# MiscellaneousUtil.java

    /*
     * 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.synapse.commons.util;

    import org.apache.axiom.om.OMElement;
    import org.apache.axiom.om.impl.builder.StAXOMBuilder;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.synapse.commons.SynapseCommonsException;

    import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.ObjectOutputStream;
    import java.util.Properties;

    /**
     *
     */
    public class MiscellaneousUtil {

    	private static Log log = LogFactory.getLog(MiscellaneousUtil.class);

    	private static final String CONF_LOCATION = "conf.location";

    	private MiscellaneousUtil() {
    	}

    	/**
    	 * Helper method to get the value of the property from a given property bag
    	 *
    	 * @param properties
    	 *            The property collection
    	 * @param name
    	 *            The name of the property
    	 * @param defaultValue
    	 *            The default value for the property
    	 * @return The value of the property if it is found , otherwise , default
    	 *         value
    	 */
    	public static String getProperty(Properties properties, String name, String defaultValue) {

    		String result = properties.getProperty(name);
    		if ((result == null || result.length() == 0) && defaultValue != null) {
    			if (log.isDebugEnabled()) {
    				log.debug("The name with '" + name + "' cannot be found. " + "Using default value : " + defaultValue);
    			}
    			result = defaultValue;
    		}
    		if (result != null) {
    			return result.trim();
    		} else {
    			return defaultValue;
    		}
    	}

    	/**
    	 * Helper method to get the value of the property from a given property bag
    	 * This method will return a value with the type equal to the type
    	 * given by the Class type parameter. Therefore, The user of this method
    	 * can ensure that he is get what he request
    	 *
    	 * @param properties
    	 *            Properties bag
    	 * @param name
    	 *            Name of the property
    	 * @param defaultValue
    	 *            Default value
    	 * @param type
    	 *            Expected Type using Class
    	 * @return Value corresponding to the given property name
    	 */
    	@SuppressWarnings({ "TypeParameterExplicitlyExtendsObject", "unchecked" })
    	public static <T extends Object> T getProperty(Properties properties, String name, T defaultValue, Class<? extends T> type) {

    		String result = properties.getProperty(name);
    		if (result == null && defaultValue != null) {
    			if (log.isDebugEnabled()) {
    				log.debug("The name with '" + name + "' cannot be found. " + "Using default value : " + defaultValue);
    			}
    			return defaultValue;
    		}

    		if (result == null || type == null) {
    			return null;
    		}

    		if (String.class.equals(type)) {
    			return (T) result;
    		} else if (Boolean.class.equals(type)) {
    			return (T) Boolean.valueOf(Boolean.parseBoolean(result));
    		} else if (Integer.class.equals(type)) {
    			return (T) Integer.valueOf(Integer.parseInt(result));
    		} else if (Long.class.equals(type)) {
    			return (T) Long.valueOf(Long.parseLong(result));
    		} else {
    			handleException("Unsupported type : " + type);
    		}

    		return null;
    	}

    	/**
    	 * Loads the properties from a given property file path
    	 *
    	 * @param filePath
    	 *            Path of the property file
    	 * @return Properties loaded from given file
    	 */
    	public static Properties loadProperties(String filePath) {

            Properties properties = new Properties();
            ClassLoader cl = Thread.currentThread().getContextClassLoader();

            if (log.isDebugEnabled()) {
                log.debug("Loading a file '" + filePath + "' from classpath");
            }

            InputStream in  = null;

            //if we reach to this assume that the we may have to looking to the customer provided external location for the
            //given properties
    		if (System.getProperty(CONF_LOCATION) != null) {
    			try {
    				in = new FileInputStream(System.getProperty(CONF_LOCATION) + File.separator + filePath);
    			} catch (FileNotFoundException e) {
    				String msg = "Error loading properties from a file at from the System defined location: " + filePath;
    				log.warn(msg);
    			}
    		}

    		if(in ==null){
    			//if can not find with system path definition looking to the class path for the given property file
    			in = cl.getResourceAsStream(filePath);
    		}

            if (in == null) {

                if (log.isDebugEnabled()) {
                    log.debug("Unable to load file  '" + filePath + "'");
                }

                filePath = "conf" +
                        File.separatorChar + filePath;
                if (log.isDebugEnabled()) {
                    log.debug("Loading a file '" + filePath + "' from classpath");
                }

                in = cl.getResourceAsStream(filePath);
                if (in == null) {
                    if (log.isDebugEnabled()) {
                        log.debug("Unable to load file  '" + filePath + "'");
                    }
                }

            }
            if (in != null) {
                try {
                    properties.load(in);
                } catch (IOException e) {
                    handleException("Error loading properties from a file at : " + filePath, e);
    						} finally {
    							try {
    								in.close();
    							} catch (IOException e) {
    								log.warn("Error while closing the input stream from the file: " + filePath, e);
    							}
    						}
    				}
            return properties;
        }

    	/**
    	 * Load xml config
    	 *
    	 * @param filePath file path
    	 * @return OMElement of build from the config file
    	 */
    	public static OMElement loadXMLConfig(String filePath) {

    		return loadXMLConfig(filePath, true);
    	}

    	/**
    	 * Load a xml configuration file
    	 *
    	 * @param filePath    file path
    	 * @param isMandatory whether this is a mandatory config
    	 * @return OMElement of build from the config file
    	 */
    	public static OMElement loadXMLConfig(String filePath, boolean isMandatory) {

            ClassLoader cl = Thread.currentThread().getContextClassLoader();

            if (log.isDebugEnabled()) {
                log.debug("Loading a file '" + filePath + "' from classpath");
            }

            InputStream in  = null;
            if (System.getProperty(CONF_LOCATION) != null) {
                try {
                    in = new FileInputStream(System.getProperty(CONF_LOCATION) + File.separator + filePath);
                } catch (FileNotFoundException e) {
    	            if (isMandatory) {
    		            String msg = "Error loading properties from file at system defined location: " + System.getProperty(
    				            CONF_LOCATION) + File.separator + filePath;
    		            log.warn(msg);
    	            }
                }
            }

            if (in == null){
                //if can not find with system path definition looking to the class path for the given config file
                in = cl.getResourceAsStream(filePath);
            }

            if (in == null) {

                if (log.isDebugEnabled()) {
                    log.debug("Unable to load file  '" + filePath + "'");
                }

                filePath = "conf" + File.separatorChar + filePath;
                if (log.isDebugEnabled()) {
                    log.debug("Loading a file '" + filePath + "' from classpath");
                }

                in = cl.getResourceAsStream(filePath);
                if (in == null) {
                    if (log.isDebugEnabled()) {
                        log.debug("Unable to load file  '" + filePath + "'");
                    }
                }
            }

            if (in != null) {
                try {
                    OMElement document = new StAXOMBuilder(in).getDocumentElement();
                    document.build();
                    return document;
                } catch (Exception e) {
                    handleException("Error while parsing the content of the file: " + filePath, e);
                } finally {
                    try {
                        in.close();
                    } catch (IOException e) {
                        log.warn("Error while closing the input stream from the file: " + filePath, e);
                    }
                }
            }
            return null;
        }

    	/**
    	 * Helper method to serialize object into a byte array
    	 *
    	 * @param data
    	 *            The object to be serialized
    	 * @return The byte array representation of the provided object
    	 */
    	public static byte[] serialize(Object data) {

    		ObjectOutputStream outputStream = null;
    		ByteArrayOutputStream binOut = null;
    		byte[] result = null;
    		try {
    			binOut = new ByteArrayOutputStream();
    			outputStream = new ObjectOutputStream(binOut);
    			outputStream.writeObject(data);
    			result = binOut.toByteArray();
    		} catch (IOException e) {
    			handleException("Error serializing object : " + data);
    		} finally {
    			if (binOut != null) {
    				try {
    					binOut.close();
    				} catch (IOException ignored) {
    				}
    			}
    			if (outputStream != null) {
    				try {
    					outputStream.close();
    				} catch (IOException ignored) {
    				}
    			}
    		}
    		return result;
    	}

    	@SuppressWarnings({ "UnusedDeclaration" })
    	public static byte[] asBytes(InputStream in) {

    		ByteArrayOutputStream out = new ByteArrayOutputStream();
    		byte[] buffer = new byte[1024];
    		int len;
    		try {
    			while ((len = in.read(buffer)) >= 0)
    				out.write(buffer, 0, len);
    		} catch (IOException e) {
    			throw new SynapseCommonsException("Error during converting a input stream " + "into a byte array", e, log);
    		} finally {
    			if (in != null) {
    				try {
    					in.close();
    				} catch (IOException ignored) {
    				}
    			}
    			try {
    				out.close();
    			} catch (IOException ignored) {
    			}
    		}
    		return out.toByteArray();
    	}

    	/**
    	 * Helper methods for handle errors.
    	 *
    	 * @param msg
    	 *            The error message
    	 */
    	private static void handleException(String msg) {
    		log.error(msg);
    		throw new SynapseCommonsException(msg);
        }

        /**
         * Helper method for handle errors.
         *
         * @param msg The error message
         * @param ex  Error exception
         */
        private static void handleException(String msg, Exception ex) {
            log.error(msg);
            throw new SynapseCommonsException(msg, ex);
        }
    }