Java基础知识系列——文件操作
对文件进行操作在编程中比较少用,但是我最近有一个任务需要用到对文件操作。
对文件有如下操作形式:
1.创建新的文件(夹)
File fileName = new File("C:/myfile.txt");
fileName.createNewFile(); //创建文件
File fileName = new File("C:/myfile");
fileName.mkdir(); //创建文件夹
2.对比两个文件路径
fileName.compareTo(anotherFileName);
3.获取文件的最后修改日期
fileName.lastModified(); //返回类型是long
4.在指定目录下创建文件
File file = null;
File dir = new File("C:/"):
file = File.creatTempFile("javeTemp",".javatemp",dir);
file.getPath(); //获取文件路径
5.判断文件是否存在
file.exists();
6.设置文件只读与可写
file.setReadOnly(); //只读
file.setWrite(); //可写
7.文件重命名
File oldName = new File("C:/program.txt");
File newName = new File("C:/java.txt");
oldName.renameTo(newName);
8.文件大小
file.exists(); //是否存在
file.isFile(); //是否是文件
file.length(); //获取文件大小
9.改变文件最后修改时间
file.setLastModified( System.currentTimeMills());
10.创建临时文件
File temp = File.createTempFile( "pattern", ".suffix");
temp.deleteOnExit();
BufferedWriter out = new BufferedWriter( new FileWriter( temp));
out.write( "aString");
11.在现有文件最后添加字符串
BufferedWriter out = new BufferedWriter( new FileWriter( "fileName"));
out.write( "aString1");
out.close();
out = new BufferedWriter( new FileWriter( "fileName"; true));
out.writer();
out.close();
12.复制文件
BufferedWriter out1 = new BufferedWriter( new FileWriter( "srcFile"));
out1.write( "String to be copied");
out1.close();
InputStream in = new FileInputStream( new File( "srcFile"));
OutputStream out = new OutputStream( new File( "destnFile"));
byte[] buf = new byte[1024];
int len = 0;
while( ( len = in.read( buf)) > 0){
out.write( buf, 0, len);
}
in.close();
out.close();
13.删除文件
file.delete(); //返回类型是boolean
14.读取文件
BufferedReader in = new BufferedReader( new FileReader( "C:/fileName"));
String str = "":
while( ( str = in.readLine()) != null){
System.out.println( str);
}
15.写入文件
BufferedWriter out = new BufferedWriter( new FileWriter( "outFileName"));
out.write( "aString");
out.close(); //一定要记得关闭,一定要管关
原文:http://www.yiibai.com/javaexamples/java_files.html