EasyExcel 自定义类型转换器Converter3种加载方式（转换字段加载类型转换器、导出时加载类型转换器、加载全局类型转换器）

朱雀 2022-08-29 09:40 469阅读 0赞

## 1 Maven依赖 ##

<dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>easyexcel</artifactId>
                <version>2.2.8</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>

## 2 转换字段加载类型转换器 ##

### 2.1 @ExcelProperty的converter属性加载类型转换器 ###

package com.dto;
    
    import com.alibaba.excel.annotation.ExcelProperty;
    import com.converter.LocalDateConverter;
    import lombok.Data;
    
    import java.time.LocalDate;
    
    @Data
    public class TestDto {
        @ExcelProperty(value = "创建时间", index = 1, converter = LocalDateConverter.class)
        private LocalDate createDate;
    }

### 2.2 调试代码 ###

/**
         * 字段加载类型转换器
         *
         * @param response
         */
        @GetMapping("/attributeConverter")
        public void attributeConverter(HttpServletResponse response) throws IOException {
            List<TestDto> sheetDataList = new ArrayList<>();
            TestDto testDto=new TestDto();
            testDto.setCreateDate(LocalDate.parse("2021-07-30", DateTimeFormatter.ofPattern("yyyy-MM-dd")));
            sheetDataList.add(testDto);
            response.addHeader("Content-Disposition", "filename=test.xlsx");
            //设置类型，扩展名为.xls
            response.setContentType("application/vnd.ms-excel");
            ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream(), TestDto.class).build();
            WriteSheet writeSheet = EasyExcel.writerSheet("模板").build();
            excelWriter.write(sheetDataList, writeSheet);
            //千万别忘记finish 会帮忙关闭流
            excelWriter.finish();
        }

### 2.3 调试结果 ###

![20210801122625618.png][]

## 3 导出时加载类型转换器 ##

### 3.1 调试代码 ###

/**
         * 导出时加载类型转换器
         *
         * @param response
         */
        @GetMapping("/exportRegisterConverter")
        public void exportRegisterConverter(HttpServletResponse response) throws IOException {
            List<List<Object>> sheetDataList = new ArrayList<>();
            List<Object> rowList = new ArrayList<>();
            rowList.add(LocalDate.parse("2021-07-30", DateTimeFormatter.ofPattern("yyyy-MM-dd")));
            sheetDataList.add(rowList);
            response.addHeader("Content-Disposition", "filename=test.xlsx");
            //设置类型，扩展名为.xls
            response.setContentType("application/vnd.ms-excel");
            ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream())
                    //加载类型转换器
                    .registerConverter(new LocalDateConverter()).build();
            WriteSheet writeSheet = EasyExcel.writerSheet("模板").build();
            excelWriter.write(sheetDataList, writeSheet);
            //千万别忘记finish 会帮忙关闭流
            excelWriter.finish();
        }

### 3.2 调试结果 ###

![20210801122833330.png][]

## 4 加载全局类型转换器 ##

### 4.1 CustomConverterLoader ###

加载自定义类型转换器（加载器）。

package com.loader;
    
    import com.alibaba.excel.converters.*;
    import com.converter.LocalDateConverter;
    import org.springframework.context.annotation.*;
    
    import java.util.Map;
    
    /**
     * 加载自定义类型转换器（加载器）
     */
    @Configuration
    public class CustomConverterLoader {
    
        @Bean
        public DefaultConverterLoader defaultConverterLoader() {
            DefaultConverterLoader converters = new DefaultConverterLoader();
            LocalDateConverter localDateConverter = new LocalDateConverter();
            Map<String, Converter> defaultWriteConverter = converters.loadDefaultWriteConverter();
            defaultWriteConverter.put(ConverterKeyBuild.buildKey(localDateConverter.supportJavaTypeKey()), localDateConverter);
            Map<String, Converter> allConverter=converters.loadAllConverter();
            allConverter.put(ConverterKeyBuild.buildKey(localDateConverter.supportJavaTypeKey(), localDateConverter.supportExcelTypeKey()), localDateConverter);
            return converters;
        }
    }

### 4.2 调试代码 ###

/**
         * 加载全局类型转换器
         *
         * @param response
         */
        @GetMapping("/loadGlobalConverter")
        public void loadGlobalConverter(HttpServletResponse response) throws IOException {
            List<List<Object>> sheetDataList = new ArrayList<>();
            List<Object> rowList = new ArrayList<>();
            rowList.add(LocalDate.parse("2021-07-30", DateTimeFormatter.ofPattern("yyyy-MM-dd")));
            rowList.add(new BigDecimal(0.11));
            sheetDataList.add(rowList);
            response.addHeader("Content-Disposition", "filename=test.xlsx");
            //设置类型，扩展名为.xls
            response.setContentType("application/vnd.ms-excel");
            ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream()).build();
            WriteSheet writeSheet = EasyExcel.writerSheet("模板").build();
            excelWriter.write(sheetDataList, writeSheet);
            //千万别忘记finish 会帮忙关闭流
            excelWriter.finish();
        }

### 4.3 调试结果 ###

![20210801172335687.png][]

## 注： ##

LocalDateConverter源码请查看以下博客。

[EasyExcel 自定义类型转换器Converter][EasyExcel _Converter]

[20210801122625618.png]: /images/20220829/ce721deea50d403d83bc92e37518eafc.png
[20210801122833330.png]: /images/20220829/9ed1bdbf90b84ed5a1d4fb9585bd08c1.png
[20210801172335687.png]: /images/20220829/fac999abc1b94be8b0e6ecdb9bb888b1.png
[EasyExcel _Converter]: https://blog.csdn.net/qq_38974638/article/details/119253114