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本文主要研究一下dubbo的ValidationFilter

ValidationFilter

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/main/java/org/apache/dubbo/validation/filter/ValidationFilter.java

@Activate(group = {CONSUMER, PROVIDER}, value = VALIDATION_KEY, order = 10000)
public class ValidationFilter implements Filter {

    private Validation validation;

    /**
     * Sets the validation instance for ValidationFilter
     * @param validation Validation instance injected by dubbo framework based on "validation" attribute value.
     */
    public void setValidation(Validation validation) {
        this.validation = validation;
    }

    /**
     * Perform the validation of before invoking the actual method based on <b>validation</b> attribute value.
     * @param invoker    service
     * @param invocation invocation.
     * @return Method invocation result
     * @throws RpcException Throws RpcException if  validation failed or any other runtime exception occurred.
     */
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        if (validation != null && !invocation.getMethodName().startsWith("$")
                && ConfigUtils.isNotEmpty(invoker.getUrl().getMethodParameter(invocation.getMethodName(), VALIDATION_KEY))) {
            try {
                Validator validator = validation.getValidator(invoker.getUrl());
                if (validator != null) {
                    validator.validate(invocation.getMethodName(), invocation.getParameterTypes(), invocation.getArguments());
                }
            } catch (RpcException e) {
                throw e;
            } catch (Throwable t) {
                return AsyncRpcResult.newDefaultAsyncResult(t, invocation);
            }
        }
        return invoker.invoke(invocation);
    }

}

• ValidationFilter实现了Filter接口，其invoke方法在validation不为null且invoker的URL中的method参数中包含有validation，且方法名不是$开头的，那么就会从validation获取validator，然后进行校验

Validation

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/main/java/org/apache/dubbo/validation/Validation.java

@SPI("jvalidation")
public interface Validation {

    /**
     * Return the instance of {@link Validator} for a given url.
     * @param url Invocation url
     * @return Instance of {@link Validator}
     */
    @Adaptive(VALIDATION_KEY)
    Validator getValidator(URL url);

}

• Validation接口定义了getValidator方法

AbstractValidation

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/main/java/org/apache/dubbo/validation/support/AbstractValidation.java

public abstract class AbstractValidation implements Validation {

    private final ConcurrentMap<String, Validator> validators = new ConcurrentHashMap<>();

    @Override
    public Validator getValidator(URL url) {
        String key = url.toFullString();
        Validator validator = validators.get(key);
        if (validator == null) {
            validators.put(key, createValidator(url));
            validator = validators.get(key);
        }
        return validator;
    }

    protected abstract Validator createValidator(URL url);

}

• AbstractValidation实现了Validation接口，它定义了一个ConcurrentHashMap类型的validators，并且实现了getValidator方法，同时定义了createValidator抽象方法供子类实现

JValidation

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/main/java/org/apache/dubbo/validation/support/jvalidation/JValidation.java

public class JValidation extends AbstractValidation {

    /**
     * Return new instance of {@link JValidator}
     * @param url Valid URL instance
     * @return Instance of JValidator
     */
    @Override
    protected Validator createValidator(URL url) {
        return new JValidator(url);
    }

}

• JValidation继承了AbstractValidation，它的createValidator创建的是JValidator

Validator

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/main/java/org/apache/dubbo/validation/Validator.java

public interface Validator {

    void validate(String methodName, Class<?>[] parameterTypes, Object[] arguments) throws Exception;

}

• Validator接口定义了validate方法

JValidator

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/main/java/org/apache/dubbo/validation/support/jvalidation/JValidator.java

public class JValidator implements Validator {

    private static final Logger logger = LoggerFactory.getLogger(JValidator.class);

    private final Class<?> clazz;

    private final Map<String, Class> methodClassMap;

    private final javax.validation.Validator validator;

    @SuppressWarnings({"unchecked", "rawtypes"})
    public JValidator(URL url) {
        this.clazz = ReflectUtils.forName(url.getServiceInterface());
        String jvalidation = url.getParameter("jvalidation");
        ValidatorFactory factory;
        if (jvalidation != null && jvalidation.length() > 0) {
            factory = Validation.byProvider((Class) ReflectUtils.forName(jvalidation)).configure().buildValidatorFactory();
        } else {
            factory = Validation.buildDefaultValidatorFactory();
        }
        this.validator = factory.getValidator();
        this.methodClassMap = new ConcurrentHashMap<>();
    }

    //......

    @Override
    public void validate(String methodName, Class<?>[] parameterTypes, Object[] arguments) throws Exception {
        List<Class<?>> groups = new ArrayList<>();
        Class<?> methodClass = methodClass(methodName);
        if (methodClass != null) {
            groups.add(methodClass);
        }
        Set<ConstraintViolation<?>> violations = new HashSet<>();
        Method method = clazz.getMethod(methodName, parameterTypes);
        Class<?>[] methodClasses;
        if (method.isAnnotationPresent(MethodValidated.class)){
            methodClasses = method.getAnnotation(MethodValidated.class).value();
            groups.addAll(Arrays.asList(methodClasses));
        }
        // add into default group
        groups.add(0, Default.class);
        groups.add(1, clazz);

        // convert list to array
        Class<?>[] classgroups = groups.toArray(new Class[groups.size()]);

        Object parameterBean = getMethodParameterBean(clazz, method, arguments);
        if (parameterBean != null) {
            violations.addAll(validator.validate(parameterBean, classgroups ));
        }

        for (Object arg : arguments) {
            validate(violations, arg, classgroups);
        }

        if (!violations.isEmpty()) {
            logger.error("Failed to validate service: " + clazz.getName() + ", method: " + methodName + ", cause: " + violations);
            throw new ConstraintViolationException("Failed to validate service: " + clazz.getName() + ", method: " + methodName + ", cause: " + violations, violations);
        }
    }

    //......
}

• JValidator实现了Validator接口，其validate方法内部使用的是javax.validation.ValidatorFactory创建的javax.validation.Validator

实例

dubbo-2.7.2/dubbo-filter/dubbo-filter-validation/src/test/java/org/apache/dubbo/validation/filter/ValidationFilterTest.java

public class ValidationFilterTest {
    private Invoker<?> invoker = mock(Invoker.class);
    private Validation validation = mock(Validation.class);
    private Validator validator = mock(Validator.class);
    private RpcInvocation invocation = mock(RpcInvocation.class);

    private ValidationFilter validationFilter;

    @BeforeEach
    public void setUp() throws Exception {
        this.validationFilter = new ValidationFilter();
    }

    @Test
    public void testItWithNotExistClass() throws Exception {
        URL url = URL.valueOf("test://test:11/test?default.validation=true");

        given(validation.getValidator(url)).willThrow(new IllegalStateException("Not found class test, cause: test"));
        given(invoker.invoke(invocation)).willReturn(new AppResponse("success"));
        given(invoker.getUrl()).willReturn(url);
        given(invocation.getMethodName()).willReturn("echo1");
        given(invocation.getParameterTypes()).willReturn(new Class<?>[]{String.class});
        given(invocation.getArguments()).willReturn(new Object[]{"arg1"});

        validationFilter.setValidation(validation);
        Result result = validationFilter.invoke(invoker, invocation);

        assertThat(result.getException().getMessage(), is("Not found class test, cause: test"));

    }

    @Test
    public void testItWithExistClass() throws Exception {
        URL url = URL.valueOf("test://test:11/test?default.validation=true");

        given(validation.getValidator(url)).willReturn(validator);
        given(invoker.invoke(invocation)).willReturn(new AppResponse("success"));
        given(invoker.getUrl()).willReturn(url);
        given(invocation.getMethodName()).willReturn("echo1");
        given(invocation.getParameterTypes()).willReturn(new Class<?>[]{String.class});
        given(invocation.getArguments()).willReturn(new Object[]{"arg1"});

        validationFilter.setValidation(validation);
        Result result = validationFilter.invoke(invoker, invocation);

        assertThat(String.valueOf(result.getValue()), is("success"));
    }

    @Test
    public void testItWithoutUrlParameters() throws Exception {
        URL url = URL.valueOf("test://test:11/test");

        given(validation.getValidator(url)).willReturn(validator);
        given(invoker.invoke(invocation)).willReturn(new AppResponse("success"));
        given(invoker.getUrl()).willReturn(url);
        given(invocation.getMethodName()).willReturn("echo1");
        given(invocation.getParameterTypes()).willReturn(new Class<?>[]{String.class});
        given(invocation.getArguments()).willReturn(new Object[]{"arg1"});

        validationFilter.setValidation(validation);
        Result result = validationFilter.invoke(invoker, invocation);

        assertThat(String.valueOf(result.getValue()), is("success"));
    }

    @Test
    public void testItWhileMethodNameStartWithDollar() throws Exception {
        URL url = URL.valueOf("test://test:11/test");

        given(validation.getValidator(url)).willReturn(validator);
        given(invoker.invoke(invocation)).willReturn(new AppResponse("success"));
        given(invoker.getUrl()).willReturn(url);
        given(invocation.getMethodName()).willReturn("$echo1");
        given(invocation.getParameterTypes()).willReturn(new Class<?>[]{String.class});
        given(invocation.getArguments()).willReturn(new Object[]{"arg1"});

        validationFilter.setValidation(validation);
        Result result = validationFilter.invoke(invoker, invocation);

        assertThat(String.valueOf(result.getValue()), is("success"));

    }


    @Test
    public void testItWhileThrowoutRpcException() throws Exception {
        Assertions.assertThrows(RpcException.class, () -> {
            URL url = URL.valueOf("test://test:11/test?default.validation=true");

            given(validation.getValidator(url)).willThrow(new RpcException("rpc exception"));
            given(invoker.invoke(invocation)).willReturn(new AppResponse("success"));
            given(invoker.getUrl()).willReturn(url);
            given(invocation.getMethodName()).willReturn("echo1");
            given(invocation.getParameterTypes()).willReturn(new Class<?>[]{String.class});
            given(invocation.getArguments()).willReturn(new Object[]{"arg1"});

            validationFilter.setValidation(validation);
            validationFilter.invoke(invoker, invocation);
        });
    }
}

• 这里分别验证了withNotExistClass、withExistClass、withoutUrlParameters、methodNameStartWithDollar、throwoutRpcException这几个场景

小结

• ValidationFilter实现了Filter接口，其invoke方法在validation不为null且invoker的URL中的method参数中包含有validation，且方法名不是$开头的，那么就会从validation获取validator，然后进行校验
• Validation接口定义了getValidator方法；JValidation继承了AbstractValidation，它的createValidator创建的是JValidator
• JValidator实现了Validator接口，其validate方法内部使用的是javax.validation.ValidatorFactory创建的javax.validation.Validator

doc

• ValidationFilter