org.makersoft.shards.ShardImpl.java Source code

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Here is the source code for org.makersoft.shards.ShardImpl.java

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/*
 * @(#)ShardImpl.java 2012-8-1 ?10:00:00
 *
 * Copyright (c) 2011-2012 Makersoft.org all rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *
 */
package org.makersoft.shards;

import static org.apache.ibatis.reflection.ExceptionUtil.unwrapThrowable;
import static org.mybatis.spring.SqlSessionUtils.closeSqlSession;
import static org.mybatis.spring.SqlSessionUtils.isSqlSessionTransactional;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Collection;
import java.util.Set;

import org.apache.ibatis.exceptions.PersistenceException;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.MyBatisExceptionTranslator;
import org.mybatis.spring.SqlSessionUtils;
import org.springframework.dao.support.PersistenceExceptionTranslator;

/**
 * 
 */
public class ShardImpl implements Shard {

    private final SqlSessionFactory sqlSessionFactory;

    private final PersistenceExceptionTranslator exceptionTranslator;

    private final SqlSession sqlSessionProxy;

    private final Set<ShardId> shardIds;

    public final ExecutorType executorType = ExecutorType.SIMPLE;

    public ShardImpl(Set<ShardId> shardIds, SqlSessionFactory sqlSessionFactory) {
        this.shardIds = shardIds;
        this.sqlSessionFactory = sqlSessionFactory;
        this.exceptionTranslator = new MyBatisExceptionTranslator(
                sqlSessionFactory.getConfiguration().getEnvironment().getDataSource(), true);
        this.sqlSessionProxy = (SqlSession) Proxy.newProxyInstance(SqlSessionFactory.class.getClassLoader(),
                new Class[] { SqlSession.class }, new SqlSessionInterceptor());
    }

    private Configuration getConfiguration() {
        return sqlSessionFactory.getConfiguration();
    }

    @Override
    public SqlSessionFactory getSqlSessionFactory() {
        return sqlSessionFactory;
    }

    @Override
    public SqlSession getSqlSession() {
        return sqlSessionProxy;
    }

    @Override
    public Set<ShardId> getShardIds() {
        return shardIds;
    }

    @Override
    public SqlSession establishSqlSession() {
        //      if(sqlSession == null){
        //         sqlSession = sqlSessionFactory.openSession();
        //      }
        return sqlSessionProxy;
    }

    @Override
    public Collection<String> getMappedStatementNames() {
        return getConfiguration().getMappedStatementNames();
    }

    @Override
    public boolean hasMapper(Class<?> type) {
        return getConfiguration().hasMapper(type);
    }

    private class SqlSessionInterceptor implements InvocationHandler {
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
            final SqlSession sqlSession = SqlSessionUtils.getSqlSession(ShardImpl.this.sqlSessionFactory,
                    ShardImpl.this.executorType, ShardImpl.this.exceptionTranslator);
            try {
                Object result = method.invoke(sqlSession, args);
                if (!isSqlSessionTransactional(sqlSession, ShardImpl.this.sqlSessionFactory)) {
                    // force commit even on non-dirty sessions because some databases require
                    // a commit/rollback before calling close()
                    sqlSession.commit(true);
                }
                return result;
            } catch (Throwable t) {
                Throwable unwrapped = unwrapThrowable(t);
                if (ShardImpl.this.exceptionTranslator != null && unwrapped instanceof PersistenceException) {
                    Throwable translated = ShardImpl.this.exceptionTranslator
                            .translateExceptionIfPossible((PersistenceException) unwrapped);
                    if (translated != null) {
                        unwrapped = translated;
                    }
                }
                throw unwrapped;
            } finally {
                closeSqlSession(sqlSession, ShardImpl.this.sqlSessionFactory);
            }
        }
    }

}