java读取txt文件

一、读取txt文件。

1、步骤 :

①、创建文件句柄

File file = new File(filePath);

②、将文件内容读取到内存中

new FileInputStream(file)

③、封装数据 InputStreamReader

InputStreamReader read = new InputStreamReader(new FileInputStream(file), encoding)

④、读取数据

BufferedReader bufferedReader = new BufferedReader(read);

　　每行数据

bufferedReader.readLine()

2、场景 ： txt文件内容 ：

123

456

...

读取每行内容, 并将每行内容用 , 拼接成 123,456

public class ReadTxt {

public static void main(String[] args) {
String filePath = "/Users/xupengwei/Downloads/test.txt";
readTxtFile(filePath );
}

public static void readTxtFile(String filePath) {
try {
String encoding = "GBK";
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;
StringBuffer sb = new StringBuffer();
while ((lineTxt = bufferedReader.readLine()) != null) {
sb.append(lineTxt);
sb.append(",");
}
System.out.println(sb.toString());
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();
}

}
}

二、拓展...

场景 : 正则匹配