className) throws AccumuloException, AccumuloSecurityException { shellState.getConnector().tableOperations().setProperty(tableName, tableProp.toString(), className); } protected void removePlugin(final CommandLine cl, final Shell shellState, final String tableName) throws AccumuloException, AccumuloSecurityException { shellState.getConnector().tableOperations().removeProperty(tableName, tableProp.toString()); } public static <T> Class<? extends T> getPluginClass(final String tableName, final Shell shellState, final Class<T> clazz, final Property pluginProp) { Iterator<Entry<String, String>> props; try { props = shellState.getConnector().tableOperations().getProperties(tableName).iterator(); } catch (AccumuloException e) { return null; } catch (TableNotFoundException e) { return null; } while (props.hasNext()) { final Entry<String, String> ent = props.next(); if (ent.getKey().equals(pluginProp.toString())) { Class<? extends T> pluginClazz; String[] args = new String[2]; try { Options o = new Options(); o.addOption(OptUtil.tableOpt()); args[0] = "-t"; args[1] = tableName; CommandLine cl = new BasicParser().parse(o, args); pluginClazz = shellState.getClassLoader(cl, shellState).loadClass(ent.getValue()) .asSubclass(clazz); } catch (ClassNotFoundException e) { LoggerFactory.getLogger(ShellPluginConfigurationCommand.class).error("Class not found {}", e.getMessage()); return null; } catch (ParseException e) { LoggerFactory.getLogger(ShellPluginConfigurationCommand.class) .error("Error parsing table: {} {}", Arrays.toString(args), e.getMessage()); return null; } catch (TableNotFoundException e) { LoggerFactory.getLogger(ShellPluginConfigurationCommand.class).error("Table not found: {} {}", tableName, e.getMessage()); return null; } catch (Exception e) { LoggerFactory.getLogger(ShellPluginConfigurationCommand.class).error("Error: {}", e.getMessage()); return null; } return pluginClazz; } } return null; } @Override public Options getOptions() { final Options o = new Options(); final OptionGroup actionGroup = new OptionGroup(); pluginClassOption = new Option(classOpt, pluginType, true, "fully qualified name of the " + pluginType + " class to use"); pluginClassOption.setArgName("className"); // Action to take: apply (default), remove, list removePluginOption = new Option("r", "remove", false, "remove the current " + pluginType + ""); listPluginOption = new Option("l", "list", false, "display the current " + pluginType + ""); actionGroup.addOption(pluginClassOption); actionGroup.addOption(removePluginOption); actionGroup.addOption(listPluginOption); actionGroup.setRequired(true); o.addOptionGroup(actionGroup); o.addOption(OptUtil.tableOpt("table to set the " + pluginType + " on")); return o; } @Override public int numArgs() { return 0; } }