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

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<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

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<?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

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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

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@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

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@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

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{"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

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{"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

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@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

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@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

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@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

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{"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

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{"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。