新增拦截器demo

quickstart.md

@@ -24,6 +24,7 @@ DEMO代码地址：[https://github.com/alibaba/easyexcel/blob/master/src/test/ja
 * [使用table去写入](#tableWrite)
 * [动态头，实时生成头写入](#dynamicHeadWrite)
 * [自动列宽(不太精确)](#longestMatchColumnWidthWrite)
+* [自定义拦截器（下拉，超链接等上面几点都不符合但是要对单元格进行操作的参照这个）](#customHandlerWrite)
 * [web中的写](#webWrite)
 
 ## 读excel样例
@@ -818,16 +819,20 @@ public class LongestMatchColumnWidthData {
      * <p>
      * poi 自带{@link SXSSFSheet#autoSizeColumn(int)} 对中文支持也不太好。目前没找到很好的算法。 有的话可以推荐下。
      *
-     * <p>1. 创建excel对应的实体对象 参照{@link DemoData}
-     * <p>3. 注册策略{@link LongestMatchColumnWidthStyleStrategy}
-     * <p>2. 直接写即可
+     * <p>
+     * 1. 创建excel对应的实体对象 参照{@link LongestMatchColumnWidthData}
+     * <p>
+     * 2. 注册策略{@link LongestMatchColumnWidthStyleStrategy}
+     * <p>
+     * 3. 直接写即可
      */
     @Test
     public void longestMatchColumnWidthWrite() {
         String fileName =
             TestFileUtil.getPath() + "longestMatchColumnWidthWrite" + System.currentTimeMillis() + ".xlsx";
         // 这里 需要指定写用哪个class去读，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
-        EasyExcel.write(fileName, LongestMatchColumnWidthData.class).sheet("模板").doWrite(dataLong());
+        EasyExcel.write(fileName, LongestMatchColumnWidthData.class)
+            .registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()).sheet("模板").doWrite(dataLong());
     }
 
     private List<LongestMatchColumnWidthData> dataLong() {
@@ -843,6 +848,33 @@ public class LongestMatchColumnWidthData {
     }
 ```
 
+### <span id="customHandlerWrite" />自定义拦截器（上面几点都不符合但是要对单元格进行操作的参照这个）
+##### excel示例
+![img](img/readme/quickstart/write/customHandlerWrite.png)
+##### 对象
+参照：[对象](#simpleWriteObject)
+##### 代码
+```java
+    /**
+     * 下拉，超链接等自定义拦截器（上面几点都不符合但是要对单元格进行操作的参照这个）
+     * <p>
+     * demo这里实现2点。1. 对第一行第一列的头超链接到:https://github.com/alibaba/easyexcel 2. 对第一列第一行和第二行的数据新增下拉框，显示 测试1 测试2
+     * <p>
+     * 1. 创建excel对应的实体对象 参照{@link DemoData}
+     * <p>
+     * 2. 注册拦截器 {@link CustomCellWriteHandler} {@link CustomSheetWriteHandler}
+     * <p>
+     * 2. 直接写即可
+     */
+    @Test
+    public void customHandlerWrite() {
+        String fileName = TestFileUtil.getPath() + "customHandlerWrite" + System.currentTimeMillis() + ".xlsx";
+        // 这里 需要指定写用哪个class去读，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
+        EasyExcel.write(fileName, DemoData.class).registerWriteHandler(new CustomSheetWriteHandler())
+            .registerWriteHandler(new CustomCellWriteHandler()).sheet("模板").doWrite(data());
+    }
+```
+
 ### <span id="webWrite" />web中的写
 ##### 示例代码
 DEMO代码地址：[https://github.com/alibaba/easyexcel/blob/master/src/test/java/com/alibaba/easyexcel/test/demo/web/WebTest.java](/src/test/java/com/alibaba/easyexcel/test/demo/web/WebTest.java)

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

@@ -0,0 +1,45 @@
+package com.alibaba.easyexcel.test.demo.write;
+
+import org.apache.poi.common.usermodel.HyperlinkType;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CreationHelper;
+import org.apache.poi.ss.usermodel.Hyperlink;
+import org.apache.poi.ss.usermodel.Row;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.alibaba.excel.metadata.CellData;
+import com.alibaba.excel.metadata.Head;
+import com.alibaba.excel.write.handler.CellWriteHandler;
+import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
+import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
+
+/**
+ * 自定义拦截器。对第一行第一列的头超链接到:https://github.com/alibaba/easyexcel
+ *
+ * @author Jiaju Zhuang
+ */
+public class CustomCellWriteHandler implements CellWriteHandler {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(CustomCellWriteHandler.class);
+
+    @Override
+    public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row,
+        Head head, int relativeRowIndex, boolean isHead) {
+
+    }
+
+    @Override
+    public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData,
+        Cell cell, Head head, int relativeRowIndex, boolean isHead) {
+        // 这里可以对cell进行任何操作
+        LOGGER.info("第{}行，第{}列写入完成。", cell.getRowIndex(), cell.getColumnIndex());
+        if (isHead && cell.getColumnIndex() == 0) {
+            CreationHelper createHelper = writeSheetHolder.getSheet().getWorkbook().getCreationHelper();
+            Hyperlink hyperlink = createHelper.createHyperlink(HyperlinkType.URL);
+            hyperlink.setAddress("https://github.com/alibaba/easyexcel");
+            cell.setHyperlink(hyperlink);
+        }
+    }
+
+}

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

@@ -0,0 +1,39 @@
+package com.alibaba.easyexcel.test.demo.write;
+
+import org.apache.poi.ss.usermodel.DataValidation;
+import org.apache.poi.ss.usermodel.DataValidationConstraint;
+import org.apache.poi.ss.usermodel.DataValidationHelper;
+import org.apache.poi.ss.util.CellRangeAddressList;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.alibaba.excel.write.handler.SheetWriteHandler;
+import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
+import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
+
+/**
+ * 自定义拦截器.对第一列第一行和第二行的数据新增下拉框，显示 测试1 测试2
+ *
+ * @author Jiaju Zhuang
+ */
+public class CustomSheetWriteHandler implements SheetWriteHandler {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(CustomSheetWriteHandler.class);
+
+    @Override
+    public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
+
+    }
+
+    @Override
+    public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
+        LOGGER.info("第{}个Sheet写入成功。", writeSheetHolder.getSheetNo());
+
+        // 区间设置 第一列第一行和第二行的数据。由于第一行是头，所以第一、二行的数据实际上是第二三行
+        CellRangeAddressList cellRangeAddressList = new CellRangeAddressList(1, 2, 0, 0);
+        DataValidationHelper helper = writeSheetHolder.getSheet().getDataValidationHelper();
+        DataValidationConstraint constraint = helper.createExplicitListConstraint(new String[] {"测试1", "测试2"});
+        DataValidation dataValidation = helper.createValidation(constraint, cellRangeAddressList);
+        writeSheetHolder.getSheet().addValidationData(dataValidation);
+    }
+}

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

@@ -311,11 +311,11 @@ public class WriteTest {
      * poi 自带{@link SXSSFSheet#autoSizeColumn(int)} 对中文支持也不太好。目前没找到很好的算法。 有的话可以推荐下。
      *
      * <p>
-     * 1. 创建excel对应的实体对象 参照{@link DemoData}
+     * 1. 创建excel对应的实体对象 参照{@link LongestMatchColumnWidthData}
      * <p>
-     * 3. 注册策略{@link LongestMatchColumnWidthStyleStrategy}
+     * 2. 注册策略{@link LongestMatchColumnWidthStyleStrategy}
      * <p>
-     * 2. 直接写即可
+     * 3. 直接写即可
      */
     @Test
     public void longestMatchColumnWidthWrite() {
@@ -326,6 +326,25 @@ public class WriteTest {
             .registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()).sheet("模板").doWrite(dataLong());
     }
 
+    /**
+     * 下拉，超链接等自定义拦截器（上面几点都不符合但是要对单元格进行操作的参照这个）
+     * <p>
+     * demo这里实现2点。1. 对第一行第一列的头超链接到:https://github.com/alibaba/easyexcel 2. 对第一列第一行和第二行的数据新增下拉框，显示 测试1 测试2
+     * <p>
+     * 1. 创建excel对应的实体对象 参照{@link DemoData}
+     * <p>
+     * 2. 注册拦截器 {@link CustomCellWriteHandler} {@link CustomSheetWriteHandler}
+     * <p>
+     * 2. 直接写即可
+     */
+    @Test
+    public void customHandlerWrite() {
+        String fileName = TestFileUtil.getPath() + "customHandlerWrite" + System.currentTimeMillis() + ".xlsx";
+        // 这里 需要指定写用哪个class去读，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
+        EasyExcel.write(fileName, DemoData.class).registerWriteHandler(new CustomSheetWriteHandler())
+            .registerWriteHandler(new CustomCellWriteHandler()).sheet("模板").doWrite(data());
+    }
+
     private List<LongestMatchColumnWidthData> dataLong() {
         List<LongestMatchColumnWidthData> list = new ArrayList<LongestMatchColumnWidthData>();
         for (int i = 0; i < 10; i++) {