Java文本文件读写

// 读文件
String filePath = "";
// new File("").getAbsolutePath()能得到模块根目录
// this.getClass().getResorce("").getPath() 能得到此类的绝对路径
// this.getClass().getResourceAsStream("") 能直接得到InputStream。""中/开头为模块内Sources的路径，没有/或者为./为同级，../为想上一级
FileInputStream inputStream = new FileInputStream(filePath);            
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);            
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);            
String lineString;            
while ((lineString = bufferedReader.readLine()) != null) {   
	// 读取每一行
}            
 
           
bufferedReader.close();
inputStreamReader.close();
inputStream.close();

// 简化版
        String filePath = "";
        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(new FileInputStream(filePath)))) {
            String lineString;
            while ((lineString = bufferedReader.readLine()) != null) {
                // 读取每一行
            }
        } catch (IOException iOException) {
            iOException.printStackTrace();
        }

// 写文件
String filePath2 = "C:/Users/Administrator/Desktop/result.txt";
File file = new File(filePath2);  
// 存在则删除重建          
if(file.exists()){            
    file.delete();            
}            

file.createNewFile();            
FileOutputStream fileOutputStream = new FileOutputStream(filePath2);            
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);            
BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);            
// 写一行
bufferedWriter.write(content + "\n");
bufferedWriter.close();// 必须加入，否则缓存区未满时不写入，最后会有部分内容缺失
fileOutputStream.close();