读取一个txt的文件，放入数据库，然后再select出表格，在写成txt的操作。
package day20181122;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.InputStreamReader;
public class ReadTxt {
private String fileName="stu.txt";
public ReadTxt(String fileName) {
this.fileName=fileName;
// System.out.println("cionstruct");
}
public void readFile()
{
try {
File file=new File(fileName);
InputStreamReader in;
in = new InputStreamReader(new FileInputStream(file),"utf-8");
BufferedReader br=new BufferedReader(in);
String line="";
line=br.readLine();
while(line!=null)
{
String[] data=line.split(";");
int len=data.length;
for(int i=0; i<len; i++)
System.out.println(data[i]+"-------");
System.out.println(line);
line=br.readLine();
}
br.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public void writeTxt(String filed)
{
String writeFileName="src/day20181122/student.txt";
try {
File f=new File(writeFileName);
if(f.exists())
f.createNewFile();
BufferedWriter bw=new BufferedWriter(new FileWriter(f));
bw.write(filed);
bw.flush();
bw.close();
System.out.println("write file succeed");
}catch(Exception e) {
e.printStackTrace();
}
}
}
多文件放入数据库，然后再select文件，写入txt中。
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class ReadTxt {
/**
* read file
* @param fileName
*/
public void readFile(String fileName)
{
//获取数据库的链接
ConnDb cb=new ConnDb();
Connection connection=null;
//采用 PreparedStatement 效率高，安全
PreparedStatement prestmt=null;
try {
connection= cb.getConnection();
connection.setAutoCommit(false);
} catch (Exception e1) {
e1.printStackTrace();
};
int count=0;//作为计数器
try {
File file=new File(fileName);
InputStreamReader in;
in = new InputStreamReader(new FileInputStream(file),"GBK");
BufferedReader br=new BufferedReader(in);
String line="";
line=br.readLine();
prestmt=connection.prepareStatement("insert into studentd(sid,sname,classes,course,score) values(?,?,?,?,?)");
long t1=System.currentTimeMillis(); //获取开始运行的时间
while(line!=null)
{
count++;
String[] data=line.split(",");
insertData(data,prestmt,connection,count);
// System.out.println(line);
line=br.readLine();
if(count%1000==0)
{
long t2=System.currentTimeMillis(); //获取时间
System.out.println("程序插入1000条的时间： "+(t2-t1)+"ms");
}
}
System.out.println("一共有的数据量为:"+count);
connection.setAutoCommit(true);
//关闭所有的流
br.close();
prestmt.close();
connection.close();
} catch (Exception e) {
e.printStackTrace();
}
}
//100条数据进行插入数据库
public void insertData(String[] das, PreparedStatement prestmt,Connection connection,int times){
try {
prestmt.setString(1, das[0]);
prestmt.setString(2, das[1]);
prestmt.setString(3, das[2]);
prestmt.setString(4, das[3]);
prestmt.setString(5, das[4]);
//批量提交
prestmt.addBatch();
if(times%100==0)
{
prestmt.executeBatch();
System.out.println(times+"提交数据成功");
connection.commit();
}
// prestmt.executeUpdate();
// connection.commit();
// System.out.println("成功插入");
} catch (Exception e) {
System.out.println("字符串有问题"+e);
}
}
public void selectDataWrite()
{
String sql="select sid,sname,classes,course,score from student";
String path="src/studentd.txt";
PreparedStatement paret=null;
ResultSet rs=null;
ConnDb cb=new ConnDb();
Connection connection=null;
//文件的东西
File f=new File(path);
BufferedWriter bw=null;
StringBuilder sb=new StringBuilder();
try {
if(!f.exists())
{
f.createNewFile();
System.out.println("create file succeed");
}
bw=new BufferedWriter(new FileWriter(f));
} catch (IOException e1) {
e1.printStackTrace();
}
try {
connection=cb.getConnection();
paret=connection.prepareStatement(sql);
rs=paret.executeQuery();
//行数
int col = rs.getMetaData().getColumnCount();
long t1=System.currentTimeMillis(); //获取开始运行的时间
while(rs.next())
{
for (int i = 1; i <= col; i++)
{
System.out.print(rs.getString(i) + "\t");
sb.append(rs.getString(i));
}
sb.append("\r\n").append("--------------------------").append("\r\n");
bw.write(sb.toString());
System.out.println();
//清空字符串
sb.setLength(0);
}
long t2=System.currentTimeMillis(); //获取时间
System.out.println("写文件的时间为： "+(t2-t1)+"ms");
//关闭所有的流
bw.close();
paret.close();
connection.close();
}catch(SQLException | IOException e){
e.printStackTrace();
}
}
}
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