springmvc使用JSR-303进行校验

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

下面提供一种springmvc的校验方案，一般没有校验或者手动写validator的话都要写好多代码好多if判断，使用JSR-303规范校验只需要在Pojo字段上加上相应的注解就可以实现校验了

1.依赖的jar包，我直接贴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">

    <!-- 默认的注解映射的支持 -->
    <mvc:annotation-driven/>
    <context:annotation-config/>
    <aop:aspectj-autoproxy/>

    <!-- 自动扫描的包名 -->
    <context:component-scan base-package="spring.test.web.controller"/>

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

</beans>

3.写java代码了

先建一个User类

public class User {
    @NotNull
    private String username;

    @NotNull(message = "密码不能为空")
    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;
    }

}

然后建一个controller试试

@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;
}

这个方法第一个参数上加了@Valid标注，第二个参数是必须的而且必须紧跟着@Valid参数之后，校验结果都在这个result里面

方法逻辑比较简单，调用result.hasErrors()看校验有没有错误，有错误的话就把所有的错误放进结果返回给客户端，如果没有错误就返回当前时间跟user对象

然后写个测试方法试试

@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());
}

第一个请求的结果是

{"success":false,"message":null,"hasErrors":true,"data":[{"name":"user","message":"may not be null"},{"name":"user","message":"密码不能为空"}]}

第二个请求结果是

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

很明显第一次请求没有用户名和密码两个字段校验都没有通过，第二次是成功的

用起来还是很简单的，但是如果我不想每次都在controller方法里写if(result.hasErrors())怎么办呢，写个切面，把if写在切面里，如果有errors直接就返回了，不用再执行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)){
                //验证对象后面没有跟bindingResult,事实上如果没有应该到不了这一步
                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"/>

然后再写个方法逻辑跟上面的类似

@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;
}

这里没有再去判断hasErrors()了，然后测试一下

写测试方式试一下

@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());
}

第一个请求结果是

{"success":false,"message":null,"hasErrors":true,"data":[{"name":"user","message":"密码不能为空"},{"name":"user","message":"may not be null"}]}

第二个请求结果是

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

效果跟上面是一样的

当然我这个切面仅仅是个示范，我拦截的是带有ResponseBody注解的方法，我这些方法会返回一个统一的格式，如果是要返回别的视图就要自己定义注解加其他参数了

JSR-303原生支持的校验注解也是有限的，如果要实现其他的验证，可以自己拓展，拓展方法就下次再说了，我也才刚接触。