/*
* Copyright 2002-2007 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
*
* 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.springframework.validation;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.springframework.util.StringUtils;
/**
* Default implementation of the {@link MessageCodesResolver} interface.
*
* <p>Will create two message codes for an object error, in the following order:
* <ul>
* <li>1.: code + "." + object name
* <li>2.: code
* </ul>
*
* <p>Will create four message codes for a field specification, in the following order:
* <ul>
* <li>1.: code + "." + object name + "." + field
* <li>2.: code + "." + field
* <li>3.: code + "." + field type
* <li>4.: code
* </ul>
*
* <p>For example, in case of code "typeMismatch", object name "user", field "age":
* <ul>
* <li>1. try "typeMismatch.user.age"
* <li>2. try "typeMismatch.age"
* <li>3. try "typeMismatch.int"
* <li>4. try "typeMismatch"
* </ul>
*
* <p>This resolution algorithm thus can be leveraged for example to show
* specific messages for binding errors like "required" and "typeMismatch":
* <ul>
* <li>at the object + field level ("age" field, but only on "user");
* <li>at the field level (all "age" fields, no matter which object name);
* <li>or at the general level (all fields, on any object).
* </ul>
*
* <p>In case of array, {@link List} or {@link java.util.Map} properties,
* both codes for specific elements and for the whole collection are
* generated. Assuming a field "name" of an array "groups" in object "user":
* <ul>
* <li>1. try "typeMismatch.user.groups[0].name"
* <li>2. try "typeMismatch.user.groups.name"
* <li>3. try "typeMismatch.groups[0].name"
* <li>4. try "typeMismatch.groups.name"
* <li>5. try "typeMismatch.name"
* <li>6. try "typeMismatch.java.lang.String"
* <li>7. try "typeMismatch"
* </ul>
*
* <p>In order to group all codes into a specific category within your resource bundles,
* e.g. "validation.typeMismatch.name" instead of the default "typeMismatch.name",
* consider specifying a {@link #setPrefix prefix} to be applied.
*
* @author Juergen Hoeller
* @since 1.0.1
*/
public class DefaultMessageCodesResolver implements MessageCodesResolver, Serializable {
/**
* The separator that this implementation uses when resolving message codes.
*/
public static final String CODE_SEPARATOR = ".";
private String prefix = "";
/**
* Specify a prefix to be applied to any code built by this resolver.
* <p>Default is none. Specify, for example, "validation." to get
* error codes like "validation.typeMismatch.name".
*/
public void setPrefix(String prefix) {
this.prefix = (prefix != null ? prefix : "");
}
/**
* Return the prefix to be applied to any code built by this resolver.
* <p>Returns an empty String in case of no prefix.
*/
protected String getPrefix() {
return this.prefix;
}
public String[] resolveMessageCodes(String errorCode, String objectName) {
return new String[] {
postProcessMessageCode(errorCode + CODE_SEPARATOR + objectName),
postProcessMessageCode(errorCode)};
}
/**
* Build the code list for the given code and field: an
* object/field-specific code, a field-specific code, a plain error code.
* <p>Arrays, Lists and Maps are resolved both for specific elements and
* the whole collection.
* <p>See the {@link DefaultMessageCodesResolver class level Javadoc} for
* details on the generated codes.
* @return the list of codes
*/
public String[] resolveMessageCodes(String errorCode, String objectName, String field, Class fieldType) {
List codeList = new ArrayList();
List fieldList = new ArrayList();
buildFieldList(field, fieldList);
for (Iterator it = fieldList.iterator(); it.hasNext();) {
String fieldInList = (String) it.next();
codeList.add(postProcessMessageCode(errorCode + CODE_SEPARATOR + objectName + CODE_SEPARATOR + fieldInList));
}
int dotIndex = field.lastIndexOf('.');
if (dotIndex != -1) {
buildFieldList(field.substring(dotIndex + 1), fieldList);
}
for (Iterator it = fieldList.iterator(); it.hasNext();) {
String fieldInList = (String) it.next();
codeList.add(postProcessMessageCode(errorCode + CODE_SEPARATOR + fieldInList));
}
if (fieldType != null) {
codeList.add(postProcessMessageCode(errorCode + CODE_SEPARATOR + fieldType.getName()));
}
codeList.add(postProcessMessageCode(errorCode));
return StringUtils.toStringArray(codeList);
}
/**
* Add both keyed and non-keyed entries for the supplied <code>field</code>
* to the supplied field list.
*/
protected void buildFieldList(String field, List fieldList) {
fieldList.add(field);
String plainField = field;
int keyIndex = plainField.lastIndexOf('[');
while (keyIndex != -1) {
int endKeyIndex = plainField.indexOf(']', keyIndex);
if (endKeyIndex != -1) {
plainField = plainField.substring(0, keyIndex) + plainField.substring(endKeyIndex + 1);
fieldList.add(plainField);
keyIndex = plainField.lastIndexOf('[');
}
else {
keyIndex = -1;
}
}
}
/**
* Post-process the given message code, built by this resolver.
* <p>The default implementation applies the specified prefix, if any.
* @param code the message code as built by this resolver
* @return the final message code to be returned
* @see #setPrefix
*/
protected String postProcessMessageCode(String code) {
return getPrefix() + code;
}
}