Java How to save a String to a File
摘要: In Java, there are many ways to write a String to a File.
In Java, there are many ways to write a String to a File.
1. Java 11 – Files.writeString
Finally, a new method added in java.nio to save a String into a File easily.
StringToFileJava11.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;
public class StringToFileJava11 {
public static void main(String[] args) {
String content = "Hello World \r\nJava!\r\n";
String path = "c:\\projects\\app.log";
try {
// Java 11 , default StandardCharsets.UTF_8
Files.writeString(Paths.get(path), content);
// encoding
// Files.writeString(Paths.get(path), content, StandardCharsets.US_ASCII);
// extra options
// Files.writeString(Paths.get(path), content,
// StandardOpenOption.CREATE, StandardOpenOption.APPEND);
} catch (IOException e) {
e.printStackTrace();
c:\\projects\\app.log
Hello World Java!
2. Java 7 – Files.write
StringToFileJava7.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;
public class StringToFileJava7 {
public static void main(String[] args) {
String content = "Hello World \r\nJava!\r\n";
String path = "c:\\projects\\app.log";
try {
// Java 7
Files.write(Paths.get(path), content.getBytes());
// encoding
// Files.write(Paths.get(path), content.getBytes(StandardCharsets.UTF_8));
// extra options
// Files.write(Paths.get(path), content.getBytes(),
// StandardOpenOption.CREATE, StandardOpenOption.APPEND);
} catch (IOException e) {
e.printStackTrace();
Output
c:\\projects\\app.log
Hello World Java!
3. Apache Commons IO
pom.xml
<dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency>
CommonsIOExample.java
package com.mkyong;
import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
public class CommonsIOExample {
public static void main(String[] args) {
String content = "Hello World \r\nJava!\r\n";
String path = "c:\\projects\\app2.log";
try {
FileUtils.writeStringToFile(new File(path), content, StandardCharsets.UTF_8);
// append
// FileUtils.writeStringToFile(new File(path), content, StandardCharsets.UTF_8, true);
} catch (IOException e) {
e.printStackTrace();
4. BufferedWriter
4.1 In the old days:
BufferedWriterExample.java
package com.mkyong;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
public class BufferedWriterExample {
public static void main(String[] args) {
String content = "Hello World \r\nJava!\r\n";
String path = "c:\\projects\\app.log";
try (FileWriter writer = new FileWriter(path);
BufferedWriter bw = new BufferedWriter(writer)) {
bw.write(content);
} catch (IOException e) {
e.printStackTrace();
4.2 Or like this, close all resources manually :)
BufferedWriterExampleBeforeJava7.java
package com.mkyong;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
public class BufferedWriterExampleBeforeJava7 {
public static void main(String[] args) {
String content = "Hello World \r\nJava!\r\n";
String path = "c:\\projects\\app.log";
BufferedWriter bw = null;
FileWriter fw = null;
try {
fw = new FileWriter(path);
bw = new BufferedWriter(fw);
bw.write(content);
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (bw != null)
bw.close();
if (fw != null)
fw.close();
} catch (IOException ex) {
ex.printStackTrace();
