Java Learning notes, file manipulation

Ava learns the flow of notes, the operation of files

For some basic knowledge, there is no longer much explanation,

Simple file Query filtering operation

Package Com.wfu.ch08;import Java.io.file;import Java.io.filenamefilter;public class Test1 {public static V      OID Main (string[] args) {file File=new file ("F:\\2017-2018-1\\javase");/////Get the directory, all the names of the files or directories consisting of an array of strings//      String[] List=file.list ()////Traverse list//for (String str:list) {//System.out.println (str);//}//              File[] List=file.listfiles ()////Traversal file array list//for (file f:list) {//if (F.isdirectory ()) {// System.out.println ("Directory:" +f.getname ());//}//else{//System.out.println ("File:" +f.getname (        );//}//}//referencing the external class implements the Filter function Myfilter filter=new myfilter ();        String[] List=file.list (filter);        for (String str:list) {System.out.println (str); }//File File=new file ("D:\\test.txt");//System.out.println ("Is it a directory?") +file.isdirectory ());//System.out.println ("File Size" +file.length ());//System.out.println ("File name: "+file.getname ());//System.out.println (" File path "+file.getpath ());//Date Date=new date (file.lastmodified ());// System.out.println ("Last Modified:" +date);//System.out.println ("Is it a file?")            "+file.isfile ()); }}//the external class to implement filtering, because FilenameFilter is not implemented class, so we have to write our own class Myfilter implements filenamefilter{@Override public boolean AC Cept (File Dr, String name) {//TODO auto-generated Method stub if (Name.endswith (". Doc") | |        Name.endswith (". docx")) {return true;        } else{return false;    }    }    }

Examples of internal classes

package com.wfu.ch08;import java.io.File;import java.io.FilenameFilter;public class Test2 {    public static void main(String[] args) {        File file=new File("F:\\2017-2018-1\\javase");        Test2 t=new Test2();        Test2.MyFilter filter=t.new MyFilter();        String[] list=file.list(filter);        for(String s:list){            System.out.println(s);        }    }        //这个类写在了类 Test2 中，所以是内部类，在调用内部类是一定要声明对象啊啊啊啊啊    class MyFilter implements FilenameFilter{        @Override        public boolean accept(File arg0, String arg1) {            // TODO Auto-generated method stub            if(arg1.endsWith(".doc")||arg1.endsWith(".docx")){                return true;            }            else{                return false;            }        }                    }}

Anonymous class examples

package com.wfu.ch08;import java.io.File;import java.io.FilenameFilter;public class Test3 {    public static void main(String[] args) {        File file=new File("F:\\2017-2018-1\\javase");                //这里的没有写类的名字，而是直接写的实现方法，这样就是匿名的内部类        String[] list=file.list(new FilenameFilter(){//这个地方本来是不能直接使用接口的，但是，因为下面的实现类也写上了，所也这里实质山是调用的实现类，而不是接口            @Override            public boolean accept(File arg0, String arg1) {                // TODO Auto-generated method stub                if(arg1.endsWith(".doc")||arg1.endsWith(".docx")){                    return true;                }                else{                    return false;                }            }                    });        for(String s:list){            System.out.println(s);        }    }}

Simple example of flow and file operation

Package Wfu;import Java.io.fileinputstream;import Java.io.fileoutputstream;import java.io.ioexception;import Java.io.inputstream;import Java.io.outputstream;public class Test3 {public static void main (string[] args) throws Ioex        ception {FileOutputStream out = new FileOutputStream ("D:\\test2.txt");        String str = "This is a bug";        Out.write (Str.getbytes ());//write character array//out.close ();        FileInputStream input = new FileInputStream ("D:\\test2.txt");        Byte[] B = new byte[1024];        Input.read (b);        System.out.println (New String (b));                Input.close ();        FileOutputStream Outto = new FileOutputStream ("F:\\test2.txt");        Out.write (Str.getbytes ());                                                Out.close (); //using the word stream will appear in Chinese garbled////So if you have Chinese words or use a character stream better//FileInputStream input = new FileInputStream ("D:\\tes        T.txt ");//int x = Input.read ();//do{//System.out.print ((char) x);//  x= input.read ();//}while (X!=-1);////Close stream//Input.close ();//////////Create file Word Section input stream//InputStream input = new FileInputStream ("D:\\test.txt");//////////////////////////////byte[] B = new 1024];//Input.read (b);//System.out.println (new string (b));//Convert to string////Close//Input.close ();//       Create a file output stream//OutputStream out = new FileOutputStream ("D:\\test1.txt");//The file does not exist automatically creates one, if any, executes this file//Out.write (b);//            Out.close (); }        }

Java Learning notes, file operations