Table of Contents

URL in Java with Examples

是 URI 的子集，標識資源可用的位置之外，還描述存取資源的主要機制形式，但反之則不然， URL in Java 介紹常見的建構子、 equals 、 toString 等方法，本篇增加了範例，並透過單元測試來驗證產出結果。

檔案目錄

./
   +- src
       +- test
       |   +- org
       |       +- ruoxue
       |           +- java_147
       |               +- net
       |                   +- url
       |                       +- URLWithExamplesTest.java

單元測試

URL Java 提供建立、取得等操作 URL 。

constructor

建立一個 URL ，提供相關資訊。

	@Test
	public void constructor() {
		try {
			String value = "http://www.ruoxue.org/java-learn";
			URL url = new URL(value);
			System.out.println(url);
			System.out.println("Protocol: " + url.getProtocol());
			System.out.println("Authority: " + url.getAuthority());
			System.out.println("UserInfo: " + url.getUserInfo());
			System.out.println("Host: " + url.getHost());
			System.out.println("Port: " + url.getPort());
			System.out.println("DefaultPort: " + url.getDefaultPort());
			System.out.println("File: " + url.getFile());
			System.out.println("Path: " + url.getPath());
			System.out.println("Query: " + url.getQuery());
			System.out.println("Ref: " + url.getRef());

			URL url2 = new URL("http", "www.ruoxue.org", 80, "/java-learn");
			System.out.println(url2);
			assertThat(url.getProtocol()).isEqualTo(url2.getProtocol());
			assertThat(url.getHost()).isEqualTo(url2.getHost());
			assertThat(url.getDefaultPort()).isEqualTo(url2.getDefaultPort());
			assertThat(url.getFile()).isEqualTo(url2.getFile());
			assertThat(url.getPath()).isEqualTo(url2.getPath());
			assertThat(url.getQuery()).isEqualTo(url2.getQuery());
			assertThat(url.getRef()).isEqualTo(url2.getRef());
		} catch (MalformedURLException ex) {
			throw new RuntimeException(ex.getMessage(), ex);
		}
	}

http://www.ruoxue.org/java-learn
Protocol: http
Authority: www.ruoxue.org
UserInfo: null
Host: www.ruoxue.org
Port: -1
DefaultPort: 80
File: /java-learn
Path: /java-learn
Query: null
Ref: null
http://www.ruoxue.org:80/java-learn

createThrowException

URL Java 建立一個 URL ，傳入無法辨識的字串，會拋出例外。

	@Test
	public void constructorThrowException() {
		assertThatCode(() -> {
			String value = "/java-learn";
			URL url = new URL(value);
			System.out.println(url);
		}).isInstanceOf(MalformedURLException.class);
	}

equalz

URL Java 建立兩個 URL ，比較是否相等。

	@Test
	public void equalz() {
		try {
			URL url = new URL("https://www.ruoxue.org/#top");
			System.out.println(url);
			URL url2 = new URL("https://WWW.RUOXUE.ORG/#top");
			System.out.println(url2);
			boolean result = url.equals(url2);
			System.out.println(result);
			assertThat(result).isTrue();

			url = new URL("https://www.ruoxue.org?s=a#bottom");
			System.out.println(url);
			url2 = new URL("https://www.ruoxue.org?s=%61#bottom");
			System.out.println(url2);
			result = url.equals(url2);
			System.out.println(result);
			assertThat(result).isFalse();
		} catch (MalformedURLException ex) {
			throw new RuntimeException(ex.getMessage(), ex);
		}
	}

https://www.ruoxue.org/#top
https://WWW.RUOXUE.ORG/#top
true
https://www.ruoxue.org?s=a#bottom
https://www.ruoxue.org?s=%61#bottom
false

toStringz

Java URL 建立一個 URL ，轉成字串。

	@Test
	public void toStringz() {
		try {
			String value = "https://www.ruoxue.org";
			URL url = new URL(value);
			System.out.println(url.toString());
			assertThat(url.toString()).isEqualTo("https://www.ruoxue.org");

			value = "mailto:ruoxueorg@gmail.com";
			url = new URL(value);
			System.out.println(url.toString());
			assertThat(url.toString()).isEqualTo("mailto:ruoxueorg@gmail.com");
		} catch (MalformedURLException ex) {
			throw new RuntimeException(ex.getMessage(), ex);
		}
	}

https://www.ruoxue.org
mailto:ruoxueorg@gmail.com

URLWithExamplesTest.java

URL in Java 新增單元測試，驗證 Java URL Example 是否符合預期。

package org.ruoxue.java_147.net.url;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatCode;

import java.net.MalformedURLException;
import java.net.URL;
import org.junit.Test;

public class URLWithExamplesTest {
	
	@Test
	public void constructor() {
		try {
			String value = "http://www.ruoxue.org/java-learn";
			URL url = new URL(value);
			System.out.println(url);
			System.out.println("Protocol: " + url.getProtocol());
			System.out.println("Authority: " + url.getAuthority());
			System.out.println("UserInfo: " + url.getUserInfo());
			System.out.println("Host: " + url.getHost());
			System.out.println("Port: " + url.getPort());
			System.out.println("DefaultPort: " + url.getDefaultPort());
			System.out.println("File: " + url.getFile());
			System.out.println("Path: " + url.getPath());
			System.out.println("Query: " + url.getQuery());
			System.out.println("Ref: " + url.getRef());

			URL url2 = new URL("http", "www.ruoxue.org", 80, "/java-learn");
			System.out.println(url2);
			assertThat(url.getProtocol()).isEqualTo(url2.getProtocol());
			assertThat(url.getHost()).isEqualTo(url2.getHost());
			assertThat(url.getDefaultPort()).isEqualTo(url2.getDefaultPort());
			assertThat(url.getFile()).isEqualTo(url2.getFile());
			assertThat(url.getPath()).isEqualTo(url2.getPath());
			assertThat(url.getQuery()).isEqualTo(url2.getQuery());
			assertThat(url.getRef()).isEqualTo(url2.getRef());
		} catch (MalformedURLException ex) {
			throw new RuntimeException(ex.getMessage(), ex);
		}
	}

	@Test
	public void constructorThrowException() {
		assertThatCode(() -> {
			String value = "/java-learn";
			URL url = new URL(value);
			System.out.println(url);
		}).isInstanceOf(MalformedURLException.class);
	}

	@Test
	public void equalz() {
		try {
			URL url = new URL("https://www.ruoxue.org/#top");
			System.out.println(url);
			URL url2 = new URL("https://WWW.RUOXUE.ORG/#top");
			System.out.println(url2);
			boolean result = url.equals(url2);
			System.out.println(result);
			assertThat(result).isTrue();

			url = new URL("https://www.ruoxue.org?s=a#bottom");
			System.out.println(url);
			url2 = new URL("https://www.ruoxue.org?s=%61#bottom");
			System.out.println(url2);
			result = url.equals(url2);
			System.out.println(result);
			assertThat(result).isFalse();
		} catch (MalformedURLException ex) {
			throw new RuntimeException(ex.getMessage(), ex);
		}
	}

	@Test
	public void toStringz() {
		try {
			String value = "https://www.ruoxue.org";
			URL url = new URL(value);
			System.out.println(url.toString());
			assertThat(url.toString()).isEqualTo("https://www.ruoxue.org");

			value = "mailto:ruoxueorg@gmail.com";
			url = new URL(value);
			System.out.println(url.toString());
			assertThat(url.toString()).isEqualTo("mailto:ruoxueorg@gmail.com");
		} catch (MalformedURLException ex) {
			throw new RuntimeException(ex.getMessage(), ex);
		}
	}
}