Java Files.readAllBytes example
By:Roy.LiuLast updated:2019-08-11
In Java, we can use Files.readAllBytes to read a file.
byte[] content = Files.readAllBytes(Paths.get("app.log")); System.out.println(new String(content));
1. Text File
A Java example to write and read a normal text file.
FileExample1.java
package com.mkyong.calculator; import java.io.IOException; import java.nio.charset.Charset; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Paths; import java.util.Arrays; import java.util.List; public class FileExample1 { public static void main(String[] args) { Charset utf8 = StandardCharsets.UTF_8; List<String> list = Arrays.asList("Line 1", "Line 2"); // Write try { Files.write(Paths.get("app.log"), list, utf8, StandardOpenOption.CREATE, StandardOpenOption.APPEND); } catch (IOException x) { System.err.format("IOException: %s%n", x); // Read try { byte[] content = Files.readAllBytes(Paths.get("app.log")); System.out.println(new String(content)); // for binary //System.out.println(Arrays.toString(content)); } catch (IOException e) { e.printStackTrace();
Output
app.log
Line 1 Line 2
2. Binary File
For binary format, we need to use Arrays.toString to convert it to a String.
FileExample2.java
package com.mkyong; import java.io.IOException; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Paths; import java.nio.file.StandardOpenOption; import java.util.Arrays; public class FileExample2 { public static void main(String[] args) { byte[] bytes = {1, 2, 3, 4, 5}; // Write into binary format try { Files.write(Paths.get("app.bin"), bytes, StandardOpenOption.CREATE, StandardOpenOption.APPEND); } catch (IOException x) { System.err.format("IOException: %s%n", x); // Read try { byte[] content = Files.readAllBytes(Paths.get("app.bin")); // for binary System.out.println(Arrays.toString(content)); } catch (IOException e) { e.printStackTrace();
Output
app.bin
[1, 2, 3, 4, 5]
From:一号门
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