FileOutputStream() 文件输出流 用来写文件
FileInputStream() 文件输入流 用来读取文件 这两个用完记得关闭
详见代码,其中try catch全为自动添加
package homework;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class T {
public static void main(String[] args) {
File file = new File("text.txt");
FileOutputStream outputStream = null;
try {
outputStream = new FileOutputStream(file,true);
//第一个参数为获取的文件 第二个参数默认false
String aString = "太好啦!又能快乐地学习啦";
byte b[] = aString.getBytes();
outputStream.write(b);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
try {
outputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
FileInputStream inputStream = null;
try {
inputStream = new FileInputStream(file);
byte[] b = new byte[200];//创建缓冲区
int len = inputStream.read(b);
System.out.println(new String(b,0,len));
//从0索引读到len 去掉多余空格
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
try {
inputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}