Java type name, simple name and canonical name example

gistfile1.txt

package pakage.subpackage.evensubberpackage;

import org.junit.Assert;
import org.junit.Test;

public class WhatIsMyName {
	@Test
	public void classHasName() {
		final Class<?> klass = WhatIsMyName.class;
		final String simpleNameExpected = "WhatIsMyName";
		Assert.assertEquals(simpleNameExpected, klass.getSimpleName());
		final String nameExpected = "pakage.subpackage.evensubberpackage.WhatIsMyName";
		Assert.assertEquals(nameExpected, klass.getName());
		Assert.assertEquals(nameExpected, klass.getCanonicalName());
	}

	@Test
	public void arrayHasName() {
		final Class<?> klass = WhatIsMyName[].class;
		final String simpleNameExpected = "WhatIsMyName[]";
		Assert.assertEquals(simpleNameExpected, klass.getSimpleName());
		final String nameExpected = "[Lpakage.subpackage.evensubberpackage.WhatIsMyName;";
		Assert.assertEquals(nameExpected, klass.getName());
		final String canonicalNameExpected = "pakage.subpackage.evensubberpackage.WhatIsMyName[]";
		Assert.assertEquals(canonicalNameExpected, klass.getCanonicalName());
	}

	class NestedClass {
	}

	@Test
	public void nestedClassHasName() {
		final Class<?> klass = NestedClass.class;
		final String simpleNameExpected = "NestedClass";
		Assert.assertEquals(simpleNameExpected, klass.getSimpleName());
		final String nameExpected = "pakage.subpackage.evensubberpackage.WhatIsMyName$NestedClass";
		Assert.assertEquals(nameExpected, klass.getName());
		final String canonicalNameExpected = "pakage.subpackage.evensubberpackage.WhatIsMyName.NestedClass";
		Assert.assertEquals(canonicalNameExpected, klass.getCanonicalName());
	}
	
	@Test
	public void methodClassHasName() {
		class MethodClass{};
		final Class<?> klass = MethodClass.class;
		final String simpleNameExpected = "MethodClass";
		Assert.assertEquals(simpleNameExpected, klass.getSimpleName());
		final String nameExpected = "pakage.subpackage.evensubberpackage.WhatIsMyName$1MethodClass";
		Assert.assertEquals(nameExpected, klass.getName());
		final String canonicalNameExpected = null;
		Assert.assertEquals(canonicalNameExpected, klass.getCanonicalName());
	}
	
	@Test
	public void anonymousClassHasName() {
		final Class<?> klass = new Object(){}.getClass();
		final String simpleNameExpected = "";
		Assert.assertEquals(simpleNameExpected, klass.getSimpleName());
		final String nameExpected = "pakage.subpackage.evensubberpackage.WhatIsMyName$1";
		Assert.assertEquals(nameExpected, klass.getName());
		final String canonicalNameExpected = null;
		Assert.assertEquals(canonicalNameExpected, klass.getCanonicalName());
	}
	
	@Test
	public void intClassHasName() {
		final Class<?> klass = int.class;
		final String intNameExpected = "int";
		Assert.assertEquals(intNameExpected, klass.getSimpleName());
		Assert.assertEquals(intNameExpected, klass.getName());
		Assert.assertEquals(intNameExpected, klass.getCanonicalName());
	}
	
	@Test
	public void intArrayClassHasName() {
		final Class<?> klass = int[].class;
		final String simpleNameExpected = "int[]";
		Assert.assertEquals(simpleNameExpected, klass.getSimpleName());
		final String nameExpected = "[I";
		Assert.assertEquals(nameExpected, klass.getName());
		final String canonicalNameExpected = "int[]";
		Assert.assertEquals(canonicalNameExpected, klass.getCanonicalName());
	}
}