💩 improved garbage code

Author: hellokaton

docs/README.md

@@ -181,8 +181,6 @@ excelPlus.export(data).writeAsResponse(ResponseWrapper.create(servletResponse, "
 
 ## 模板导出
 
-<b>该功能尚未实现</b>
-
 有时候我们需要导出的 Excel 表格样式比较复杂，可以事先设置好一个模板表格，数据为空，
 由程序向模板中填入数据，然后导出即可，这样就满足了美观的需求。
 

pom.xml

@@ -50,12 +50,6 @@
             <version>3.0.1</version>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>io.github.benas</groupId>
-            <artifactId>random-beans</artifactId>
-            <version>3.7.0</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>

src/main/java/io/github/biezhi/excel/plus/writer/ExcelWriter.java

@@ -8,7 +8,7 @@
 import org.apache.poi.ss.usermodel.*;
 import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 
-import java.io.File;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Iterator;
@@ -36,58 +36,45 @@ default <T> void export(Exporter<T> exporter, OutputStream outputStream) throws
             throw new ExcelException("Export excel data is empty.");
         }
         try {
+
+            Sheet     sheet;
             Workbook  workbook;
             CellStyle headerStyle;
-            CellStyle columnStyle;
-
-            if (null != exporter.getTemplatePath()) {
-                workbook = WorkbookFactory.create(new File(exporter.getTemplatePath()));
-            } else {
-                workbook = exporter.getExcelType().equals(ExcelType.XLSX) ? new XSSFWorkbook() : new HSSFWorkbook();
-            }
-
-            T     data0 = data.iterator().next();
-            Sheet sheet = workbook.createSheet(ExcelUtils.getSheetName(data0));
-
-            Row rowHead = sheet.createRow(0);
+            CellStyle columnStyle = null;
+            CellStyle rowStyle    = null;
 
+            T data0 = data.iterator().next();
             // Set Excel header
             Iterator<T>  iterator   = data.iterator();
             List<String> fieldNames = ExcelUtils.getWriteFieldNames(data0.getClass());
-            int          rows       = data.size();
             int          cols       = fieldNames.size();
+            int          startRow   = exporter.startRow();
 
-            if (null != exporter.getHeaderStyle()) {
-                headerStyle = exporter.getHeaderStyle().apply(workbook);
-            } else {
-                headerStyle = defaultHeaderStyle(workbook);
-            }
-
-            if (null != exporter.getColumnStyle()) {
-                columnStyle = exporter.getColumnStyle().apply(workbook);
+            if (null != exporter.getTemplatePath()) {
+                InputStream in = ExcelWriter.class.getClassLoader().getResourceAsStream(exporter.getTemplatePath());
+                workbook = WorkbookFactory.create(in);
+                sheet = workbook.getSheetAt(0);
             } else {
-                columnStyle = defaultColumnStyle(workbook);
-            }
+                workbook = exporter.getExcelType().equals(ExcelType.XLSX) ? new XSSFWorkbook() : new HSSFWorkbook();
+                sheet = workbook.createSheet(ExcelUtils.getSheetName(data0));
 
-            for (int col = 0; col < cols; col++) {
-                Cell cell = rowHead.createCell(col);
-                cell.setCellStyle(headerStyle);
-                cell.setCellValue(fieldNames.get(col));
-                sheet.autoSizeColumn(col);
-            }
+                if (null != exporter.getHeaderStyle()) {
+                    headerStyle = exporter.getHeaderStyle().apply(workbook);
+                } else {
+                    headerStyle = defaultHeaderStyle(workbook);
+                }
 
-            for (int rowNum = 1; iterator.hasNext() && rowNum <= rows; rowNum++) {
-                T   item = iterator.next();
-                Row row  = sheet.createRow(rowNum);
-                for (int col = 0; col < cols; col++) {
-                    Cell   cell  = row.createCell(col);
-                    String value = ExcelUtils.getColumnValue(item, col);
-                    cell.setCellStyle(columnStyle);
-                    cell.setCellValue(value);
-                    sheet.autoSizeColumn(col);
+                if (null != exporter.getColumnStyle()) {
+                    columnStyle = exporter.getColumnStyle().apply(workbook);
+                } else {
+                    columnStyle = defaultColumnStyle(workbook);
                 }
+
+                this.writeRowHead(headerStyle, sheet, fieldNames, cols);
             }
 
+            this.writeRows(sheet, columnStyle, rowStyle, iterator, cols, startRow);
+
             workbook.write(outputStream);
             outputStream.flush();
             outputStream.close();
@@ -96,6 +83,37 @@ default <T> void export(Exporter<T> exporter, OutputStream outputStream) throws
         }
     }
 
+    default void writeRowHead(CellStyle headerStyle, Sheet sheet, List<String> fieldNames, int cols) {
+        Row rowHead = sheet.createRow(0);
+        for (int col = 0; col < cols; col++) {
+            Cell cell = rowHead.createCell(col);
+            if (null != headerStyle) {
+                cell.setCellStyle(headerStyle);
+            }
+            cell.setCellValue(fieldNames.get(col));
+            sheet.autoSizeColumn(col);
+        }
+    }
+
+    default <T> void writeRows(Sheet sheet, CellStyle columnStyle, CellStyle rowStyle, Iterator<T> iterator, int cols, int startRow) {
+        for (int rowNum = startRow; iterator.hasNext(); rowNum++) {
+            T   item = iterator.next();
+            Row row  = sheet.createRow(rowNum);
+            if (null != rowStyle) {
+                row.setRowStyle(rowStyle);
+            }
+            for (int col = 0; col < cols; col++) {
+                Cell   cell  = row.createCell(col);
+                String value = ExcelUtils.getColumnValue(item, col);
+                if (null != columnStyle) {
+                    cell.setCellStyle(columnStyle);
+                }
+                cell.setCellValue(value);
+                sheet.autoSizeColumn(col);
+            }
+        }
+    }
+
     /**
      * The default Excel header style.
      *

src/main/java/io/github/biezhi/excel/plus/writer/Exporter.java

@@ -18,6 +18,7 @@ public class Exporter<T> {
     private String        templatePath;
     private ExcelType     excelType;
     private Collection<T> data;
+    private int startRow = 1;
 
     private Function<Workbook, CellStyle> headerStyle;
     private Function<Workbook, CellStyle> columnStyle;
@@ -43,6 +44,15 @@ public Exporter<T> byTemplate(String templatePath) {
         return this;
     }
 
+    public Exporter<T> startRow(int startRow) {
+        this.startRow = startRow;
+        return this;
+    }
+
+    public int startRow(){
+        return this.startRow;
+    }
+
     public Function<Workbook, CellStyle> getHeaderStyle() {
         return headerStyle;
     }

src/test/java/io/github/biezhi/excel/plus/BeanData.java

@@ -97,7 +97,9 @@ public void testExportStyle() throws ExcelException {
     @Test
     public void testExportByTpl() throws ExcelException {
         List<CardSecret> cardSecrets = this.buildCardSecrets();
-        excelPlus.export(Exporter.create(cardSecrets).byTemplate("")).writeAsFile(new File("template_rows.xls"));
+        excelPlus.export(
+                Exporter.create(cardSecrets).byTemplate("tpl.xls").startRow(2)
+        ).writeAsFile(new File("template_rows.xls"));
     }
 
     @Test

src/test/java/io/github/biezhi/excel/plus/Examples.java

@@ -15,7 +15,7 @@
  */
 public class CardSecret implements Serializable {
 
-    @ExcelField(order = 0, columnName = "卡密类型", convertType = CardTypeConverter.class)
+    @ExcelField(order = 0, columnName = "运营商", convertType = CardTypeConverter.class)
     private Integer cardType;
 
     @ExcelField(order = 1, columnName = "卡密")