Java reads and writes the properties configuration file, and the properties configuration file

Java reads and writes the properties configuration file, and the properties configuration file
1.1. Read the properties configuration file 1.1.1. The file to be read

You can use the colon [:] and equal sign [=] between the key and value of the configuration file.

Test. properties

Name: \ u5F20 \ u4E09 Password: \ u5BC6 \ u7801 Age: 22

1.1.2. Read program code

PropertiesTest. java

/*** Read the configuration File * @ throws IOException */@ Test public void read () throws IOException {Properties properties = new Properties (); file File = new File ("test. properties "); FileInputStream FD = new FileInputStream (file); properties. load (FCM); Set <Object> keySet = properties. keySet (); for (Object object: keySet) {System. out. println (object. toString () + ":" + properties. getProperty (object. toString ()));}}

1.1.3. Results

Result printed in the background

Age: 22 Password: password Name: James

1.2. write operation on the propertiest configuration file 1.2.1. Write Program code

PropertiesTest. java

/*** Write content to the configuration file * @ throws IOException */@ Test public void write () throws IOException {Properties properties = new Properties (); String file = "aa. properties "; FileOutputStream fos = new FileOutputStream (file); properties. setProperty ("aa", "123"); properties. setproperties ("bb", "456"); properties. setProperty ("cc", "789"); properties. setProperty ("name", "Michael"); properties. store (fos, "save files"); fos. close ();}

1.2.2. Result

Aa. propertiest

# \ U4FDD \ u5B58 \ u6587 \ u4EF6 # SunJan25 14:06:25 CST 2015 Name = \ u5F20 \ u4E09 Aa = 123 Bb = 1, 456 Cc = 789

1.3. Modify the properties configuration file 1.3.1. The configuration file before modification

Test. properties

Age = 22 Password = Password Name = James

1.3.2. modify the program code

PropertiesTest. java

/*** Modify the configuration file * @ throws IOException */@ Test public void update () throws IOException {Properties properties Properties = new Properties (); file file = new File ("test. properties "); FileInputStream FD = new FileInputStream (file); FileOutputStream fos = new FileOutputStream (file); properties. load (FCM); properties. setProperty ("name", "Li Si"); properties. setProperty ("age", "222"); properties. setProperty ("age3", "222"); properties. store (fos, "Update Configuration File"); fos. close (); FCM. close ();}

1.3.3. Modified File Content

Test. properties

# \ U66F4 \ u65B0 \ u914D \ u7F6E \ u6587 \ u4EF6 # SunJan25 15:20:40 CST 2015 Age = 222 Name = \ u674E \ u56DB Password = \ u5BC6 \ u7801 Age3 = 222

1.4. Delete the properties configuration file 1.4.1. Contents of the configuration file before deletion

Test. properties

# \ U66F4 \ u65B0 \ u914D \ u7F6E \ u6587 \ u4EF6 # SunJan25 15:20:40 CST 2015 Age = 222 Name = \ u674E \ u56DB Password = \ u5BC6 \ u7801 Age3 = 222

1.4.2. delete program code

PropertiesTest. java

/*** Delete the key in the configuration file * @ throws IOException **/@ Test public void delete () throws IOException {Properties properties = new Properties (); file file = new File ("test. properties "); FileInputStream FD = new FileInputStream (file); properties. load (FCM); // all the content must be saved first with map. Otherwise, Map <String, String> map = new HashMap <String, string> (); Set <Object> keySet = properties. keySet (); System. out. println (keySet. size (); for (Object object: keySet) {String key = (String) object; String value = (String) properties. get (key); System. out. println (key + "=" + value); map. put (key, value);} // deletes the key map. remove ("age3"); properties. remove ("age3"); for (java. util. map. entry <String, String> entry: map. entrySet () {properties. setProperty (entry. getKey (), entry. getValue ();} FileOutputStream fos = new FileOutputStream (file); properties. store (fos, "delete key: age3 in the configuration file"); fos. close (); FCM. close ();}

1.4.3. Deleted Configuration File Content

Test. properties

# \ U5220 \ u9664 \ u914D \ u7F6E \ u6587 \ u4EF6 \ u4E2D \ u7684key: age3 # SunJan25 15:23:58 CST 2015 Age = 222 Name = \ u674E \ u56DB Password = \ u5BC6 \ u7801

1.5. Complete program code

PropertieTest. java

Import java. io. file; import java. io. fileInputStream; import java. io. fileOutputStream; import java. io. IOException; import java. util. hashMap; import java. util. map; import java. util. properties; import java. util. set; import org. junit. test; public class PropertiesTest {public static void main (String [] args) {}/*** delete the key * @ throws IOException in the configuration file **/@ Test public void delete () throws IOException {Properties properties Properties = new Properties (); file file = new File ("test. properties "); FileInputStream FD = new FileInputStream (file); properties. load (FCM); // all the content must be saved first with map. Otherwise, Map <String, String> map = new HashMap <String, string> (); Set <Object> keySet = properties. keySet (); System. out. println (keySet. size (); for (Object object: keySet) {String key = (String) object; String value = (String) properties. get (key); System. out. println (key + "=" + value); map. put (key, value);} // deletes the key map. remove ("age3"); properties. remove ("age3"); for (java. util. map. entry <String, String> entry: map. entrySet () {properties. setProperty (entry. getKey (), entry. getValue ();} FileOutputStream fos = new FileOutputStream (file); properties. store (fos, "delete key: age3 in the configuration file"); fos. close (); FCM. close ();}/*** modify the configuration file * @ throws IOException */@ Test public void update () throws IOException {Properties properties Properties = new Properties (); file file = new File ("test. properties "); FileInputStream FD = new FileInputStream (file); properties. load (FCM); // all the content must be saved first with map. Otherwise, the original content is not updated with Map <String, String> map = new HashMap <String, string> (); Set <Object> keySet = properties. keySet (); System. out. println (keySet. size (); for (Object object: keySet) {String key = (String) object; String value = (String) properties. get (key); System. out. println (key + "=" + value); map. put (key, value);} map. put ("name", "Li Si"); map. put ("age", "222"); map. put ("age3", "222"); for (java. util. map. entry <String, String> entry: map. entrySet () {properties. setProperty (entry. getKey (), entry. getValue ();} FileOutputStream fos = new FileOutputStream (file); properties. store (fos, "Update Configuration File"); fos. close (); FCM. close ();}/*** write content to the configuration file * @ throws IOException */@ Test public void write () throws IOException {Properties properties Properties = new Properties (); string file = "aa. properties "; FileOutputStream fos = new FileOutputStream (file); properties. setProperty ("aa", "123"); properties. setproperties ("bb", "456"); properties. setProperty ("cc", "789"); properties. setProperty ("name", "Michael"); properties. store (fos, "save files"); fos. close ();}/*** read configuration file * @ throws IOException */@ Test public void read () throws IOException {Properties properties Properties = new Properties (); file file = new File ("test. properties "); FileInputStream FD = new FileInputStream (file); properties. load (FCM); Set <Object> keySet = properties. keySet (); for (Object object: keySet) {System. out. println (object. toString () + "=" + properties. getProperty (object. toString ()));}}}