1. JUnit test for method toString() in SalariedEmployee - import org.junit.Assert; import org.junit.Test; import org.junit.runner.RunWith; import org.mockito.runners.MockitoJUnitRunner; @RunWith(MockitoJUnitRunner.class) public class SalariedEmployeeTest { @Test public void testToString(){ String name=\"name\"; double salary=3000; double bonus=1000; SalariedEmployee employee= new SalariedEmployee(name,salary,bonus); employee.toString(); } } 2. JAva program to replace \"is\" with \"was\" - import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class StringReplace { public static void main(String[] args) throws IOException { BufferedReader br = null; File file = new File(\"/My Stuffs/Root/Workspace/TestJava/src/com/test/output.txt\"); FileWriter fw = new FileWriter(file.getAbsoluteFile()); BufferedWriter bw = new BufferedWriter(fw); if (!file.exists()) { file.createNewFile(); } try { String sCurrentLine; br = new BufferedReader(new FileReader(\"/My Stuffs/Root/Workspace/TestJava/src/com/test/testing.txt\")); while ((sCurrentLine = br.readLine()) != null) { System.out.println(sCurrentLine); String rep=sCurrentLine.replaceAll(\" is \",\" was \"); System.out.println(rep); bw.write(rep); } } catch (IOException e) { e.printStackTrace(); } finally { try { if (br != null)br.close(); if(bw!=null)bw.close(); } catch (IOException ex) { ex.printStackTrace(); } } } } Solution 1. JUnit test for method toString() in SalariedEmployee - import org.junit.Assert; import org.junit.Test; import org.junit.runner.RunWith; import org.mockito.runners.MockitoJUnitRunner; @RunWith(MockitoJUnitRunner.class) public class SalariedEmployeeTest { @Test public void testToString(){ String name=\"name\"; double salary=3000; double bonus=1000; SalariedEmployee employee= new SalariedEmployee(name,salary,bonus); employee.toString(); } } 2. JAva program to replace \"is\" with \"was\" - import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class StringReplace { public static void main(String[] args) throws IOException { BufferedReader br = null; File file = new File(\"/My Stuffs/Root/Workspace/TestJava/src/com/test/output.txt\"); FileWriter fw = new FileWriter(file.getAbsoluteFile()); BufferedWriter bw = new BufferedWriter(fw); if (!file.exists()) { file.createNewFile(); } try { String sCurrentLine; br = new BufferedReader(new FileReader(\"/My Stuffs/Root/Workspace/TestJava/src/com/test/testing.txt\")); while ((sCurrentLine = br.readLine()) != null) { System.out.println(sCurrentLine); String rep=sCurrentLine.replaceAll(\" is \",\" was \"); System.out.println(rep); bw.write(rep); } } catch (IOException e) { e.printStackTrace(); } finally { try { if (br != null)br.close(); if(bw!=null)bw.close(); } catch (IOException ex) { ex.printStackTrace(); } } } }.