#009 Tour of java.lang.* and java.util.* classes

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects.
•  Click Next.

• Under Name and Location pane, for the Project Name field, type in BooleanWrapper as project name.
• For Create Main Class field, type in BooleanWrapper.
• Click Finish.

• Observe that BooleanWrapper project appears and IDE generated BooleanWrapper.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated BooleanWrapper.java as shown in Code-1.121 below.

class BooleanWrapper { public static void main(String args[]) { boolean booleanVar = 1>2; Boolean booleanObj = new Boolean(“TRue”); /* primitive to object; can also use valueOf method */ Boolean booleanObj2 = new Boolean(booleanVar); System.out.println(“booleanVar = ” + booleanVar); System.out.println(“booleanObj = ” + booleanObj); System.out.println(“booleanObj2 = ” + booleanObj2); System.out.println(“compare 2 wrapper objects: ” + booleanObj.equals(booleanObj2)); /* object to primitive */ booleanVar = booleanObj.booleanValue(); System.out.println(“booleanVar = ” + booleanVar); } }

Code-1.11: BooleanWrapper.java

3. Build and run the project

• Right click BooleanWrapper project and select Run.
• Observe the result in the Output window. (Figure-1.12 below)

booleanVar = false booleanObj = true booleanObj2 = false compare 2 wrapper objects: false booleanVar = true

Figure-1.12: Result of running BooleanWrapper application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/BooleanWrapper.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects. Click Next.
• Under Name and Location pane, for the Project Name field, type in DataTypePrintTest as project name.
• For Create Main Class field, type in DataTypePrintTest.
• Click Finish.

• Observe that DataTypePrintTest project appears and IDE generated DataTypePrintTest.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated DataTypePrintTest.java as shown in Code-1.21 below.

public class DataTypePrintTest { public static void main(String[] args) { Thread objectData = new Thread(); String stringData = “Java Mania”; char[] charArrayData = { ‘a’, ‘b’, ‘c’ }; int integerData = 4; long longData = Long.MIN_VALUE; float floatData = Float.MAX_VALUE; double doubleData = Math.PI; boolean booleanData = true; System.out.println(objectData); System.out.println(stringData); System.out.println(charArrayData); System.out.println(integerData); System.out.println(longData); System.out.println(floatData); System.out.println(doubleData); System.out.println(booleanData); } }

Code-1.21: DataTypePrintTest.java

3. Build and run the project

• Right click DataTypePrintTest project and select Run.
• Observe the result in the Output window. (Figure-1.22 below)

Thread[Thread-0,5,main] Java Mania abc 4 -9223372036854775808 3.4028235E38 3.141592653589793 true

Figure-1.22: Result of running DataTypePrintTest application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/DataTypePrintTest.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects. Click Next.
• Under Name and Location pane, for the Project Name field, type in DateTest as project name.
• For Create Main Class field, type in DateTest.
• Click Finish.

• Observe that DateTest project appears and IDE generated DateTest.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated DateTest.java as shown in Code-1.31 below.  Study the code by paying special attention to the bold fonted parts.

import java.util.Date; public class DateTest { public static void main(String[] args) { // Return the number of milliseconds in the Date // as a long, using the getTime() method Date d1 = new Date(); // timed code goes here for (int i=0; i<10000000; i++) { int j = i;} Date d2 = new Date(); long elapsed_time = d2.getTime() – d1.getTime(); System.out.println(“That took ” + elapsed_time + ” milliseconds”); } }

Code-1.31: DateTest.java

3. Build and run the project

• Right click DateTest project and select Run.
• Observe the result in the Output window. (Figure-1.32 below)

That took 15 milliseconds

Figure-1.32: Result of running DateTest application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/DateTest.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects.
• Click Next.

• Under Name and Location pane, for the Project Name field, type in MathDemo as project name.
• For Create Main Class field, type in MathDemo.
• Click Finish.

• Observe that MathDemo project appears and IDE generated MathDemo.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated MathDemo.java as shown in Code-1.41 below.

class MathDemo { public static void main(String args[]) { System.out.println(“absolute value of -5: ” +  Math.abs(-5)); System.out.println(“absolute value of 5: ” +  Math.abs(5)); System.out.println(“random number(max is 10): ” + Math.random()*10); System.out.println(“max of 3.5 and 1.2: ” + Math.max(3.5,1.2)); System.out.println(“min of 3.5 and 1.2: ” + Math.min(3.5,1.2)); System.out.println(“ceiling of 3.5: ” + Math.ceil(3.5)); System.out.println(“floor of 3.5: ” + Math.floor(3.5)); System.out.println(“e raised to 1: ” + Math.exp(1)); System.out.println(“log 10: ” + Math.log(10)); System.out.println(“10 raised to 3: ” + Math.pow(10,3)); System.out.println(“rounded off value of pi: ” + Math.round(Math.PI)); System.out.println(“square root of 5 = ” + Math.sqrt(5)); System.out.println(“10 radian = ” + Math.toDegrees(10) + ” degrees”); System.out.println(“sin(90): ” + Math.sin(Math.toRadians(90))); } }

Code-1.41: MathDemo.java

3. Build and run the project

• Right click MathDemo project and select Run.
• Observe the result in the Output window. (Figure-1.42 below)

absolute value of -5: 5 absolute value of 5: 5 random number(max is 10): 5.992489039705273 max of 3.5 and 1.2: 3.5 min of 3.5 and 1.2: 1.2 ceiling of 3.5: 4.0 floor of 3.5: 3.0 e raised to 1: 2.7182818284590455 log 10: 2.302585092994046 10 raised to 3: 1000.0 rounded off value of pi: 3 square root of 5 = 2.23606797749979 10 radian = 572.9577951308232 degrees sin(90): 1.0

Figure-1.42: Result of running MathDemo application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/MathDemo.  You can just open it and run it.

In this exercise, you are going to learn how to get and set system properties.

1. Display user name property
2. Display all system properties
3. Set system property

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects.
• Click Next.

• Under Name and Location pane, for the Project Name field, type in UserNameTest as project name.
• For Create Main Class field, type in UserNameTest.
• Click Finish.

Figure-2.21: New Java Application dialog box

• Observe that UserNameTest project appears and IDE generated UserNameTest.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated UserNameTest.java as shown in Code-2.22 below.  Study the code by paying special attention to the bold fonted parts.

public class UserNameTest { public static void main(String[] args) { String name = System.getProperty(“user.name”); System.out.println(“user.name property = ” + name); } }

Code-2.22: UserNameTest.java

3. Build and run the project

• Right click UserNameTest project and select Run.
• Observe the result in the Output window. (Figure-2.23 below)

user.name property = sang

Figure-2.23: Result of running UserNameTest application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/UserNameTest.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects.
• Click Next.

• Under Name and Location pane, for the Project Name field, type in DisplaySystemProps as project name.
• For Create Main Class field, type in DisplaySystemProps.
• Click Finish.

• Observe that DisplaySystemProps project appears and IDE generated DisplaySystemProps.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated DisplaySystemProps.java as shown in Code-2.21 below.  Study the code by paying special attention to the bold fonted parts.

import java.util.Properties; public class DisplaySystemProps { public static void main(String[] args) { // Get all system properties and display them. Properties p1 = System.getProperties(); p1.list(System.out); } }

Code-2.21: DisplaySystemProps.java

3. Build and run the project

• Right click DisplaySystemProps project and select Run.
• Observe the result in the Output window. (Figure-2.22 below)

— listing properties — java.runtime.name=Java(TM) 2 Runtime Environment, Stand… sun.boot.library.path=C:\Program Files\Java\jdk1.5.0_06\jre… java.vm.version=1.5.0_06-b05 java.vm.vendor=Sun Microsystems Inc. java.vendor.url=http://java.sun.com/ path.separator=; java.vm.name=Java HotSpot(TM) Client VM file.encoding.pkg=sun.io user.country=US sun.os.patch.level=Service Pack 2 java.vm.specification.name=Java Virtual Machine Specification user.dir=C:\handson2\development\javalang\samp… java.runtime.version=1.5.0_06-b05 java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment java.endorsed.dirs=C:\Program Files\Java\jdk1.5.0_06\jre… os.arch=x86 java.io.tmpdir=C:\DOCUME~1\sang\LOCALS~1\Temp\ line.separator= java.vm.specification.vendor=Sun Microsystems Inc. user.variant= os.name=Windows XP sun.jnu.encoding=Cp1252 java.library.path=C:\Program Files\Java\jdk1.5.0_06\jre… java.specification.name=Java Platform API Specification java.class.version=49.0 sun.management.compiler=HotSpot Client Compiler os.version=5.1 user.home=C:\Documents and Settings\sang user.timezone= java.awt.printerjob=sun.awt.windows.WPrinterJob file.encoding=Cp1252 java.specification.version=1.5 user.name=sang java.class.path=C:\handson2\development\javalang\samp… java.vm.specification.version=1.0 sun.arch.data.model=32 java.home=C:\Program Files\Java\jdk1.5.0_06\jre java.specification.vendor=Sun Microsystems Inc. user.language=en awt.toolkit=sun.awt.windows.WToolkit java.vm.info=mixed mode, sharing java.version=1.5.0_06 java.ext.dirs=C:\Program Files\Java\jdk1.5.0_06\jre… sun.boot.class.path=C:\Program Files\Java\jdk1.5.0_06\jre… java.vendor=Sun Microsystems Inc. file.separator=\ java.vendor.url.bug=http://java.sun.com/cgi-bin/bugreport… sun.cpu.endian=little sun.io.unicode.encoding=UnicodeLittle sun.desktop=windows sun.cpu.isalist=

Figure-2.22: Result of running DisplaySystemProps application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/DisplaySystemProps.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects.
• Click Next.

• Under Name and Location pane, for the Project Name field, type in SetSystemProperties as project name.
• For Create Main Class field, type in SetSystemProperties.
• Click Finish.

Figure-2.31: New Java Application

• Observe that SetSystemProperties project appears and IDE generated SetSystemProperties.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated SetSystemProperties.java as shown in Code-2.32 below.  Study the code by paying special attention to the bold fonted parts.

import java.io.FileInputStream; import java.util.Properties; public class SetSystemProperties { public static void main(String[] args) throws Exception { // set up new properties object // from file “myProperties.txt” FileInputStream propFile = new FileInputStream( “myProperties.txt”); Properties p = new Properties(System.getProperties()); p.load(propFile); // set a property through setProperty() method p.setProperty(“myKey1”, “myValue1”); // set the system properties System.setProperties(p); // display new properties System.getProperties().list(System.out); } }

Code-2.32: SetSystemProperties.java

You will experience compile error as shown below.  This is expected.

Figure-2.33: SetSystemProperties

3. Provide myProperties.txt as an input file.

• Right click  SetSystemProperties project and select New->Other.

Figure-2.34: New->Other

• Observe the New File dialog box appears.
• Choose Other under Categories and Empty File under File Types.  (Figure-2.35 below)

Figure-2.35: Create Empty File

• Observe that the New Empty File dialog box appears.
• For the File Name field, type in myProperties.txt.
• Observe that the empty myProperties.txt appears in the editor window.
• Cut and paste the contents from the input file (File-2.36) below to the empty file.

subliminal.message=Buy Java Now! myown.property=Life is worth living with Passion!

File-2.36: myProperties.txt

4. Build and run the project

• Right click SetSystemProperties project and select Run.
• Observe the result in the Output window. (Figure-2.37 below)

— listing properties — java.runtime.name=Java(TM) 2 Runtime Environment, Stand… sun.boot.library.path=C:\Program Files\Java\jdk1.5.0_06\jre… java.vm.version=1.5.0_06-b05 java.vm.vendor=Sun Microsystems Inc. java.vendor.url=http://java.sun.com/ path.separator=; java.vm.name=Java HotSpot(TM) Client VM file.encoding.pkg=sun.io user.country=US sun.os.patch.level=Service Pack 2 java.vm.specification.name=Java Virtual Machine Specification user.dir=C:\handson2\development\javalang\samp… java.runtime.version=1.5.0_06-b05 java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment java.endorsed.dirs=C:\Program Files\Java\jdk1.5.0_06\jre… os.arch=x86 java.io.tmpdir=C:\DOCUME~1\sang\LOCALS~1\Temp\ line.separator= java.vm.specification.vendor=Sun Microsystems Inc. user.variant= os.name=Windows XP myown.property=Life is worth living with Passion! sun.jnu.encoding=Cp1252 subliminal.message=Buy Java Now! java.library.path=C:\Program Files\Java\jdk1.5.0_06\jre… java.specification.name=Java Platform API Specification java.class.version=49.0 sun.management.compiler=HotSpot Client Compiler os.version=5.1 user.home=C:\Documents and Settings\sang user.timezone= java.awt.printerjob=sun.awt.windows.WPrinterJob file.encoding=Cp1252 java.specification.version=1.5 user.name=sang java.class.path=C:\handson2\development\javalang\samp… java.vm.specification.version=1.0 sun.arch.data.model=32 java.home=C:\Program Files\Java\jdk1.5.0_06\jre java.specification.vendor=Sun Microsystems Inc. user.language=en awt.toolkit=sun.awt.windows.WToolkit java.vm.info=mixed mode, sharing java.version=1.5.0_06 java.ext.dirs=C:\Program Files\Java\jdk1.5.0_06\jre… sun.boot.class.path=C:\Program Files\Java\jdk1.5.0_06\jre… java.vendor=Sun Microsystems Inc. file.separator=\ java.vendor.url.bug=http://java.sun.com/cgi-bin/bugreport… sun.cpu.endian=little sun.io.unicode.encoding=UnicodeLittle sun.desktop=windows sun.cpu.isalist=

Figure-2.37: Result of running SetSystemProperties application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/SetSystemProperties.  You can just open it and run it.

In this exercise, you are going to run various methods of the System class.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects. Click Next.
• Under Name and Location pane, for the Project Name field, type in SystemClass as project name.
• For Create Main Class field, type in SystemClass.
• Click Finish.

• Observe that SystemClass project appears and IDE generated SystemClass.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated SystemClass.java as shown in Code-3.11 below.  Study the code by paying special attention to the bold fonted parts.

import java.io.*; class SystemClass { public static void main(String args[]) throws IOException { int arr1[] = new int[1050000]; int arr2[] = new int[1050000]; long startTime, endTime; /* initialize arr1 */ for (int i = 0; i < arr1.length; i++) { arr1[i] = i + 1; } /* copying manually */ startTime = System.currentTimeMillis(); for (int i = 0; i < arr1.length; i++) { arr2[i] = arr1[i]; } endTime = System.currentTimeMillis(); System.out.println(“Time for manual copy: ” + (endTime-startTime) + ” ms.”); /* using the copy utility provided by java */ startTime = System.currentTimeMillis(); System.arraycopy(arr1, 0, arr2, 0, arr1.length); endTime = System.currentTimeMillis(); System.out.println(“Time for copy utility provided: ” + (endTime-startTime) + ” ms.”); System.gc();    //request garbage collector to work System.exit(0); } }

Code-3.11: SystemClass.java

3. Build and run the project

• Right click SystemClass project and select Run.
• Observe the result in the Output window. (Figure-3.12 below)

Time for manual copy: 44 ms. Time for copy utility provided: 5 ms.

Figure-3.12: Result of running SystemClass application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/SystemClass.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects. Click Next.
• Under Name and Location pane, for the Project Name field, type in SystemClass2 as project name.
• For Create Main Class field, type in SystemClass2.
• Click Finish.

• Observe that SystemClass2 project appears and IDE generated SystemClass2.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated SystemClass2.java as shown in Code-3.21 below.  Study the code by paying special attention to the bold fonted parts.

import java.util.Map; class SystemClass2 { public static void main(String args[]){ Map m1 = System.getenv(); System.out.println(“System environment variables = ” + m1); } }

Code-3.21: SystemClass2.java

3. Build and run the project

• Right click SystemClass2 project and select Run.
• Observe the result in the Output window. (Figure-3.22 below)

System environment variables = {PROCESSOR_ARCHITECTURE=x86, LOGONSERVER=\\PASSION2, HOMEDRIVE=C:, HOMEPATH=\Documents and Settings\sang, SESSIONNAME=Console, TMP=C:\DOCUME~1\sang\LOCALS~1\Temp, windir=C:\WINDOWS, PROCESSOR_IDENTIFIER=x86 Family 15 Model 72 Stepping 2, AuthenticAMD, SystemDrive=C:, USERPROFILE=C:\Documents and Settings\sang, PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH, CommonProgramFiles=C:\Program Files\Common Files, =::=::\, NUMBER_OF_PROCESSORS=2, ComSpec=C:\WINDOWS\system32\cmd.exe, COMPUTERNAME=PASSION2, OS=Windows_NT, USERNAME=sang, TEMP=C:\DOCUME~1\sang\LOCALS~1\Temp, USERDOMAIN=PASSION2, ALLUSERSPROFILE=C:\Documents and Settings\All Users, PROCESSOR_LEVEL=15, SystemRoot=C:\WINDOWS, APPDATA=C:\Documents and Settings\sang\Application Data, Path=d:\bin;c:\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files\ATI Technologies\ATI.ACE\;”C:\Program Files\Java\jdk1.5.0_06″\bin;c:\cygwin\bin;C:\Sun\AppServer9\bin;;C:\PROGRA~1\COMMON~1\MUVEET~1\030625, JAVA_HOME=”C:\Program Files\Java\jdk1.5.0_06″, FP_NO_HOST_CHECK=NO, PROCESSOR_REVISION=4802, ProgramFiles=C:\Program Files}

Figure-3.22: Result of running SystemClass2 application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/SystemClass2.  You can just open it and run it.

In this exercise, you have learned how to invoke methods of System class.

In this exercise, you are going to run OS specific programs using Runtime class.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects. Click Next.
• Under Name and Location pane, for the Project Name field, type in RunOSProgram as project name.
• For Create Main Class field, type in RunOSProgram.
• Click Finish.

• Observe that RunOSProgram project appears and IDE generated RunOSProgram.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated RunOSProgram.java as shown in Code-4.11 below.  Study the code by paying special attention to the bold fonted parts.

class RunOSProgram { public static void main(String args[]) { Runtime rt = Runtime.getRuntime(); Process proc; try { if (System.getProperty(“os.name”).startsWith(“Windows”)){ // Run a OS specific program proc = rt.exec(“notepad”); } else{ proc = rt.exec(“gedit”); } proc.waitFor();    //try removing this line } catch (Exception e) { System.out.println(“notepad is an unknown command.”); } } }

Code-4.11: RunOSProgram.java

3. Build and run the project

• Right click RunOSProgram project and select Run.
• Observe that a OS specific program gets run.  (Figure-4.12 below)

Figure-4.12: Notepad program under Windows platform gets executed

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/RunOSProgram.  You can just open it and run it.

1. Create a new NetBeans project

• Select File->New Project (Ctrl+Shift+N). The New Project dialog box appears.
• Under Choose Project pane, select General under Categories and Java Application under Projects. Click Next.
• Under Name and Location pane, for the Project Name field, type in RuntimeClass as project name.
• For Create Main Class field, type in RuntimeClass.
• Click Finish.

• Observe that RuntimeClass project appears and IDE generated RuntimeClass.java is displayed in the source editor window of NetBeans IDE.

2. Modify the IDE generated RuntimeClass.java as shown in Code-4.21 below.  Study the code by paying special attention to the bold fonted parts.

class RuntimeClass { public static void main(String args[]) { Runtime rt = Runtime.getRuntime(); long maxMemory = rt.maxMemory(); long totalMemory = rt.totalMemory(); System.out.println(“Maximum amount of memory that the Java virtual machine will attempt to use = ” + maxMemory + ” bytes”); System.out.println(“Total amount of memory currently available for current and future objects, measured in bytes = ” + totalMemory + ” bytes”); } }

Code-4.21: RuntimeClass.java

3. Build and run the project

• Right click RuntimeClass project and select Run.
• Observe the result in the Output window. (Figure-4.22 below)

Maximum amount of memory that the Java virtual machine will attempt to use = 66650112 bytes Total amount of memory currently available for current and future objects, measured in bytes = 2031616 bytes

Figure-4.22: Result of running RuntimeClass application

Solution: This exercise up to this point is provided as a ready-to-open-and-run NetBeans project as part of hands-on lab zip file. You can find it as <LAB_UNZIPPED_DIRECTORY>/javalang/samples/RuntimeClass.  You can just open it and run it.

In this exercise, you have learned how to use memory related methods of the Runtime class.