通过java导入csv文件到oracle（mysql）数据库

<pre name="code" class="java">上一篇文章讲了如何利用java将oracle（mysql）数据库中的数据导出到csv文件，这篇文章我们将把上篇文章中的csv文件导入到数据库中。

本程序能解决的问题是将csv文件导入数据库，可以将数据库中原记录删除后导入csv文件中的记录，也可以通过建立临时表（原表以"_tmp"结尾）将csv文件中的数据合并到目标表中。

需要注意的是：

csv文件中的日期格式在dateutil.java文件中调整，如果日期格式不对将会设置为计算机起始时间。

csv文件中要有表头，如果没有表头需要人为添加表头（添加表头的代码没有上传）；

csv文件可以以逗号结束，也可以不以逗号结束；

本程序的测试方法用到了<span style="font-family: Arial, Helvetica, sans-serif;">guessTableName</span>方法，需要根据个人情况调整。

本程序中用到了将一些特殊字符串替换，可以自己屏蔽掉，不屏蔽也应该不影响。

入库比导出相对麻烦些了。

package com.blog.laishaobin.db;import java.sql.Connection;import java.util.ArrayList;import java.util.List;import org.apache.commons.io.FilenameUtils;import com.blog.laishaobin.form.CSVImportForm;public class BlogCSVToTable {public static void main(String[] args) {List<String> lstable = new ArrayList<String>();List<CSVImportForm> csvFormList = new ArrayList<CSVImportForm>();lstable.add("C:\\Users\\John\\workspace\\blog\\T_TEERIE_FLOW_RELATE_20150523.csv");lstable.add("C:\\Users\\John\\workspace\\blog\\T_TEERIE_IDENTIFY_20150523.csv");for (String s : lstable) {CSVImportForm form = new CSVImportForm(s, CSVImportForm.INSERTTYPE, guessTableName(s));csvFormList.add(form);}try {new BlogCSVToTable(csvFormList);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}//根据文件路径获取表名（根据个人情况修改本函数）private static String guessTableName(String localFilePath) {String tableName = null;tableName = FilenameUtils.getBaseName(localFilePath);tableName = tableName.substring(0, tableName.length() - 9);return tableName;}public BlogCSVToTable(List<CSVImportForm> csvFormList) throws Exception {for(CSVImportForm c : csvFormList) {try {if (c.isInsert()) {Connection conn = new DBConnections(DBConnections.URL, DBConnections.USERNAME, DBConnections.PASSWORD).getConn();CSVLoader csvLoader = new CSVLoader(conn);csvLoader.setSeprator(c.getSeprator());csvLoader.loadCSV(c.getLocalFilePath(), c.getTableName(), true);} else if (c.isUpdate()) {Connection conn = new DBConnections(DBConnections.URL, DBConnections.USERNAME, DBConnections.PASSWORD).getConn();CSVLoader csvLoader = new CSVLoader(conn);csvLoader.setSeprator(c.getSeprator());csvLoader.loadCSV(c.getLocalFilePath(), getTempTable(c.getTableName()), true);conn = new DBConnections(DBConnections.URL, DBConnections.USERNAME, DBConnections.PASSWORD).getConn();new MergeInto(getTempTable(c.getTableName()), c.getTableName(), "SYS_SEQ_NO",null, null, conn);}}catch (Exception e) {e.printStackTrace();throw new Exception(e.getMessage());}}}private String getTempTable(String tableName) {return tableName.toUpperCase() + "_TMP";}}

package com.blog.laishaobin.form;public class CSVImportForm {public static final String INSERTTYPE = "01";public static final String UPDATETYPE = "02";//文件路径String localFilePath;//文件分隔符char seprator = ',';//入库类型String sqlType;//数据库表名String tableName;/*** @param localFilePath* 			本地文件路径* @param sqlType* 			INSERTTYPE  or   UPDATETYPE* @param tableName* 			数据库表名*/public CSVImportForm(String localFilePath,String sqlType, String tableName) {this.localFilePath = localFilePath;this.sqlType = sqlType;this.tableName = tableName;}/*** @param localFilePath* 本地文件路径* @param sqlType* INSERTTYPE or UPDATETYPE* @param tableName* 			数据库表名* @param seprator* 			文件分割符*/public CSVImportForm(String localFilePath,String sqlType, String tableName, char seprator) {this.localFilePath = localFilePath;this.sqlType = sqlType;this.tableName = tableName;this.seprator = seprator;}public char getSeprator() {return seprator;}public void setSeprator(char seprator) {this.seprator = seprator;}public String getTableName() {return tableName;}public void setTableName(String tableName) {this.tableName = tableName;}public String getLocalFilePath() {return localFilePath;}public void setLocalFilePath(String localFilePath) {this.localFilePath = localFilePath;}public String getSqlType() {return sqlType;}public void setSqlType(String sqlType) {this.sqlType = sqlType;}public boolean isInsert() {return sqlType.equals(INSERTTYPE);}public boolean isUpdate() {return sqlType.equals(UPDATETYPE);}}

package com.blog.laishaobin.db;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;/*** @author John**/public class MergeInto {private String from;private String to;private String joinField;private String insertCondition;private String updteCondition;private Connection conn;/*** @param from* 			源表* @param to*			 目标表* @param joinField* 			join字段* @param insertCondition* 			insert的条件，可以为null， 不带where* @param updateCondition* 			update的条件， 可以为null， 不带where* @throws Exception*/public MergeInto(String from, String to, String joinField, String insertCondition, String updateCondition, Connection conn) throws Exception {this.from = from;this.to = to;this.joinField = joinField;if (insertCondition != null) {this.insertCondition = " where " + insertCondition + " ";} elsethis.insertCondition = " ";if (updateCondition != null) {this.updteCondition = " where " + updateCondition + " ";} else {this.updteCondition = " ";}this.conn = conn;merge();}private void merge() throws Exception {Statement stmt = conn.createStatement();String sql = "merge into " + to;sql += " using " + from;sql += " on (" + to + "." + joinField + " = " + from + "." + joinField + ") ";sql += "when matched then update set " + generateSetSql(to, from, conn, joinField);sql += updteCondition;sql += "when not matched then " + generateInsertSql(to, from, conn);sql += insertCondition;System.out.println(sql);stmt.executeQuery(sql);stmt.close();conn.close();}private String generateInsertSql(String to, String from, Connection conn) throws SQLException {Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);String[] fields = getTableTitle(to, stmt);String resultStr = "insert (";for (int i = 0; i < fields.length; i++) {resultStr += (to + "." + fields[i]);if (i != fields.length - 1) {resultStr += ",";} else {resultStr += ")";}}resultStr += " valu4000es(";for (int i = 0; i < fields.length; i++) {resultStr += (from + "." + fields[i]);if (i != fields.length - 1) {resultStr += ",";} elseresultStr += ")";}return resultStr;}/*** @param tableName* 			数据库表名* @param conn* 			数据库连接* @return 表名title的数组* @throws SQLException*/public static String[] getTableTitle(String tableName, Statement stmt) throws SQLException {String sql = "select column_name from user_tab_columns where table_name = '" + tableName.toUpperCase() + "'";System.out.println(sql);ResultSet rs = stmt.executeQuery(sql);int count = 0;while (rs.next()) {count++;}System.out.println(count);rs.first();String[] array;array = new String[count];int i = 0;do {array[i] = rs.getString(1);i++;} while (rs.next());stmt.close();return array;}private String generateSetSql(String to, String from, Connection conn, String exclusiveField) throws SQLException {Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);String[] fields = getTableTitle(to, stmt);String resultStr = "";for (int i = 0; i < fields.length; i++) {if (!fields[i].equals(exclusiveField)){resultStr += mergeTwoStringWithSetFormat(to, from, fields[i]);if (i != fields.length -1)resultStr += " , ";}}return resultStr;}private String mergeTwoStringWithSetFormat(String alias1, String alias2, String field) {return (alias1 + "." + field + "=" + alias2 + "." + field + " ");}public String getFrom() {return from;}public void setFrom(String from) {this.from = from;}public String getTo() {return to;}public void setTo(String to) {this.to = to;}public String getJoinField() {return joinField;}public void setJoinField(String joinField) {this.joinField = joinField;}public String getInsertCondition() {return insertCondition;}public void setInsertCondition(String insertCondition) {this.insertCondition = insertCondition;}public String getUpdteCondition() {return updteCondition;}public void setUpdteCondition(String updteCondition) {this.updteCondition = updteCondition;}}

package com.blog.laishaobin.db;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.List;public class DateUtil {// List of all date formats that we want to parse.// Add your own format here.private static List<SimpleDateFormat>dateFormats = new ArrayList<SimpleDateFormat>() {/****/private static final long serialVersionUID = 1L;{add(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));add(new SimpleDateFormat("yyyyMMdd"));add(new SimpleDateFormat("yyyy-MM-dd"));}};/*** Convert String with various formats into java.util.Date** @param input*            Date as a string* @return java.util.Date object if input string is parsed*          successfully else returns null*/public static Date convertToDate(String input) {Date date = null;if(null == input) {return null;}for (SimpleDateFormat format : dateFormats) {try {format.setLenient(false);date = format.parse(input);} catch (ParseException e) {//Shhh.. try other formats}if (date != null) {break;}}return date;}}

package com.blog.laishaobin.db;import java.sql.Connection;import java.sql.DriverManager;public class DBConnections {public static final String URL = "jdbc:oracle:thin:@192.168.1.179:1521:orcl";public static final String USERNAME = "blog";public static final String PASSWORD = "laishaobin";private String url;private String username;private String password;public DBConnections(String url, String username, String password) {this.url = url;this.username = username;this.password = password;}public Connection getConn() throws Exception {Connection conn = null;try {Class.forName("oracle.jdbc.driver.OracleDriver");conn = DriverManager.getConnection(url, username, password);conn.setAutoCommit(false);} catch (Exception e) {e.printStackTrace();throw new Exception(e.getMessage());}return conn;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}}package com.blog.laishaobin.db;import java.io.FileNotFoundException;import java.io.FileReader;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.Statement;import java.sql.Types;import java.util.ArrayList;import java.util.Arrays;import java.util.Date;import java.util.List;import org.apache.commons.lang3.StringUtils;import com.opencsv.CSVReader;/**** @author viralpatel.net**/public class CSVLoader {private static finalString SQL_INSERT = "INSERT INTO ${table}(${keys}) VALUES(${values})";private static final String TABLE_REGEX = "\\$\\{table\\}";private static final String KEYS_REGEX = "\\$\\{keys\\}";private static final String VALUES_REGEX = "\\$\\{values\\}";private Connection connection;private char seprator;/*** Public constructor to build CSVLoader object with* Connection details. The connection is closed on success* or failure.* @param connection*/public CSVLoader(Connection connection) {this.connection = connection;//Set default separatorthis.seprator = ',';}/*** Parse CSV file using OpenCSV library and load in* given database table.* @param csvFile Input CSV file* @param tableName Database table name to import data* @param truncateBeforeLoad Truncate the table before inserting* new records.* @throws Exception*/public void loadCSV(String csvFile, String tableName,boolean truncateBeforeLoad) throws Exception {CSVReader csvReader = null;if(null == this.connection) {throw new Exception("Not a valid connection.");}try {csvReader = new CSVReader(new FileReader(csvFile), this.seprator);} catch (Exception e) {e.printStackTrace();throw new Exception("Error occured while executing file. "+ e.getMessage());}String[] headerRow = csvReader.readNext();// if (null == headerRow) {// throw new FileNotFoundException(// "No columns defined in given CSV file." +// "Please check the CSV file format.");// }if (null == headerRow) {return;}int realLength = headerRow.length;if (headerRow[realLength - 1].isEmpty())realLength--;String[] newHeaderRow = new String[realLength];for (int i = 0; i < realLength; i++) {newHeaderRow[i] = headerRow[i];}Statement stmt = connection.createStatement();ResultSet rs = stmt.executeQuery("select * from " + tableName);ResultSetMetaData rsmd = rs.getMetaData();int[] types = new int[rsmd.getColumnCount()];for (int i = 0; i < rsmd.getColumnCount(); i++) {types[i] = rsmd.getColumnType(i+1);}stmt.close();if (types.length != realLength) {throw new Exception("表结构和文件中的不一致！ 表：" + tableName.toUpperCase());}String questionmarks = StringUtils.repeat("?,", newHeaderRow.length);questionmarks = (String) questionmarks.subSequence(0, questionmarks.length() - 1);String query = SQL_INSERT.replaceFirst(TABLE_REGEX, tableName);query = query.replaceFirst(KEYS_REGEX, StringUtils.join(newHeaderRow, ","));query = query.replaceFirst(VALUES_REGEX, questionmarks);String[] nextLine;Connection con = null;PreparedStatement ps = null;try {con = this.connection;con.setAutoCommit(false);ps = con.prepareStatement(query);if(truncateBeforeLoad) {//delete data from table before loading csvcon.createStatement().execute("DELETE FROM " + tableName);}final int batchSize = 1000;int count = 0;Date date = null;while ((nextLine = csvReader.readNext()) != null) {if (null != nextLine && nextLine.length >= realLength) {int index = 1;for (String string : nextLine) {if (index <= realLength) {if (types[index-1] == Types.TIMESTAMP) {date = DateUtil.convertToDate(string);if (null != date) {ps.setTimestamp(index++, new java.sql.Timestamp(date.getTime()));} else {//日期转换失败时使用最初时间ps.setTimestamp(index++, new java.sql.Timestamp(0));}} else {string = string.replaceAll("&%&", ","); //这里进行了特殊字符串替换，因为我导出是进行了替换string = string.replaceAll("&#&", "\n");ps.setString(index++, string);}}}ps.addBatch();}if (++count % batchSize == 0) {ps.executeBatch();}}ps.executeBatch(); // insert remaining recordscon.commit();} catch (Exception e) {con.rollback();e.printStackTrace();throw new Exception("Error occured while loading data from file to database."+ e.getMessage());} finally {if (null != ps)ps.close();if (null != con)con.close();csvReader.close();}}public char getSeprator() {return seprator;}public void setSeprator(char seprator) {this.seprator = seprator;}}