練習用JAVA讀取及寫入TXT檔案，一併順手記錄下來。
會使用到BufferedReader跟FileReader還有FileWriter
先用一支程式來建立TXT檔，再來把這TXT檔案的內容寫到另一個新的文字檔
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import java.io.FileWriter; public class Write { public static void main(String[] args) { try { // Constructs a FileWriter object given a file name. FileWriter fw = new FileWriter("one.txt"); fw.write("This is one!"); fw.flush(); fw.close(); } catch (Exception e) { System.out.println("Something Error"); } } } |
編譯跟執行一下
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javac Write.java java -cp . Write |
就可以在目錄底下看到「one.txt」這個檔案
接下來就到我們的主題了，我們要把這檔案讀出來然後寫入到另一個檔案
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import java.io.BufferedReader; import java.io.FileReader; import java.io.FileWriter; public class ReadAndWrite { public static void main(String[] args) { try { // Creates a new FileReader, given the name of the file to read from. FileReader fr = new FileReader("one.txt"); // Creates a buffering character-input stream that uses a default-sized input buffer. BufferedReader br = new BufferedReader(fr); String content = ""; while (br.ready()) { content = br.readLine(); System.out.println("Ready... read txt"); System.out.println("-------------"); System.out.println(content); System.out.println("-------------"); } // Constructs a FileWriter object given a file name. FileWriter fw = new FileWriter("target.txt"); fw.write(content); fw.flush(); System.out.println("Write Complete!"); // After used close. fr.close(); fw.close(); } catch (Exception e) { System.out.println("Something Error"); } } } |
編譯執行了之後，就會出現「target.txt」的檔案
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javac ReadAndWrite.java java -cp . ReadAndWrite |
完成！
之後有機會再分享讀取及寫入多行的方式。