springmvc使用JSR-303進行校驗

源自：http://blog.csdn.net/tsingheng/article/details/42555307

下面提供一種springmvc的校驗方案，一般沒有校驗或者手動寫validator的話都要寫好多代碼好多if判斷，使用JSR-303規範校驗只需要在Pojo字段上加上相應的註解就可以實現校驗了

1.依賴的jar包，我直接貼pom了

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <spring.version>4.1.1.RELEASE</spring.version>
</properties>

<dependencies>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.4.0</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.4.0</version>
    </dependency>
    <dependency>
        <groupId>commons-fileupload</groupId>
        <artifactId>commons-fileupload</artifactId>
        <version>1.3.1</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
    </dependency>
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>1.1.0.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>5.1.3.Final</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.7</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.4</version>
    </dependency>
    <dependency>
        <groupId>javax.el</groupId>
        <artifactId>javax.el-api</artifactId>
        <version>3.0.0</version>
    </dependency>
</dependencies>

2.springmvc配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">

    <!-- 默認的註解映射的支持 -->
    <mvc:annotation-driven/>
    <context:annotation-config/>
    <aop:aspectj-autoproxy/>

    <!-- 自動掃描的包名 -->
    <context:component-scan base-package="spring.test.web.controller"/>

    <bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />

</beans>

3.寫java代碼了

先建一個User類

public class User {
    @NotNull
    private String username;

    @NotNull(message = "密碼不能爲空")
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

}

然後建一個controller試試

@ResponseBody
@RequestMapping("/test1")
public AjaxResponse validateTest1(@Valid User user, BindingResult result){
    AjaxResponse ajaxResponse = new AjaxResponse();
    Map<String, Object> map = new HashMap<>();
    if(result.hasErrors()){
        ajaxResponse.setSuccess(false);
        ajaxResponse.setHasErrors(true);
        map.put("errors", result.getAllErrors());
    }
    else {
        map.put("now", new Date());
        map.put("user", user);
    }
    ajaxResponse.setData(map);
    return ajaxResponse;
}

這個方法第一個參數上加了@Valid標註，第二個參數是必須的而且必須緊跟着@Valid參數之後，校驗結果都在這個result裏面

方法邏輯比較簡單，調用result.hasErrors()看校驗有沒有錯誤，有錯誤的話就把所有的錯誤放進結果返回給客戶端，如果沒有錯誤就返回當前時間跟user對象

然後寫個測試方法試試

@Test
public void test1() throws Exception{
    this.mockMvc.perform(post("/validator/test1")).andDo(print());
    this.mockMvc.perform(post("/validator/test1").param("username", "testusername").param("password", "testpassword")).andDo(print());
}

第一個請求的結果是

{"success":false,"message":null,"hasErrors":true,"data":[{"name":"user","message":"may not be null"},{"name":"user","message":"密碼不能爲空"}]}

第二個請求結果是

{"success":true,"message":null,"hasErrors":false,"data":{"now":1420788232169,"user":{"username":"testusername","password":"testpassword"}}}

很明顯第一次請求沒有用戶名和密碼兩個字段校驗都沒有通過，第二次是成功的

用起來還是很簡單的，但是如果我不想每次都在controller方法裏寫if(result.hasErrors())怎麼辦呢，寫個切面，把if寫在切面裏，如果有errors直接就返回了，不用再執行controller方法了

@Aspect
public class ValidAspect {

    @Autowired private Validator validator;

    @Around("@annotation(org.springframework.web.bind.annotation.ResponseBody)")
    public Object doTest(ProceedingJoinPoint pjp) throws Throwable{
        MethodSignature signature = (MethodSignature) pjp.getSignature();
        Method method = signature.getMethod();
        if(!AjaxResponse.class.equals(method.getReturnType())){
            pjp.proceed();
        }
        Object[] args = pjp.getArgs();
        Annotation[][] annotations = method.getParameterAnnotations();
        for(int i = 0; i < annotations.length; i++){
            if(!hasValidAnnotation(annotations[i])){
                continue;
            }
            if(!(i < annotations.length-1 && args[i+1] instanceof BindingResult)){
                //驗證對象後面沒有跟bindingResult,事實上如果沒有應該到不了這一步
                continue;
            }
            BindingResult result = (BindingResult) args[i+1];
            if(result.hasErrors()){
                AjaxResponse ajaxResponse = new AjaxResponse();
                ajaxResponse.setSuccess(false);
                ajaxResponse.setHasErrors(true);
                ajaxResponse.setData(processErrors(result));
                return ajaxResponse;
            }
        }
        return pjp.proceed();
    }

    private boolean hasValidAnnotation(Annotation[] annotations){
        if(annotations == null){
            return false;
        }
        for(Annotation annotation : annotations){
            if(annotation instanceof Valid){
                return true;
            }
        }
        return false;
    }

    private List<BindingError> processErrors(BindingResult result){
        if(result != null && result.hasErrors()){
            List<BindingError> list = new ArrayList<BindingError>();
            for(ObjectError error : result.getAllErrors()){
                BindingError be = new BindingError();
                be.setMessage(error.getDefaultMessage());
                be.setName(error.getObjectName());
                list.add(be);
            }
            return list;
        }
        return null;
    }
}

注意要在springmvc配置文件加一行<bean class="spring.test.web.aop.ValidAspect"/>

然後再寫個方法邏輯跟上面的類似

@ResponseBody
@RequestMapping("/test2")
public AjaxResponse validateTest2(@Valid User user, BindingResult result){
    AjaxResponse ajaxResponse = new AjaxResponse();
    Map<String, Object> map = new HashMap<>();
    map.put("now", new Date());
    map.put("user", user);
    ajaxResponse.setData(map);
    return ajaxResponse;
}

這裏沒有再去判斷hasErrors()了，然後測試一下

寫測試方式試一下

@Test
public void test2() throws Exception{
    this.mockMvc.perform(post("/validator/test2")).andDo(print());
    this.mockMvc.perform(post("/validator/test2").param("username", "testusername").param("password", "testpassword")).andDo(print());
}

第一個請求結果是

{"success":false,"message":null,"hasErrors":true,"data":[{"name":"user","message":"密碼不能爲空"},{"name":"user","message":"may not be null"}]}

第二個請求結果是

{"success":true,"message":null,"hasErrors":false,"data":{"now":1420788479105,"user":{"username":"testusername","password":"testpassword"}}}

效果跟上面是一樣的

當然我這個切面僅僅是個示範，我攔截的是帶有ResponseBody註解的方法，我這些方法會返回一個統一的格式，如果是要返回別的視圖就要自己定義註解加其他參數了

JSR-303原生支持的校驗註解也是有限的，如果要實現其他的驗證，可以自己拓展，拓展方法就下次再說了，我也纔剛接觸。