{"id":10211,"date":"2014-06-11T18:10:50","date_gmt":"2014-06-11T15:10:50","guid":{"rendered":"http:\/\/examples.javacodegeeks.com\/?p=10211"},"modified":"2014-06-12T08:13:51","modified_gmt":"2014-06-12T05:13:51","slug":"java-net-url-example","status":"publish","type":"post","link":"https:\/\/examples.javacodegeeks.com\/java-development\/core-java\/net\/url\/java-net-url-example\/","title":{"rendered":"java.net.URL Example"},"content":{"rendered":"

In this example, we will show the range of functionality provided by the java.net.URL<\/a> class. This class represents a Uniform Resource Locator, a pointer to a “resource” on the World Wide Web.<\/p>\n

An URL is a text string that identifies a resource, tells where to find it, and specifies a method for communicating with it or retrieving it from its source. URLs can have many forms. The most common form has four components; a network host<\/em> or server, the name<\/em> of the resource, its location<\/em> on that host, and a protocol<\/em> by which the host should communicate: protocol:\/\/hostname\/path\/resource-name<\/em>.<\/p>\n

protocol<\/em> is an identifier such as http<\/em> or ftp<\/em>; hostname<\/em> is usually an Internet host and domain name; and the path<\/em> and resource-name<\/em> components form a unique path that identifies the object on that host.<\/p>\n

Let’s code one of the most common task for which java.net.URL class is used: Read a file using the http<\/em> protocol.<\/p>\n

 <\/p>\n

1. Example of java.net.URL class<\/h2>\n

JavaNetURLExample.java<\/span><\/em><\/p>\n

package com.javacodegeeks.examples;\r\n\r\nimport java.io.BufferedReader;\r\nimport java.io.IOException;\r\nimport java.io.InputStreamReader;\r\nimport java.net.MalformedURLException;\r\nimport java.net.URL;\r\n\r\npublic class JavaNetURLExample {\r\n\tpublic static void main(String[] args) {\r\n\t\ttry {\r\n\t\t\t\/\/ Generate absolute URL\r\n\t\t\t\/\/ Base URL = www.gnu.org\r\n\t\t\tURL url1 = new URL(\"http:\/\/www.gnu.org\");\r\n\t\t\tSystem.out.println(\"URL1: \" + url1.toString());\r\n\r\n\t\t\t\/\/ Generate URL for pages with a common base\r\n\t\t\tURL url2 = new URL(url1, \"licenses\/gpl.txt\");\r\n\t\t\tSystem.out.println(\"URL2: \" + url2.toString());\r\n\r\n\t\t\t\/\/ Generate URLs from different pieces of data\r\n\t\t\tURL url3 = new URL(\"http\", \"www.gnu.org\", \"\/licenses\/gpl.txt\");\r\n\t\t\tSystem.out.println(\"URL3: \" + url3.toString());\t\r\n\t\t\t\r\n\t\t\tURL url4 = new URL(\"http\", \"www.gnu.org\", 80, \"\/licenses\/gpl.txt\");\r\n\t\t\tSystem.out.println(\"URL4: \" + url4.toString() + \"\\n\");\r\n\r\n\t\t\t\/\/ Open URL stream as an input stream and print contents to command line\r\n\t\t\ttry (BufferedReader in = new BufferedReader(new InputStreamReader(url4.openStream()))) {\r\n\t\t\t\tString inputLine;\r\n\r\n\t\t\t\t\/\/ Read the \"gpl.txt\" text file from its URL representation\r\n\t\t\t\tSystem.out.println(\"\/***** File content (URL4) *****\/n\");\r\n\t\t\t\twhile((inputLine = in.readLine()) != null) {\r\n\t\t\t\t\tSystem.out.println(inputLine);\r\n\t\t\t\t}\r\n\t\t\t} catch (IOException ioe) {\r\n\t\t\t\tioe.printStackTrace(System.err);\r\n\t\t\t}\r\n\t\t} catch (MalformedURLException mue) {\r\n\t\t\tmue.printStackTrace(System.err);\r\n\t\t}\r\n\t}\r\n}\r\n<\/pre>\n
Let\u2019s explain the methods used in the above example.<\/p>\n