co.cask.cdap.internal.app.runtime.procedure.DefaultProcedureRequest.java Source code

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Here is the source code for co.cask.cdap.internal.app.runtime.procedure.DefaultProcedureRequest.java

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/*
 * Copyright  2014 Cask Data, Inc.
 *
 * 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 co.cask.cdap.internal.app.runtime.procedure;

import co.cask.cdap.api.procedure.ProcedureRequest;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableMap;
import com.google.gson.internal.Primitives;

import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.util.Map;

/**
 *
 */
final class DefaultProcedureRequest implements ProcedureRequest {

    private final String method;
    private final Map<String, String> arguments;

    DefaultProcedureRequest(String method, Map<String, String> arguments) {
        this.method = method;
        this.arguments = ImmutableMap.copyOf(arguments);
    }

    @Override
    public String getMethod() {
        return method;
    }

    @Override
    public Map<String, String> getArguments() {
        return arguments;
    }

    @Override
    public String getArgument(String key) {
        return arguments.get(key);
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> T getArgument(String key, Class<T> type) {
        Preconditions.checkNotNull(type, "Type cannnot be null.");
        Preconditions.checkArgument(!Void.class.equals(type) && !Void.TYPE.equals(type),
                "Void type not supported.");

        String value = getArgument(key);

        if (String.class.equals(type)) {
            return (T) value;
        }

        Class<T> resolvedType = type;
        if (Primitives.isPrimitive(resolvedType)) {
            resolvedType = Primitives.wrap(type);
        }
        if (Primitives.isWrapperType(resolvedType)) {
            // All wrapper has the valueOf(String) method
            try {
                return (T) resolvedType.getMethod("valueOf", String.class).invoke(null, value);
            } catch (Exception e) {
                // Should not happen
                throw Throwables.propagate(e);
            }
        }
        if (URL.class.equals(type)) {
            try {
                return (T) new URL(value);
            } catch (MalformedURLException e) {
                throw Throwables.propagate(e);
            }
        }
        if (URI.class.equals(type)) {
            return (T) URI.create(value);
        }

        // TODO: Maybe support gson decode the type??
        throw new ClassCastException("Fail to convert from String to " + type);
    }
}