Last update on December 21 2024 09:58:24 (UTC/GMT +8 hours) Write a Java program to read the first 3 lines of a file. Sample Solution: Java Code: importjava.io.BufferedReader;importjava.io.FileNotFoundException;importjava.io.LineNumberReader;importjava.io.IOException;importjava.io.InputStre...
TheBufferedReaderreads text from a character-input stream, buffering characters so as toprovide for the efficient reading of characters, arrays, and lines by minimizing the number of I/O operations. 1.1. Creating BufferedReder To use aBufferedReader, we should wrap it around anyReaderwhoseread()o...
@Test public void givenFile_whenUsingFileUtils_thenExtractedLastLinesCorrect() throws IOException{ File file = new File(FILE_PATH); List<String> lines = FileUtils.readLines(file, "UTF-8"); StringBuilder stringBuilder = new StringBuilder(); for (int i = (lines.size() - LAST_LINES_TO_READ)...
1.Files.lines()– Stream through Lines of a File in Java 8 TheFiles.lines()is a new addition in Java 8. It reads all lines from a file as aStream. The returned stream contains a reference to an open file. Thefile is closed by closing the stream. It is important to note that the...
Read all lines from a file. This method ensures that the file is closed when all bytes have been read or an I/O error, or other runtime exception, is thrown. Bytes from the file are decoded into characters using the specified charset. ...
importjava.io.BufferedReader;importjava.io.FileReader;importjava.io.IOException;publicclassReadSpecificLineFromFile{publicstaticvoidmain(String[]args){StringfilePath="example.txt";inttargetLine=3;try(BufferedReaderbr=newBufferedReader(newFileReader(filePath))){Stringline=null;for(inti=1;i<targetLine;i...
Another option to read text files is to use the Java streaming API. TheFiles.linesreads all lines from a file as a stream. The bytes from the file are decoded into characters using theStandardCharsets.UTF-8charset. Main.java import java.io.IOException; ...
lines()method read all lines from a file to stream and populates lazily as thestreamis consumed. Bytes from the file are decoded into characters using the specified charset. lines()方法从文件中读取所有行,通过流(stream)的方式读到内存。 使用指定的字符集将文件中的二进制字节解码转换为字符。
//file中的 line数据格式:name,age,address -> NAME,AGE,ADDRESS, String[] contents = line.split(","); for (int i=0;i newLine.concat(contents[i].toLowerCase()); } lines.add(newLine); //将处理后的数写入新的文件 outFile FileUtils.writeLines(outFile,lines,true); ...
packagecom.journaldev.readfileslinebyline;importjava.io.IOException;importjava.nio.file.Files;importjava.nio.file.Paths;importjava.util.List;publicclassReadFileLineByLineUsingFiles{publicmain[]args){try{List<String>allLines=Files.readAllLines(Paths.get("sample.txt"));for(Stringline:allLines){System...