數據校驗在web應用裏是非常重要的功能，尤其是在表單輸入中。在這裏采用Hibernate-Validator進行校驗，該方法實現了JSR-303驗證框架支持註解風格的驗證。

一、導入jar包

若要實現數據校驗功能，需要導入必要的jar包，主要包括以下幾個：

• classmate-1.3.1.jar
• hibernate-validator-5.4.1.Final.jar
• hibernate-validator-annotation-processor-5.4.1.Final.jar
• hibernate-validator-cdi-5.4.1.Final.jar
• jboss-logging-3.3.0.Final.jar
• validation-api-1.1.0.Final.jar

二、常用的校驗註解

三、修改實體類

在類的屬性上進行標註，如：

public class User {
    @NotBlank(message = "Username can not be empty")
    private String username;
    @NotBlank(message = "password can not be blank")
    @Length(min = 6, max = 16, message = "The length of the password must be between 6 and 16 bits")
    private String password;
    @Range(min = 18, max = 60, message = "Age must be between 18 and 60 years old")
    private Integer age;
    @Pattern(regexp = "^1[3|4|5|7|8][0-9]{9}$", message = "Please enter the correct format of the phone number")
    private String phone;
    @Email(message = "Please enter a valid email address")
    private String email;

    // other...   
}

四、修改相應的處理方法

@RequestMapping(value = "/register")
public String register(@Valid  @ModelAttribute("user") User user, Errors errors,Model model) {
    if(errors.hasErrors()){
        return "register";
    }
    model.addAttribute("user", user);
    return "success";
}

五、視圖輸出

校驗之後，我們通常需要在表單的輸入框後進行文字反饋：

<form:form modelAttribute="user" method="post" action="register">
    <fieldset>
        <legend>register</legend>
        <p>
            <label>name:</label>
            <form:input path="username" />
            <form:errors path="username" cssStyle="color:red"/>
        </p>
         ...
    </fieldset>
</form:form>

然而，有些時候並不推薦直接將錯誤信息寫在註解的message屬性裏，這樣不方便國際化。因此可以做以下幾處修改：

1. 新建validatemessages.properties

username.not.blank = "username cannot be empty..."
password.not.blank = "password cannot be empty"
password.not.length = "password should be in 6-10"
age.not.range = "age should be in 10-70"
phone.not.pattern = "phone should be in format"
email.not.format = "email should be in format"

2. 實體類中的註解使用相對引用

public class User {
    
    @NotBlank(message = "{username.not.blank}")
    private String username;
    
    @NotBlank(message = "{password.not.blank}")
    @Length(min = 6, max = 10, message = "{password.not.length}")
    private String password;
    
    @Range(min = 10, max = 70, message = "{age.not.range}")
    private Integer age;
    
    @Pattern(regexp = "^1[3|4|5|7|8][0-9]{9}$", message = "{phone.not.pattern}")
    private String phone;
    
    @Email(message = "{email.not.format}")
    private String email;
    
    // other...
}

3. 修改配置文件

    <!-- 默認的註解映射的支持 -->  
    <mvc:annotation-driven validator="validator" conversion-service="conversion-service" />
    
    <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
        <property name="providerClass"  value="org.hibernate.validator.HibernateValidator"/>
        <!--不設置則默認為classpath下的 ValidationMessages.properties -->
        <property name="validationMessageSource" ref="validatemessageSource"/>
    </bean>
    <bean id="conversion-service" class="org.springframework.format.support.FormattingConversionServiceFactoryBean" />
    <bean id="validatemessageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">  
        <property name="basename" value="classpath:validatemessages"/>  
        <property name="fileEncodings" value="utf-8"/>  
        <property name="cacheSeconds" value="120"/>  
    </bean>

特別註意：value="classpath:validatemessages"，文件名不加後綴！

至此，數據校驗的整個過程就結束了。

最後還要特別強調的重點是：

• 視圖中<form:form modelAttribute="contentModel" method="post">的modelAttribute="xxx"[email protected] @ModelAttribute("xxx") 中的xxx名稱一致，否則模型數據和錯誤信息都綁定不到。
• <form:errors path="name"></form:errors>即會顯示模型對應屬性的錯誤信息，當path="*"時則顯示模型全部屬性的錯誤信息。

參考地址：

http://www.cnblogs.com/liukemng/p/3738055.html

SpringMVC——數據校驗