简单的io操作

来源：互联网发布：python with statement 编辑：程序博客网时间：2024/04/30 20:58

import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStreamReader;import java.util.ArrayList;public class Testio {    public static void readTxtFile(String filePath){        ArrayList<String> list=new ArrayList<>();        try {                String encoding="UTF-8";                File file=new File(filePath);                if(file.isFile() && file.exists()){ //判断文件是否存在                    InputStreamReader read = new InputStreamReader(                    new FileInputStream(file),encoding);//考虑到编码格式                    BufferedReader bufferedReader = new BufferedReader(read);                    String lineTxt = null;                    while((lineTxt = bufferedReader.readLine()) != null){                        System.out.println(lineTxt);                    }                    read.close();        }else{            System.out.println("找不到指定的文件");        }        } catch (Exception e) {            System.out.println("读取文件内容出错");            e.printStackTrace();        }    }    public static void writeFile() {           String str = "Hello World !";        try {              FileOutputStream out = new FileOutputStream("D:test.txt"); // 输出文件路径              out.write(str.getBytes());              out.close();          } catch (Exception e) {              e.printStackTrace();          }      }      public static void main(String[] args) {        readTxtFile("D:test.txt");        writeFile();    }

把void返回类型改为list或string即可对读取的数据进行操作。

import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStreamReader;import java.util.ArrayList;public class testio2 {    public static ArrayList<String> readTxtFile(String filePath){        ArrayList<String> list=new ArrayList<>();        try {                String encoding="UTF-8";                File file=new File(filePath);                if(file.isFile() && file.exists()){ //判断文件是否存在                    InputStreamReader read = new InputStreamReader(                    new FileInputStream(file),encoding);//考虑到编码格式                    BufferedReader bufferedReader = new BufferedReader(read);                    String lineTxt = null;                    while((lineTxt = bufferedReader.readLine()) != null){                        //System.out.println(lineTxt);                        list.add(lineTxt);                    }                    read.close();        }else{            System.out.println("找不到指定的文件");        }        } catch (Exception e) {            System.out.println("读取文件内容出错");            e.printStackTrace();        }        return list;    }    public static void writeFile() {           String str = "Hello World !";        try {              FileOutputStream out = new FileOutputStream("D:test.txt"); // 输出文件路径              out.write(str.getBytes());              out.close();          } catch (Exception e) {              e.printStackTrace();          }      }      public static void main(String[] args) {        //writeFile();        ArrayList<String> list = readTxtFile("D:test.txt");        System.out.println(list);    }

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