The java.lang.SecurityManager class permits applications to actualize a security arrangement. It permits an application to decide, before playing out a potentially perilous or delicate operation, what the operation is and whether it is being endeavored in a security setting that permits the operation to be performed. The application can permit or refuse the operation. Following is the syntax for java.lang.SecurityManager class. [java] public class SecurityManager extends Object [/java]

Following are the methods of java.lang SecurityManager class.

Following are the constructors of java.lang SecurityManager.

Following is an example by using java.lang.SecurityManager.checkAccept(String host, int port) method. DemoSecurityManager.java [java] package com.SPlessons; public class DemoSecurityManager { public static void main(String[] args) { // set the policy file as the system security policy System.setProperty("java.security.policy", "file:/C:/java.policy"); // create a security manager SecurityManager sm = new SecurityManager(); // set the system security manager System.setSecurityManager(sm); // check if accepting socket connection is enabled sm.checkAccept("www.splessons.com", 8080); // print a message if we passed the check System.out.println("Allowed!"); } } [/java] Following is the syntax declaration of this method. [java]public void checkAccept(String host, int port)[/java] Output: When compile the code result will be as follows. [java] Exception in thread "main" java.security.AccessControlException: access denied (java.net.SocketPermission www.splessons.com:8080 accept,resolve) [/java] Where port is the port number of the socket connection. [java] package com.SPlessons; public class DemoSecurityManager extends SecurityManager { // check access needs to overriden @Override public void checkAccess(Thread t) { throw new SecurityException("Not allowed."); } public static void main(String[] args) { // set the policy file as the system securuty policy System.setProperty("java.security.policy", "file:/C:/java.policy"); // create a security manager DemoSecurityManager sm = new DemoSecurityManager(); // set the system security manager System.setSecurityManager(sm); // check if accepting access for thread is enabled sm.checkAccess(Thread.currentThread()); // print a message if we passed the check System.out.println("Allowed!"); } } [/java] Following is the syntax declaration of this method. [java]public void checkAccess(Thread t)[/java] Where t is the thread to be checked. Output: When compile the code result will be as follows. [java] Exception in thread "main" java.lang.SecurityException: Not allowed. at com.SPlessons.DemoSecurityManager.checkAccess(DemoSecurityManager.java:7) at com.SPlessons.DemoSecurityManager.main(DemoSecurityManager.java:22) [/java] [java] package com.SPlessons; public class DemoSecurityManager extends SecurityManager { public static void main(String[] args) { // set the policy file as the system securuty policy System.setProperty("java.security.policy", "file:/C:/java.policy"); // create a security manager SecurityManager sm = new SecurityManager(); // set the system security manager System.setSecurityManager(sm); // perform the check sm.checkConnect("www.splessons.com", 8080); // print a message if we passed the check System.out.println("Allowed!"); } } [/java] The java.lang.SecurityManager.checkConnect(String host, int port) method does not return any value, the following is the syntax declaration. [java]public void checkConnect(String host, int port)[/java] Output: When compile the code result will be as follows. [java] Exception in thread "main" java.security.AccessControlException: access denied ("java.net.SocketPermission" "www.splessons.com:8080" "connect,resolve") [/java] [java]package com.SPlessons; public class DemoSecurityManager extends SecurityManager { // checkExit needs to be overridden. @Override public void checkExit(int status) { throw new SecurityException("Not allowed."); } public static void main(String[] args) { // set the policy file as the system securuty policy System.setProperty("java.security.policy", "file:/C:/java.policy"); // create a security manager DemoSecurityManager sm = new DemoSecurityManager(); // set the system security manager System.setSecurityManager(sm); // perform the check sm.checkExit(5); // print a message if we passed the check System.out.println("Allowed!"); } } [/java] Following is the syntax declaration of the java.lang.SecurityManager.checkExit(int status) method. [java]public void checkExit(int status)[/java] Output: When compile the code result will be as follows. [java]Exception in thread "main" java.lang.SecurityException: Not allowed.[/java] [java] package com.SPlessons; public class DemoSecurityManager { public static void main(String[] args) { // set the policy file as the system securuty policy System.setProperty("java.security.policy", "file:/C:/java.policy"); // create a security manager SecurityManager sm = new SecurityManager(); // set the system security manager System.setSecurityManager(sm); // perform the check sm.checkLink("JDBC - ODBC"); // print a message if we passed the check System.out.println("Allowed!"); } } [/java] Following is the syntax declaration of java.lang.SecurityManager.checkLink() method. [java]public void checkLink(String lib)[/java] Where lib is nothing but name of the library. Output: When compile the code result will be as follows. [java] Exception in thread "main" java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "loadLibrary.JDBC - ODBC") [/java]

• The inCheck is the field of SecurityManager class.
• The classDepth(String) method is used To give back the stack profundity of the predetermined class.