{"id":1294,"date":"2022-02-27T06:03:05","date_gmt":"2022-02-27T06:03:05","guid":{"rendered":"https:\/\/mdr.foobrdigital.com\/?p=1294"},"modified":"2022-02-27T06:03:05","modified_gmt":"2022-02-27T06:03:05","slug":"reader-class","status":"publish","type":"post","link":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/2022\/02\/27\/reader-class\/","title":{"rendered":"Reader Class"},"content":{"rendered":"\n

In this tutorial, we will learn about Java Reader, its subclasses and its methods with the help of an example.<\/p>\n\n\n\n

The Reader<\/code> class of the java.io<\/code> package is an abstract superclass that represents a stream of characters.<\/p>\n\n\n\n

Since Reader<\/code> is an abstract class, it is not useful by itself. However, its subclasses can be used to read data.<\/p>\n\n\n\n

\n\n\n\n

Subclasses of Reader<\/h2>\n\n\n\n

In order to use the functionality of Reader<\/code>, we can use its subclasses. Some of them are:<\/p>\n\n\n\n

  • BufferedReader<\/li>
  • InputStreamReader<\/li>
  • FileReader<\/li>
  • StringReader<\/li><\/ul>\n\n\n\n
    \"Subclasses<\/figure>\n\n\n\n

    We will learn about all these subclasses in the next tutorial.<\/p>\n\n\n\n

    \n\n\n\n

    Create a Reader<\/h2>\n\n\n\n

    In order to create a Reader<\/code>, we must import the java.io.Reader<\/code> package first. Once we import the package, here is how we can create the reader.<\/p>\n\n\n\n

    \/\/ Creates a Reader\nReader input = new FileReader();\n<\/code><\/pre>\n\n\n\n
    Here, we have created a reader using the FileReader<\/code> class. It is because Reader<\/code> is an abstract class. Hence we cannot create an object of Reader<\/code>.<\/p>\n\n\n\n
    Note<\/strong>: We can also create readers from other subclasses of Reader<\/code>.<\/p>\n\n\n\n
    \n\n\n\n
    Methods of Reader<\/h2>\n\n\n\n
    The Reader<\/code> class provides different methods that are implemented by its subclasses. Here are some of the commonly used methods:<\/p>\n\n\n\n
    • ready()<\/code> – checks if the reader is ready to be read<\/li>
    • read(char[] array)<\/code> – reads the characters from the stream and stores in the specified array<\/li>
    • read(char[] array, int start, int length)<\/code> – reads the number of characters equal to length<\/var> from the stream and stores in the specified array starting from the start<\/var><\/li>
    • mark()<\/code> – marks the position in the stream up to which data has been read<\/li>
    • reset()<\/code> – returns the control to the point in the stream where the mark is set<\/li>
    • skip()<\/code> – discards the specified number of characters from the stream<\/li><\/ul>\n\n\n\n
      \n\n\n\n
      Example: Reader Using FileReader<\/h2>\n\n\n\n
      Here is how we can implement Reader<\/code> using the FileReader<\/code> class.<\/p>\n\n\n\n
      Suppose we have a file named input.txt<\/strong> with the following content.<\/p>\n\n\n\n
      This is a line of text inside the file.\n<\/code><\/pre>\n\n\n\n
      Let’s try to read this file using FileReader<\/code> (a subclass of Reader<\/code>).<\/p>\n\n\n\n
      import java.io.Reader;\nimport java.io.FileReader;\n\nclass Main {\n    public static void main(String[] args) {\n\n        \/\/ Creates an array of character\n        char[] array = new char[100];\n\n        try {\n            \/\/ Creates a reader using the FileReader\n            Reader input = new FileReader(\"input.txt\");\n\n            \/\/ Checks if reader is ready \n            System.out.println(\"Is there data in the stream?  \" + input.ready());\n\n            \/\/ Reads characters\n            input.read(array);\n            System.out.println(\"Data in the stream:\");\n            System.out.println(array);\n\n            \/\/ Closes the reader\n            input.close();\n        }\n\n        catch(Exception e) {\n            e.getStackTrace();\n        }\n    }\n}\n<\/code><\/pre>\n\n\n\n
      Output<\/strong><\/p>\n\n\n\n
      Is there data in the stream?  true\nData in the stream:\nThis is a line of text inside the file.\n<\/samp><\/code><\/pre>\n\n\n\n
      In the above example, we have created a reader using the FileReader<\/code> class. The reader is linked with the file input.txt<\/strong>.<\/p>\n\n\n\n
      Reader input = new FileReader(\"input.txt\");\n<\/code><\/pre>\n\n\n\n
      To read data from the input.txt<\/strong> file, we have implemented these methods.<\/p>\n\n\n\n
      input.read();\n       \/\/ to read data from the reader\ninput.close(); \n     \/\/ to close the reader<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
      In this tutorial, we will learn about Java Reader, its subclasses and its methods with the help of an example. The Reader class of the java.io package is an abstract superclass that represents a stream of characters. Since Reader is an abstract class, it is not useful by itself. However, its subclasses can be used to read data. Subclasses of Reader […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[532],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1294"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=1294"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1294\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=1294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=1294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=1294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}