Java tutorial
/** * Copyright (C) 2015 BonitaSoft S.A. * BonitaSoft, 32 rue Gustave Eiffel - 38000 Grenoble * This library is free software; you can redistribute it and/or modify it under the terms * of the GNU Lesser General Public License as published by the Free Software Foundation * version 2.1 of the License. * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Lesser General Public License for more details. * You should have received a copy of the GNU Lesser General Public License along with this * program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth * Floor, Boston, MA 02110-1301, USA. **/ package org.bonitasoft.engine.bdm; import java.io.File; import java.io.IOException; import java.io.PrintStream; import java.lang.annotation.Annotation; import java.lang.annotation.ElementType; import java.lang.annotation.Target; import java.util.ArrayList; import java.util.Collection; import java.util.HashSet; import java.util.List; import java.util.Set; import javax.lang.model.SourceVersion; import org.apache.commons.lang3.text.WordUtils; import org.bonitasoft.engine.bdm.model.field.Field; import org.bonitasoft.engine.bdm.model.field.FieldType; import org.bonitasoft.engine.bdm.model.field.RelationField; import org.bonitasoft.engine.bdm.model.field.SimpleField; import com.sun.codemodel.ClassType; import com.sun.codemodel.JAnnotatable; import com.sun.codemodel.JAnnotationUse; import com.sun.codemodel.JBlock; import com.sun.codemodel.JClass; import com.sun.codemodel.JClassAlreadyExistsException; import com.sun.codemodel.JCodeModel; import com.sun.codemodel.JConditional; import com.sun.codemodel.JDefinedClass; import com.sun.codemodel.JExpr; import com.sun.codemodel.JExpression; import com.sun.codemodel.JFieldRef; import com.sun.codemodel.JFieldVar; import com.sun.codemodel.JMethod; import com.sun.codemodel.JMod; import com.sun.codemodel.JType; import com.sun.codemodel.JVar; import com.sun.tools.xjc.util.NullStream; /** * @author Romain Bioteau * @author Matthieu Chaffotte */ public class CodeGenerator { private final JCodeModel model; private final EqualsBuilder equalsBuilder; private final HashCodeBuilder hashCodeBuilder; public CodeGenerator() { model = new JCodeModel(); equalsBuilder = new EqualsBuilder(); hashCodeBuilder = new HashCodeBuilder(); } public void generate(final File destDir) throws IOException { final PrintStream stream = new PrintStream(new NullStream()); try { model.build(destDir, stream); } finally { stream.close(); } } public JDefinedClass addClass(final String fullyqualifiedName) throws JClassAlreadyExistsException { if (fullyqualifiedName == null || fullyqualifiedName.isEmpty()) { throw new IllegalArgumentException("Classname cannot cannot be null or empty"); } if (!SourceVersion.isName(fullyqualifiedName)) { throw new IllegalArgumentException( "Classname " + fullyqualifiedName + " is not a valid qualified name"); } return model._class(fullyqualifiedName); } public JDefinedClass addInterface(final JDefinedClass definedClass, final String fullyqualifiedName) { return definedClass._implements(model.ref(fullyqualifiedName)); } public JDefinedClass addInterface(final String fullyqualifiedName) throws JClassAlreadyExistsException { if (fullyqualifiedName.indexOf(".") == -1) { return model.rootPackage()._class(JMod.PUBLIC, fullyqualifiedName, ClassType.INTERFACE); } return model._class(fullyqualifiedName, ClassType.INTERFACE); } public JFieldVar addField(final JDefinedClass definedClass, final String fieldName, final Class<?> type) { validateFieldName(fieldName); if (type == null) { throw new IllegalArgumentException("Field type cannot be null"); } return definedClass.field(JMod.PRIVATE, type, fieldName); } public JFieldVar addField(final JDefinedClass definedClass, final Field field) { return addField(definedClass, field.getName(), toJavaClass(field)); } public JFieldVar addField(final JDefinedClass definedClass, final String fieldName, final JClass type) { validateFieldName(fieldName); if (type == null) { throw new IllegalArgumentException("Field type cannot be null"); } return definedClass.field(JMod.PRIVATE, type, fieldName); } private void validateFieldName(final String fieldName) { if (fieldName == null || fieldName.isEmpty()) { throw new IllegalArgumentException("Field name cannot be null or empty"); } if (SourceVersion.isKeyword(fieldName)) { throw new IllegalArgumentException("Field " + fieldName + " is a resered keyword"); } if (!SourceVersion.isIdentifier(fieldName)) { throw new IllegalArgumentException("Field " + fieldName + " is not a valid Java identifier"); } } @SuppressWarnings("rawtypes") protected JClass narrowClass(final Class<? extends Collection> collectionClass, final JClass narrowClass) { final JClass collectionJClass = getModel().ref(collectionClass); return collectionJClass.narrow(narrowClass); } protected JFieldVar addListField(final JDefinedClass entityClass, final Field field) { final JClass fieldClass = toJavaClass(field); final JClass fieldListClass = narrowClass(List.class, fieldClass); final JClass arrayListFieldClazz = narrowClass(ArrayList.class, fieldClass); final JFieldVar listFieldVar = entityClass.field(JMod.PRIVATE, fieldListClass, field.getName()); final JExpression newInstance = JExpr._new(arrayListFieldClazz).arg(JExpr.lit(10)); listFieldVar.init(newInstance); return listFieldVar; } public JClass toJavaClass(final Field field) { if (field instanceof SimpleField) { final Class<?> fieldClass = ((SimpleField) field).getType().getClazz(); return getModel().ref(fieldClass); } final String qualifiedName = ((RelationField) field).getReference().getQualifiedName(); return getModel().ref(qualifiedName); } public JClass toJavaClass(final FieldType type) { return getModel().ref(type.getClazz()); } public void addDefaultConstructor(final JDefinedClass definedClass) { definedClass.constructor(JMod.PUBLIC); } public JMethod addSetter(final JDefinedClass definedClass, final JFieldVar field) { final JMethod method = definedClass.method(JMod.PUBLIC, Void.TYPE, getSetterName(field)); method.param(field.type(), field.name()); method.body().assign(JExpr._this().ref(field.name()), JExpr.ref(field.name())); return method; } public JMethod addListSetter(final JDefinedClass definedClass, final JFieldVar field) { final JMethod method = definedClass.method(JMod.PUBLIC, Void.TYPE, getSetterName(field)); method.param(field.type(), field.name()); final JFieldRef thisField = JExpr._this().ref(field.name()); final JConditional ifListIsNull = method.body()._if(thisField.eq(JExpr._null())); ifListIsNull._then().assign(JExpr._this().ref(field.name()), JExpr.ref(field.name())); final JBlock elseBlock = ifListIsNull._else(); elseBlock.invoke(JExpr._this().ref(field.name()), "clear"); elseBlock.invoke(JExpr._this().ref(field.name()), "addAll").arg(field); return method; } public JMethod addGetter(final JDefinedClass definedClass, final JFieldVar field) { final JMethod method = definedClass.method(JMod.PUBLIC, field.type(), getGetterName(field)); final JBlock block = method.body(); block._return(field); return method; } public JMethod addMethodSignature(final JDefinedClass definedClass, final String methodName, final JType returnType) { return definedClass.method(JMod.PUBLIC, returnType, methodName); } public JMethod addAddMethod(final JDefinedClass definedClass, final Field field) { return addListMethod(definedClass, field, "add", "addTo"); } public JMethod addRemoveMethod(final JDefinedClass definedClass, final Field field) { return addListMethod(definedClass, field, "remove", "removeFrom"); } private JMethod addListMethod(final JDefinedClass definedClass, final Field field, final String listMethodName, final String parameterName) { final JClass fieldClass = toJavaClass(field); final StringBuilder builder = new StringBuilder(parameterName); builder.append(WordUtils.capitalize(field.getName())); final JMethod method = definedClass.method(JMod.PUBLIC, void.class, builder.toString()); final JVar adderParam = method.param(fieldClass, parameterName); final JBlock body = method.body(); final JVar decl = body.decl(getModel().ref(List.class), field.getName(), JExpr.invoke(getGetterName(field))); body.add(decl.invoke(listMethodName).arg(adderParam)); return method; } public JMethod addEqualsMethod(final JDefinedClass definedClass) { final JMethod equalsMethod = equalsBuilder.generate(definedClass); addAnnotation(equalsMethod, Override.class); return equalsMethod; } public JMethod addHashCodeMethod(final JDefinedClass definedClass) { final JMethod hashCodeMethod = hashCodeBuilder.generate(definedClass); addAnnotation(hashCodeMethod, Override.class); return hashCodeMethod; } public String getGetterName(final JVar field) { final JType type = field.type(); final boolean bool = Boolean.class.getName().equals(type.fullName()); return getGetterName(bool, field.name()); } public String getGetterName(final Field field) { final boolean bool = field instanceof SimpleField && FieldType.BOOLEAN.equals(((SimpleField) field).getType()) && !field.isCollection(); return getGetterName(bool, field.getName()); } private String getGetterName(final boolean bool, final String fieldName) { final StringBuilder builder = new StringBuilder(); if (bool) { builder.append("is"); } else { builder.append("get"); } builder.append(WordUtils.capitalize(fieldName)); return builder.toString(); } public String getSetterName(final JVar field) { return "set" + WordUtils.capitalize(field.name()); } public JCodeModel getModel() { return model; } protected JAnnotationUse addAnnotation(final JAnnotatable annotable, final Class<? extends Annotation> annotationType) { final Set<ElementType> supportedElementTypes = getSupportedElementTypes(annotationType); checkAnnotationTarget(annotable, annotationType, supportedElementTypes); return annotable.annotate(model.ref(annotationType)); } protected void checkAnnotationTarget(final JAnnotatable annotable, final Class<? extends Annotation> annotationType, final Set<ElementType> supportedElementTypes) { if (annotable instanceof JClass && !supportedElementTypes.isEmpty() && !supportedElementTypes.contains(ElementType.TYPE)) { throw new IllegalArgumentException(annotationType.getName() + " is not supported for " + annotable); } if (annotable instanceof JFieldVar && !supportedElementTypes.isEmpty() && !supportedElementTypes.contains(ElementType.FIELD)) { throw new IllegalArgumentException(annotationType.getName() + " is not supported for " + annotable); } if (annotable instanceof JMethod && !supportedElementTypes.isEmpty() && !supportedElementTypes.contains(ElementType.METHOD)) { throw new IllegalArgumentException(annotationType.getName() + " is not supported for " + annotable); } } protected Set<ElementType> getSupportedElementTypes(final Class<? extends Annotation> annotationType) { final Set<ElementType> elementTypes = new HashSet<ElementType>(); final Target targetAnnotation = annotationType.getAnnotation(Target.class); if (targetAnnotation != null) { final ElementType[] value = targetAnnotation.value(); if (value != null) { for (final ElementType et : value) { elementTypes.add(et); } } } return elementTypes; } }