java文件输出流是一种用于处理原始二进制数据的字节流类。为了将数据写入到文件中，必须将数据转换为字节，并保存到文件。

复制代码 代码如下:
package com.yiibai.io;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class WriteFileExample {
public static void main(String[] args) {

FileOutputStream fop = null;
File file;
String content = "This is the text content";

try {

file = new File("c:/newfile.txt");
fop = new FileOutputStream(file);

// if file doesnt exists, then create it
if (!file.exists()) {
file.createNewFile();
}

// get the content in bytes
byte[] contentInBytes = content.getBytes();

fop.write(contentInBytes);
fop.flush();
fop.close();

System.out.println("Done");

} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (fop != null) {
fop.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
//更新的JDK7例如，使用新的“尝试资源关闭”的方法来轻松处理文件。
package com.yiibai.io;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class WriteFileExample {
public static void main(String[] args) {

File file = new File("c:/newfile.txt");
String content = "This is the text content";

try (FileOutputStream fop = new FileOutputStream(file)) {

// if file doesn't exists, then create it
if (!file.exists()) {
file.createNewFile();
}

// get the content in bytes
byte[] contentInBytes = content.getBytes();

fop.write(contentInBytes);
fop.flush();
fop.close();

System.out.println("Done");

} catch (IOException e) {
e.printStackTrace();
}
}
}