appfuse学习笔记（四）struts2的表单校验

(1) 添加校验项
修改文件
src/main/resources/com/mycompany/app/model/Person-validation.xml

    "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

	
        
            
        
    
    
        
            
        
    

重新编译，重新访问添加人员的页面，姓、名设置为空直接保存，报错
校验起了作用
(2) struts.xml文件的配置说明

......

    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    

。。。。。。

(3) 校验流程分析
struts.xml中定义默认包时

而在struts-default.xml中,配置了如下的拦截器

                    input,back,cancel
                
	

当执行添加操作时会被validation拦截器拦截
AnnotationValidationInterceptor中的doIntercept方法

protected String doIntercept(ActionInvocation invocation) throws Exception {
        Object action = invocation.getAction();
        if (action != null) {
            Method method = getActionMethod(action.getClass(), invocation.getProxy().getMethod());
            SkipValidation skip = (SkipValidation) method.getAnnotation(SkipValidation.class);
            if (skip != null) {
                return invocation.invoke();
            }
        }
        return super.doIntercept(invocation);
}

再看父类的doIntercept方法

protected String doIntercept(ActionInvocation invocation) throws Exception {
doBeforeInvocation(invocation);
    return invocation.invoke();
}

再看触发前要执行的方法doBeforeInvocation(invocation)

protected void doBeforeInvocation(ActionInvocation invocation) throws Exception {
        Object action = invocation.getAction();
        String context = invocation.getProxy().getActionName();
        String method = invocation.getProxy().getMethod();
        if (log.isDebugEnabled()) {
            log.debug("Validating "
                    + invocation.getProxy().getNamespace() + "/" + invocation.getProxy().getActionName() + " with method "+ method +".");
        }
        if (validateAnnotatedMethodOnly) {
           ActionValidatorManagerFactory.getInstance().validate(action, context, method);
        } else {
            ActionValidatorManagerFactory.getInstance().validate(action, context);
        }
}

再看ActionValidatorManagerFactory.getInstance()

public class ActionValidatorManagerFactory {
    private static final Log LOG = LogFactory.getLog(ActionValidatorManagerFactory.class);
    private static ActionValidatorManager instance = new DefaultActionValidatorManager();
    static {
        try {
            Class c = ClassLoaderUtil.loadClass("com.opensymphony.xwork2.validator.AnnotationActionValidatorManager", ActionValidatorManagerFactory.class);
            LOG.info("Detected AnnotationActionValidatorManager, initializing it...");
            instance = (ActionValidatorManager) c.newInstance();
        } catch (ClassNotFoundException e) {
            // this is fine, just fall back to the default object type determiner
        } catch (Exception e) {
            throw new XWorkException(e);
        }
    }
    public static void setInstance(ActionValidatorManager instance) {
        ActionValidatorManagerFactory.instance = instance;
    }
    public static ActionValidatorManager getInstance() {
        return instance;
    }
}

再看com.opensymphony.xwork2.validator.AnnotationActionValidatorManager中的validate(Object object, String context, ValidatorContext validatorContext, String method)方法

public void validate(Object object, String context, ValidatorContext validatorContext, String method) throws ValidationException {
        List validators = getValidators(object.getClass(), context, method);
        Set shortcircuitedFields = null;

        for (final Validator validator: validators) {
            try {
                validator.setValidatorContext(validatorContext);

                if (LOG.isDebugEnabled()) {
                    LOG.debug("Running validator: " + validator + " for object " + object + " and method " + method);
                }

                FieldValidator fValidator = null;
                String fullFieldName = null;

                if (validator instanceof FieldValidator) {
                    fValidator = (FieldValidator) validator;
                    fullFieldName = fValidator.getValidatorContext().getFullFieldName(fValidator.getFieldName());

                    if ((shortcircuitedFields != null) && shortcircuitedFields.contains(fullFieldName)) {
                        if (LOG.isDebugEnabled()) {
                            LOG.debug("Short-circuited, skipping");
                        }

                        continue;
                    }
                }

                if (validator instanceof ShortCircuitableValidator && ((ShortCircuitableValidator) validator).isShortCircuit())
                {
                    // get number of existing errors
                    List errs = null;

                    if (fValidator != null) {
                        if (validatorContext.hasFieldErrors()) {
                            Collection fieldErrors = (Collection) validatorContext.getFieldErrors().get(fullFieldName);

                            if (fieldErrors != null) {
                                errs = new ArrayList(fieldErrors);
                            }
                        }
                    } else if (validatorContext.hasActionErrors()) {
                        Collection actionErrors = validatorContext.getActionErrors();

                        if (actionErrors != null) {
                            errs = new ArrayList(actionErrors);
                        }
                    }

                    validator.validate(object);

                    if (fValidator != null) {
                        if (validatorContext.hasFieldErrors()) {
                            Collection errCol = (Collection) validatorContext.getFieldErrors().get(fullFieldName);

                            if ((errCol != null) && !errCol.equals(errs)) {
                                if (LOG.isDebugEnabled()) {
                                    LOG.debug("Short-circuiting on field validation");
                                }

                                if (shortcircuitedFields == null) {
                                    shortcircuitedFields = new TreeSet();
                                }

                                shortcircuitedFields.add(fullFieldName);
                            }
                        }
                    } else if (validatorContext.hasActionErrors()) {
                        Collection errCol = validatorContext.getActionErrors();

                        if ((errCol != null) && !errCol.equals(errs)) {
                            if (LOG.isDebugEnabled()) {
                                LOG.debug("Short-circuiting");
                            }

                            break;
                        }
                    }

                    continue;
                }

                validator.validate(object);
            } finally {
                validator.setValidatorContext( null );
            }

        }
    }

最后看一下校验必填项的实现

public class RequiredFieldValidator extends FieldValidatorSupport {

    public void validate(Object object) throws ValidationException {
        String fieldName = getFieldName();
        Object value = this.getFieldValue(fieldName, object);

        if (value == null) {
            addFieldError(fieldName, object);
        }
    }
}

到这里，校验表单，出错后将执行addFieldError方法