| /* |
| * |
| * 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.qpid.tools.util; |
| |
| |
| import java.lang.reflect.Field; |
| import java.lang.reflect.Modifier; |
| import java.util.Set; |
| |
| public class ArgumentsParser |
| { |
| public ArgumentsParser() |
| { |
| } |
| |
| public <T> T parse(String[] args, Class<T> pojoClass) |
| { |
| T object; |
| try |
| { |
| object = pojoClass.newInstance(); |
| } |
| catch (Exception e) |
| { |
| throw new IllegalArgumentException("Cannot instantiate object of class " + pojoClass, e); |
| } |
| |
| for (String arg: args) |
| { |
| int pos = arg.indexOf('='); |
| if (pos == -1) |
| { |
| throw new IllegalArgumentException("Invalid argument '" + arg + "' Argument should be specified in format <name>=<value>"); |
| } |
| String name = arg.substring(0, pos); |
| String value = arg.substring(pos + 1); |
| |
| Field field = findField(pojoClass, name); |
| if (field != null) |
| { |
| setField(object, field, value); |
| } |
| } |
| return object; |
| } |
| |
| private Field findField(Class<?> objectClass, String name) |
| { |
| Field[] fields = objectClass.getDeclaredFields(); |
| |
| Field field = null; |
| for (int i = 0 ; i< fields.length ; i++) |
| { |
| if (fields[i].getName().equals(name) && !Modifier.isFinal(fields[i].getModifiers())) |
| { |
| field = fields[i]; |
| break; |
| } |
| } |
| return field; |
| } |
| |
| private void setField(Object object, Field field, String value) |
| { |
| Object convertedValue = convertStringToType(value, field.getType(), field.getName()); |
| |
| field.setAccessible(true); |
| |
| try |
| { |
| field.set(object, convertedValue); |
| } |
| catch (IllegalAccessException e) |
| { |
| throw new RuntimeException("Cannot access field " + field.getName()); |
| } |
| } |
| |
| private Object convertStringToType(String value, Class<?> fieldType, String fieldName) |
| { |
| Object o; |
| if (fieldType == String.class) |
| { |
| o = value; |
| } |
| else if (fieldType == boolean.class) |
| { |
| try |
| { |
| o = Boolean.parseBoolean(value); |
| } |
| catch(Exception e) |
| { |
| throw new RuntimeException("Cannot convert to boolean argument " + fieldName); |
| } |
| } |
| else if (fieldType == int.class) |
| { |
| try |
| { |
| o = Integer.parseInt(value); |
| } |
| catch(Exception e) |
| { |
| throw new RuntimeException("Cannot convert to int argument " + fieldName); |
| } |
| } |
| else |
| { |
| throw new RuntimeException("Unsupported tye " + fieldType + " in " + fieldName); |
| } |
| return o; |
| } |
| |
| public void usage(Class<?> objectClass, Set<String> requiredFields) |
| { |
| System.out.println("Supported arguments:"); |
| Field[] fields = objectClass.getDeclaredFields(); |
| |
| Object object = null; |
| try |
| { |
| object = objectClass.newInstance(); |
| } |
| catch(Exception e) |
| { |
| // ignore any |
| } |
| |
| for (int i = 0 ; i< fields.length ; i++) |
| { |
| Field field = fields[i]; |
| if (!Modifier.isFinal(field.getModifiers())) |
| { |
| Object defaultValue = null; |
| try |
| { |
| field.setAccessible(true); |
| defaultValue = field.get(object); |
| } |
| catch(Exception e) |
| { |
| // ignore any |
| } |
| |
| System.out.println(" " + field.getName() + " ( type: " |
| + field.getType().getSimpleName().toLowerCase() |
| + (object != null ? ", default: " + defaultValue : "") |
| + (requiredFields != null && requiredFields.contains(field.getName()) ? ", mandatory" : "") |
| + ")"); |
| } |
| } |
| } |
| } |