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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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.stratos.cli.utils; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import org.apache.commons.cli.Option; import org.apache.commons.cli.Options; import org.apache.commons.lang3.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HttpResponse; import org.apache.stratos.cli.exception.ExceptionMapper; import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.SocketException; import java.text.MessageFormat; import java.util.ResourceBundle; public class CliUtils { private static Log log = LogFactory.getLog(CliUtils.class); private static final String LINE_SEPARATOR = System.getProperty("line.separator"); private static final ResourceBundle BUNDLE = ResourceBundle.getBundle("Resources"); public static <T> void printTable(T[] data, RowMapper<T> mapper, String... headers) { if (data == null) { return; } // The maximum number of columns // All data String[] length must be equal to this int columns = headers.length; int rows = data.length + 1; String[][] table = new String[rows][columns]; table[0] = headers; for (int i = 0; i < data.length; i++) { T t = data[i]; table[i + 1] = mapper.getData(t); } // Find the maximum length of a string in each column int[] lengths = new int[columns]; for (int i = 0; i < table.length; i++) { for (int j = 0; j < table[i].length; j++) { lengths[j] = Math.max(table[i][j].length(), lengths[j]); } } // The border rows String borders[] = new String[lengths.length]; // Generate a format string for each column String[] formats = new String[lengths.length]; for (int i = 0; i < lengths.length; i++) { StringBuilder stringBuilder = new StringBuilder(); stringBuilder.append("+"); for (int j = 0; j < lengths[i] + 2; j++) { stringBuilder.append("-"); } boolean finalColumn = (i + 1 == lengths.length); if (finalColumn) { stringBuilder.append("+\n"); } borders[i] = stringBuilder.toString(); formats[i] = "| %1$-" + lengths[i] + "s " + (finalColumn ? "|\n" : ""); } // Print the table for (int i = 0; i < table.length; i++) { for (int j = 0; j < table[i].length; j++) { System.out.print(borders[j]); } for (int j = 0; j < table[i].length; j++) { System.out.format(formats[j], table[i][j]); } if (i + 1 == table.length) { for (int j = 0; j < table[i].length; j++) { System.out.print(borders[j]); } } } } public static String getMessage(String key, Object... args) { String message = BUNDLE.getString(key); if (args != null && args.length > 0) { message = MessageFormat.format(message, args); } return message; } public static String readResource(String fileName) throws IOException { BufferedReader br = new BufferedReader(new FileReader(fileName)); try { StringBuilder sb = new StringBuilder(); String line = br.readLine(); while (line != null) { sb.append(line); sb.append(LINE_SEPARATOR); line = br.readLine(); } return sb.toString(); } finally { br.close(); } } /** * Extract HTTP response body as a string * * @param response * @return */ public static String getHttpResponseString(HttpResponse response) { try { String output; String result = ""; if ((response != null) && (response.getEntity() != null) && (response.getEntity().getContent() != null)) { BufferedReader reader = new BufferedReader( new InputStreamReader((response.getEntity().getContent()))); while ((output = reader.readLine()) != null) { result += output; } } return result; } catch (SocketException e) { String message = "A connection error occurred while reading response message: " + e.getMessage(); System.out.println(message); log.error(message, e); return null; } catch (IOException e) { String message = "An IO error occurred while reading response message: " + e.getMessage(); System.out.println(message); log.error(message, e); return null; } catch (Exception e) { String message = "An unknown error occurred while reading response message: " + e.getMessage(); System.out.println(message); log.error(message, e); return null; } } public static void printError(HttpResponse response) { String resultString = CliUtils.getHttpResponseString(response); if (StringUtils.isNotBlank(resultString)) { // Response body found, try to extract exception information boolean exceptionMapperInstanceFound = false; try { GsonBuilder gsonBuilder = new GsonBuilder(); Gson gson = gsonBuilder.create(); ExceptionMapper exception = gson.fromJson(resultString, ExceptionMapper.class); if (exception != null) { System.out.println(exception); exceptionMapperInstanceFound = true; } } catch (Exception ignore) { // Could not find an ExceptionMapper instance } finally { if (!exceptionMapperInstanceFound) { System.out.println(response.getStatusLine().toString()); } } } else { // No response body found System.out.println(response.getStatusLine().toString()); } } public static Options mergeOptionArrays(Option[] a, Option[] b) { Options opts = new Options(); for (Option o : a) { opts.addOption(o); } for (Option o : b) { opts.addOption(o); } return opts; } }