抱怨來(lái)了

dbunit這么多人用兆衅，這個(gè)項(xiàng)目居然好像沒(méi)有人在維護(hù)了镀层，自動(dòng)2012年9月release一個(gè)版本后，再?zèng)]有更新了船逮，寒心啊顾腊。

dbunit有一個(gè)大大的BUG，即會(huì)解釋不了MySQL表的結(jié)構(gòu)傻唾，在使用@DataSet準(zhǔn)備數(shù)據(jù)時(shí)投慈，會(huì)拋出類(lèi)似如下的異常：

Caused by: org.unitils.core.UnitilsException: Error while executing DataSetLoadStrategy
    at org.unitils.dbunit.datasetloadstrategy.impl.BaseDataSetLoadStrategy.execute(BaseDataSetLoadStrategy.java:46)
    at org.unitils.dbunit.DbUnitModule.insertDataSet(DbUnitModule.java:230)
    at org.unitils.dbunit.DbUnitModule.insertDataSet(DbUnitModule.java:153)
    ... 35 more
Caused by: org.dbunit.dataset.NoSuchColumnException: t_upload_file.ID -  (Non-uppercase input column: id) in ColumnNameToIndexes cache map. Note that the map's column names are NOT case sensitive.
    at org.dbunit.dataset.AbstractTableMetaData.getColumnIndex(AbstractTableMetaData.java:117)
    at org.dbunit.operation.AbstractOperation.getOperationMetaData(AbstractOperation.java:89)
    at org.dbunit.operation.AbstractBatchOperation.execute(AbstractBatchOperation.java:140)
    at org.dbunit.operation.CompositeOperation.execute(CompositeOperation.java:79)
    at org.unitils.dbunit.datasetloadstrategy.impl.CleanInsertLoadStrategy.doExecute(CleanInsertLoadStrategy.java:45)
    at org.unitils.dbunit.datasetloadstrategy.impl.BaseDataSetLoadStrategy.execute(BaseDataSetLoadStrategy.java:44)
    ... 37 more

網(wǎng)上有很多痛苦的人在苦苦尋答案，但都依舊痛苦著...
http://zfanxu.iteye.com/blog/1508339
http://zfanxu.iteye.com/blog/1508339

其實(shí)這是dbunit的一個(gè)BUG冠骄，好像很多版本都有這個(gè)問(wèn)題伪煤，報(bào)告說(shuō)解決了，其實(shí)并沒(méi)有解決凛辣。我使用最新的2.4.9的版本照樣會(huì)拋出這個(gè)問(wèn)題抱既。

解決辦法

碰到問(wèn)題光抱怨是沒(méi)有用的，又不能指望dbunit的作者改扁誓，只能自己著騰了防泵。按照網(wǎng)上的幾篇文章改了dbunit的源碼，重新編譯上傳到自己的Maven私服上蝗敢。終于解決了捷泞。

為了避免大家再重新更改編譯，我把已經(jīng)解譯好的dbunit jar放在附件中寿谴，大家需要的話可以下載使用锁右。

繼續(xù)...

最近又在整基于DB2的unitils框架，發(fā)現(xiàn)又出現(xiàn)問(wèn)題了，結(jié)果再次好好跟蹤了unitils及dbunit的源碼咏瑟，終于有了顛覆性的重大發(fā)現(xiàn)：

原來(lái)網(wǎng)上一直說(shuō)的是DBUNIT框架導(dǎo)致這個(gè)問(wèn)題的說(shuō)明是錯(cuò)誤的拂到，真正的錯(cuò)誤是unitils框架的錯(cuò)誤！码泞！

因?yàn)镈BUNIT已經(jīng)為不同數(shù)據(jù)庫(kù)提供了不同的接口實(shí)現(xiàn)：

org.dbunit.database.IMetadataHandler
而unitils(具體地說(shuō)是DbUnitModule模塊)不管你什么數(shù)據(jù)庫(kù)兄旬，它統(tǒng)一使用這個(gè)類(lèi)：
org.dbunit.database.DefaultMetadataHandler

如果數(shù)據(jù)庫(kù)不特殊，當(dāng)然用DefaultMetadataHandler這個(gè)沒(méi)有問(wèn)題余寥，如果特殊领铐，則就取不到數(shù)據(jù)庫(kù)的Metadata信息了，結(jié)果異常就發(fā)生了宋舷。

但是罐孝，目前的DBUnit的Db2MetadataHandler確實(shí)是有BUG的，所以我的解決方法是：

1）復(fù)寫(xiě)了unitils的DbUnitModule實(shí)現(xiàn)類(lèi)肥缔；
2）復(fù)寫(xiě)了dbunit的Db2MetadataHandler實(shí)現(xiàn)類(lèi)莲兢；
3）配置unitils的配置文件，應(yīng)用這些自定義的實(shí)現(xiàn)類(lèi)续膳。

package com.ridge.test.unitils.ext;

import org.dbunit.database.DatabaseConfig;
import org.dbunit.database.DefaultMetadataHandler;
import org.dbunit.dataset.DataSetException;
import org.dbunit.dataset.IDataSet;
import org.dbunit.dataset.datatype.IDataTypeFactory;
import org.dbunit.dataset.filter.ITableFilterSimple;
import org.dbunit.ext.db2.Db2DataTypeFactory;
import org.dbunit.ext.db2.Db2MetadataHandler;
import org.dbunit.ext.mysql.MySqlDataTypeFactory;
import org.dbunit.ext.mysql.MySqlMetadataHandler;
import org.unitils.core.UnitilsException;
import org.unitils.core.dbsupport.DbSupport;
import org.unitils.core.dbsupport.DefaultSQLHandler;
import org.unitils.core.dbsupport.SQLHandler;
import org.unitils.dbunit.DbUnitModule;
import org.unitils.dbunit.util.DbUnitDatabaseConnection;

import javax.sql.DataSource;

import static org.dbunit.database.DatabaseConfig.FEATURE_BATCHED_STATEMENTS;
import static org.dbunit.database.DatabaseConfig.PROPERTY_DATATYPE_FACTORY;
import static org.dbunit.database.DatabaseConfig.PROPERTY_ESCAPE_PATTERN;
import static org.unitils.core.dbsupport.DbSupportFactory.getDbSupport;
import static org.unitils.core.util.ConfigUtils.getInstanceOf;

/**
 * @author : chenxh(quickselect@163.com)
 * @date: 13-10-9
 */
public class MyDbunitModule extends DbUnitModule {

    protected DbUnitDatabaseConnection createDbUnitConnection(String schemaName) {
        // A DbSupport instance is fetched in order to get the schema name in correct case
        DataSource dataSource = getDatabaseModule().getDataSourceAndActivateTransactionIfNeeded();
        SQLHandler sqlHandler = new DefaultSQLHandler(dataSource);
        DbSupport dbSupport = getDbSupport(configuration, sqlHandler, schemaName);

        // Create connection
        DbUnitDatabaseConnection connection = new DbUnitDatabaseConnection(dataSource, dbSupport.getSchemaName());
        DatabaseConfig config = connection.getConfig();

        // Make sure that dbunit's correct IDataTypeFactory, that handles dbms specific data type issues, is used
        IDataTypeFactory dataTypeFactory = getInstanceOf(IDataTypeFactory.class, configuration, dbSupport.getDatabaseDialect());
        config.setProperty(PROPERTY_DATATYPE_FACTORY, dataTypeFactory);
        // Make sure that table and column names are escaped using the dbms-specific identifier quote string
        if (dbSupport.getIdentifierQuoteString() != null)
            config.setProperty(PROPERTY_ESCAPE_PATTERN, dbSupport.getIdentifierQuoteString() + '?' + dbSupport.getIdentifierQuoteString());
        // Make sure that batched statements are used to insert the data into the database
        config.setProperty(FEATURE_BATCHED_STATEMENTS, "true");
        // Make sure that Oracle's recycled tables (BIN$) are ignored (value is used to ensure dbunit-2.2 compliancy)
        config.setProperty("http://www.dbunit.org/features/skipOracleRecycleBinTables", "true");

        //注意這兒：根據(jù)不同的數(shù)據(jù)庫(kù)(unitils的database.dialect配置參數(shù)）為dbunit
        //指定使用不同的IMetadataHandler實(shí)現(xiàn)（其它數(shù)據(jù)庫(kù)都可以用默認(rèn)的改艇，還有一個(gè)Netezza也是特別的，這里忽略了）
        if("db2".equalsIgnoreCase(configuration.getProperty("database.dialect"))){
            config.setProperty(DatabaseConfig.PROPERTY_DATATYPE_FACTORY,
                    new Db2DataTypeFactory());
            
            //由于dbunit自身提供的Db2MetadataHandler有BUG坟岔，所以這里使用自己寫(xiě)的
            //MyDb2MetadataHandler,源碼在后面了谒兄。
            config.setProperty(DatabaseConfig.PROPERTY_METADATA_HANDLER,
                    new MyDb2MetadataHandler());
        }else if("mysql".equalsIgnoreCase(configuration.getProperty("database.dialect"))){
            config.setProperty(DatabaseConfig.PROPERTY_DATATYPE_FACTORY,
                    new MySqlDataTypeFactory());
            config.setProperty(DatabaseConfig.PROPERTY_METADATA_HANDLER,
                    new MySqlMetadataHandler());
        }
        return connection;
    }
}

下面是MyDb2MetadataHandler的源碼：

package com.ridge.test.unitils.ext;

import org.dbunit.ext.db2.Db2MetadataHandler;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.dbunit.util.SQLHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author : chenxh(quickselect@163.com)
 * @date: 13-10-9
 */
public class MyDb2MetadataHandler extends Db2MetadataHandler {
    private static final Logger logger = LoggerFactory.getLogger(MyDb2MetadataHandler.class);

    public ResultSet getTables(DatabaseMetaData metaData, String schemaName, String[] tableType)
            throws SQLException
    {
        if(logger.isTraceEnabled())
            logger.trace("tableExists(metaData={}, schemaName={}, tableType={}) - start",
                    new Object[] {metaData, schemaName, tableType} );
        return metaData.getTables(null, schemaName, "%", tableType);
    }

    public boolean tableExists(DatabaseMetaData metaData, String schema, String tableName)
            throws SQLException
    {
        ResultSet tableRs = metaData.getTables(null, schema, tableName, null);
        try
        {
            return tableRs.next();
        }
        finally
        {
            SQLHelper.close(tableRs);
        }
    }

    public ResultSet getColumns(DatabaseMetaData databaseMetaData, String schemaName, String tableName)
            throws SQLException {
        // Note that MySQL uses the catalogName instead of the schemaName, so
        // pass in the given schema name as catalog name (first argument).

        ResultSet resultSet = databaseMetaData.getColumns(
                null, schemaName, tableName, "%");
        return resultSet;
    }

    public boolean matches(ResultSet columnsResultSet, String catalog,
                           String schema, String table, String column,
                           boolean caseSensitive) throws SQLException
    {
        String catalogName = columnsResultSet.getString(1);
        String schemaName = columnsResultSet.getString(2);
        String tableName = columnsResultSet.getString(3);
        String columnName = columnsResultSet.getString(4);

        // MYSQL provides only a catalog but no schema
        if(schema != null && schemaName == null && catalog==null && catalogName != null){
            logger.debug("Switching catalog/schema because the are mutually null");
            schemaName = catalogName;
            catalogName = null;
        }

        boolean areEqual =
                areEqualIgnoreNull(table, tableName, caseSensitive) &&
                        areEqualIgnoreNull(column, columnName, caseSensitive);
        return areEqual;
    }

    private boolean areEqualIgnoreNull(String value1, String value2,
                                       boolean caseSensitive) {
        return SQLHelper.areEqualIgnoreNull(value1, value2, caseSensitive);
    }
}

最后一步，更改unitils.properties的配置：

...
unitils.module.dbunit.className=com.ridge.test.unitils.ext.MyDbunitModule
...

總結(jié)一下

采用前面的解決方案只能解決mysql的問(wèn)題社付，且直接改dbunit的源碼承疲，是不好的方案，現(xiàn)在我把它廢棄了鸥咖，大家就不要了燕鸽。

采用第二種方案吧，是優(yōu)雅的解決方案啼辣，沒(méi)有更改dbunit的源碼啊研，僅通過(guò)unitils的擴(kuò)展配置實(shí)現(xiàn)了，所以你不要下載附件的dbunit-2.4.8.2.jar了鸥拧，直接使用最新的dbunit版本吧：

        <dependency>
            <groupId>org.dbunit</groupId>
            <artifactId>dbunit</artifactId>
            <version>2.4.9</version>>
            </exclusions>
        </dependency>

這個(gè)問(wèn)題啊党远，讓我死幾回的心都有了，現(xiàn)在終于解決了富弦，希望對(duì)大家有幫助沟娱！