新增jdk8的版本

src/main/java/com/alibaba/excel/ExcelWriter.java

 package com.alibaba.excel;
 
 import java.util.Collection;
+import java.util.function.Supplier;
 
 import com.alibaba.excel.context.WriteContext;
 import com.alibaba.excel.write.ExcelBuilder;
@@ -41,25 +42,31 @@ public class ExcelWriter {
     /**
      * Write data to a sheet
      *
-     * @param data
-     *            Data to be written
-     * @param writeSheet
-     *            Write to this sheet
+     * @param data       Data to be written
+     * @param writeSheet Write to this sheet
      * @return this current writer
      */
     public ExcelWriter write(Collection<?> data, WriteSheet writeSheet) {
         return write(data, writeSheet, null);
     }
 
+    /**
+     * Write data to a sheet
+     *
+     * @param supplier   Data to be written
+     * @param writeSheet Write to this sheet
+     * @return this current writer
+     */
+    public ExcelWriter write(Supplier<Collection<?>> supplier, WriteSheet writeSheet) {
+        return write(supplier.get(), writeSheet, null);
+    }
+
     /**
      * Write value to a sheet
      *
-     * @param data
-     *            Data to be written
-     * @param writeSheet
-     *            Write to this sheet
-     * @param writeTable
-     *            Write to this table
+     * @param data       Data to be written
+     * @param writeSheet Write to this sheet
+     * @param writeTable Write to this table
      * @return this
      */
     public ExcelWriter write(Collection<?> data, WriteSheet writeSheet, WriteTable writeTable) {
@@ -67,6 +74,19 @@ public class ExcelWriter {
         return this;
     }
 
+    /**
+     * Write value to a sheet
+     *
+     * @param supplier   Data to be written
+     * @param writeSheet Write to this sheet
+     * @param writeTable Write to this table
+     * @return this
+     */
+    public ExcelWriter write(Supplier<Collection<?>> supplier, WriteSheet writeSheet, WriteTable writeTable) {
+        excelBuilder.addContent(supplier.get(), writeSheet, writeTable);
+        return this;
+    }
+
     /**
      * Fill value to a sheet
      *
@@ -91,6 +111,30 @@ public class ExcelWriter {
         return this;
     }
 
+    /**
+     * Fill value to a sheet
+     *
+     * @param supplier
+     * @param writeSheet
+     * @return
+     */
+    public ExcelWriter fill(Supplier<Object> supplier, WriteSheet writeSheet) {
+        return fill(supplier.get(), null, writeSheet);
+    }
+
+    /**
+     * Fill value to a sheet
+     *
+     * @param supplier
+     * @param fillConfig
+     * @param writeSheet
+     * @return
+     */
+    public ExcelWriter fill(Supplier<Object> supplier, FillConfig fillConfig, WriteSheet writeSheet) {
+        excelBuilder.fill(supplier.get(), fillConfig, writeSheet);
+        return this;
+    }
+
     /**
      * Close IO
      */
@@ -102,7 +146,6 @@ public class ExcelWriter {
 
     /**
      * Prevents calls to {@link #finish} from freeing the cache
-     *
      */
     @Override
     protected void finalize() {

src/main/java/com/alibaba/excel/write/builder/ExcelWriterSheetBuilder.java

 package com.alibaba.excel.write.builder;
 
 import java.util.Collection;
+import java.util.function.Supplier;
 
 import com.alibaba.excel.ExcelWriter;
 import com.alibaba.excel.exception.ExcelGenerateException;
@@ -74,6 +75,18 @@ public class ExcelWriterSheetBuilder extends AbstractExcelWriterParameterBuilder
         excelWriter.finish();
     }
 
+    public void doWrite(Supplier<Collection<?>> supplier) {
+        doWrite(supplier.get());
+    }
+
+    public void doFill(Supplier<Object> supplier) {
+        doFill(supplier.get());
+    }
+
+    public void doFill(Supplier<Object> supplier, FillConfig fillConfig) {
+        doFill(supplier.get(), fillConfig);
+    }
+
     public ExcelWriterTableBuilder table() {
         return table(null);
     }

src/main/java/com/alibaba/excel/write/builder/ExcelWriterTableBuilder.java

 package com.alibaba.excel.write.builder;
 
 import java.util.Collection;
+import java.util.function.Supplier;
 
 import com.alibaba.excel.ExcelWriter;
 import com.alibaba.excel.exception.ExcelGenerateException;
@@ -55,6 +56,10 @@ public class ExcelWriterTableBuilder extends AbstractExcelWriterParameterBuilder
         excelWriter.finish();
     }
 
+    public void doWrite(Supplier<Collection<?>> supplier) {
+        doWrite(supplier.get());
+    }
+
     @Override
     protected WriteTable parameter() {
         return writeTable;

src/test/java/com/alibaba/easyexcel/test/demo/fill/FillTest.java

@@ -7,9 +7,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.junit.Ignore;
-import org.junit.Test;
-
 import com.alibaba.easyexcel.test.util.TestFileUtil;
 import com.alibaba.excel.EasyExcel;
 import com.alibaba.excel.ExcelWriter;
@@ -18,11 +15,14 @@ import com.alibaba.excel.write.metadata.WriteSheet;
 import com.alibaba.excel.write.metadata.fill.FillConfig;
 import com.alibaba.excel.write.metadata.fill.FillWrapper;
 
+import org.junit.Ignore;
+import org.junit.Test;
+
 /**
  * 写的填充写法
  *
- * @since 2.1.1
  * @author Jiaju Zhuang
+ * @since 2.1.1
  */
 @Ignore
 public class FillTest {
@@ -71,7 +71,17 @@ public class FillTest {
         // 这里 会填充到第一个sheet， 然后文件流会自动关闭
         EasyExcel.write(fileName).withTemplate(templateFileName).sheet().doFill(data());
 
-        // 方案2 分多次 填充 会使用文件缓存（省内存）
+        // 方案2 分多次 填充 会使用文件缓存（省内存） jdk8
+        fileName = TestFileUtil.getPath() + "listFill" + System.currentTimeMillis() + ".xlsx";
+        EasyExcel.write(fileName)
+            .withTemplate(templateFileName)
+            .sheet()
+            .doFill(() -> {
+                // 分页查询数据
+                return data();
+            });
+
+        // 方案3 分多次 填充 会使用文件缓存（省内存）
         fileName = TestFileUtil.getPath() + "listFill" + System.currentTimeMillis() + ".xlsx";
         ExcelWriter excelWriter = EasyExcel.write(fileName).withTemplate(templateFileName).build();
         WriteSheet writeSheet = EasyExcel.writerSheet().build();

src/test/java/com/alibaba/easyexcel/test/demo/write/WriteTest.java

@@ -59,14 +59,25 @@ public class WriteTest {
      */
     @Test
     public void simpleWrite() {
-        // 写法1
+        // 写法1 JDK8+
         String fileName = TestFileUtil.getPath() + "simpleWrite" + System.currentTimeMillis() + ".xlsx";
         // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
         // 如果这里想使用03 则 传入excelType参数即可
-        EasyExcel.write(fileName, DemoData.class).sheet("模板").doWrite(data());
+        EasyExcel.write(fileName, DemoData.class)
+            .sheet("模板")
+            .doWrite(() -> {
+                // 分页查询数据
+                return data();
+            });
 
         // 写法2
         fileName = TestFileUtil.getPath() + "simpleWrite" + System.currentTimeMillis() + ".xlsx";
+        // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
+        // 如果这里想使用03 则 传入excelType参数即可
+        EasyExcel.write(fileName, DemoData.class).sheet("模板").doWrite(data());
+
+        // 写法3
+        fileName = TestFileUtil.getPath() + "simpleWrite" + System.currentTimeMillis() + ".xlsx";
         // 这里 需要指定写用哪个class去写
         ExcelWriter excelWriter = null;
         try {
@@ -329,7 +340,6 @@ public class WriteTest {
         commentData.setRelativeLastColumnIndex(1);
         commentData.setRelativeLastRowIndex(1);
 
-
         // 设置公式
         WriteCellData<String> formula = new WriteCellData<>();
         writeCellDemoData.setFormulaData(formula);
@@ -339,7 +349,6 @@ public class WriteTest {
         // 这里只是例子 如果真的涉及到公式 能内存算好尽量内存算好 公式能不用尽量不用
         formulaData.setFormulaValue("REPLACE(123456789,1,1,2)");
 
-
         // 设置单个单元格的样式 当然样式 很多的话 也可以用注解等方式。
         WriteCellData<String> writeCellStyle = new WriteCellData<>("单元格样式");
         writeCellDemoData.setWriteCellStyle(writeCellStyle);