当使用两个以上选项时，Java在Switch-Case中给出NullPointerException

Question

当使用两个以上的选项时，Java给我NullPointerException（请注意情况1和3具有相同的方法），并且我想使用情况1或情况3，但情况3给了我该错误。当我输入案例1时，我没有得到任何错误，但是当我输入案例3时，我得到了这个错误：

Exception in thread "main" java.lang.NullPointerException
    at Files.FileSearch.searchDirectory(FileSearch.java:124)
    at Files.FileSearch.main(FileSearch.java:93)

这很奇怪，因为这甚至都不会发生，并且仅在使用案例3时显示错误。我的代码如下：

package Files;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JFrame;
import javax.swing.JOptionPane;

import Plan.Generator;
import Plan.PathDesingerHTML;

public class FileSearch {

    private String fileNameToSearch;
    private String path;
    private List<String> result = new ArrayList<String>();

    public String getFileNameToSearch() {
        return fileNameToSearch;
    }

    public void setFileNameToSearch(String fileNameToSearch) {
        this.fileNameToSearch = fileNameToSearch;
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public List<String> getResult() {
        return result;
    }

    private static File resultTemp = null;
    private static String fullPath = null;
    private static String partialPath = "C:\\Users\\etopete\\Desktop\\Designer Proyectos\\";
    private static String name = null;
    private static int option = 0;
    private static int count = 0;
    private static boolean flag = true;

    public static File getResultTemp() {
        return resultTemp;
    }

    public static String getFullPath() {
        return fullPath;
    }

    public static String getName() {
        return name;
    }

    public static int getCount() {
        return count;
    }

    public static void main(String[] args) throws IOException {

        FileSearch fileSearch= new FileSearch();
        FindJars find= new FindJars();
        PathDesingerHTML designerHTML = new PathDesingerHTML();
        Generator generate =  new Generator();


        final JFrame parent = new JFrame();

        name = JOptionPane.showInputDialog(parent, "Folder to search in?", null);
        option = new Integer(JOptionPane.showInputDialog(parent, "Option?", null));

        switch (option) {
        case 1:
            fileSearch.searchDirectory(new File(fullPath = partialPath + name + "\\build\\cobis\\dev\\projects"), ".jar");

            fileSearch.getDirectory();

            //find.Jars();
            break;
        case 2:
            fileSearch.searchDirectory(new File(fullPath = partialPath + name + "\\build\\cobis\\web\\views"), ".html");

            fileSearch.getDirectory();

            designerHTML.DesingerHTML();
            break;
        case 3:
            fileSearch.searchDirectory(new File(fullPath = partialPath + name + "\\build\\cobis\\dev\\projects"), ".jar");

            fileSearch.getDirectory();

            //find.Jars();
            break;
        }

        // try different directory and filename :)


    }

    public void getDirectory() {
        count = getResult().size();
        if (count == 0) {
            System.out.println("\nNo result found!");
        } else {
            System.out.println("\nFound " + count + " result!\n");
            for (String matched : getResult()) {
                System.out.println("Found : " + matched);
            }
        }
    }

    public void searchDirectory(File directory, String fileNameToSearch) {

        setFileNameToSearch(fileNameToSearch);

        if (directory.isDirectory()) {
            search(directory);
            System.out.println(resultTemp.toString());
            setPath(resultTemp.toString());
            System.out.println("Path is: " + getPath());
        } else {
            System.out.println(directory.getAbsoluteFile() + " is not a directory!");
        }
    }

    private File search(File file) {

        if (file.isDirectory()) {
            System.out.println("Searching directory ... " + file.getAbsoluteFile());

            // do you have permission to read this directory?
            if (file.canRead()) {

                for (File temp : file.listFiles()) {
                    if (temp.isDirectory()) {
                        search(temp);
                    } else {
                        /*
                         * if (getFileNameToSearch().equals(temp.getName().toLowerCase())) {
                         * 
                         * }
                         */
                        if(option == 1) {
                            if (temp.getAbsoluteFile().toString().endsWith(".jar")) {
                                result.add(temp.getAbsoluteFile().toString());
                                resultTemp = (File) temp.getAbsoluteFile();
                                if(flag == true) {
                                    flag = false;
                                    return new File(temp.getAbsoluteFile().toString());
                                }
                            }
                        }
                        else if(option == 2) {
                            if (temp.getAbsoluteFile().toString().endsWith(".html")) {
                                result.add(temp.getAbsoluteFile().toString());
                                resultTemp = (File) temp.getAbsoluteFile();
                                if(flag == true) {
                                    flag = false;
                                    return new File(temp.getAbsoluteFile().toString());
                                }
                            }
                        }

                    }
                }
            } else {
                System.out.println(file.getAbsoluteFile() + "Permission Denied");
            }
        }
        return null;
    }

}