Java Properties load() Method

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Description

The Java Properties load(InputStream inStream) method reads a property list (key and element pairs) from the input byte stream. The input stream is in a simple line-oriented format as specified in load(Reader) and is assumed to use the ISO 8859-1 character encoding; that is each byte is one Latin1 character.

Declaration

Following is the declaration for java.util.Properties.load() method

 public void load(InputStream inStream) 

Parameters

inStream − the input stream.

Return Value

This method does not return a value.

Exception

• IOException − if an error occurred when reading from the input stream.

• IllegalArgumentException − if the input stream contains a malformed Unicode escape sequence.

Java Properties load(Reader reader) Method

Description

The java.util.Properties.load(Reader reader) method Reads a property list (key and element pairs) from the input character stream in a simple line-oriented format.

Declaration

Following is the declaration for java.util.Properties.load(Reader reader) method

 public void load(Reader reader) 

Parameters

reader − the input character stream.

Return Value

This method does not return a value.

Exception

• IOException − if an error occurred when reading from the input stream.

• IllegalArgumentException − if the input stream contains a malformed Unicode escape sequence.

Loading Properties From a TXT File Example

The following example shows the usage of Java Properties load(InputStream) method to load the properties from a stream.

 package com.tutorialspoint; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.Properties; public class PropertiesDemo { public static void main(String[] args) { Properties prop = new Properties(); String s = "Height=200"; String s2 = "Width=15"; try { // create a new input and output stream FileOutputStream fos = new FileOutputStream("properties.txt"); FileInputStream fis = new FileInputStream("properties.txt"); // write the first property in the output stream file fos.write(s.getBytes()); // change the line between the two properties fos.write("\n".getBytes()); // write next property fos.write(s2.getBytes()); // load from input stream prop.load(fis); // print the properties list from System.out prop.list(System.out); } catch (IOException ex) { ex.printStackTrace(); } } } 

Output

Let us compile and run the above program, this will produce the following result −

 -- listing properties -- Width=15 Height=200 

Loading Properties From a String Example

The following example shows the usage of Java Properties load(Reader) method to load the properties from a reader.

 package com.tutorialspoint; import java.io.IOException; import java.io.StringReader; import java.util.Properties; public class PropertiesDemo { public static void main(String[] args) { Properties prop = new Properties(); String s = "Height=200\nWidth=15"; // create a new reader StringReader reader = new StringReader(s); try { // load from input stream prop.load(reader); // print the properties list from System.out prop.list(System.out); } catch (IOException ex) { ex.printStackTrace(); } } } 

Output

Let us compile and run the above program, this will produce the following result −

 -- listing properties -- Width=15 Height=200