Java IO stream-properties

2017-11-05 21:37:50

• Properties

Properties：Propertiesclass represents a persisted set of properties. Propertiescan be saved in a stream or loaded from a stream. Each key and its corresponding value in the property list is a string.

Properties is an attribute collection class that is a collection class that can be combined with an IO stream.

The properties class can be stored in a stream or loaded from a stream, which is a subclass of Hashtable, or a subclass of map.

* Construction Method

* Common Methods

~ Properties as the use of the map collection

public class Main {public    static void Main (string[] args) {        //No generics, not generic-class        Properties prop = new properties (); c3/>//add element        prop.put ("1", "Hello");        Prop.put ("2", "World");        Prop.put ("3", "!");        Traversal set        set<object> set = Prop.keyset ();        For (object K:set) {            object val = Prop.get (k);            System.out.println (k + "---" +val);}}}    

~ Special Features of properties

1. Public Object setProperty (String key,string value)
2. public string GetProperty (string key)
3. Public set<string> Stringpropertynames ()

public class Main {public    static void Main (string[] args) {        //No generics, not generic-class        Properties prop = new properties (); c3/>//add element        prop.setproperty ("1", "Hello");        Prop.setproperty ("2", "World");        Prop.setproperty ("3", "!");        Traversal set        set<string> set = Prop.stringpropertynames ();        for (string k:set) {            string val = Prop.getproperty (k);            System.out.println (k + "---" +val);}}}    

~ Combination of properties and IO streams

1. public void load (Reader reader): The data in the file is read into the Properties collection, and the data in the file must be in the form of a key-value pair.
2. public void Store (Writer writer,string Comments): Stores the data in the collection into a file.

        No generics, not generic-class        Properties prop = new properties ();        add element        Prop.setproperty ("1", "Hello");        Prop.setproperty ("2", "World");        Prop.setproperty ("3", "!");        Writer w = new FileWriter ("E:/test.txt");        Prop.store (W, "HelloWorld");

#helloworld #sun Nov 22:06:16 CST 20171=hello2=world3=\!

        Properties prop = new properties ();        Reader r = new FileReader ("E:/test.txt");        Prop.load (r);        R.close ();

Java IO stream-properties