Java tutorial
/* * Copyright 2002-2019 the original author or authors. * * 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 * * https://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.springframework.validation; import org.springframework.context.support.DefaultMessageSourceResolvable; import org.springframework.lang.Nullable; import org.springframework.util.Assert; /** * Encapsulates an object error, that is, a global reason for rejecting * an object. * * <p>See the {@link DefaultMessageCodesResolver} javadoc for details on * how a message code list is built for an {@code ObjectError}. * * @author Juergen Hoeller * @since 10.03.2003 * @see FieldError * @see DefaultMessageCodesResolver */ @SuppressWarnings("serial") public class ObjectError extends DefaultMessageSourceResolvable { private final String objectName; @Nullable private transient Object source; /** * Create a new instance of the ObjectError class. * @param objectName the name of the affected object * @param defaultMessage the default message to be used to resolve this message */ public ObjectError(String objectName, String defaultMessage) { this(objectName, null, null, defaultMessage); } /** * Create a new instance of the ObjectError class. * @param objectName the name of the affected object * @param codes the codes to be used to resolve this message * @param arguments the array of arguments to be used to resolve this message * @param defaultMessage the default message to be used to resolve this message */ public ObjectError(String objectName, @Nullable String[] codes, @Nullable Object[] arguments, @Nullable String defaultMessage) { super(codes, arguments, defaultMessage); Assert.notNull(objectName, "Object name must not be null"); this.objectName = objectName; } /** * Return the name of the affected object. */ public String getObjectName() { return this.objectName; } /** * Preserve the source behind this error: possibly an {@link Exception} * (typically {@link org.springframework.beans.PropertyAccessException}) * or a Bean Validation {@link javax.validation.ConstraintViolation}. * <p>Note that any such source object is being stored as transient: * that is, it won't be part of a serialized error representation. * @param source the source object * @since 5.0.4 */ public void wrap(Object source) { if (this.source != null) { throw new IllegalStateException("Already wrapping " + this.source); } this.source = source; } /** * Unwrap the source behind this error: possibly an {@link Exception} * (typically {@link org.springframework.beans.PropertyAccessException}) * or a Bean Validation {@link javax.validation.ConstraintViolation}. * <p>The cause of the outermost exception will be introspected as well, * e.g. the underlying conversion exception or exception thrown from a setter * (instead of having to unwrap the {@code PropertyAccessException} in turn). * @return the source object of the given type * @throws IllegalArgumentException if no such source object is available * (i.e. none specified or not available anymore after deserialization) * @since 5.0.4 */ public <T> T unwrap(Class<T> sourceType) { if (sourceType.isInstance(this.source)) { return sourceType.cast(this.source); } else if (this.source instanceof Throwable) { Throwable cause = ((Throwable) this.source).getCause(); if (sourceType.isInstance(cause)) { return sourceType.cast(cause); } } throw new IllegalArgumentException("No source object of the given type available: " + sourceType); } /** * Check the source behind this error: possibly an {@link Exception} * (typically {@link org.springframework.beans.PropertyAccessException}) * or a Bean Validation {@link javax.validation.ConstraintViolation}. * <p>The cause of the outermost exception will be introspected as well, * e.g. the underlying conversion exception or exception thrown from a setter * (instead of having to unwrap the {@code PropertyAccessException} in turn). * @return whether this error has been caused by a source object of the given type * @since 5.0.4 */ public boolean contains(Class<?> sourceType) { return (sourceType.isInstance(this.source) || (this.source instanceof Throwable && sourceType.isInstance(((Throwable) this.source).getCause()))); } @Override public boolean equals(@Nullable Object other) { if (this == other) { return true; } if (other == null || other.getClass() != getClass() || !super.equals(other)) { return false; } ObjectError otherError = (ObjectError) other; return getObjectName().equals(otherError.getObjectName()); } @Override public int hashCode() { return (29 * super.hashCode() + getObjectName().hashCode()); } @Override public String toString() { return "Error in object '" + this.objectName + "': " + resolvableToString(); } }