我将 TomCat 5.5 与 MyFaces 1.1 一起使用，并尝试实现自定义正则表达式验证标签。
我的 RegExValidator 类如下所示：
public class RegExValidator implements Validator, StateHolder {
private String regex;
private boolean transientValue = false;
public RegExValidator() {
super();
}
public RegExValidator(String regex) {
this();
this.regex = regex;
}
public void validate(FacesContext context, UIComponent component, Object toValidate) throws ValidatorException {
if ((context == null) || (component == null)) {
throw new NullPointerException();
}
if (!(component instanceof UIInput)) {
return;
}
if (null == regex || null == toValidate) {
return;
}
String val = (String) toValidate;
if (!val.matches(regex)) {
FacesMessage errMsg = MessageFactory.createFacesMessage(context, Constants.FORMAT_INVALID_MESSAGE_ID, FacesMessage.SEVERITY_ERROR, (new Object[]{regex}));
throw new ValidatorException(errMsg);
}
}
public Object saveState(FacesContext context) {
Object[] values = new Object[1];
values[0] = regex;
return (values);
}
public void restoreState(FacesContext context, Object state) {
Object[] values = (Object[]) state;
regex = (String) values[0];
}
public String getRegex() {
return regex;
}
public void setRegex(String regex) {
this.regex = regex;
}
public boolean isTransient() {
return transientValue;
}
public void setTransient(boolean transientValue) {
this.transientValue = transientValue;
}
}
我的 RegExValidatorTag 类如下所示：
@SuppressWarnings("serial")
public class RegExValidatorTag extends ValidatorELTag {
private static String validatorID = null;
protected ValueExpression regex = null;
public RegExValidatorTag() {
super();
if (validatorID == null) {
validatorID = "RegExValidator";
}
}
public Validator createValidator() throws JspException {
FacesContext facesContext = FacesContext.getCurrentInstance();
RegExValidator result = null;
if (validatorID != null) {
result = (RegExValidator) facesContext.getApplication().createValidator(validatorID);
}
String patterns = null;
if (regex != null) {
if (!regex.isLiteralText()) {
patterns = (String) regex.getValue(facesContext.getELContext());
} else {
patterns = regex.getExpressionString();
}
}
result.setRegex(patterns);
return result;
}
public void setValidatorID(String validatorID) {
RegExValidatorTag.validatorID = validatorID;
}
/**
* @param regex
* the regex to set
*/
public void setRegex(ValueExpression regex) {
this.regex = regex;
}
}
我的标签库描述符如下所示：
<tag>
<name>regexValidator</name>
<tag-class>com.company.components.taglib.RegExValidatorTag</tag-class>
<attribute>
<name>regex</name>
<required>true</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
</tag>
我的 face-common-config.xml 有一个 Validator 标签，如下所示：
<validator>
<description>
Validate an input string value against a regular
expression specified by the "regex" attribute.
</description>
<validator-id>RegExValidator</validator-id>
<validator-class>com.company.components.validators.RegExValidator</validator-class>
<attribute>
<description>
The regular expression to test the value against
</description>
<attribute-name>regex</attribute-name>
<attribute-class>java.lang.String</attribute-class>
</attribute>
</validator>
后来它应该在这样的jsp文件中使用：
<tc:in value="${dataBean.currentBean.field}">
<a:regexValidator regex="${dataBean.currentBean.validationRegEx}" />
</tc:in>
调用页面时出现如下错误：
javax.servlet.ServletException：javax.servlet.jsp.JspException：org.apache.jasper.JasperException：无法将字符串“[\d{4}]”转换为属性“regex”的类“javax.el.ValueExpression”：未向 PropertyEditorManager 注册属性编辑器
原因：org.apache.jasper.JasperException - 无法将字符串“[\d{4}]”转换为属性“regex”的类“javax.el.ValueExpression”：属性编辑器未向 PropertyEditorManager 注册
我希望我提供了足够的细节来帮助我解决这个问题......