Đây là giải pháp của tôi. Mã để chèn vào những lớp học chính:
import java.io.*;
import java.sql.*;
import com.company.*;
/**
* Created by MAXNIGELNEGRO
*/
String[] filePath = new String[] {"C:\\Users\\Documents\\MyFile.csv"};
String[] driverDB = new String[] {"oracle.jdbc.driver.OracleDriver"};
String[] stringConnDB = new String[] {"jdbc:oracle:thin:@//127.0.0.1:1881/mydb"};
String[] userDB = new String[] {"pippo"};
String[] passDB = new String[] {"pluto"};
String[] charSep = new String[] {";"};
Boolean colomn= new Boolean (true);
String[] queryDB = new String[] {"select * FROM MYQUERY"};
try{
System.out.println("---------------File exist?------------" + filePath[0]);
File fileTemp = new File(filePath[0].toString());
if (fileTemp.exists()){
fileTemp.delete();
System.out.println("---------------DELETE FILE------------" + filePath[0]);
}
System.out.println("QUERY: ---->"+ queryDB[0].toString());
exportQueryToCsv exp = new exportQueryToCsv();
exp.exportQueryToCsv(filePath,driverDB,stringConnDB,userDB,passDB,queryDB, colomn,charSep);
if (fileTemp.exists()){
System.out.println("---File created---" + filePath[0]);
}
}
catch(Exception e){
e.printStackTrace();
}
Lớp lõi:
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
* Created by MAXNIGELNEGRO
*/
public class exportQueryToCsv {
public exportQueryToCsv(){}
public static void exportQueryToCsv (String[] filename, String[] driverDB, String[] connDB
, String[] userDB, String[] passDB, String[] queryDB, Boolean intestaFile
, String[] charSep) throws SQLException, IOException {
Statement stmt=null;
ResultSet rset=null;
Connection conn=null;
try { DBConn connessione = new DBConn();
conn=connessione.connect(driverDB[0],connDB[0],userDB[0],passDB[0]);
conn.setAutoCommit(false);
stmt = conn.createStatement();
rset = stmt.executeQuery(queryDB[0]);
ExportData2CSV csv = new ExportData2CSV();
csv.ExportData2CSV(rset,filename[0],intestaFile,charSep[0]);
csv.createFileCsv();
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
finally {
if (stmt != null) {stmt.close();}
if (conn != null) {conn.close();}
if (rset != null) {rset.close();}
}
}
}
Đây là lớp DBConn cho kết nối tới cơ sở dữ liệu
import java.sql.*;
/**
* Created by MAXNIGELNEGRO
*/
public class DBConn {
public DBConn() {
}
public Connection connect(String driverDB, String db_connect_str, String db_userid, String db_password) {
Connection conn;
try {
Class.forName(driverDB).newInstance();
conn = DriverManager.getConnection(db_connect_str, db_userid, db_password);
} catch (Exception e) {
e.printStackTrace();
conn = null;
}
return conn;
}
}
Đây là lớp học cho lấy dữ liệu từ bảng để ResultSet và ghi vào tập tin csv
package com.company;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
/**
* Created by MAXNIGELNEGRO
*/
public class ExportData2CSV {
public ResultSet rset;
public String filename;
public Boolean colomnName;
public String charSep;
public void ExportData2CSV(ResultSet rset, String filename, Boolean colomnName, String charSep) {
this.rset = rset;
this.filename = filename;
this.colomnName = colomnName;
this.charSep = charSep;
}
public void createFileCsv() throws SQLException, IOException {
FileWriter cname = null;
try {
// WRITE COLOMN NAME
ResultSetMetaData rsmd = rset.getMetaData();
cname = new FileWriter(filename);
if (colomnName) {
for (int i = 1; i <= rsmd.getColumnCount(); i++) {
cname.append(rsmd.getColumnName(i));
cname.append(charSep);
cname.flush();
}
cname.append(System.getProperty("line.separator"));
}
// WRITE DATA
while (rset.next()) {
for (int i = 1; i <= rsmd.getColumnCount(); i++) {
if (rset.getObject(i) != null) {
String data = rset.getObject(i).toString().replaceAll(charSep, "");
cname.append(data);
cname.append(charSep);
} else {
String data = "null";
cname.append(data);
cname.append(charSep);
}
}
//new line entered after each row
cname.append(System.getProperty("line.separator"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (cname != null) {
cname.flush();
cname.close();
}
if (rset != null) {
rset.close();
}
}
}
}
Đây là chính xác những gì bạn đang tìm kiếm: https://www.youtube.com/watch?v=hlY_PoJhlMk (https://mvnrepository.com/ artifact/net.sf.automatic-report-generator) –