Java Properties load() Method

---

---

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