package com.cmb.lul.lulm.service.data.sink; import com.cmb.dtpframework.exception.AppException; import com.cmb.dtpframework.utils.SpringContextHolder; import com.cmb.dtpframework.utils.StringUtil; import com.cmb.lp.za20.util.BaseLayerFacade; import com.cmb.lul.lulm.service.data.cache.metadata.ColumnMetadata; import com.cmb.lul.lulm.service.data.cache.metadata.JdbcMetadataManager; import com.cmb.lul.lulm.service.data.cache.metadata.TableMetadata; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import java.math.BigDecimal; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.Types; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import java.util.stream.Collectors; public abstract class AbstractTableSink implements TableSink { protected final String sinkDbName; protected final String sinkSchemaName; protected final String sinkTableName; protected final TableMetadata sinkDsTableMetadata; protected final String indexName; protected final List<Map<String, String>> datas; protected final List<String> dataColumnNames; protected final List<String> primaryKeys; protected final List<String> updateColumnNames; protected long connectCostMs = 0L; protected long sinkCostMs = 0L; public AbstractTableSink(String sinkSchemaName, String sinkTableName, String indexName, List<String> primaryKeys, List<Map<String, String>> datas) { this.sinkDbName = sinkSchemaName; this.sinkSchemaName = sinkSchemaName; this.sinkTableName = sinkTableName; this.indexName = indexName; this.primaryKeys = primaryKeys; this.sinkDsTableMetadata = BaseLayerFacade.getSingleton(JdbcMetadataManager.class).getTableMetadata(sinkSchemaName, sinkTableName); this.datas = datas; this.dataColumnNames = getAndSortDataColumnNames(sinkDsTableMetadata, datas); this.updateColumnNames = dataColumnNames.stream().filter(column -> !primaryKeys.contains(column)).collect(Collectors.toList()); } public AbstractTableSink(String sinkSchemaName, String sinkTableName, List<String> primaryKeys, List<Map<String, String>> datas) { this(sinkSchemaName, sinkTableName, null, primaryKeys, datas); } protected List<String> getAndSortDataColumnNames(TableMetadata sinkDsTableMetadata, List<Map<String, String>> datas) { // 用源表data数据确定要写哪些字段 Set<String> tempDataColumnNamesSet = new HashSet<>(16); datas.forEach(data -> tempDataColumnNamesSet.addAll(data.keySet())); // 用目标表metadata重排列字段顺序 List<String> tempDataColumnNamesList = new ArrayList<>(tempDataColumnNamesSet.size()); sinkDsTableMetadata.getColumnMetadatas().keySet().forEach(metadataColumnName -> { if (tempDataColumnNamesSet.contains(metadataColumnName)) { tempDataColumnNamesList.add(metadataColumnName); tempDataColumnNamesSet.remove(metadataColumnName); } }); // 源表data中存在，但目标表metadata中不存在的字段放到最后（这部分写的时候会报错，表明目标表字段比源表少） tempDataColumnNamesList.addAll(tempDataColumnNamesSet); return tempDataColumnNamesList; } @Override public void doSink() { if (!datas.isEmpty()) { /* 构建sql语句 */ String sql = buildSql(); SqlSession session = null; try { long beforeConnectTime = System.currentTimeMillis(); session = SpringContextHolder.getBean(SqlSessionFactory.class).openSession(); Connection connection = session.getConnection(); long afterConnectTime = System.currentTimeMillis(); try (PreparedStatement preparedStatement = connection.prepareStatement(sql)) { /* 设置参数 */ for (Map<String, String> data : datas) { // 设置参数 setPreparedStatementParameter(preparedStatement, data); preparedStatement.addBatch(); } int[] results = preparedStatement.executeBatch(); } /* 事务提交 */ session.commit(true); long afterSinkTime = System.currentTimeMillis(); connectCostMs = afterConnectTime - beforeConnectTime; sinkCostMs = afterSinkTime - afterConnectTime; } catch (Exception e) { if (null != session) { /* 事务回滚 */ session.rollback(true); } throw new AppException(e, "LULM605", sinkDbName, sinkTableName, sql, e.getMessage()); } finally { if (null != session) { session.close(); } } } } protected String buildSql() { StringBuilder sql = new StringBuilder(); sql.append("MERGE "); if (indexName != null) { sql.append("/*+INDEX(").append(sinkTableName).append(" ").append(indexName).append(") */ "); } sql.append("INTO ").append(buildTableName()).append(" USING DUAL ON \n") .append("(").append(buildWhereCondition()).append(") \n") .append(" WHEN MATCHED THEN UPDATE SET \n") .append(buildOnDuplicateKeyUpdateStatement()).append(" \n") .append(" WHEN NOT MATCHED THEN INSERT \n") .append("(").append(buildColumnNamesSpiltByComma()).append(") \n") .append("values (").append(buildPlaceHoldersSpiltByComma()).append(")"); return sql.toString(); } protected String buildWhereCondition() { StringBuilder result = new StringBuilder(); for (int i = 0; i < primaryKeys.size(); i++) { String primaryKey = primaryKeys.get(i); result.append(primaryKeys.get(i)); result.append((i < primaryKeys.size() - 1) ? " = ? AND " : " = ?"); } return result.toString(); } protected String buildTableName() { StringBuilder tableName = new StringBuilder(); tableName.append(sinkSchemaName).append(".") .append(sinkTableName); return tableName.toString(); } protected String buildColumnNamesSpiltByComma() { StringBuilder columnNamesSpiltByComma = new StringBuilder(); for (String columnName : dataColumnNames) { columnNamesSpiltByComma.append(columnName).append(","); } if (columnNamesSpiltByComma.length() >= 1) { columnNamesSpiltByComma.deleteCharAt(columnNamesSpiltByComma.length() - 1); } return columnNamesSpiltByComma.toString(); } protected String buildPlaceHoldersSpiltByComma() { StringBuilder placeHolders = new StringBuilder(); for (int i = 0; i < dataColumnNames.size(); i++) { placeHolders.append("?,"); } if (placeHolders.length() >= 1) { placeHolders.deleteCharAt(placeHolders.length() - 1); } return placeHolders.toString(); } protected String buildOnDuplicateKeyUpdateStatement() { StringBuilder updateStatement = new StringBuilder(); for (String columnName : updateColumnNames) { updateStatement.append(columnName).append(" = ?,"); } if (updateStatement.length() >= 1) { updateStatement.deleteCharAt(updateStatement.length() - 1); } return updateStatement.toString(); } protected void setPreparedStatementParameter(PreparedStatement preparedStatement, Map<String, String> data) { // 设置参数 // 通过binlog字段找metadata，找不到时getDsTableColumnMetadata(columnName)会报错，以此确保所有binlog数据字段都被写入目标表 int i = 1; for (String primaryKey : primaryKeys) { setOneColumn(preparedStatement, i, primaryKey, data, true); i++; } for (String columnName : updateColumnNames) { setOneColumn(preparedStatement, i, columnName, data, false); i++; } for (String columnName : dataColumnNames) { setOneColumn(preparedStatement, i, columnName, data, false); i++; } } protected void setOneColumn(PreparedStatement preparedStatement, int index, String columnName, Map<String, String> data, boolean format) { String columnValue = data.get(columnName); int columnDataType = -1; int columnSize = 0; try { ColumnMetadata metadata = sinkDsTableMetadata.getColumnMetadata(columnName); if (metadata == null) { throw new IllegalArgumentException("目标表不存在该字段！"); } columnDataType = metadata.getDataType(); columnSize = metadata.getColumnSize(); preparedStatement.setObject(index, transferData(columnName, columnDataType, columnValue, columnSize, format), columnDataType); } catch (Exception e) { throw new AppException(e, "LULM606", sinkDbName, sinkTableName, columnName, columnDataType, columnValue, columnValue.getClass().getName(), e.getMessage()); } } private Object transferData(String columnName, int columnType, String columnValue, int columnSize, boolean format) { switch (columnType) { case Types.CHAR: if (format) { if (columnValue == null) { columnValue = ""; } return columnValue.length() < columnSize ? String.format("%-" + columnSize + "s", columnValue) : columnValue; } return checkEmpty(columnValue) ? " " : columnValue; case Types.VARCHAR: case Types.LONGVARCHAR: return checkEmpty(columnValue) ? " " : columnValue; case Types.SMALLINT: return checkEmpty(columnValue) ? 0 : Short.parseShort(columnValue); case Types.INTEGER: return checkEmpty(columnValue) ? 0 : Integer.parseInt(columnValue); case Types.BIGINT: return checkEmpty(columnValue) ? 0 : Long.parseLong(columnValue); case Types.FLOAT: case Types.DOUBLE: return checkEmpty(columnValue) ? 0 : Double.parseDouble(columnValue); case Types.NUMERIC: case Types.DECIMAL: return checkEmpty(columnValue) ? BigDecimal.ZERO : new BigDecimal(columnValue); case Types.DATE: case Types.TIMESTAMP: case Types.TIME: return checkEmpty(columnValue) ? 0 : columnValue; default: throw new AppException("LULM603", sinkDbName, sinkSchemaName, sinkTableName, columnName, columnType); } } private boolean checkEmpty(Object value) { return value == null || (value instanceof String && StringUtil.isBlank((String)value)); } } 请你给我详细分析解释一下这段代码