org.apache.zeppelin.lens.LensSimpleExecutionStrategy.java Source code

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Here is the source code for org.apache.zeppelin.lens.LensSimpleExecutionStrategy.java

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/*
 * Copyright 2011-2012 the original author or authors.
 *
 * 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 org.apache.zeppelin.lens;

import org.springframework.shell.core.*;

import java.util.logging.Logger;

import org.springframework.shell.event.ParseResult;
import org.springframework.shell.support.logging.HandlerUtils;
import org.springframework.util.Assert;
import org.springframework.util.ReflectionUtils;

/**
 * workaround for https://github.com/spring-projects/spring-shell/issues/73
 */
public class LensSimpleExecutionStrategy implements ExecutionStrategy {

    private static final Logger logger = HandlerUtils.getLogger(LensSimpleExecutionStrategy.class);

    public Object execute(ParseResult parseResult) throws RuntimeException {
        Assert.notNull(parseResult, "Parse result required");
        logger.info("LensSimpleExecutionStrategy execute method invoked");
        synchronized (this) {
            Assert.isTrue(isReadyForCommands(), "SimpleExecutionStrategy not yet ready for commands");
            Object target = parseResult.getInstance();
            if (target instanceof ExecutionProcessor) {
                ExecutionProcessor processor = ((ExecutionProcessor) target);
                parseResult = processor.beforeInvocation(parseResult);
                try {
                    Object result = invoke(parseResult);
                    processor.afterReturningInvocation(parseResult, result);
                    return result;
                } catch (Throwable th) {
                    processor.afterThrowingInvocation(parseResult, th);
                    return handleThrowable(th);
                }
            } else {
                return invoke(parseResult);
            }
        }
    }

    private Object invoke(ParseResult parseResult) {
        try {
            return ReflectionUtils.invokeMethod(parseResult.getMethod(), parseResult.getInstance(),
                    parseResult.getArguments());
        } catch (Throwable th) {
            logger.severe("Command failed " + th);
            return handleThrowable(th);
        }
    }

    private Object handleThrowable(Throwable th) {
        if (th instanceof Error) {
            throw ((Error) th);
        }
        if (th instanceof RuntimeException) {
            throw ((RuntimeException) th);
        }
        throw new RuntimeException(th);
    }

    public boolean isReadyForCommands() {
        return true;
    }

    public void terminate() {
        // do nothing
    }

}