org.springframework.data.hadoop.hbase.HbaseInterceptor.java Source code

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Here is the source code for org.springframework.data.hadoop.hbase.HbaseInterceptor.java

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/*
 * Copyright 2011-2013 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.springframework.data.hadoop.hbase;

import java.io.IOException;
import java.util.LinkedHashSet;
import java.util.Set;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.springframework.util.Assert;

/**
 * AOP interceptor that binds a new Hbase table to the thread before a method call, closing and removing it afterwards in case of any method outcome.
 * If there is already a pre-bound table (from a previous call or transaction), the interceptor simply participates in it.
 * Typically used alongside {@link HbaseSynchronizationManager}.
 * 
 * @author Costin Leau
 */
public class HbaseInterceptor extends HbaseAccessor implements MethodInterceptor {

    private static final Log log = LogFactory.getLog(HbaseInterceptor.class);

    private boolean exceptionConversionEnabled = true;
    private String[] tableNames;

    public void afterPropertiesSet() {
        super.afterPropertiesSet();
        Assert.notEmpty(tableNames, "at least one table needs to be specified");
    }

    public Object invoke(MethodInvocation methodInvocation) throws Throwable {
        Set<String> boundTables = new LinkedHashSet<String>();

        for (String tableName : tableNames) {
            if (!HbaseSynchronizationManager.hasResource(tableName)) {
                boundTables.add(tableName);
                HTableInterface table = HbaseUtils.getHTable(tableName, getConfiguration(), getCharset(),
                        getTableFactory());
                HbaseSynchronizationManager.bindResource(tableName, table);
            }
        }

        try {
            Object retVal = methodInvocation.proceed();
            return retVal;
        } catch (Exception ex) {
            if (this.exceptionConversionEnabled) {
                throw convertHBaseException(ex);
            } else {
                throw ex;
            }
        } finally {
            for (String tableName : boundTables) {
                HTableInterface table = (HTableInterface) HbaseSynchronizationManager
                        .unbindResourceIfPossible(tableName);
                if (table != null) {
                    HbaseUtils.releaseTable(tableName, table);
                } else {
                    log.warn("Table [" + tableName
                            + "] unbound from the thread by somebody else; cannot guarantee proper clean-up");
                }
            }
        }
    }

    private Exception convertHBaseException(Exception ex) {
        return HbaseUtils.convertHbaseException(ex);
    }

    public void setTableNames(String[] tableNames) {
        this.tableNames = tableNames;
    }

    /**
     * Sets whether to convert any {@link IOException} raised to a Spring DataAccessException,
     * compatible with the <code>org.springframework.dao</code> exception hierarchy.
     * <p>Default is "true". Turn this flag off to let the caller receive raw exceptions
     * as-is, without any wrapping.
     * @see org.springframework.dao.DataAccessException
     */
    public void setExceptionConversionEnabled(boolean exceptionConversionEnabled) {
        this.exceptionConversionEnabled = exceptionConversionEnabled;
    }
}