update: update singleton instance

src/main/java/config/EnvironmentVariable.java

@@ -9,18 +9,20 @@
 import java.util.Map;
 
 public class EnvironmentVariable {
+    private static EnvironmentVariable uniqueInstance;
     InputStream inputStream;
-    static EnvironmentVariable env;
     public Map<String, Object> data;
 
-    public EnvironmentVariable() throws FileNotFoundException {
+    private EnvironmentVariable() throws FileNotFoundException {
         this.inputStream = new FileInputStream("config.yml");
         Yaml yaml = new Yaml();
         this.data = yaml.load(inputStream);
     }
 
     public static EnvironmentVariable getInstance() throws FileNotFoundException {
-        env = new EnvironmentVariable();
-        return env;
+        if (uniqueInstance == null) {
+            uniqueInstance = new EnvironmentVariable();
+        }
+        return uniqueInstance;
     }
 }

src/main/java/module/DataProcessor.java

@@ -1,15 +1,21 @@
 package module;
 
 import config.EnvironmentVariable;
+
 import java.io.FileNotFoundException;
 import java.util.ArrayList;
 
 public class DataProcessor {
+    private static DataProcessor uniqueInstance;
 
     private DataProcessor() {
     }
 
     public static DataProcessor getInstance() {
+        if (uniqueInstance == null) {
+            uniqueInstance = new DataProcessor();
+        }
+
         return new DataProcessor();
     }
 

src/main/java/module/ExcelManipulate.java

@@ -19,15 +19,19 @@
 import org.apache.poi.ss.util.CellRangeAddress;
 
 public class ExcelManipulate {
-
+    private static ExcelManipulate excelManipulate;
     static Workbook wb = new HSSFWorkbook();
 
     private ExcelManipulate() {
 
     }
 
     public static ExcelManipulate getInstance() {
-        return new ExcelManipulate();
+        if (excelManipulate == null) {
+            excelManipulate = new ExcelManipulate();
+        }
+
+        return excelManipulate;
     }
 
     public void saveDataInExcel(List<String> list, String path) throws IOException {
@@ -51,7 +55,7 @@ private Sheet createFirstSheet(List<String> list) throws FileNotFoundException {
         Cell title_cell = title_row.createCell(0);
 
         // Set up the header
-        String headers[] = new String[] {"報帳條碼", "經費或計畫名稱", "計畫代碼", "經費別", "金額", "報帳日", "傳票號碼",
+        String headers[] = new String[]{"報帳條碼", "經費或計畫名稱", "計畫代碼", "經費別", "金額", "報帳日", "傳票號碼",
                 "付款資料", "報帳ID", "列印次數", "受款人", "備註", "稅前金額"};
 
         Row header_row = first.createRow(1);
@@ -99,7 +103,7 @@ private Sheet createSecondSheet(List<String> list) {
         title_row.setHeight((short) (40 * 20));
         Cell title_cell = title_row.createCell(0);
 
-        String headers[] = new String[] {"報帳條碼", "經費或計畫名稱", "計畫代碼", "經費別", "金額", "報帳日", "傳票號碼",
+        String headers[] = new String[]{"報帳條碼", "經費或計畫名稱", "計畫代碼", "經費別", "金額", "報帳日", "傳票號碼",
                 "付款資料", "報帳ID", "列印次數", "受款人", "備註"};
         Row header_row = second.createRow(1);
         header_row.setHeight((short) (20 * 24));
@@ -135,7 +139,7 @@ private Sheet createThirdSheet(Sheet first, Sheet second) {
         title_row.setHeight((short) (40 * 20));
         Cell title_cell = title_row.createCell(0);
 
-        String headers[] = new String[] {"報帳條碼", "經費或計畫名稱", "計畫代碼", "經費別", "金額", "報帳日", "傳票號碼",
+        String headers[] = new String[]{"報帳條碼", "經費或計畫名稱", "計畫代碼", "經費別", "金額", "報帳日", "傳票號碼",
                 "付款資料", "報帳ID", "列印次數", "受款人", "備註"};
         Row header_row = third.createRow(1);
         header_row.setHeight((short) (20 * 24));