Java Java.io.LineNumberInputStream.getLineNumber() 方法

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  描述

  java.io.LineNumberInputStream.getLineNumber()方法返回当前行号。
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  声明

  以下是java.io.LineNumberInputStream.getLineNumber()方法的声明-

   public int getLineNumber()

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  参数

  不适用
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  返回值

  该方法返回当前行号。
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  异常

  不适用
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  例子

  以下示例显示java.io.LineNumberInputStream.getLineNumber()方法的用法。

   
  package com.jc2182;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.LineNumberInputStream;
  
  public class LineNumberInputStreamDemo {
     public static void main(String[] args) throws IOException {
        LineNumberInputStream lnis = null;
        FileInputStream fis = null;
        int i,j;
        char c;
        
        try {
           // create new input streams
           fis = new FileInputStream("C:/test.txt");
           lnis = new LineNumberInputStream(fis);
           
           // reads till the end of the stream
           while((i = lnis.read())!=-1) {
           
              // converts int to char
              c = (char)i;
              
              // if the character is not new line 
              if(i!=10) {
              
                 // prints char
                 System.out.print("Character read: "+c);
                 
                 // get the line number
                 j = lnis.getLineNumber();
                 System.out.println(" at line: "+j);
              }
           }
           
        } catch(Exception e) {
           // if any error occurs
           e.printStackTrace();
        } finally {
           // closes the stream and releases any system resources
           if(fis!=null)
              fis.close();
           if(lnis!=null)
              lnis.close();      
        }
     }
  }
  

  假设我们有一个文本文件c:/test.txt ，其内容如下。该文件将用作示例程序的输入-

   ABCDE

  让我们编译并运行以上程序，这将产生以下结果-

   
  Character read: A at line: 0
  Character read: B at line: 0
  Character read: C at line: 0
  Character read: D at line: 0
  Character read: E at line: 0
  Character read: F at line: 1
  Character read: G at line: 1
  Character read: H at line: 1
  Character read: I at line: 1
  Character read: J at line: 1
  Character read: K at line: 2
  Character read: L at line: 2
  Character read: M at line: 2
  Character read: N at line: 2
  Character read: O at line: 2
  Character read: P at line: 3
  Character read: Q at line: 3
  Character read: R at line: 3
  Character read: S at line: 3
  Character read: T at line: 3