1 /*
2 * Copyright 2004-2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springmodules.validation.commons;
18
19 import java.util.Locale;
20
21 import org.apache.commons.validator.ValidatorException;
22 import org.slf4j.Logger;
23 import org.slf4j.LoggerFactory;
24 import org.springframework.validation.Errors;
25 import org.springframework.validation.Validator;
26
27 /**
28 * @author Rob Harrop
29 */
30 public abstract class AbstractBeanValidator implements Validator {
31
32 private static final Logger log = LoggerFactory.getLogger(AbstractBeanValidator.class);
33
34 private ValidatorFactory validatorFactory;
35
36 /**
37 * Checks if the validatorFactory is configured to handle this class. Will
38 * convert the class into a form name, suitable for commons validator.
39 *
40 * @return <code>true</code> if the validatorFactory supports the class,
41 * or <code>false</code> if not
42 * @see #getFormName(Class)
43 */
44 public boolean supports(Class clazz) {
45 boolean canSupport = validatorFactory.hasRulesForBean(getFormName(clazz), getLocale());
46 if (log.isDebugEnabled()) {
47 log.debug("validatorFactory " + (canSupport ? "does" : "does not")
48 + " support class " + clazz + " with form name " + getFormName(clazz));
49 }
50 return canSupport;
51 }
52
53 /**
54 * Validates the supplied object using a <code>org.apache.commons.validator.Validator</code> loaded from
55 * the configured <code>ValidatorFactory</code>.
56 *
57 * @see ValidatorFactory
58 */
59 public void validate(Object obj, Errors errors) {
60 org.apache.commons.validator.Validator commonsValidator = getValidator(obj, errors);
61 initValidator(commonsValidator);
62 try {
63 commonsValidator.validate();
64 }
65 catch (ValidatorException e) {
66 log.error("Exception while validating object " + obj, e);
67 } finally {
68 cleanupValidator(commonsValidator);
69 }
70 }
71
72 public void setValidatorFactory(ValidatorFactory validatorFactory) {
73 this.validatorFactory = validatorFactory;
74 }
75
76 /**
77 * Gets the <code>Locale</code> used to lookup <code>Validator</code> instances. Default implementation
78 * returns the value of <code>Locale.getDefault()</code>. Subclasses can override this to change
79 * <code>Locale</code>-handling behavior.
80 */
81 protected Locale getLocale() {
82 return Locale.getDefault();
83 }
84
85 /**
86 * Retrieves an instance of <code>org.apache.commons.validator.Validator</code>
87 * for the specified <code>Object</code>
88 * from the configured <code>ValidatorFactory</code>.
89 *
90 * @param obj the <code>Object</code> being validated.
91 * @param errors the <code>Errors</code> object to write validation errors to.
92 */
93 private org.apache.commons.validator.Validator getValidator(Object obj, Errors errors) {
94 return this.validatorFactory.getValidator(getFormName(obj.getClass()), obj, errors);
95 }
96
97 /**
98 * A callback method that is called just before the validate() method is called on the given validator.
99 * This can be used to further configure the validator.
100 *
101 * @param validator
102 */
103 protected void initValidator(org.apache.commons.validator.Validator validator) {
104 }
105
106 /**
107 * A callback method that is called just after the validate() method is called on the given validator.
108 * This method can be used to clean up all the extra configuration added in the {@link #initValidator(org.apache.commons.validator.Validator)}
109 * method.
110 *
111 * @param validator
112 */
113 protected void cleanupValidator(org.apache.commons.validator.Validator validator) {
114 }
115
116 /**
117 * Returns the name of the Commons Validator <code>Form</code> used to
118 * validate instances of the supplied class.
119 *
120 * @param aClass
121 * @return the form name that Commons Validator can use to look up a form
122 */
123 protected abstract String getFormName(Class aClass);
124 }