java中如何實現文件的讀入與讀出

一、文檔讀取

1、將文件讀取為String

public static String TxtToString(File file) {     String result = "";     try {         BufferedReader br = new BufferedReader(new FileReader(file));         //構造一個BufferedReader類來讀取文件         String s = null;         while ((s = br.readLine()) != null) {//使用readLine方法，一次讀一行             result = result + "n" + s;         }         br.close();     } catch (Exception e) {         e.printStackTrace();     }     return result; }

2、將文件讀取為List集合（按行）（免費視頻教程分享：java免費視頻教程）

public static List<String> TxtToStringList(File file) {     List<String> result = new ArrayList<>();     try {         if (!file.exists()){             return null;         }         BufferedReader br = new BufferedReader(new FileReader(file));         //構造一個BufferedReader類來讀取文件         String s = null;         while ((s = br.readLine()) != null) {//使用readLine方法，一次讀一行             result.add(s);         }         br.close();     } catch (Exception e) {         e.printStackTrace();     }     return result; }

二、Java存儲文件

1、將list按行寫入到txt文件中

public static void writeFileContext(List<String> strings) throws Exception {     File file = new File("D:\IntellijIDEAProject\KeChenSheJi\data\WordLibrary_index");     //如果沒有文件就創建     if (!file.isFile()) {         file.createNewFile();     }     BufferedWriter writer = new BufferedWriter(new FileWriter     ("D:\IntellijIDEAProject\KeChenSheJi\data\WordLibrary_index"));     for (String l:strings){         writer.write(l + "rn");     }     writer.close(); }

2、按照名字將string類型的集合存入文件

public static void writeFileContext_Find(List<String> strings,String name) throws Exception {     File file = new File("D:\IntellijIDEAProject\KeChenSheJi\data\wordIndex");     //如果沒有文件就創建     if (!file.isFile()) {         file.createNewFile();     }     BufferedWriter writer = new BufferedWriter(new FileWriter     ("D:\IntellijIDEAProject\KeChenSheJi\data\wordIndex\"+name));     for (String l:strings){         writer.write(l + "rn");     }     writer.close();

3、將Sting類型的list集合按文件地址存儲

public static void writeFileContext_Found(List<String> strings,String filename) throws Exception {     File file = new File(filename);     //如果沒有文件就創建     if (!file.isFile()) {         file.createNewFile();     }     BufferedWriter writer = new BufferedWriter(new FileWriter     ("D:\IntellijIDEAProject\KeChenSheJi\data\file_index\"+file.getName()));     for (String l:strings){         writer.write(l + "rn");     }     writer.close(); }

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