Introduction to Java Programming, Comprehensive Version 10th Edition, Liang, Chapter 37 Question 5: Write an HTML form to prompt the user to enter taxable income and filing status, as shown in Figure 37.30a. Clicking the Compute Tax button invokes a servlet to compute and display the tax, as shown in Figure 37.30b. Use the computeTax method introduced in Listing 3.7, ComputingTax.java, to compute tax.

ComputeTax.java:

package computeTax;

public class ComputeTax {

int status; double income;

public int getStatus() { return status; }

public void setStatus(int status) { this.status = status; }

public double getIncome() { return income; }

public void setIncome(double income) { this.income = income; } public double getTax() { return computetax(status, income); }

private double computetax(int status, double income) { double tax = 0;

if (status == 0) { // Compute tax for single filers if (income <= 8350) { tax = income * 0.10; } else if (income <= 33950) { tax = 8350 * 0.10 + (income - 8350) * 0.15; } else if (income <= 82250) { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (income - 33950) * 0.25; } else if (income <= 171550) { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (82250 - 33950) * 0.25 + (income - 82250) * 0.28; } else if (income <= 372950) { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (82250 - 33950) * 0.25 + (171550 - 82250) * 0.28 + (income - 171550) * 0.33; } else { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (82250 - 33950) * 0.25 + (171550 - 82250) * 0.28 + (372950 - 171550) * 0.33 + (income - 372950) * 0.35; } } else if (status == 1) { // Compute tax for married file jointly if (income <= 16700) { tax = income * 0.10; } else if (income <= 67900) { tax = 16700 * 0.10 + (income - 16700) * 0.15; } else if (income <= 137050) { tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (income - 67900) * 0.25; } else if (income <= 208850) { tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (82250 - 67900) * 0.25 + (income - 137050) * 0.28; } else if (income <= 372950) { tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (82250 - 67900) * 0.25 + (208850 - 137050) * 0.28 + (income - 208850) * 0.33; } else { tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (82250 - 67900) * 0.25 + (208850 - 137050) * 0.28 + (372950 - 208850) * 0.33 + (income - 372950) * 0.35; } } else if (status == 2) { // Compute tax for married separately if (income <= 8350) { tax = income * 0.10; } else if (income <= 33950) { tax = 8350 * 0.10 + (income - 8350) * 0.15; } else if (income <= 68525) { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (income - 33950) * 0.25; } else if (income <= 104425) { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (68525 - 33950) * 0.25 + (income - 68525) * 0.28; } else if (income <= 186475) { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (68525 - 33950) * 0.25 + (104425 - 68525) * 0.28 + (income - 104425) * 0.33; } else { tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (68525 - 33950) * 0.25 + (104425 - 68525) * 0.28 + (186475 - 104425) * 0.33 + (income - 186475) * 0.35; } } else if (status == 3) { // Compute tax for head of household if (income <= 11950) { tax = income * 0.10; } else if (income <= 45500) { tax = 11950 * 0.10 + (income - 11950) * 0.15; } else if (income <= 117450) { tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (income - 45500) * 0.25; } else if (income <= 190200) { tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (117450 - 45500) * 0.25 + (income - 117450) * 0.28; } else if (income <= 372950) { tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (117450 - 45500) * 0.25 + (190200 - 117450) * 0.28 + (income - 190200) * 0.33; } else { tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (117450 - 45500) * 0.25 + (190200 - 117450) * 0.28 + (372950 - 190200) * 0.33 + (income - 372950) * 0.35; } } else { throw new IllegalArgumentException("Invalid status"); } return tax; } }