JDBC实现Mysql数据库表同步
用于Mysql数据库间数据迁移
package com.lingyi.sync.util;
import org.apache.log4j.Logger;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLDecoder;
import java.sql.*;
import java.util.*;
import java.util.Date;
public class JdbcUtil {
//日志
private static Logger logger = Logger.getLogger(JdbcUtil.class.getClass());
//开始时间
private static Long startTime = 0L;
//结束时间
private static Long endTime =0L;
public static enum DatabaseType {
MySQL_LOCAL("mysql_local"),
MySQL_REMOTE("mysql_remote");
private String name;
private DatabaseType(String name) {
this.name = name;
}
public String getName() {
return name;
}
};
//配置文件
private static Properties props;
//项目运行路径
private static String filePath =null;
//获取项目运行路径
static {
URL url = JdbcUtil.class.getProtectionDomain().getCodeSource().getLocation();
try {
filePath = URLDecoder.decode(url.getPath(), "utf-8");// 转化为utf-8编码，支持中文
} catch (Exception e) {
e.printStackTrace();
}
filePath = filePath.replace("target/classes/", "");
if (filePath.endsWith(".jar")) {// 可执行jar包运行的结果里包含".jar"
// 获取jar包所在目录
filePath = filePath.substring(0, filePath.lastIndexOf("/") + 1);
}
if (System.getProperty("os.name").contains("dows")){
File file = new File(filePath);
filePath = file.getAbsolutePath();//得到windows下的正确路径
}
}
//加载配置文件safe_exam_db.properties
static {
try {
props = new Properties();
InputStream in = new FileInputStream(new File(filePath + "/config/safe_exam_db.properties"));
props.load(in);
} catch (IOException e) {
throw new RuntimeException("没有找到外部配置文件");
}
}
/**
* 获取数据库连接
* @param type 要操作的数据库
* @return
*/
public static Connection getConnection(DatabaseType type){
//加载驱动
try {
Class.forName(props.getProperty(type.getName() + ".driver"));
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
String jdbcUrl = props.getProperty(type.getName() + ".jdbcUrl");
String user = props.getProperty(type.getName() + ".user");
String password = props.getProperty(type.getName() + ".password");
//链接数据库
try {
return DriverManager.getConnection(jdbcUrl, user, password);
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("连接数据库失败");
}
}
/**
* 将查询的数据复制到另一个数据库的表中，要求两张表的字段名，字段类型完全相同。
* @param src 要查询的数据库
* @param srcTableName 要查询的表
* @param dest 目标数据库
* @param destTableName 目标表名称
* @return
*/
public int[] copy(DatabaseType src,String srcTableName, DatabaseType dest, String destTableName ) {
startTime = System.currentTimeMillis();
int count[] = new int[0];
//创建表
createTable(src,srcTableName,dest,destTableName);
//查询数据
String sql = String.format("select * from %s ", srcTableName);
List<Map<String,Object>> query = query(src, sql);
//插入数据
String insertSql = "insert into %s(%s) values(%s)";
StringBuilder key = new StringBuilder();
StringBuilder value = new StringBuilder();
List<String> columns = new ArrayList<>();
List<List<Object>> params = new ArrayList<>();
if(query.size() > 0) {
for(String column : query.get(0).keySet()) {
key.append(column).append(",");
value.append("?,");
columns.add(column);
}
insertSql = String.format(insertSql,
destTableName,
key.substring(0, key.length()-1).toString(),
value.substring(0, value.length()-1).toString());
for (Map<String, Object> map : query) {
List<Object> param = new ArrayList<>();
for (String column : columns) {
param.add(map.get(column));
}
params.add(param);
}
count = executeBatch(dest, insertSql, params);
endTime = System.currentTimeMillis();
logger.debug("复制表"+destTableName+"成功"+"用时"+(endTime-startTime)+"ms");
}
return count;
}
/**
* 查询数据并封装到 List 集合中
* @param type 要查询的数据库
* @param sql SQL 语句
* @param args 参数列表
* @return List>
*/
public static List<Map<String, Object>> query(DatabaseType type, String sql, Object...args) {
List<Map<String, Object>> result = new ArrayList<>();
Connection conn = null;
PreparedStatement pst = null;
ResultSet rs = null;
try {
conn = getConnection(type);
pst = conn.prepareStatement(sql);
for(int i = 0; i < args.length; i++) {
pst.setObject(i + 1, args[i]);
}
rs = pst.executeQuery();
ResultSetMetaData rsmd = rs.getMetaData();
//获取字段数量
int columnCount = rsmd.getColumnCount();
List<String> columns = new ArrayList<>(columnCount);
for(int i = 1; i <= columnCount; i++) {
columns.add(rsmd.getColumnName(i)); // 字段名
}
//封装数据
while(rs.next()) {
Map<String, Object> map = new HashMap<>();
for (String column : columns) {
map.put(column, rs.getObject(column));
}
result.add(map);
}
} catch (Exception e) {
throw new RuntimeException("查询异常"+e.getMessage());
} finally {
closeStatement(pst);
closeConnection(conn);
closeResultSet(rs);
}
return result;
}
/**
* 从源数据库查询建表语句，在目标数据库执行
* @param src 要查询的数据库
* @param srcTableName 要查询的表名
* @param dest 目标数据库
* @param destTableName 目标表名称
*/
public void createTable(DatabaseType src,String srcTableName,DatabaseType dest, String destTableName){
String sql1 = String.format("DROP TABLE IF EXISTS %s ", destTableName);//如果目标数据库存在就删除
String sql2 = getDDL(src, srcTableName,destTableName);
ArrayList<String> list = new ArrayList<>();
list.add(sql1);
list.add(sql2);
executeBatch(dest,list);
}
/**
* 查询建表语句(不同数据库复制表，需要重写此方法获得建表语句)
* @param src 要查询的数据库
* @param srcTableName 目标表名称
* @return
*/
public String getDDL(DatabaseType src,String srcTableName,String destTableName){
return null;
}
/**
* 批量执行多条 SQL 语句
* @param type 要执行的数据库
* @param sqls SQL 语句
* @return
*/
public static int[] executeBatch(DatabaseType type, List<String> sqls) {
int count[] = new int[0];
Connection conn = null;
Statement stmt = null;
try {
conn = getConnection(type);
boolean autoCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
stmt = conn.createStatement();
for (String sql : sqls) {
stmt.addBatch(sql);
}
count = stmt.executeBatch();
conn.commit();
conn.setAutoCommit(autoCommit);
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
closeStatement(stmt);
closeConnection(conn);
}
return count;
}
/**
* 批量执行一个 SQL 语句，可以传不同的参数
* @param type 要执行的数据库
* @param sql SQL 语句
* @param params 参数列表
* @return
*/
public static int[] executeBatch(DatabaseType type, String sql, List<List<Object>> params) {
int count[] = new int[0];
Connection conn = null;
PreparedStatement pst = null;
try {
conn = getConnection(type);
boolean autoCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
pst = conn.prepareStatement(sql);
for (List<Object> list : params) {
for(int i = 0; i < list.size(); i++) {
pst.setObject(i + 1, list.get(i));
}
pst.addBatch();
}
count = pst.executeBatch();
conn.commit();
conn.setAutoCommit(autoCommit);
} catch (Exception e) {
logger.error("插入数据失败"+e.getMessage());
throw new RuntimeException("插入数据失败"+e.getMessage());
} finally {
closeStatement(pst);
closeConnection(conn);
}
return count;
}
/**
* 执行单条 SQL 语句
* @param type 要执行的数据库
* @param sql SQL 语句
* @param args 参数列表
* @return
*/
public static int execute(DatabaseType type, String sql, Object...args) {
int count = 0;
Connection conn = null;
PreparedStatement pst = null;
try {
conn = getConnection(type);
boolean autoCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
pst = conn.prepareStatement(sql);
for(int i = 0; i < args.length; i++) {
pst.setObject(i + 1, args[i]);
}
count = pst.executeUpdate();
conn.commit();
conn.setAutoCommit(autoCommit);
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
closeStatement(pst);
closeConnection(conn);
}
return count;
}
/**
* 关闭 Statement
* @param stmt
* @return
*/
public static boolean closeStatement(Statement stmt) {
boolean flag = true;
if(stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
flag = false;
}
}
return flag;
}
/**
* 关闭 ResultSet
* @param rs
* @return
*/
public static boolean closeResultSet(ResultSet rs) {
boolean flag = true;
if(rs != null) {
try {
rs.close();
} catch (SQLException e) {
flag = false;
}
}
return flag;
}
/**
* 关闭 Connection
* @param conn
* @return
*/
public static boolean closeConnection(Connection conn) {
boolean flag = true;
if(conn != null) {
try {
conn.close();
} catch (SQLException e) {
flag = false;
}
}
return flag;
}
}
配置文件放在项目根目录下config/safe_exam_db.properties
#MySQL_LOCAL
mysql_local.driver=com.mysql.cj.jdbc.Driver
mysql_local.jdbcUrl=jdbc:mysql://localhost:3306/jeecg24
mysql_local.user=root
mysql_local.password=root
#MySQL_REMOTE
mysql_remote.driver=com.mysql.cj.jdbc.Driver
mysql_remote.jdbcUrl=jdbc:mysql://localhost:3306/labv2
mysql_remote.user=root
mysql_remote.password=root
当从mysql复制到mysql时，编写JdbcUtil子类重写getDDL方法获取建表语句
package com.lingyi.sync;
import com.lingyi.sync.util.JdbcUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class Mysql2Mysql extends JdbcUtil {
/**获取建表语句
* 不同数据库查询建表语句不同，需要重写获取建表语句
* @param src 要查询的数据库
* @param srcTableName 目标表名称
* @return
*/
@Override
public String getDDL(DatabaseType src, String srcTableName,String destTableName) {
Connection conn = null;
PreparedStatement pstm = null;
ResultSet rs = null;
String ddl = null;
String sql = String.format("SHOW CREATE TABLE %s", srcTableName);//查询sql
try {
conn = getConnection(src);
pstm = conn.prepareStatement(sql);
rs = pstm.executeQuery();
while (rs.next()) {
ddl = rs.getString(2);
}
String newDDL = ddl.replace(srcTableName, destTableName);
return newDDL;
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("查询建表语句失败" + e.getMessage());
} finally {
closeStatement(pstm);
closeConnection(conn);
closeResultSet(rs);
}
}
}
执行复制操作
// 将 源mysql数据库中的表中的数据插入到目标mysql数据库中
mysql.copy(JdbcUtil.DatabaseType.MySQL_REMOTE,"idata_exam_v_chengji", JdbcUtil.DatabaseType.MySQL_LOCAL, "idata_exam_v_chengji");