monasca.api.app.validation.ValueMetaValidation.java Source code

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Here is the source code for monasca.api.app.validation.ValueMetaValidation.java

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/*
 * Copyright (c) 2015 Hewlett-Packard Development Company, L.P.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package monasca.api.app.validation;

import com.google.common.base.CharMatcher;
import com.google.common.base.Strings;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import monasca.api.resource.exception.Exceptions;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.ws.rs.WebApplicationException;

/**
 * Utilities for validating valueMeta.
 */
public final class ValueMetaValidation {
    private static final int VALUE_META_MAX_NUMBER = 16;
    private static final int VALUE_META_VALUE_MAX_LENGTH = 2048;
    private static final int VALUE_META_NAME_MAX_LENGTH = 255;
    private static final Map<String, String> EMPTY_VALUE_META = Collections
            .unmodifiableMap(new HashMap<String, String>());

    private static final ObjectMapper objectMapper = new ObjectMapper();

    private ValueMetaValidation() {
    }

    /**
     * Normalizes valueMeta by stripping whitespace from name. validate() must
     * already have been called on the valueMeta
     */
    public static Map<String, String> normalize(Map<String, String> valueMeta) {
        if (valueMeta == null || valueMeta.isEmpty()) {
            return EMPTY_VALUE_META;
        }
        final Map<String, String> result = new HashMap<>();
        for (Map.Entry<String, String> entry : valueMeta.entrySet()) {
            final String key = CharMatcher.WHITESPACE.trimFrom(entry.getKey());
            result.put(key, entry.getValue());
        }

        return result;
    }

    /**
     * Validates that the given {@code valueMetas} are valid.
     *
     * @throws WebApplicationException if validation fails
     */
    public static void validate(Map<String, String> valueMetas) {
        if (valueMetas.size() > VALUE_META_MAX_NUMBER) {
            throw Exceptions.unprocessableEntity("Maximum number of valueMeta key/value pairs is %d",
                    VALUE_META_MAX_NUMBER);
        }

        // Validate valueMeta names and values
        for (Map.Entry<String, String> valueMeta : valueMetas.entrySet()) {
            // Have to check for null first because later check is for trimmed name
            if (valueMeta.getKey() == null) {
                throw Exceptions.unprocessableEntity("valueMeta name cannot be empty");
            }
            final String name = CharMatcher.WHITESPACE.trimFrom(valueMeta.getKey());
            String value = valueMeta.getValue();
            if (value == null) {
                // Store nulls as empty strings
                value = "";
            }

            // General validations
            if (Strings.isNullOrEmpty(name)) {
                throw Exceptions.unprocessableEntity("valueMeta name cannot be empty");
            }
            if (name.length() > VALUE_META_NAME_MAX_LENGTH) {
                throw Exceptions.unprocessableEntity("valueMeta name %s must be %d characters or less", name,
                        VALUE_META_NAME_MAX_LENGTH);
            }
        }
        verifyValueMetaStringLength(valueMetas);
    }

    private static void verifyValueMetaStringLength(Map<String, String> valueMetas) {

        try {
            String valueMetaString = objectMapper.writeValueAsString(valueMetas);

            if (valueMetaString.length() > VALUE_META_VALUE_MAX_LENGTH) {
                throw Exceptions.unprocessableEntity(
                        "valueMeta name value combinations %s must be %d characters or less", valueMetaString,
                        VALUE_META_VALUE_MAX_LENGTH);
            }
        } catch (JsonProcessingException e) {
            throw Exceptions.unprocessableEntity("Failed to serialize valueMeta combinations %s", valueMetas);
        }
    }
}