java怎么读取数据

java怎么读取数据

1、从控制台读取数据

使用Scanner类来读取控制台的输入（推荐教程：java教程）

public static void main(String[] args) {     Scanner in = new Scanner(System.in);   String a = in.nextLine();   System.out.println(a); }

2、从本地读取文件

 public void readTxtFile(String filePath) {         try {             File file = new File(filePath);             if (file.isFile() && file.exists()) {                 InputStreamReader isr = new InputStreamReader(new FileInputStream(file), "utf-8");                 BufferedReader br = new BufferedReader(isr);                 String lineTxt = null;                 while ((lineTxt = br.readLine()) != null) {                     System.out.println(lineTxt);                 }                 br.close();             } else {                 System.out.println("文件不存在!");             }         } catch (Exception e) {             System.out.println("文件读取错误!");         }     }

3、从网络读取文件

public class Main {     public static void main(String[] args) {     String url = "http://www.php.cn/test.txt";     String result = "";     BufferedReader in = null;     try {         //生成URL         URL realUrl = new URL(url);         //初始化连接到特定URL的连接通道         URLConnection connection = realUrl.openConnection();         //开始实际连接         connection.connect();         //数据读取         in = new BufferedReader(new InputStreamReader(connection.getInputStream()));                  //临时存储一行数据         String line;         while((line = in.readLine()) != null) {             result += line;         }     } catch (Exception e) {         e.printStackTrace();     } finally {         try {             if (in != null) {                 in.close();             }         } catch (Exception e2) {             e2.printStackTrace();         }     }     System.out.println(result);   } }

以上就是java怎么读取数据的详细内容，更多内容请关注技术你好其它相关文章！