从文本文件读取/写入变量到变量

Question

我需要建立一个系统来存储客户信息和所有报价到外部文件，以及输入更多的客户，列出客户，并与报价相同。除此之外，我还需要将所有报价/客户链接到ID。我基本上需要在java中执行SQL。但是，我真的需要输入和输出系统的帮助，并将所有信息写入数组。我有两个主要的代码片段，但效率非常低，需要一些建议，改进或完全不同的系统。从文件中的代码 输入：

import java.io.*; //import classes 
import java.util.ArrayList; 
import java.util.Iterator; 
public class MyTextReader{ 
    public static void main(String[] args){ 
    String myDirectory = System.getProperty("user.dir"); 
    String fullDirectory = myDirectory + "\\myText.txt"; 
    String input_line = null; 
     ArrayList<String> textItems = new ArrayList<String>(); //create array   list 
    try{ 
     BufferedReader re = new BufferedReader(new FileReader(fullDirectory)); 
     while((input_line = re.readLine()) != null){ 
      textItems.add(input_line); //add item to array list 
     } 
    }catch(Exception ex){ 
      System.out.println("Error: " + ex); 
    } 
     Iterator myIteration = textItems.iterator(); //use Iterator to cycle list 
     while(myIteration.hasNext()){ //while items exist 
     System.out.println(myIteration.next()); //print item to command-line 
     } 
    }  
} 

输出到文件

import java.io.FileWriter; //import classes 
import java.io.PrintWriter; 
public class MyTextWriter{ 
    public static void main(String[] args){ 
     FileWriter writeObj; //declare variables (uninstantiated) 
     PrintWriter printObj; 
      String myText = "Hello Text file"; 
     try{ //risky behaviour – catch any errors 
       writeObj = new FileWriter("C:\\Documents\\myText.txt" , true); 
      printObj = new PrintWriter(writeObj);//create both objects 
      printObj.println(myText); //print to file 
      printObj.close(); //close stream 
      }catch(Exception ex){ 
     System.out.println("Error: " + ex); 
      }  
    } 
} 

Answer 1

从文件

FileReader fr = new FileReader("YourFile.txt"); 
      BufferedReader br = new BufferedReader(fr); 
      String s=""; 
      s=br.readLine(); 
System.out.println(s); 

阅读文本书面方式文本文件

PrintWriter writeText = new PrintWriter("YourFile.txt", "UTF-8"); 
     writeText.println("The first line"); 
     writeText.println("The second line"); 
     writeText.close();