Help with try-catch blocks. I just can't seem them to work right. Help!

import java.text.DecimalFormat; import javafx.scene.layout.AnchorPane; import javafx.scene.layout.BorderPane; import javafx.scene.layout.HBox; import javafx.scene.layout.StackPane; import javafx.scene.text.Text; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.scene.Scene; import javafx.scene.text.*; import javafx.scene.control.Alert; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.TextArea; import javafx.scene.control.TextField; import javafx.scene.image.ImageView; import javafx.geometry.Insets; import javafx.geometry.Pos; import javafx.application.Application; import javafx.stage.Stage; import javafx.stage.WindowEvent; import javafx.application.Platform;

public class LoanComparison extends Application { public static void main(String[] args) { launch(args); } // Creating and naming private variables for text fields(user input). private TextField LoanAmount = new TextField(); private TextField NumberOfYears = new TextField(); private TextArea ResultsTable = new TextArea(); //Creating button that when pressed displays the results table. private Button ShowTable = new Button("Show Table");

@Override public void start(Stage primaryStage) { //Creating new Border Pane final BorderPane pane = new BorderPane(); //Creating HBox for user interface HBox Interface = new HBox(12); //Creating labels for text fields Label LoanAmt = new Label("Loan Amount: "); Label NumYears = new Label("Years: "); //Setting width of text fields LoanAmount.setPrefWidth(150); NumberOfYears.setPrefWidth(35); //Centering interface Interface.setAlignment(Pos.CENTER); //Adding TextFields, Labels and Button to Interface. Interface.getChildren().addAll(LoanAmt, LoanAmount, NumberOfYears, NumYears, ShowTable); //Adding Interface to the top of pane and ResultsTable to the center. pane.setTop(Interface); pane.setCenter(ResultsTable);

//Setting margins and padding for BorderPane.setMargin(ResultsTable, new Insets(5, 1, 1, 1)); pane.setPadding(new Insets(5, 5, 5, 5)); //Method that caculates and outputs the results when the user presses the "Show Table" button ShowTable.setOnAction(e -> Calculate()); //Setting the size the pane Scene scene = new Scene(pane,500, 500); //Naming the pane primaryStage.setTitle("Loan Comparison"); primaryStage.setScene(scene); primaryStage.show(); ResultsTable.setEditable(false); }

private void Calculate() {

//Declaring/Defining variables for calculations and try catch blocks. boolean ValidInput = true; Loan Lloan = new Loan (); //Try Catch block for catches vales less than 1000 or greater than 100000. try {

Lloan.setAnnualInterestRate(5); Lloan.setLoanAmount(Double.parseDouble(LoanAmount.getText())); if (Lloan.getLoanAmount() < 1000 || Lloan.getLoanAmount() > 100000) { throw new Exception();

} } catch(Exception e){ new Alert(Alert.AlertType.ERROR,("Invalid Input: Only loan amounts from 1000 to 100000 will be accepted.")).showAndWait(); ValidInput = false;

}

try{ Double LoanYears = 0.0; Lloan.setNumberOfYears(Integer.parseInt(NumberOfYears.getText())); if(LoanYears < 1 || LoanYears > 20) { throw new Exception();

} } catch(Exception f) { new Alert(Alert.AlertType.ERROR,("Invalid Input: The number of years must be from 1 to 20.")).showAndWait(); ValidInput = false;

} if (ValidInput = true) { //Adding column names to table. ResultsTable.setText("Interest Rate Monthly Payment " + "Total Payment "); //Do While loop for calculating/printing values until the interest rate reaches 8% do {

ResultsTable.appendText(new DecimalFormat("0.000%").format(Lloan.getAnnualInterestRate()/100.0) + " " + new DecimalFormat("$###,##0.00").format(Lloan.getMonthlyPayment()) + " " + new DecimalFormat("$###,##0.00").format(Lloan.getTotalPayment()) + " "); Lloan.setAnnualInterestRate(Lloan.getAnnualInterestRate() + 0.125);

} while (Lloan.getAnnualInterestRate() <= 8); }

} }

public class Loan { private double annualInterestRate; private int numberOfYears; private double loanAmount; private java.util.Date loanDate;

/** Default constructor */ public Loan() { this(2.5, 1, 1000); }

/** Construct a loan with specified annual interest rate, number of years, and loan amount */ public Loan(double annualInterestRate, int numberOfYears, double loanAmount) { this.annualInterestRate = annualInterestRate; this.numberOfYears = numberOfYears; this.loanAmount = loanAmount; loanDate = new java.util.Date(); }

/** Return annualInterestRate */ public double getAnnualInterestRate() { return annualInterestRate; }

/** Set a new annualInterestRate */ public void setAnnualInterestRate(double annualInterestRate) { this.annualInterestRate = annualInterestRate; }

/** Return numberOfYears */ public int getNumberOfYears() { return numberOfYears; }

/** Set a new numberOfYears */ public void setNumberOfYears(int numberOfYears) { this.numberOfYears = numberOfYears; }

/** Return loanAmount */ public double getLoanAmount() { return loanAmount; }

/** Set a newloanAmount */ public void setLoanAmount(double loanAmount) { this.loanAmount = loanAmount; }

/** Find monthly payment */ public double getMonthlyPayment() { double monthlyInterestRate = annualInterestRate / 1200; double monthlyPayment = loanAmount * monthlyInterestRate / (1 - (1 / Math.pow(1 + monthlyInterestRate, numberOfYears * 12))); return monthlyPayment; }

/** Find total payment */ public double getTotalPayment() { double totalPayment = getMonthlyPayment() * numberOfYears * 12; return totalPayment; }

/** Return loan date */ public java.util.Date getLoanDate() { return loanDate; } }