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Diffstat (limited to 'bpmn/MSOCoreBPMN/src/main/java/org/openecomp/mso/bpmn/core/BaseTask.java')
| -rw-r--r-- | bpmn/MSOCoreBPMN/src/main/java/org/openecomp/mso/bpmn/core/BaseTask.java | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/bpmn/MSOCoreBPMN/src/main/java/org/openecomp/mso/bpmn/core/BaseTask.java b/bpmn/MSOCoreBPMN/src/main/java/org/openecomp/mso/bpmn/core/BaseTask.java new file mode 100644 index 0000000000..849c8ba4f8 --- /dev/null +++ b/bpmn/MSOCoreBPMN/src/main/java/org/openecomp/mso/bpmn/core/BaseTask.java @@ -0,0 +1,529 @@ +/*- + * ============LICENSE_START======================================================= + * OPENECOMP - MSO + * ================================================================================ + * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved. + * ================================================================================ + * 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. + * ============LICENSE_END========================================================= + */ + +package org.openecomp.mso.bpmn.core; + +import org.camunda.bpm.engine.delegate.DelegateExecution; +import org.camunda.bpm.engine.delegate.Expression; +import org.camunda.bpm.engine.delegate.JavaDelegate; + +/** + * Base class for service tasks. + */ +public abstract class BaseTask implements JavaDelegate { + + /** + * Get the value of a required field. This method throws + * MissingInjectedFieldException if the expression is null, and + * BadInjectedFieldException if the expression evaluates to a null + * value. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value + */ + protected Object getField(Expression expression, + DelegateExecution execution, String fieldName) { + return getFieldImpl(expression, execution, fieldName, false); + } + + /** + * Gets the value of an optional field. There are three conditions + * in which this method returns null: + * <p> + * <ol> + * <li> The expression itself is null (i.e. the field is missing + * altogether.</li> + * <li>The expression evaluates to a null value.</li> + * <li>The expression references a single variable which has not + * been set.</li> + * </ol> + * <p> + * Examples:<br> + * Expression ${x} when x is null: return null<br> + * Expression ${x} when x is unset: return null<br> + * Expression ${x+y} when x and/or y are unset: exception<br> + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value, possibly null + */ + protected Object getOptionalField(Expression expression, + DelegateExecution execution, String fieldName) { + return getFieldImpl(expression, execution, fieldName, true); + } + + /** + * Get the value of a required output variable field. This method + * throws MissingInjectedFieldException if the expression is null, and + * BadInjectedFieldException if the expression produces a null or + * illegal variable name. Legal variable names contain only letters, + * numbers, and the underscore character ('_'). + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the output variable name + */ + protected String getOutputField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, false); + if (o instanceof String) { + String variable = (String) o; + if (!isLegalVariable(variable)) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "'" + variable + + "' is not a legal variable name"); + } + return variable; + } else { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "expected a variable name string" + + ", got object of type " + o.getClass().getName()); + } + } + + /** + * Get the value of an optional output variable field. This method + * throws BadInjectedFieldException if the expression produces an illegal + * variable name. Legal variable names contain only letters, numbers, + * and the underscore character ('_'). + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the output variable name, possibly null + */ + protected String getOptionalOutputField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, true); + if (o instanceof String) { + String variable = (String) o; + if (!isLegalVariable(variable)) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "'" + variable + + "' is not a legal variable name"); + } + return variable; + } else if (o == null) { + return null; + } else { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "expected a variable name string" + + ", got object of type " + o.getClass().getName()); + } + } + + /** + * Get the value of a required string field. This method throws + * MissingInjectedFieldException if the expression is null, and + * BadInjectedFieldException if the expression evaluates to a null + * value. + * <p> + * Note: the result is coerced to a string value, if necessary. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value + */ + protected String getStringField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, false); + if (o instanceof String) { + return (String) o; + } else { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "cannot convert '" + o.toString() + + "' to Integer"); + } + } + + /** + * Gets the value of an optional string field. There are three conditions + * in which this method returns null: + * <p> + * <ol> + * <li> The expression itself is null (i.e. the field is missing + * altogether.</li> + * <li>The expression evaluates to a null value.</li> + * <li>The expression references a single variable which has not + * been set.</li> + * </ol> + * <p> + * Examples:<br> + * Expression ${x} when x is null: return null<br> + * Expression ${x} when x is unset: return null<br> + * Expression ${x+y} when x and/or y are unset: exception<br> + * <p> + * Note: the result is coerced to a string value, if necessary. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value, possibly null + */ + protected String getOptionalStringField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, true); + if (o instanceof String) { + return (String) o; + } else if (o == null) { + return null; + } else { + return o.toString(); + } + } + + /** + * Get the value of a required integer field. This method throws + * MissingInjectedFieldException if the expression is null, and + * BadInjectedFieldException if the expression evaluates to a null + * value or a value that cannot be coerced to an integer. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value + */ + protected Integer getIntegerField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, false); + if (o instanceof Integer) { + return (Integer) o; + } else { + try { + return Integer.parseInt(o.toString()); + } catch (NumberFormatException e) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "cannot convert '" + o.toString() + + "' to Integer"); + } + } + } + + /** + * Gets the value of an optional integer field. There are three conditions + * in which this method returns null: + * <p> + * <ol> + * <li> The expression itself is null (i.e. the field is missing + * altogether.</li> + * <li>The expression evaluates to a null value.</li> + * <li>The expression references a single variable which has not + * been set.</li> + * </ol> + * <p> + * Examples:<br> + * Expression ${x} when x is null: return null<br> + * Expression ${x} when x is unset: return null<br> + * Expression ${x+y} when x and/or y are unset: exception<br> + * <p> + * Note: the result is coerced to an integer value, if necessary. This + * method throws BadInjectedFieldException if the result cannot be coerced + * to an integer. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value, possibly null + */ + protected Integer getOptionalIntegerField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, true); + if (o instanceof Integer) { + return (Integer) o; + } else if (o == null) { + return null; + } else { + try { + return Integer.parseInt(o.toString()); + } catch (NumberFormatException e) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "cannot convert '" + o.toString() + + "' to Integer"); + } + } + } + + /** + * Gets the value of an optional long field. There are three conditions + * in which this method returns null: + * <p> + * <ol> + * <li> The expression itself is null (i.e. the field is missing + * altogether.</li> + * <li>The expression evaluates to a null value.</li> + * <li>The expression references a single variable which has not + * been set.</li> + * </ol> + * <p> + * Examples:<br> + * Expression ${x} when x is null: return null<br> + * Expression ${x} when x is unset: return null<br> + * Expression ${x+y} when x and/or y are unset: exception<br> + * <p> + * Note: the result is coerced to a long value, if necessary. This + * method throws BadInjectedFieldException if the result cannot be coerced + * to a long. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value, possibly null + */ + protected Long getOptionalLongField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, true); + if (o instanceof Long) { + return (Long) o; + } else if (o == null) { + return null; + } else { + try { + return Long.parseLong(o.toString()); + } catch (NumberFormatException e) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "cannot convert '" + o.toString() + + "' to Long"); + } + } + } + + /** + * Get the value of a required long field. This method throws + * MissingInjectedFieldException if the expression is null, and + * BadInjectedFieldException if the expression evaluates to a null + * value or a value that cannot be coerced to a long. + * + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @return the field value + */ + protected Long getLongField(Expression expression, + DelegateExecution execution, String fieldName) { + Object o = getFieldImpl(expression, execution, fieldName, false); + if (o instanceof Long) { + return (Long) o; + } else { + try { + return Long.parseLong(o.toString()); + } catch (NumberFormatException e) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "cannot convert '" + o.toString() + + "' to Long"); + } + } + } + + /** + * Common implementation for field "getter" methods. + * @param expression the expression + * @param execution the execution + * @param fieldName the field name (for logging and exceptions) + * @param optional true if the field is optional + * @return the field value, possibly null + */ + private Object getFieldImpl(Expression expression, + DelegateExecution execution, String fieldName, boolean optional) { + if (expression == null) { + if (!optional) { + throw new MissingInjectedFieldException( + fieldName, getTaskName()); + } + return null; + } + + Object value; + + try { + value = expression.getValue(execution); + } catch (Exception e) { + if (!optional) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + + // At this point, we have an exception that occurred while + // evaluating an expression for an optional field. A common + // problem is that the expression is a simple reference to a + // variable which has never been set, e.g. the expression is + // ${x}. The normal activiti behavior is to throw an exception, + // but we don't like that, so we have the following workaround, + // which parses the expression text to see if it is a "simple" + // variable reference, and if so, returns null. If the + // expression is anything other than a single variable + // reference, then an exception is thrown, as it would have + // been without this workaround. + + // Get the expression text so we can parse it + String s = expression.getExpressionText(); + +// if (isDebugEnabled(execution)) { +// logDebug(execution, getTaskName() + " field '" + fieldName +// + "' expression evaluation failed: " + s); +// } + + int len = s.length(); + int i = 0; + + // Skip whitespace + while (i < len && Character.isWhitespace(s.charAt(i))) { + i++; + } + + // Next character must be '$' + if (i == len || s.charAt(i++) != '$') { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + + // Skip whitespace + while (i < len && Character.isWhitespace(s.charAt(i))) { + i++; + } + + // Next character must be '{' + if (i == len || s.charAt(i++) != '{') { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + + // Skip whitespace + while (i < len && Character.isWhitespace(s.charAt(i))) { + i++; + } + + // Collect the variable name + StringBuilder variable = new StringBuilder(); + while (i < len && isWordCharacter(s.charAt(i))) { + variable.append(s.charAt(i)); + i++; + } + + if (variable.length() == 0) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + + // Skip whitespace + while (i < len && Character.isWhitespace(s.charAt(i))) { + i++; + } + + // Next character must be '}' + if (i == len || s.charAt(i++) != '}') { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + + // Skip whitespace + while (i < len && Character.isWhitespace(s.charAt(i))) { + i++; + } + + // Must be at end of string + if (i != len) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + +// if (isDebugEnabled(execution)) { +// logDebug(execution, "Checking if variable '" +// + variable.toString() + "' exists"); +// } + + // If the variable exists then the problem was + // something else... + if (execution.hasVariable(variable.toString())) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), e.getClass().getSimpleName(), e); + } + + // The variable doesn't exist. + +// if (isDebugEnabled(execution)) { +// logDebug(execution, "Variable '" + variable.toString() +// + "' does not exist [ok]"); +// } + + value = null; + } + + if (value == null && !optional) { + throw new BadInjectedFieldException( + fieldName, getTaskName(), "required field has null value"); + } + + return value; + } + + /** + * Tests if a character is a "word" character. + * @param c the character + * @return true if the character is a "word" character. + */ + private boolean isWordCharacter(char c) { + return (Character.isLetterOrDigit(c) || c == '_'); + } + + /** + * Tests if the specified string is a legal flow variable name. + * @param name the string + * @return true if the string is a legal flow variable name + */ + private boolean isLegalVariable(String name) { + if (name == null) { + return false; + } + + int len = name.length(); + + if (len == 0) { + return false; + } + + char c = name.charAt(0); + + if (!Character.isLetter(c) && c != '_') { + return false; + } + + for (int i = 1; i < len; i++) { + c = name.charAt(i); + if (!Character.isLetterOrDigit(c) && c != '_') { + return false; + } + } + + return true; + } + + /** + * Returns the name of the task (normally the java class name). + * @return the name of the task + */ + public String getTaskName() { + return getClass().getSimpleName(); + } +} |