JSF Gossip: 错误讯息处理

在使用标准转换器或验证器时，当发生错误时，会有一些预设的错误讯息显示，这些讯息可以使用或标签来显示出来，而这些预设的错误讯息也是可以修改的，您所要作的是提供一个讯息资源档案，例如：

• messages.properties

javax.faces.component.UIInput.CONVERSION=Format Error.


javax.faces.component.UIInput.REQUIRED=Please input your data.


.... 

javax.faces.component.UIInput.CONVERSION是用来设定当转换器发现错误时显示的讯息，而 javax.faces.component.UIInput.REQUIRED是在标签设定了required为true，而使用者没有在栏位输入时显示的错误讯息。

在这边我们设定了讯息档案的名称为 messages_xx_YY.properties ，其中 xx_YY 是根据您的 Locale 来决定，转换器或验证器的错误讯息如果有设定的话，就使用设定值，如果没有设定的话，就使用预设值。

验证器错误讯息，除了上面的 javax.faces.component.UIInput.REQUIRED 之外，还有以下的几个：

讯息识别	预设讯息	用于
javax.faces.validator.NOT_IN_RANGE	Validation Error: Specified attribute is not between the expected values of {0} and {1}.	DoubleRangeValidator 与 LongRangeValidator ， {0} 与 {1} 分别代表 minimum 与 maximum 所设定的属性
javax.faces.validator.DoubleRangeValidator.MAXIMUM 、 javax.faces.validator.LongRangeValidator.MAXIMUM	Validation Error: Value is greater than allowable maximum of '{0}'.	DoubleRangeValidator 或 LongRangeValidator ， {0} 表示 maximum 属性
javax.faces.validator.DoubleRangeValidator.MINIMUM 、 javax.faces.validator.LongRangeValidator.MINIMUM	Validation Error: Value is less than allowable minimum of '{0}'.	DoubleRangeValidator 或 LongRangeValidator ， {0} 代表 minimum 属性
javax.faces.validator.DoubleRangeValidator.TYPE 、 javax.faces.validator.LongRangeValidator.TYPE	Validation Error: Value is not of the correct type.	DoubleRangeValidator 或 LongRangeValidator
javax.faces.validator.LengthValidator.MAXIMUM	Validation Error: Value is greater than allowable maximum of ''{0}''.	LengthValidator ， {0} 代表 maximum
javax.faces.validator.LengthValidator.MINIMUM	Validation Error: Value is less than allowable minimum of ''{0}''.	LengthValidator ， {0} 代表 minimum 属性

在您提供自订讯息的时候，也可以提供 {0} 或 {1} 来设定显示相对的属性值，以提供详细正确的错误提示讯息。

 

补充：

可以在jsf-api包中的Message_xx.properties中，

找到相应validator或converter的key值

 

参考代码

• register . jsp

<%@ page language = "java" contentType = "text/html; charset=ISO-8859-1"       pageEncoding = "ISO-8859-1" %> <%@ taglib prefix = "f" uri = "http://java.sun.com/jsf/core" %> <%@ taglib prefix = "h" uri = "http://java.sun.com/jsf/html" %> DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd" > < html > < head > < meta http-equiv = "Content-Type" content = "text/html; charset=ISO-8859-1" > < title > Insert title here title > < style > .error {       color : red ;       font-style : italic ; } style > head > < body > < f:view >       < f:loadBundle var = "msgs" basename = "messages" />       < h:outputText value = "#{msgs.DateTime}" > h:outputText >       < h:messages > h:messages >       < h:form >             < h:panelGrid columns = "3" >             User Name : < h:inputText id = "name"                         value = "#{user_validator_message.name}" required = "true"                         label = "userName" >                   h:inputText >                   < h:message for = "name" styleClass = "error" > h:message >                               Password : < h:inputSecret id = "password"                         value = "#{user_validator_message.password}" required = "true"                         label = "password" >                         < f:validateLength minimum = "4" > f:validateLength >                   h:inputSecret >                   < h:message for = "password" styleClass = "error" />                               Age : < h:inputText id = "age" value = "#{user_validator_message.age}"                         size = "3" label = "age" required = "true" >                         < f:validateLongRange minimum = "1" maximum = "100" > f:validateLongRange >                   h:inputText >                   < h:message for = "age" styleClass = "error" />               Amount : < h:inputText id = "amount"                         value = "#{user_validator_message.amount}" label = "amount"                         required = "true" >                         < f:validateDoubleRange minimum = "100" maximum = "20000" > f:validateDoubleRange >                   h:inputText >                   < h:message for = "amount" styleClass = "error" > h:message >                               Birthday : < h:inputText id = "birthday"                         value = "#{user_validator_message.birthday}" label = "birthday"                         required = "true" >                         < f:converter converterId = "javax.faces.DateTime" />                   h:inputText >                   < h:message for = "birthday" > h:message >                   < h:commandButton value = "register" action = "register" > h:commandButton >             h:panelGrid >         h:form > f:view > body > html >

 

 

 

·         faces-config-validator-messages.xml

xml version = "1.0" encoding = "UTF-8" ?> < faces-config xmlns = "http://java.sun.com/xml/ns/javaee"       xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns:xi = "http://www.w3.org/2001/XInclude"       xsi:schemaLocation = "http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd"       version = "1.2" >       < application >             < locale-config >                   < default-locale > en default-locale >                   < supported-locale > zh_CN supported-locale >             locale-config >             < message-bundle > messages message-bundle >       application >       < navigation-rule >             < from-view-id > /pages/standard_validator_message/register.jsp from-view-id >             < navigation-case >                   < from-outcome > register from-outcome >                   < to-view-id > /pages/standard_validator_message/welcome.jsp to-view-id >                   < redirect />             navigation-case >       navigation-rule >             < managed-bean >             < managed-bean-name > user_validator_message managed-bean-name >             < managed-bean-class > com .jxhuang .validator .standard_message.bean.User managed-bean-class >             < managed-bean-scope > session managed-bean-scope >       managed-bean > faces-config >

 

·         messages.properties

javax.faces.component.UIInput.CONVERSION= Format Error. javax.faces.component.UIInput.REQUIRED= Please input {0} data. javax.faces.validator.LengthValidator.MINIMUM = {1} length is supposed longer than {0} . javax.faces.validator.LongRangeValidator.NOT_IN_RANGE = {2} the range is {0} to {1} . javax.faces.validator.DoubleRangeValidator.NOT_IN_RANGE= {2} the range is {0} to {1} . DateTime= is against the pattern. javax.faces.DateTime= is against the pattern.